Head gasket replacement? Oil in coolant...

[deagle12]

My girlfriend's 05 Trailblazer has 220k miles. It overheated last week. Turns out the water pump was leaking like crazy, so I replaced it.

I'm in the process of flushing it - I used a garden hose, then did a few passes with distilled water.

She drove it for 15mins and it didn't overheat. Only saw 200-205. But when it cooled down, I noticed a gunky white hardened paste on the radiator tube (to the upper radiator). I'm pretty sure it is oil that is mixing with the coolant.

I did a oil change and the oil looks fine.

Should I replace the head gasket? How much of a nightmare is this? I've never pulled an engine.

Unfortunately she doesn't have many options. She has 12-15k in credit card debt and just started grad school. So I don't think she should really replace this. But is it worth all the labor and money to go to this?

The trans oil has smelled burnt for a while... not sure how much longer it will last :\

 

[Sparky]

I don't think oil turna into hard white paste. Clean it, run it, check again? Head gasket issues are rare on these.

Oh, and I'd be changing that trans fluid out if it is bad. And the filter. No machine power flushes or anything like that. At most, do the may03lt fluid change method (youtube it, I'm on mobile and don't have the time/patience to screw with getting a link into here at the moment but it comes up easy when searching for a sec). Course check the other thing first.

 

[deagle12]

Yeah I've heard they aren't common, but it really seems like it. Take a look at these pictures.

https://imgur.com/a/QSe6SNC

The orange is from the first time it overheated. The whiteish stuff is from running it 15mins with the new pump.

I can also do a leak down test later to double check. And yeah I was debating about the trans fluid - there's that age old debate right? Just saying I'm not sure whether it is worth going through all this trouble.

I just watched the trailblazer valve job video on youtube, and it looks like I could replace the gasket without removing the engine? The #3 cylinder also has some oil in the spark plug hole for a while now, and it does stall here and there. So I wonder if getting the head machined too would get a few more years outta this.

 

[Mooseman]

A little oil in the plug well is "normal" on these. Just the valve cover losing its sealing ability.

I'd make sure that it's flushed out well, fill and monitor. There is a possibility it's the tranny cooler in the rad that's leaking and it has been known to happen.

Run it a while and get the oil analyzed, maybe also the tranny fluid. If there's any leakage or other stuff going on, they'll know.

 

[NJTB]

Usually, a bad head gasket with anti freeze leaking into the oil will make the oil look like a strawberry milk shake. If it is a head gasket, you may have caught it right away.
With 220k, you might want to try a can of the stuff you put in the radiator to seal it. Not a good repair, but may keep the car on the road until you can replace it.

 

[Mooseman]

Sealers usually end up breaking more stuff than it solves by clogging everything up.

 

[Reprise]

My girlfriend's 05 Trailblazer has 220k miles. It overheated last week. Turns out the water pump was leaking like crazy, so I replaced it.

I'm in the process of flushing it - I used a garden hose, then did a few passes with distilled water.

She drove it for 15mins and it didn't overheat. Only saw 200-205. But when it cooled down, I noticed a gunky white hardened paste on the radiator tube (to the upper radiator). I'm pretty sure it is oil that is mixing with the coolant.

I did a oil change and the oil looks fine.

Should I replace the head gasket? How much of a nightmare is this? I've never pulled an engine.

Unfortunately she doesn't have many options. She has 12-15k in credit card debt and just started grad school. So I don't think she should really replace this. But is it worth all the labor and money to go to this?

The trans oil has smelled burnt for a while... not sure how much longer it will last :\

Based on your description / pics, I agree with the others - I don't think that's oil in your coolant.
Usually when a head gasket goes south (due to overheating), you'll see the opposite - coolant getting through passages that were previously closed off, and (depending on the severity) lots of white smoke out the tailpipe.

I'm guessing that the overheating was noticed when the needle was much farther over than "200-205" (this being the post-WP install temp). Get her to point out where the needle was when it overheated. Above 230F for 15min, and I'd almost guarantee the head gasket has been compromised. May not be readily apparent, but it'll need to be replaced at some point. Not 'today', though (more below).

Replacing the head gasket - on this engine, being an OHC, there's more involved. If you had the V8, I'd say 'go for it' - I did a set (in-car) in a Camaro years ago, and knocked both heads out in a day and a half. But it's easier on an OHV engine. You *should* be able to do it in-car, though, if it turns out the head gasket is blown.

The trans fluid should be changed out ASAP. It's a simple job, especially if you have a drain plug in the pan. If you were able to do the WP by yourself, I'd recommend a filter change (you have to drop the pan, but it's pretty straightforward. Torque the pan bolts to 10ft/lb (the spec is in inch-pounds, but I've done the conversion for you) in a crisscross pattern, in at least 2 passes (if you want to tighten in steps (e.g.; 5 ft/lb, then to 10), that's fine - just make sure you do a final (duplicate) pass at 10 (at least one bolt will yield the second time, so it's important to 'see' 10 across all 13 (?) bolts.
If you have a pan with a 'stepped' section by the exhaust where it crosses over - that's a 'deep pan' (which most 360s have) - make sure you get a filter kit that matches. Oh, and don't worry about the O-ring that is in the pickup tube, unless it shows signs of being damaged, or the filter won't stay seated (very unlikely). The O-ring is very tough to get out, and generally can be reused. Do inspect it, but you can likely leave it as-is.

After you've got your coolant replaced, oil replaced, and trans fluid replaced - drive for 1000mi, take a sample of the oil, and send it in for analysis. If you still have the old oil, send that in, first. That will give you a baseline to compare against, post-fix. If your coolant PPM is still roughly at the same level on the second pass, you'll pretty much know the head gasket is compromised. The company that does the oil analysis will probably give you an idea (especially with two samples) of how bad it will get, how fast. That's when you make your decision on next steps.

If you do the headgasket - You mention sending the head out to be machined (we'll assume you're talking just a cleaning / descaling / 'hot tanking'). If you're going to go that far, you may as well rebuild the head, as you have to remove all the valves, seals, etc., in order to clean it. Personally, I wouldn't do that. Just remove the head, clean it as best you can with your cleaner of choice with the valvetrain intact, and put a good quality headgasket on (FelPro tends to be the trusted brand for most people / daily driver applications.)

If you have the tools / knowledge, measure the deck (block) and head surfaces, to ensure they aren't warped. If they are...well, things get more complicated from there. But it's a good idea to do this, since the motor did overheat, and it's an all-aluminum one, to boot (iron blocks / heads can withstand higher temps before warpage occurs). If either surface is warped, but only slightly, you can try a slightly thicker (or different material) gasket to compensate, if available. Check FelPro's catalogs, etc. For now, let's assume neither surface is warped.

I believe you're going to need a new set of head bolts, as they're likely TTY (torque-to-yield), and those are only supposed to be used once. Some people ignore this - cost & mileage will factor into this decision for you.

On to the other potential leakage source - the radiator.
I think I might just replace this outright, since it has 220K on it - there's a cost to doing this, but if that's where the leakage / intermingling of fluids is occurring, it's a lot cheaper / easier than doing a head gasket.

And finally, we come to cost and "is it worth it, given the mileage?"
- do nothing & roll dice
- fix yourself at some cost
- ditch the truck, figuring that at 230K, it doesn't have much left to give.

Of those three, the last is the most expensive, and it doesn't sound like either of you are comfortable with incurring the expense for a new vehicle. You'll be fixing whatever replacement you get anyway, unless she gets something 'new-ish'. So take that into account.

Choice #2 can be really satisfying, and will score you some major points with the GF
I'd guess that if you fixed it, you'd get her through the 2yrs of grad school with the truck. You may need to oversee the maintenance, down to checking the oil weekly, but it would last 2yrs. Parts are still plentiful, and this site is one of the best on the web to use as a knowledge base. The LL8 is a proven motor - plenty of examples of over 200K, so you're not an outlier.

'Do nothing' is always a choice - but start putting money aside. You've already subconsciously decided not to make this choice anyway, based on your efforts to date.

 

[Mooseman]

The head bolts are TTY so you must replace them. And one thing that wasn't mentioned is that some ALWAYS break on removal. When somebody comes along and says they didn't break a single one, we tell them to go buy a lottery ticket right now because it happens so rarely. This should be factored into the cost as you will need more specialized tools to get them out of the block (and it's always the worst ones at the back).

You will also need special tools to hold the timing chain and its tensioner in place while you pull the head. If it's not done right, you're looking at double the work to pull the oil pan and front cover to put the chain and tensioner back in place properly.

 

[deagle12]

Thank you all for the replies, and especially Reprise for such in depth advice.

I hope it is not oil in the coolant! That would make life so much easier. Unfortunately the coolant temp in the gauge cluster isn't working (big surprise right?!). I soldered new stepper motors but I must have messed up on just that one... was such a pain to get it out that we left it like that.

She said the check gauges started blinking and she drove it around 10-15mins. So it sounds like the head gasket probably was compromised. When she stopped and opened the hood smoke was coming from the valve cover edge...

I will plan on doing the trans fluid. I've dropped the pan on my ford truck before so it shouldn't be too hard.

Unfortunately there will be quite some cost to the head gasket repair if we do end up going that way... engine hoist, head bolts, gasket, etc. But I will follow your advice as far as driving it 1000 mi and checking in on it regularly. The oil analysis is a good idea.

Does anyone have any idea what this white hardened gunk is, then? Is there any way to clean this out?

 

[mrrsm]

Your problems compound from here if what I think just happened... has happened:

(1) Your problems won't be coming from any Oil in the Coolant... But from having an abundance of Coolant mixing in with the Engine Oil.

(2) You can confirm or eliminate this possibility by pulling the Dipstick and looking for signs of "Chocolate Pudding" on the Dipstick... or finding the latest crop of the stuff under the Radiator Cap.

(3) If you have this "Brown, Soupy Mudd" down in the Crankcase... Then the Poly- Ethylene- Glycol represents a real danger to the innards ...mostly to anything made of Aluminum... such as the entire Engine Block and Head... as well as the Aluminum Silicate Bearings surrounding the Crankshaft and Connecting Rods.

(4) This is because those metal items dissolve like butter in the presence of the Acidic PEG Pudding that got circulated throughout the motor within a short time before your wife turned of the steaming engine.

(5) Normally... the entire contents of the Crankcase can get circulated through the LL8 engine at the rate of over 11 Gallons per minute. So every single area, oil gallery and space within the engine block gets coated with that crap.

(6) The longer the Aluminum Bearings sit in contact with the Cast Iron Journals... the faster Electrolytic Corrosion will set up in between... and dissolve them.

(7) Regardless of the Quality of the Motor Oil in the engine... Once it mixes with PEG/Anti-Freeze... it completely loses all of its lubricity and is rendered useless in protecting the Rotating Engine Assembly.

(8) The best thing to do if your intentions are to salvage this engine some time later on ...if it will even start and idle... is to immediately change out that Gumbo-Filled Oil Filter and fill the crankcase with Cheap Organic Motor Oil... only 6 Quarts and use either 1 Quart of Engine Flush or Transmission Fluid and allow the engine to idle and get warm for around 5 Minutes. Don't race the Engine... let it idle and then while it is still Hot and Bothered... Drain the Engine Oil and change the Oil Filter with another Cheap Oil Filter and the same recipe...twice.

(9) Keep each and every Oil Filter and perform an Autopsy that involves cutting off the end and popping out the gooey innards and look closely at the junk inside ...using a Neodymium Magnet and be wary of anything Ferrous in them. If you have anything sticking to the magnet... Steel and Cast Iron parts will be involved. You should stop right there if this occurs.

(10) If this turns out to be the case... rebuilding an All Aluminum Engine versus a Sturdy and resilient Cast Iron Engine Block that can handle the PEG problem with aplomb is like night to day... and finding a low mileage Swap Motor from a Later Model might be the best route. You can't afford to rebuild an engine like this... the Parts, the Pieces and the Labor and the Knowledge Curve involved are all a HUGE PITA when rebuilding this engine.

 

[Reprise]

If the OP finds what @MRRSM described in the oil, I'd agree - both coolant & oil systems have been compromised, and it's probably better to do an engine swap, for the long term, as the corrosion in the rotating assembly will eventually ruin it, starting with the bearings.

OP mentioned that his 'oil looked fine', so we'll *assume* that it is - for now. But definitely do some investigation going forward, and look for even a start of that 'pudding' forming. Follow @MRRSM 's advice re: flush & oil filter analysis.

Back to our cooling system...
A quick google search suggests that the white residue is probably aluminum oxides - a corrosion byproduct. Besides the engine, that could be from the head gasket or from the breakdown of the old WP. My search also suggested that that residue is further indicative of a head gasket issue, so (along with your gage issue), I'll 'up' my probability on the gasket having gone south on you.

Yes, there will be cost involved in doing the head gasket. But not as much as an engine swap. And neither of those as much as a new vehicle. From an effort perspective, the inverse is (mostly) true. On an engine swap, you have to take the total mileage on the trans into account, as well, especially since you indicated it was burnt, meaning there's been some damage to the clutches and / or the torque converter. Normally, you'll start seeing the stock 4L60e approach end of life by about 250K or so. One of the TransGo corrective kits (orange box) that we all know / love here *might* help extend the life of the trans, but it really doesn't address clutch wear (directly). Do-able in a day / weekend, with trans in-car (you have to remove the valve body).

BTW, you shouldn't need a hoist to do the headgasket. But follow @Mooseman's guidance on what to do re: I/E cams (and study what's involved, before you crack the first nut). From your description of things you've done in the past, I know you have some ability / experience, so I think you could get through doing the gasket on your own.

Finally, that temp gage - while the one in the dash isn't a 'true' gage (you can find posts on this), it's the ONE gage that I personally find indispensable, especially with an all-aluminum motor. I'd give up every other one (including the tach / speedo), first.

There's a saying - "you can't manage what you can't measure" - and it holds true, here.

Your coolant issue was probably going on for awhile; had you had a working gauge, you might not be where you find yourself today (not trying to browbeat you; it is what it is).
The damage is done, now, but for the future, I'd either hook up an auxiliary temp gauge (and it would be 'real'...lol), or monitor it via smartphone / OBD reader (Torque / Car Gauge Pro, etc.) Again, the 'barn door's been opened' on that, but if I were going to the trouble of doing the head gasket, I'd hook up a gauge.

Finally, give some thought to replacing the t-stat, when you do the head gasket, as a preventative measure. Good luck, and keep us posted on what you two decide.

 

[Kelly@PCMofNC]

Have you checked for combustion in the coolant? Your local parts store should sell little strips for testing this. That will help decide if the HG should be replaced also.

 

[Reprise]

Good point - it was remiss of me to not mention doing confirmation diags to ensure the HG was faulty, *before* ripping off the head (I know they're out there, but didn't know what all of them are, exactly). Just prepping for the likelihood that the HG will need replacement.

 

[deagle12]

Hey everyone, took me several days but I got a block tester that changes cooler when it detects combustion gases. It fortunately did not change color, so it looks like we may be good. I wonder what the residue is though. There's a lot of it, and once it got wet I could scrape it off with a screwdriver.

I added some coolant flush to the system and the GF will drive it for a couple days. Maybe it is some mineral deposits from using tap water to flush it?

 

[mrrsm]

I would suggest sitting your GF down for a "Kinesic Interview" and study very carefully how she reacts to this one Question...

"So Honey... Is there any chance that you accidentally... poured Motor Oil ( or perhaps Pork Fat) into the Radiator... Hmmmm?" :>)

 

[deagle12]

Well... it didn't even make it a day. On the drive home she saw temps get up to 220, but was so close to home she just chose to make it home. At home it got to 233.

At that point she said water was flowing out, near the passenger side tire. She said she could actually see white deposits.

I just got home and it is too hot to touch. But it looks like the (oil?) clogged up the rad and it overflowed out of the recovery tank.

Not sure where to go from here... it really seems like oil is getting into the coolant - fast. But the tester showed no exhaust gases? It really looks like to fix this right it's going to be a head gasket and now maybe a new rad?

 

[mrrsm]

All of what came out on the Passenger Side Tire was probably due to the Radiator Cap doing its job to release the excess pressure inside of the overheated system. If you decide to replace the Radiator... do a Bang Up Job with replacing the Upper and Lower Radiator Hoses as well ...since they have already been stressed by excessive Heat and Pressure. There are some very helpful Threads here on GMTN on how to R&R the Radiator that include where to find the Best OEM version for the Price.

If you ran the vehicle for any length of time with Pure Water (Distilled or TAP) and did not have a proper 50/50 Mix of the correct Dexcool (Orange) versus any of the Green Flavors... then the Water would boil at 212 Degrees Fahrenheit at sea Level and at lower temperatures via higher elevations and cause steam to form under conditions that can only be withstood by Dexcool.

This engine should NEVER have Pure Water inside the Radiator and Engine Block. One other thing to consider is that if you were to take a 5 Gallon Cauldron filled with Water and lay it in the Lava Field over a Volcano... the Water Temperature will NEVER exceed 212 Degrees... no matter how much Heat you add to the Water... because it will phase change into Steam-Water Vapor before that can happen. And THAT stuff can become Super-Heated to incredibly High Temperatures.... Hot enough in fact to penetrate the Teflon Coating of the Head Gasket and melt itself a path in between the layers ...and escape.

You should also check along the firewall on the Passenger Side for fractures and leaks in the Heater Hose Connector Locations (IN and OUT) that feed into the Heater Core under the Passenger Side interior Under Dash area. These Plastic-PolyCarbonate Couplers are constructed in Two Different Sizes... with one Male and One Female Kit per Hose and come as Kits that can be had at Autozone or Amazon as well. Before attempting this Hose Coupler Repair... there are several Threads that cover this R&R. Watch the ChrisFix Youtube Video below on How To Flush out the Heater Core...as the Coolant Circuit Temperatures WILL elevate if the Heater Core is Clogged with Sludge:

 

[m.mcmillen]

it really seems like oil is getting into the coolant - fast. But the tester showed no exhaust gases? It really looks like to fix this right it's going to be a head gasket and now maybe a new rad?

There doesn't have to be exhaust gas in the coolant to say that the gasket is bad. It really depends on where the head gasket has failed. If the gasket fails next to the "fire rings" on the gasket, it will blow a channel in the gasket and usually goes right to a water jacket because that is what is closest to the cylinder wall. That is how you get exhaust gases in your cooling system.

If the gasket goes bad around a coolant passage, it can run across into an oil drain hole and that is how the coolant and oil mix.

The head gaskets on these engines are MLS (multi layered steel) and lately, not necessarily on these engines, I have seen where the gasket coating deteriorates and coolant and oil mix freely.

Something that you can check is to do an old fashioned pressure test on the cooling system. I have found on some that are leaking quite bad that if you drain the oil and then leave the drain plug out while you're doing the pressure test that you can actually see coolant run out of the oil pan drain hole. If you don't have a pressure tester, most parts store like Advance, AutoZone, or O'Reillys will rent one out to you for free. Just leave a deposit and when you bring the tool back they give you your money back.

 

[deagle12]

Thanks all, great information. I was wondering that - if the gasket can fail without leaking exhaust gases.

I actually did do a pressure test on the cooling system before this drive, and it held 14psi no problem for 15 minutes.

 

[mrrsm]

With an All Aluminum "Waste Foam Cast" Engine Head with such an extended length present in the GM LL8 Engine... the chances are that it has become warped enough to warrant having a Machine Shop go through it. Alternatively... In the long run... getting a Re-manufactured Engine Head may prove to be less costly and more durable without relying upon a high mileage or damaged one with worn Rocker Arms, Push Rods, Valves, Valve Guides, Valve Stem Seals and roughed up Camshaft(s) Lobes and worn out Valve Seats as well.

 

[m.mcmillen]

Don’t forget about worn camshafts and bearings.

I’ve bought a lot of cylinder heads from Odessa Cylinder Head. They have a store on eBay.

http://rover.ebay.com/rover/1/711-5...0001&campid=5338077216&icep_item=222062799300

 

[deagle12]

Agreed, I'm starting to think about going that route. But at $400-450 is there any argument to just dropping a new engine in it?

Also, like I mentioned before - my GF has credit card debt and while we want something reliable and that's going to work for a couple years, we obviously want to reduce cost as much as possible too. But at 220k mi and being broke, I guess you can't have your cake and eat it too. I'm adding up the cost of the rad, engine hoist, tools, gasket, etc.... pretty unfortunate situation financially

 

[Sparky]

I don't get the oil making white deposits thing. Neither oil nor coolant is white, and oil and water don't mix...

 

[mrrsm]

This is the part where you have to be completely honest with yourself ...and her... concerning just how deeply down inside of the Rabbit Hole you are willing to travel as a Mechanic... and to be Sure as Hell about your level of Mechanical Knowledge and Ability to do this job for the Long Haul. Unless you own your own Repair Shop with a Hydraulic Vehicle Lift... You will never encounter a more difficult job than having to wrangle the R&R of either just the Engine Head...or the Complete Engine Swap of GM 4.2L Engine.

GM Basic Crate Motors run between $3,000.00 to $4,000.00 and a complete rebuild settles out for around $2,000.00 if you are willing to do your own work. Even with just replacing the Engine Head... you will still have to invest in Gaskets, Tools and other replacement components that you would be foolish to overlook... such as the Entire Timing Chain Set, Water Pump and ACDelco Special Casement Sealants that will also run into costing more in time, labor and money. Last but not least... is the Knowledge needed to perform the myriad tasks that only begin to come into view as soon as you raise the hood on her SUV.

It might be time to figure out how to get the thing running just long enough to find a replacement vehicle... and trade it in ASAP with the lowest possible finance rate that she can afford. If worse comes to worse.... at some point...you should start practicing telling her..."NO...Honey... That is NOT possible under the presents circumstances.... " and hold your own against the barrage of pleas and tears you will have to bear up under. The Trailblazer and Envoy Vehicles can become Money Pits and take you down a Very Long Road... With NO Turns in it.

 

[deagle12]

Sparky, I would say it doesn't seem to be completely mixing.. the deposits kind of get stuck along the tube of the rad, and once it heats up, I can scrape the deposits off with a flathead.

MRRSM, I agree and unfortunately this would be the first time I ever take apart an engine more than doing spark plugs! Although I love learning and have come quite far with YouTube, shop manuals, etc. But I just don't have a whole lot of time these days with my job. I am up for this task but it would probably take me a couple months. Hell I am planning on moving in a month or two, so I wouldn't even start this until then... and I don't know if I can take this hanging over my head for a long stint like that.

And that is my worry, in throwing more money at this and still not getting things completely right in the long run. But of course it doesn't make sense to me for her to take out a high interest loan for a $5-8k new vehicle... just seems like no decision is that "right."

 

[NJTB]

I'm dieing to know what these white deposits are.

 

[Mooseman]

I'd get the coolant tested before going forward to identify the contaminant.

Since you seem to be a fairly novice DYI'er (from your own admission), I do not recommend you do a head job on this engine. These engines are notoriously difficult to work on to begin with and head bolts ALWAYS break on removal making it even more difficult. And at that mileage and possible tranny condition, it may not be worth it.

A blown head gasket shouldn't cause overheating in itself but would be the result of overheating. Was the thermostat replaced? Did you use a flush? The white deposits could be calcium that could have been left behind by a prior bad coolant replacement using either the wrong coolant or poor quality water. I'd probably replace the radiator too just for good measure. Maybe someone in the past use a leak sealer, which is notorious at clogging stuff.

Again, a coolant analysis might shed some light.

 

[Reprise]

I had surmised aluminum oxides, earlier. @MRRSM brought up Teflon-like coating on the HG, which is another distinct possibility. If you do get the coolant analyzed and HG material is indicated, ditch the truck for another vehicle, as outright failure of the gasket will be certain (and unpredictable.)

I *do* think the floating substance is different than the caked-up residue, but that's just a hunch on my part, and likely immaterial, now.

You mention that the GF actually saw flow coming from the engine... that sounds like a leak that might have started small but is now getting worse - ? If you can find it, short of a cracked block / head, you can probably fix it. Even expansion (freeze) plugs are repairable, most of the time, in-car.

@Mooseman makes some good points (and I did say earlier that it would be tricky with the DOHC). If you two think what he advises makes sense - then sell or use the TB as trade bait, while it's running. And do it soon. Engines aren't constructed to withstand catastrophic overheating on a regular basis (well, maybe a Northstar, but that's another thread.)

While it may be blasphemy to say this on a GM board... if you can find a ratty but halfway decent running old Corolla or Civic - it'll likely last the rest of the GFs way through school. Just make sure the oil stays topped off.
Alternately, you may be able to find another TB / other 360 for a song, but the cheaper you find one, the more TLC it's probably going to need. Which almost puts you back at square one.

 

[JayArr]

Hey Deagle
I'm in the same boat as you, my head gasket blew and it all overheated. Let me give you some pointers to save you some time and $$.

1) My oil didn't turn to chocolate shake either, it looked and smelled OK even though two cylinders had breached. I was losing coolant from the water jacket into the cylinder, this doesn't change the oil but the engine quickly runs out of coolant and overheats.

2) I pulled the head with the engine in the car, it's a total pain in the ass! You still need an engine hoist because the head is so damn big and heavy and set so far back that it can't be picked up by one man. My advice is... Don't do it! Once the head was out I took it to the machine shop for a clean up and was quickly told it was toast. These heads are long and are only allowed to be warped by 4 thou and mine was warped 28 thou! I'll bet yours is the same. It was explained to me that they could mill it flat but since it's OHC that wouldn't correct the cam journals. All the effort I spent pulling the head (about 6 hours) was basically wasted. And YES I did break three head bolts, luckily they were up front where I could drill them out, if you break a rear bolt you can't get a hand drill back there so you have to pull the engine.

3) A rebuilt head was going to cost $900Cdn so I called the local wrecker and he sold me a running engine from a trailblazer that was in a collision for $860. Maybe a wrecking yard near you has a running engine. I may have overpaid, you could get one for less.

4) Pulling the rest of the engine was almost easier than pulling the head, there are four bolts at the top of the bell housing that look impossible to get but you just undo the driveshaft and lower the tail end of the tranny and a big space opens up and you can get them easily with long extensions.

So... my advice is that your head gasket is probably blown and your head is probably warped and it's no use trying to pull just the head. The solution is to just pull the engine. If you want to pull the head after the engine is out then that's just a 1 hour job and if the head bolts break you have complete acces to them to remove them (hint - go buy a set of reverse drills on eBay, they were less than $10 and the remains of my head bolts "uncrewed" themselves and came out as I was drillin them.) This is only the 4th engine I've swapped so I'm no pro but it was relatively easy compared to the others.

 

[Reprise]

Helluva first post, @JayArr - welcome, and thanks for the info!

 

[JayArr]

Thanks Reprise, I like to contribute what I can.

Here's another tip/hack that may help others. The manual lists a special GM part as the second hoist point and instructs you to remove the valve halfway down the side of the head and to use the bolt hole locations in the head to attach the part so you have two hoist points. (The other gets left on the engine up by the alternator) I had some doubts about the engine balancing but it works really well. A lot better than tying straps around the exhaust manifold.

Pictures attached, I didn't have the GM part so I welded up some scrap iron I had and drilled the two holes into it for mounting, It's not too pretty but it works great and the engine is going to be easy to install.