Cylinder head repair

[steve]

I can't believe I today was the first time I'd ever heard of this site. This place is a dream compared to another place that will go unnamed.

Today I brought my 2005 4.2L TB in to the dealer because of a misfire. Well they are thinking it's a cylinder head that needs machining. The dealer will confirm tomorrow after they run a leak down test at which time they will give me a quote to repair. I asked for a rough idea what it would cost & was told $3,500. Is that a reasonable price for the repair? It sounds awfully expensive but then again I'm no expert. I was told they need to remove the front of the engine, & then retime it when they are done, & replace the head gasket. Am I being raked over the coals here??

 

[RayVoy]

Yeah, it's a big job... because it's an overhead cam engine, the cams and the chain that drives them, must be removed before you can remove the head.

Mis-fires can be caused by a leak in one of the cylinders, but there are a number of things that can cause a mis-fire.
IMO, this is one of those times when paying for a 2nd opinion is a good thing.

 

[Mooseman]

Misfires can caused by any number of things. In descending order of probability/seriousness:
- bad spark plug
- bad ignition coil
- bad/plugged fuel injector
- vacuum leak
- blown head gasket
- cracked head
- block/piston/ring issue

Although a leak down test will certainly give precise information, a basic compression test that anybody can do will give a good ballpark idea as to the health of your engine. If all your cylinders are within 10% or so of each other, then you can pretty much rule out a mechanical issue.

So a second opinion from a reputable non-stealership shop would be recommended, starting with basic troubleshooting and a compression test.

 

[limequat]

For $3500:

1) Buy a used 2006 engine for $1000, bolt it in and enjoy your 16 extra horsepowers.

2)Spend $2500 buying hookers and blow.

3) ...

4) Profit!

 

[Mooseman]

Sure, if you can do it yourself, otherwise, the labour is WORSE to swap out an engine in these things. Trust me, I know!

 

[jimmyjam]

Sure, if you can do it yourself, otherwise, the labour is WORSE to swap out an engine in these things. Trust me, I know!

its really not as bad as you make it sound

 

[steve]

The dealer gave me a final quote for the head repair. Actually they want to replace it since GM recommends not repairing it. They want $3,700

 

[The_Roadie]

They want $3,700

And I want a pony for Christmas. Something tells me we're both going to be disappointed.

Time to shop it around, and talk to an independent mechanic who will DISCUSS the compression and leakdown tests with you.

 

[steve]

that's the plan for this week. I called another local dealer & they want $3,000 for the same repair. So at least we are headed in the right direction.

 

[Mooseman]

its really not as bad as you make it sound

What's the shop estimate to swap an engine? IIRC, it's something like 19 hours? That's a lot of labour $.

To the OP, yes take it to a good independent shop. We don't call them "stealerships" for nothing. A third or even fourth opinion would be good at this point.

 

[steve]

Today I called GM customer service to see if they could offer any assistance. Let me say I couldn't be happier with how well they handled the situation. I explained to the customer service rep my situation & how the service tech told me they have done three in the last year. She took all my info & contacted the dealer. The dealer agreed to drop the price to $2,200 which is 40% off. Considering my TB is seven years old I couldn't be happier. So tuesday it goes in for a new cylinder head, gaskets, & timing chain & tensioner. Should have it back in 3-4 days according to the dealer.

 

[DJones]

Wow. That is some good service on GM's part. As long as they follow through with it.

 

[steve]

Well tomorrow will be day 4 of my TB being at the dealer. Apparently 4 bolts broke when they got to point of removing the cylinder head. Unfortunatly from what I was told three of them are where the motor is under the windshield. Sounds like PITA to get those out. Anyway they say I might have it back by Saturday.

I have a question I hope someone here can answer. They are putting on a new timing chain & tensioner while they have it all apart. When they retime the motor will involve them doing anything to the PCM? I'm wondering if I'll have to send it to pcmforless to have it reflashed?

 

[Wooluf1952]

A new timing chain just involves lining up timing marks on cams and crank. There should be no reason to re-flash the PCM.

 

[CaptainXL]

Well tomorrow will be day 4 of my TB being at the dealer. Apparently 4 bolts broke when they got to point of removing the cylinder head. Unfortunatly from what I was told three of them are where the motor is under the windshield.

Reason being is because there is no clearance to rap on the bolt heads like the GM service manual states to do.

 

[Mooseman]

They could decide to reflash if they either see if it has a modified flash or think it needs to be updated. If not, then they will probably just do a CASE relearn which does not involve flashing. It is a form of timing but just for angle errors between the crank and camshaft.

 

[steve]

Got another update today. I spoke with the service manager who informed me I won't get my TB back until Tuesday. They got all the broken bolts out but have run into a couple other problems. When they removed the bolts from the manifold apparently part of the manifold fell off. He said the flange where a bolt goes thru was just broken off. Then I found out that my drain pan also broke. To change the timing chain they need to drop the oil pan to get to some bolt for the chain. He said the front differential has a component that attaches some how to the pan. When they removed it the pan was so rusted in that area it actually came apart. He said they need to call GM to get the parts covered by the deal we reached last week. Hopefully that works out ok. The service manager invited me to come down Monday & he'll show me everything they have done. So we will see how that goes.

 

[CaptainXL]

Got another update today. I spoke with the service manager who informed me I won't get my TB back until Tuesday. They got all the broken bolts out but have run into a couple other problems. When they removed the bolts from the manifold apparently part of the manifold fell off. He said the flange where a bolt goes thru was just broken off. Then I found out that my drain pan also broke. To change the timing chain they need to drop the oil pan to get to some bolt for the chain. He said the front differential has a component that attaches some how to the pan. When they removed it the pan was so rusted in that area it actually came apart. He said they need to call GM to get the parts covered by the deal we reached last week. Hopefully that works out ok. The service manager invited me to come down Monday & he'll show me everything they have done. So we will see how that goes.

You realize everything they are explaining to you is because they are efing up. Don't let them charge you for their mistakes. The final bill you receive could easily go over $5000. You might want to consult an attorney.

 

[steve]

Given this is one of the most reputable dealers around here I'll give them the benefit of the doubt for now. We will see how it goes though as anything can happen. I'll be sure to post an update come monday. By then everything will be ironed out.

 

[gmcman]

I'm not sure how to start this but I really hope your TB comes out of the dealer running just fine. What I don't like is the fact you took it in for a misfire and they quoted you a head job without a leakdown test.

Did you purchase this new and have you ever changed the plugs, how many miles on the plugs? The list Mooseman gave is pretty much what happens with these motors, and that's not saying you don't have a bad cyl head.

I know your TB was already at the dealer when you started this thread so we couldn't really do much at that point. I know you say it's a reputable dealer but sounds like they are hacking up your motor. Is this under some type of extended warranty?

Sorry to sound callous but I don't know of any other way to put it. I just don't think the proper protocol was taken to determine the root cause of your problem and I hope that i'm wrong.

 

[steve]

I'm not sure how to start this but I really hope your TB comes out of the dealer running just fine. What I don't like is the fact you took it in for a misfire and they quoted you a head job without a leakdown test.

Did you purchase this new and have you ever changed the plugs, how many miles on the plugs? The list Mooseman gave is pretty much what happens with these motors, and that's not saying you don't have a bad cyl head.

I know your TB was already at the dealer when you started this thread so we couldn't really do much at that point. I know you say it's a reputable dealer but sounds like they are hacking up your motor. Is this under some type of extended warranty?

Sorry to sound callous but I don't know of any other way to put it. I just don't think the proper protocol was taken to determine the root cause of your problem and I hope that i'm wrong.

They checked all the plugs & coil packs, checked the fuel injectors, & after that did a leak down test when I brought it in for the misfire. There was one other test they ran but I can't remember what it was. Anyways they found cylinder #2 was failing. No it is not under warranty. What happened is I called GM & they worked out a deal with the dealer. The service manager already said they weren't going to charge me for any extra hours they have had. They are going to try & get GM to cover the new manifold & drain pan as part of the agreement. That way the original price will not be affected. Right now it seems worst case is I have to pay for the new manifold & drain pan. He did tell me that it would have been much easier for them to just have replaced the motor. I'm planning to bring my camera so I can take a couple pics of the parts. I'll post them monday.

 

[khill]

Holy crap man, sounds like you took your baby in for surgery and they put edward scissor hands on the job

Just wondering, but how severe of a misfire were you having before you decided to take it in? I only ask because I had an occasional misfire at idle that the stealership wanted $2000 to fix a "small timing issue".


Best of luck to you.

Keith

 

[steve]

Holy crap man, sounds like you took your baby in for surgery and they put edward scissor hands on the job

Just wondering, but how severe of a misfire were you having before you decided to take it in? I only ask because I had an occasional misfire at idle that the stealership wanted $2000 to fix a "small timing issue".


Best of luck to you.

Keith

Honestly it really wasn't to bad. The truck would bounce a little so I could feel it & the rpms would drop, go up, & drop again at idle while in gear. Sometimes you could feel it while in park. The mechanic that did my O2 sensor last year commented he could hear it. The sound was really noticable when next to a building, like in a drive thru line. It's been acting this way for a while & I just got to the point I wanted it repaired. That is when I brought it in last week to have it diagnosed. So here I am today waiting to get this repair completed.

 

[revamp]

I experience the same hesitation in my idle. I fear the worst and I have been pricing rebuilt and used engines to see what the pricing looks like. It's great GM said they would work with you. I, too am anxious to see the outcome of this, as well as your pictures.

Good luck!

 

[steve]

Well I made it into the dealer to meet the service manager & check out the repairs. It was well worth the time.

This is the failed cylinder head. Turns out talking to the mechanic & not the service person at the counter I got much more detail into the problems of my cylinder head. Only one cylinder was functioning how it's supposed to, four where at varying degrees of functioning/failing, & cylinder #2 is the one that had failed completely. That is a lot more info than the person at the counter gave me when I had it diagnosed. The one with the green liquid is the only one that wasn't messed up.

The other issue they ran into was when they were trying to change the timing chain. When replacing the timing chain you need to drop the drain pan to access a bolt. For some damn reason a brainiac at GM decided to run a shaft for the front differential thru the drain pan. To remove the pan the differential needs to be seperated from the pan. Unfortunately one side has seized itself to the pan. In the process of heating & working the part. The metal actually broke & left a flange in the pan. The shaft can not be removed until this piece is removed. Luckily they were able to remove it a couple hours after I left & didn't have to cut the shaft. This & the drain pan both need to be replaced. Here are some pics of what broke.

This is the drivers side where the differential came out without a problem.

This is the flange stuck in the drain pan on the passanger side. You can see the shaft sticking thru.

Here is the part that used to be attached to that flange.

The last issue that came up was the manifold. The flange where it bolts on broke.

Now to the good stuff. All of this will be covered under the original agreement I made with GM & the dealer & not cost me a dime more. The dealer had been trying to get the district GM guy to come in and approve the parts being covered. They were unable to get him so they have decided to cover the parts themselves & deal with GM later. I'm not happy I had to deal with this repair. However I am extremely happy with GM & my Chevy dealer for standing by their product covering this repair. This chevy dealer has earned a loyal customer for many many years to come. They get an A+ in my book. It was all put back together today & they will have it tomorrow to drive & make sure there are no issues before I get it back. I'll be picking it up Thursday.

 

[Mooseman]

Wow. Talk about a can or worms . Good on them on honouring the original agreement. What failed exactly in the head? Leaking valves? And I wonder what they used to replace the passenger side axle disconnect since GM stopped making them and are supposedly no longer available new.

 

[jimmyjam]

Here is the part that used to be attached to that flange.

wow how the heck did that happen

 

[Mooseman]

It's a tight fit between the disconnect and the pan. Corrosion just makes it even tighter. Mine was very tight but was able to twist and pry it out. Cleaned it good and added anti-seize for future removal.

 

[steve]

Leaking valves was the problem with the head. They had the cylinder head & drain pan in stock.

I never asked about the passenger side axle disconnect. I just assumed it was in stock too. I'll ask them on thursday when I talk to them.

 

[CaptainXL]

wow how the heck did that happen

Looks like the mechanic used the shaft to try and pry it off. I think your supposed to rotate it back and forth like mooseman said. Its a good thing they are covering it because the cost is getting out of hand now.

 

[Sparky]

That broken disconnect looks familiar...

 

[steve]

Well I picked her up today from the dealership & it runs like new. It's amazing how much power the motor has in it now. Again I commend GM for standing behind their product. They did a tremendous job repairing my truck.

I was reading the repair report & noticed they listed that during the leak down test cylinders 2 & 4 both failed at 30%.

 

[Mooseman]

So did they repalce that broken disconnect with a new one or a used one from somewhere? Just curious if GM is keeping a secret stash of new ones for themselves.

 

[ElAviator72]

I'm glad that a GM dealer wasn't afraid to turn a wrench on a modern engine (maybe with a a little coaxing from GM corporate).

But on the other hand, I'm left wondering what caused the problem to begin with?!?!? Just old age and a ton of miles?

 

[Mooseman]

I'm glad that a GM dealer wasn't afraid to turn a wrench on a modern engine (maybe with a a little coaxing from GM corporate).

But on the other hand, I'm left wondering what caused the problem to begin with?!?!? Just old age and a ton of miles?

I don't think it's age as we would have had a lot more of these with the number of aging trucks now on the road. Same for a design flaw. I guess it could have just been a one off defect. Maybe it was built by a Friday afternoon crew

 

[steve]

So did they repalce that broken disconnect with a new one or a used one from somewhere? Just curious if GM is keeping a secret stash of new ones for themselves.

They had a new one in stock. They actually had the cylinder head & the drain pan in stock. All of which I would think they'd had to get from elsewhere.

 

[steve]

I'm glad that a GM dealer wasn't afraid to turn a wrench on a modern engine (maybe with a a little coaxing from GM corporate).

Just old age and a ton of miles?

The truck only has 88,000 miles on it. So it's not likely the mileage. Seems someone just did a crap job.

 

[Opeth]

My truck is sitting at the dealership for the exact same problem. I had a misfire I couldn't cure/ solve and after compression test #6 was 70%+ less than the other cylinders. Tore the head off and there was a severe carbon build up on only that one cylinder ruling out neglectifulness on my part. I have an extended warranty on my truck, an inspector looked at it Thursday and warranty company requested quotes for a new engine or new head and lower half decked at machine shop.

I would assume this failed valve is covered under " all internally oiled components" or it damn well better be... A $100 deductible will be better than the $3k + repair tag. Hopefully will know what I will be getting Monday, my truck only has 74k miles.

 

[steve]

Based on everything I just went through & conversations with my dealership. It will save everyone time & money to just replace the engine. Also if it comes up, don't let the warranty company force you to get the head machined. GM says it must be replaced if defective.

 

[CaptainXL]

Based on everything I just went through & conversations with my dealership. It will save everyone time & money to just replace the engine. Also if it comes up, don't let the warranty company force you to get the head machined. GM says it must be replaced if defective.

It all depends how much you want to spend. Sounds like you used a warranty which is probably the smartest to do. However, there are multiple scenarios here which all differ in cost.

Scenario 1: Have shop R&R with new engine
Scenario 2: Have shop R&R with used engine
Scenario 3: Have shop repair engine
Scenario 4: DIY R&R with new engine
Scenario 5: DIY R&R with used engine
Scenario 6: DIY repair engine