SOLVED: Water pump on it's way out after just 6 months?

[dkvasnicka]

So I did the water pump last October. I used an aftermarket pump from a company called Thermotec, I think they're making them in Poland or something. In case you're wondering why anyone here in Europe bothers manufacturing water pumps for Vortecs it's because of the Hummer H3... anyway, I noticed that my unwelcomed "foot massage" feature is back. It's a vibration through gas pedal under moderate/light acceleration from a complete stop or when coasting and then stepping on the gas a bit (that produces a kind of vibration surge that then goes away as RPMs go up). No vibration under heavy acceleration. And it's worse when warm.

I took the belt off and tried to wiggle the water pump (sorry for the messy video, I tried to capture it as close as I could):

As you can see the shaft has quite a lot of play. That's bad, right? My previous pump was a lot worse when it started making the "rocks in a cup" sound but this seems bad as well.
Here you can see the fan wobble a little bit:

As you may or may not see it seems like it's just the fan that wobbles a bit, not the whole shaft & the bell (from what I could see). Is a wobble like this able to wiggle the pump bearings and seals to death in just a half of a year and 2000 miles? At the center of the clutch it doesn't seem to move that agressively. Should I expect a 10 yo fan assembly to be completely balanced and do I need a new fan with the next pump?

 

[djthumper]

I had to replace 2 aftermarket ones rather quickly, the first was at about 6 months. The last one lasted a couple of years. This time I purchased an AC Delco for less then the after market one so we shall see.

 

[mrrsm]

@dkvasnicka Again and again... whenever factory components are destined to fail for one reason or another on this unique GM Atlas 4.2L LL8 Engine... The only replacements to be considered should be GM, Delphi and in this case... AC-Delco. The tightness of the bearings inside this OEM replacement water pump will be such that the impeller will NOT spin freely and it might seem like the axial motion is just a but bit too snug.... but it won't be... The Tighter... The Better.

This is the only acceptable replacement Water Pump and they come as the same item offered with two different price tags.... but they will be essentially the same. The same standard applies to the Metal Gasket and the requirement to use the correct fasteners. The later model vehicles may call for the use of TTY Fasteners... and if so... obtain New Ones and Toss the Old. There will be differing opinions about the use of RTV as an alternative... but the Metal Gasket follows the need to prevent shifting of the pump under processes of heavy rotational forces and vibrations being constantly transmitted through the case mountings to the Engine Block. RTV will work...but... Why risk any problems later on? The images shown as attachments are from a pump I purchased from Amazon.com as the Best Price & Availability for this component. Other members may have better sourcing for this component.

EDIT:

Check with @Matt for his epic post on how to do this R&R yourself... He has penned a Write-Up on "How to Replace The Water Pump" that has an absolutely Brilliant and Simple way to Secure the Water Pump Bolts in a manner that will make removing the Clutch Fan Nut a breeze to perform:

http://gmtnation.com/forums/threads/how-to-replace-the-water-pump.15639/#post-505126

 

[dkvasnicka]

Thanks for an epic response, MRRSM If there is a way I can get it from Canada for an interesting price I'll definitely consider it.

Which reminds me of one thing I forgot to mention... when I took the aftermarket pump out of the box when it came and tried to wiggle the shaft there actually was some tiny play... it was very subtle but when I tried I could make it move a liiiitle bit. I thought that little of a play should not be lethal for the pump and proceeded with installation (my previous pump was really bad and I was in a time press).

Looks like I'm about to reap the benefits of my decision! As I like to say: I'm not that rich to be able to afford buying cheap things...

 

[Mooseman]

It's not cheap here, about $100 + shipping. RockAuto may be the best option. They list another ACDelco part number 282-822. This one says it's professional and the other, listed at $103, says it's OE. I can't see the difference.

 

[dkvasnicka]

It's weird, the "OE Design" one is more than twice as expensive as the "Professional" one... and it's the same on eBay. After my recent experience I'm almost inclined to buy the most expensive one and be done with it. On the other hand I don't want to fund someone's marketing department...

 

[djthumper]

I bought mine on Amazon http://www.amazon.com/dp/B000IYXKBO/?tag=gmtnation-20

 

[Mooseman]

I'd go with the Professional. Any way you look at it, it's gotta be better than the other junk out there. When I swapped my engine, I put in a Gates. Couple of years later, I had to replace it with a Cardone because I needed it NOW. It's been a couple of years now with this one and I expect to change it but it has lasted surprisingly well.

 

[dkvasnicka]

ACDelco Professional came in. No play whatsoever and is absolutely silent when I turn it by hand. Waiting for a new clutch and also a new blade - I decided to invest in these things with the hope that I'll have a velvety I6 whose cooling system won't have to be touched for a loooong time

 

[mrrsm]

Daniel... @dkvasnicka
I don't know whether or not your new replacement Electro-Viscous Fan Clutch and Impeller have come in yet... but since your last post, I came across an excellent and instructive video concerning how to diagnose problems like these that turn out NOT to be the Water Pump... created by an important member here at GMT Nation... Drew (@MAY03LT)... that he made a while back that should definitely be added to the Mechanic's Lexicon of what to do when encountering...

"The Case of the Mysterious GM 4.2L Engine Noises"

 

[dkvasnicka]

Cool, thanks! I've spent a lot of time on his vids already but not this one

 

[AzTruckGuy]

So for those that changed the water pumps, did you also change the fan clutch too? I will soon be replacing a T-Stat and wasn't going to take the fan belt off to do it, as some have done it through the wheel well, but I guess I'm going the take the alt off route now, and if I'm going that route might as well replace the water pump since I'm there. I'm having no issues on my water pump or fan clutch, but when I price the fan clutch, its expensive at $225+

 

[mrrsm]

Az... when you pull the Alternator... review what Drew did with his and not only spin it in both directions axially to see how it sounds... but grab the small Serpentine Pulley on the the front of the Alternator unit at three points with one hand and try to feel what happens when you attempt to move the shaft in and out for excessive end play...and try to "tilt" the shaft on an off angle to see if there is any excessive wear in either the front or rear roller bearing housings. The "Howl" sound and vibration that @MAY03LT discovered was caused by the chatter of the bearings in a loose race contacting the inner bearing housing... with the front of the engine acting like a drum head to amplify that Awful "End-of-the-World-as-We-Know-It" engine noise. Do you think Drew was relieved to find out otherwise? "OH.. HELL YEAH...!" as he would say... LOL.

The way to see if the bearings in the Water Pump are sketchy is (after removing the serpentine belt) to grab the outer edge of the Impeller Blades at the top and also at the sides and try to tilt the blades in and out, "Teeter-Totter" style. If you detect even the slightest tilt movement...changing out the Water pump at the same time you replace the Thermostat (and Alternator, if necessary) along with Electro -Viscous Fan Clutch... won't cost too much more... and such preventive maintenance will allow you to Kill Four Birds with One Stone.

 

[dkvasnicka]

When I did my water pump the first time I did just the pump. As it's dying now (shaft can be moved by gripping the blade even with the belt on and it does all kinds of animal sounds under moderate acceleration) I decided to do the clutch as well and the blade too. There are too many stories of people doing the pump and then the clutch a while later

Thermostat I already did last year and I'm not sure I would want to try it through the wheel well... The alternator way is a PITA but it's bearable.

 

[Mooseman]

So for those that changed the water pumps, did you also change the fan clutch too?

Just test it to see if it works:
How to test the electro-viscous fan clutch

 

[dkvasnicka]

Done. I'm very glad I bought the clutch too. When I started to take things apart I found out the clutch bearings are FUBAR too. I would have banged my head against a wall till it fell off had I only bought the pump...

Unfortunately, my slight vibrations in gas pedal are not gone, just a bit less pronounced. Which is agonizing. I would be willing to tolerate many quirks in a (10 yo) car but this is so annoying it's crazy. I noticed that the brand new fan still has some irregularity to it, seems like there are millimeter "bumps" in the places where the blades connect to the outer rim (normal?). When idling a little wobble can be seen but nothing serious... No visible wobble side to side (to/from engine). I guess it's not possible for these to be completely balanced. I noticed there are 2 little weights on the old fan on one of the blades. Are those being installed in the factory when they test the piece on a balancer (do they?), or is this typically work of a shop? I'm thinking maybe I should have changed just the pump and the clutch an stick to the old blade... dunno.
But then again, my foot vibrations are probably caused by something different, too. My spark plugs interval is nearing (10k km to it), could old plugs cause vibrations without setting a misfire code?

 

[mrrsm]

Daniel... It is very likely that after 10 years of driving in what we might guess is a fairly mountainous region where you are in Finland... that the likely culprits as the source of the vibrations might be your Motor Mounts or Transmission Mounts... Or a combination of the three. I'm not sure whether or not you have the same type and arrangements in your Saab... But the Trailblazer MMs are bulbous, rubber lumps with short shafts above and below to fix them in place on the brackets between the engine block mounts and the body frame mounts and are filled with a viscous jelly-like liquid that occasionally will leak out should the rubber carcasses "spring a leak". I believe there are a few videos on YouTube that cover their R&R... And here again...finding the OEM flavor of these items is better than anything that looks the same ... But is "cheaper"... in every perjorative sense of what that word implies. When installing these... please be mindful not to twist the shafts too much when tightening the hardware...lest the rubber shells rupture and leak... and render the new mounts useless.

 

[dkvasnicka]

I thought bad motor mounts mean vibrations in idle, throughout the whole body, so I was not placing them very high on the potential culprit list. But the car has 10 yrs so they'll probably go to hell sooner than later... I inspected them visually and touched them (the parts I could reach) and they seem to be intact, with the fluid still in.

Anyway, I've done some not-just-test driving today and it seems that the foot vibrations really went mostly away... there is still some here and there but it's difficult to pinpoint. Before it was all over the 1500 - 2000 range when accelerating moderately and also plenty of vibration when accelerating (non-aggressivelly) from a standstill. So I should probably do you all a favor and stop bitching about it... till they come back again

But then there's the fan wobble. I did two videos and please tell me if it's normal (the first one looks like there's nothing wrong happening, the second video is a close up on the blade).

Thoughts? As I said: NEW pump, NEW clutch, NEW blade. All I'm worried about is whether this is normal or whether I'm on the road to yet another water pump job. Also, is it normal for the 4.2 to shake visibly (although very subtly) when fully warmed?

Btw, I'm not from Finland (although it's a beautiful country), I'm from the Czech republic and the car was originally sold in Italy

 

[mrrsm]

The fan wobble seems quite minimal if you consider its large outside diameter and center shaft axle radius... revolving at a minimum of 600 times a minute. But it would help us to visualize these vibrations better if you were to follow the example shown in the movie "Jurrasic Park" ...and set a clear plastic cup filled half-full with water with a wide base on the level front of the Radiator just after starting the engine at idle... and then observe whether these vibrations manifest enough violence to cause water droplets to spray out of the cup... Or if instead they form lazy and low idle waves happening either from the center... or from multiple points inside the cup. If the latter happens... then more than one source of vibration is at play... some of which may involve sympathetic vibrations, perhaps being amplified by loose suspension components. If these "shakes" are not loosening your eye teeth and the vehicle is otherwise sound... Ease your mind a bit and just keep on driving.

On occasion... If the vehicle has an Automatic Transmission... a clogged vane or vanes inside the impeller of the Torque Converter will vibrate out of balance when the hydraulic fluid motion subsides while the vehicle is at idle. Also, if any of the three bolts holding the Flexplate to the Torque Converter are improperly torqued or loosened... similar vibrations may occur at idle. In the case of a heavy Flywheel... Sometimes ...unless it is keyed or drilled out for precise placement on the tail of the crankshaft... removing and re-installing the Flywheel at 90 Degrees to its original position might even out the vibrations of the engine at idle... But use caution here as this action may do more harm than good on this unusual engine.

 

[dkvasnicka]

Well, some updates.

1) The new ACDelco pump was quite hard to turn by hand. I guess that's by design, good seals & stuff... The two previous pumps I took out could be turned by hand pretty easily, one of them was outright freewheeling when I spun it. However, I noticed that my car now sometimes drops out of OD when cruising in low speeds right above the threshold where the torque converter locks. Like 45 - 50 MPH. It happens on a level stretch of a 4-lane road where I'm absolutely sure the car should stay (and always stayed) locked and it's only happening within like first 10 miles of a drive, with the engine already fully warmed. As if something was holding it back and the car had to travel some distance to "stretch it's legs"... But there is no apparent lack of power. Can this be due to the new pump having more resistance? Is this normal? Previously the car could stay locked between 45 - 50 MPH even with more people in it and on a slight incline, which was quite impressive to me...
No OD drop-outs in freeway speeds.

2) Vibrations. I started getting slight but noticeable and annoying vibrations throughout the body with the car stopped and on the breaks. It does it both in D and neutral and I think I only noticed it when warm, not in the morning when I started it and it was in P. Also, as I've already hinted at, the engine seems to have more visible vibrations in the engine bay compared to what I was used to. But that's just a feeling, I can't prove it. I know it can simply be bad engine mounts but such a coincidence? I'd expect bad mounts to show themselves in winter, not now that the temps are up again... I checked the driver's side mount from under the car and the lower part of the mount seems to be quite a bit deteriorated, with the rubber a bit torn and forming "fringes" on the outside... it seem to be just a surface problem, though. The mount still seems to retain it's original shape and I also think it still has the oil in it.

Or are the OD drop-outs and the vibrations somehow related and is it all something different happening? You know, because broken A/C condenser isn't enough and what if I became bored after fixing my cooling system?? Here, have some fucked up tranny as a good measure... right?

Sigh...

 

[mrrsm]

Rubber materials... even high durability components made of such materials ...are subject to breaking down over time due to repeat exposure to high temperatures, vibration and similar to what happens with bending metals overs and over... "Work Hardening" to the point of cracking, drying out and failing as a result. Any motor or transmission mounts after ten years will display such signs of fatigue and even conceal these affects in their outward appearance. For example... a substantial amount of fluid can leak out of the bottom of the Motor Mounts and leave only a trace of an oily, sticky film adjacent to the brackets and frame and not reveal their source or their lack of integrity.

3rd and 4th gear drop-outs are more likely to involve either PCM Codes, low transmission fluid, sketchy shift solenoids or worn bands and friction discs... or any combination of the aforementioned items. They say that "All Solutions... Breed New Problems..."... but I doubt there is a connection to your recent change outs. If the New Water Pump was able to act with such an enormous drag on the engine at higher RPM... The Serpentine Belt would begin to Squeal like a Stuck Pig as the friction on the immovable WP drive wheel drags against the belt.

This is easily investigated by simply removing the belt and trying to move the Water Pump impeller by hand... then taking the vehicle on a very brief test drive (with the headlights turned off to save power) to investigate and try to duplicate the shift problems. Afterwards... it will be necessary to put the belt right back on and re-charge the Battery which will have been substantially drained during the test. The Water Pump should be tight and not spin freely like a top... However, if it fails to turn with firm hand pressure... then your bad luck with Water Pumps will appear to continue. If it does not... then the sudden overdrive drop-outs must be explained and attributed to something internal to the 4L60E Transmission. It is not uncommon for disparate problems to develop in clusters... even Shakespeare once observed in the play "Hamlet" that:

"Troubles Come... Not as Single Spies... But in Battalions..."

Fortunately... There is a wealth of knowledge, experience and many documented repairs to investigate further that others here have the ability to contribute to this thread... even if the topic morphs into an entirely different solution path.

 

[dkvasnicka]

Went to start the car and the vibration was there right away in P, subsided a bit as RPMs went down, never came completely away. Let the truck warm, shifted a bit, checked tranny fluid, level is OK, color too, no burnt smell. I did the pan drop and filter change last summer, nothing weird. The colour was nice even before the change.
The new pump could be easily turned by hand when gripped properly, it's just that it was a substantial difference to the old pump, which could be turned like nothing, probably because everything in it was loose. I too think that for a water pump to develop resistance that can cause a OD drop-out at 1500 RPM with an empty car on a level road... that would be something.

I'll do the plugs and oil change which need to be done anyway (oil has 1 year, doing it regardless of the mileage, which is below 6k miles) and will see.

Unfortunately engine mounts on an AWD GMT360 are a PITA At least the pass side one, IIRC.

 

[mrrsm]

Changing the oil in the GM 4.2L at "Under 6,000 Miles" is a great idea... as long as you add an extra one in between at around 3,000 Miles...

 

[dkvasnicka]

Really? All the opinions on changing oil after 3k miles I've ever read here or on the OS stated that it's a overkill... I thought doing it every year at under 10k km is perfectly ok. I am doing around 7-8k km / yr

 

[Mooseman]

Definitely does sound like the mounts are the cause. Well documented for vibes at idle.

The transmission TC dropping out of lockup would be done by the PCM unless it's slippage, then that would be the TC clutch failure or the valve controlling it but that usually throws a code. If it's just straight out disengages, then something is making the PCM disengage it.

 

[dkvasnicka]

But bad mounts don't vibrate in P/N, do they? I mean, really bad ones probably do but my problem came at once, not progressively I think.

As for the tranny: It locks pretty early and firm, as it always used to. But after a few secs unlocks and then locks again. Doesn't feel like slippage to me... but then again I've never had a proven slipping tranny.
Also, later during the drive this behaviour stops and the TC stays locked as it always did, even when you can feel the engine is taking some load...
In other words I think it's the control module thinking it doesn't have enough power.

 

[Mooseman]

But bad mounts don't vibrate in P/N, do they? I mean, really bad ones probably do but my problem came at once, not progressively I think.

I don't think it matters. D or P, it would vibrate. I know mine are due and it shakes either way.

Oh, and guess what? ACDelco only for the mounts. Aftermarket don't work right with this engine.

 

[dkvasnicka]

Did some searching on the TC drop-out and I'm afraid it's exactly what people with mischievous TCC valve experience... the only difference (so far) is that in my case the behavior goes away during every (so far) drive. Also I'm still perplexed by it starting to happen the very first TC-lockup-using drive I did after my pump/clutch/fan job (the vibrations came a day or so later).
Mind blown.

One possible scenario would be that I damaged the tranny lines when touching them to remove them from the fan shroud. But that would require a leak and a fluid loss and that's not my case.

 

[Mooseman]

Damaged line wouldn't cause this. If it was kinked or something, it would overheat the tranny from lack of flow.

 

[mrrsm]

Really? All the opinions on changing oil after 3k miles I've ever read here or on the OS stated that it's a overkill... I thought doing it every year at under 10k km is perfectly ok. I am doing around 7-8k km / yr

When it comes to engines designed with very close internal tolerances that begin life with an expectation of living a healthy, lubricated existence that can comfortably surpass engines manufactured during the 1930s to the 1980s by more than 100,000 miles of endurance... Regular, Early Oil Changes at 3,000 Miles using Quality, Synthetic Oil and High Quality Oil Filters are what make this phenomena possible.

Engine Oil bears all the earmarks of Human Blood in that it is a Liquid... with Solids Suspended in it. Those solids often include common environmental dirt particles... but over time as the engine begins to wear in and wear down... the by-products of incomplete combustion including Carbon and other gasoline (Pure Gas is THE Quintessential Lubricity Killer) and burned additives that are durable enough to pass the rings around the pistons...migrate down into the oil pan and are picked up and added to the Oil Stream to add to the things that Increase Friction, Journal, Galley and Oil Pump Clogging Gunk...and Ultimately... Engine Wear.

If the Oil in an Engine is allowed to continuously carry these increasing amounts of damaging junk by as much as an additional 3,000 miles... the Life Expectancy of these Engines will diminish substantially. Oil Filters that are pressed to go an additional 3,000 miles on High Mileage Engines are prone to filling up with too much crap... and plugging to the point of collapsing enough to cause the Oil to Over-Pressurize and push the By-Pass Spring Loaded Valve to open...and allow Unfiltered, Dirt-Ridden, Low-Lubricity Oil to Run Rampant through the system and hasten the death of these engines. Every time you Change the Oil and Filter in your Engine...you give it a Brand New, Fresh Start towards having a Long, Lasting and Healthy Life!

 

[dkvasnicka]

The vibrations weren't as pronounced today, which would strongly hint at the mounts, 'cause temps were a bit higher today...
I also took the belt off and engine is still shaking visibly. It's a very irregular shake, though, not a steady 10Hz shake. Like spikes... seems like it's almost calm and then you see it "jump". Shiver is the right word, maybe? Those interior vibrations I described before (steering wheel, doors, center tunnel) had the same characteristics.

I also recorded the engine, maybe someone with an ear trained for the Vortec 4200 will hear something weird or bad. This is a moderately cold engine right after start (like this). Hell, now that I'm listening to it it sounds like a frikkin' diesel...

 

[Mooseman]

Cold it does sound a bit rough but gets better. Doesn't completely go away though.

 

[mrrsm]

Daniel... I was wondering whether you removed the CPAS and either cleaned it out with spray solvent to see if the filter screens are still intact...or replaced it with a new one from AC-Delco and include replacing the CPS as well. If the CPAS is dirty... the sensor will act up with the Variable Valve Timing at low RPM and can make the engine idle rough... and throw misses and skips very similar to bad plugs at higher RPM at highway speeds. Are the local streets all paved in red fire brick...or is that your driveway in the latest video? The reason I ask... is because if all the local streets are of a cobblestone design... that surface will make the SUV suspension and engine-transmission mounts shake like a Chihuahua Sh*tting a Peach Pit and cause rapid wear and tear on them. if needed, there are some very excellent Youtubes on How-To R&R the CPAS and CPS sensors.

 

[dkvasnicka]

CPS & CPAS are the cam position sensor and the cam position actuator solenoid, right? Will check them out, thanks. I have no CEL, though.

The street design is just my driveway and it's very flat, it's not a proper bumpy cobblestone, it's just concrete-made pattern. Car rides smooth on it.

btw, can any of these things we discussed here cause vibrations on freeway too? 70 mph, CC on? (mounts, sensors...)

 

[mrrsm]

Yes... You have correctly identified both components... The R&R of the CPS is fairly easy... But you will have to completely remove the three bolts that secure the Power Steering Pump and remove it in order to gain access to, unbolt and slide out the CPAS unit. It's got to be AC-Delco here, Daniel for the CPAS unit...but the CPS can be an alternative brand. It is important to stress that the operative expression "Variable" for the VVT Related CPAS solenoid here is why it can go sideways in performance... And never throw Any codes! This is because it is relying upon Oil Pressure to perform its job...and only indirectly relates to the CPS, the CKP (crankshaft position sensor) and the knitting together of all these sensor reads inside the PCM.

The engine is designed to perform in "limp" mode if any one of these sensors goes bad and completely fails to perform. Google "How to Clean the CPAS" or words like that to see the raft of good R&R videos on YouTube to make life so much easier. When it comes to sketchy engine performance, unfortunately... these sensors and their potential to malfunction are very often overlooked...or never investigated as the real cause of the problems. The weird hesitations you can feel happening between 60 and 70 MPH may very well be caused by these components misbehaving... And this is primarily due to the fact that the VVT Actuator is dynamic through a very wide range of RPM, Power Demands and Torque Demands... relying upon Oil Pressure that can change infinitely across this broad performance spectrum. Ergo... If something is wrong with the CPAS being clogged and non-responsive... The PCM has no direct means to realize that there is a problem... and hence, no codes get thrown.

EDIT

It is crucial to change the oil and oil filter at the same the CPAS and CPS Solenoids are changed out or cleaned... or you run the risk of completely clogging the CPAS all over again!

 

[dkvasnicka]

The ACDelco solenoid is quite hard to find. Not even Rockauto has it. Is it really crucial that it's OEM?

 

[mrrsm]

@Mooseman has some valid input here regarding using the Dorman flavor of the CPAS instead and can give further guidance. Fortunately... the changeout is not so labour intensive as to preclude a repeat replacement sooner than later... But if you yank yours out and it is either badly gummed up inside or shows signs of the three screens suffering breakdown... Any newer one will wind up performing better than one in such a bad condition. It may also be that those who change their CPAS with the OEM version... but skip doing the Oil and Filter change have a higher follow up failure rate as these two events MUST coincide if you expect the problem to go away. The most "crucial" part is the Oil and Filter Changes.

 

[Mooseman]

With the CPAS, failure without a code is usually indicated with oil inside the connector.

As for Dorman, anything electrical is sketchy at best. Better stick with ACDelco or Delphi.

 

[dkvasnicka]

My mounts. 2 pics for the driver side, one for the pass side. Do they look collapsed or anything?

 

[Realism]

They do look a little bit worn. Then again, years of being the middle man . . .
Have you made a visual inspection with a partner. ie. have them start the engine (with P-brake on) and put it in gear while you watch if the engine shows excessive movement and lifting when increasing throttle. forward and reverse.
could also try to get a pry bar in there at the base and see if you can lift much.
Your's doesnt appear to have leaked, but here is a little comparison