GM Certified Techs or anyone with help

[flyfisherman]

Contact the Service Manager at your local Chevy Dealership before you pull the head. If he goes into, "It's not under warranty", ask for a meeting with the factory rep. (do it in writing). He has to meet with you if you request it.

You may find that they are willing to help. If this is a recognized factory defect, they may well help you out. I know that I would have. GM is very concerned about customer loyalty.

BTW......if it's that rare, I wouldn't be concerned about the other head unless you just want to do a valve job anyway.

One other thing....."KW Block Sealer" is amazing stuff. I once used it on a cracked cylinder block. There was actually water seeping out of the block in a steady stream. I put in a can of "KW Block Sealer" and drove that truck for 2 more years before I sold it. It doesn't gum up your colling system either. Do a Google search on it. I'm not even sure if it is still on the market.

Wayne ~ I see that KW Block Sealer is used for blown head gaskets but what do you think about this situation of a "cracked" head?



Fly

[wavery]

Wayne ~ I see that KW Block Sealer is used for blown head gaskets but what do you think about this situation of a "cracked" head?



Fly

I think it would be ideal. In fact, I'd lay a bet on it. If the crack were in the intake or exhaust port, I may want to hedge my bet due to the extreme heat.

[flyfisherman]

Engine - Coolant Loss With No Visible Leaks
Bulletin No.: 06-06-01-019B
Date: June 12, 2007
Subject:
Information on Gradual Coolant Loss Over Time With No Evidence of Leak Found
Models:
2004-2006 Buick Rainier
2001-2006 Cadillac Escalade Models
2001-2006 Chevrolet Avalanche, Blazer, Silverado, Suburban, Tahoe, TrailBlazer Models
2001-2006 GMC Envoy, Jimmy, Sierra, Yukon Models
2001-2004 Oldsmobile Bravada
2005-2006 Saab 9-7X
with 4.8L or 5.3L VORTEC(R) GEN III, GEN IV V8 Engine (VINs V, T, M, B, Z - RPOs LR4, LM7, LH6, L33, L59)

Some vehicles may experience a gradual coolant loss over time. A very low percentage of cylinder head(s) manufactured with an embossed Castech logo may develop a porosity crack in a very specific area.

Inspect the cylinder head assembly to determine if the casting was manufactured by Castech. This can be accomplished by inspecting for their casting logo located on top of the intake port, under the rocker arm support rail and in the spring deck cavity portion of the cylinder head.

If the cylinder head(s) is a Castech casting, inspect the area around the five oil drain holes for witness marks indicating coolant seepage over time.

If No evidence of coolant loss is found on inspection of Castech casting cylinder head(s), follow normal diagnostic procedures in SI to determine the cause of the coolant loss.

The crack location can be found in any of the five cylinder head(s) oil drains. This can be seen as a clean or shiny area, on an otherwise stained surface. Pressurizing the cooling system at this time may reveal coolant, air, or a combination, weeping in the described area. If inspection reveals evidence of coolant witness marks, replace the entire cylinder head(s) assembly.

Sure enough, I stopped by at my friendly MrGoodWrench dealer where I bought my GMC new (really a great dealer) and my vin matches the suspect numbers. They are going to have a look see at my heads this coming week ... the rub is I have to stand for the labor ~ $72.00 ~ and if it indeed looks suspect, I then have to plead my case to GM. Where are yo at with your repairs?

Thanks again ...

Fly

[oreo57]

Fly, Got the heads off friday night and the right head was bad. So now I'm trying to locate a remfg. set, but everyone say's 3-4 days. So in the meantime ill pull the oil pan and get out all the sludge. The best price on the heads is $200.00 ea rebuilt 3 yr. warranty plus shipping of $35.00 there in AZ. so I'll get more info tomorrow as most machine shops are closed on wkends so I may find something locally.$72.00 isnt bad for a little peace of mind if there not bad.also go to GM-trucks.com and take a look at post 38 it has some pictures that makes it easier to referance.
 
Heres the link

[wavery]

Fly, Got the heads off friday night and the right head was bad. So now I'm trying to locate a remfg. set, but everyone say's 3-4 days. So in the meantime ill pull the oil pan and get out all the sludge. The best price on the heads is $200.00 ea rebuilt 3 yr. warranty plus shipping of $35.00 there in AZ. so I'll get more info tomorrow as most machine shops are closed on wkends so I may find something locally.$72.00 isnt bad for a little peace of mind if there not bad.also go to GM-trucks.com and take a look at post 38 it has some pictures that makes it easier to referance.
 
Heres the link

Mike,

While you've got the pan off, it would sure be easy to stick a set of rod bearings in there. They're relatively cheap and there is a chance that they could be damaged.

[flyfisherman]

Contact the Service Manager at your local Chevy Dealership before you pull the head. If he goes into, "It's not under warranty", ask for a meeting with the factory rep. (do it in writing). He has to meet with you if you request it.

You may find that they are willing to help. If this is a recognized factory defect, they may well help you out. I know that I would have. GM is very concerned about customer loyalty.

Wayne ~ I'll be having a look-see at the heads on my GMC this week and if there should be a problem the proceedure (as I understand it) is for me to call the GM owner's service center and state my case.

Let me ask ... are you saying it would be better for me to follow the route you just outlined?



Fly

[oreo57]

Well, Just a note: ordered heads today and will rebuild this weekend..OH JOY.

Heads are being shipped 2day air from Mississippi , very hard to find ?? Brand new and ready to install. Will drop the pan tomorrow and clean sludge and take Wayne's suggestion of changing the bearings ( sort of ).I'll check them very well and if necessary will do it. It's been 15 yrs or better since my last rebuild, but other than messing with the FI, its all the same....... to continue

[wavery]

Well, Just a note: ordered heads today and will rebuild this weekend..OH JOY.

Heads are being shipped 2day air from Mississippi , very hard to find ?? Brand new and ready to install. Will drop the pan tomorrow and clean sludge and take Wayne's suggestion of changing the bearings ( sort of ).I'll check them very well and if necessary will do it. It's been 15 yrs or better since my last rebuild, but other than messing with the FI, its all the same....... to continue

If you're gonna pull the bearings, might just as well stick new ones in. They don't cost that much.

They may have dark grey wear marks on them. Very common after getting anti-freeze in the oil   . Just remember to stamp the rod caps with the cylinder # before taking them off. I always replaced the rod nuts. Very rare to have any damage on the crankshaft.

If you find a lot of wear on the bearings, it may be a good idea to knock the pistons out of the holes and replace the rings.

Was there any scaring on the cylinder walls? That is rare but it does happen.

Pull all of the lifters and check them while they are exposed. If you find any flat lifters, now's the time to check the camshaft. Sure don't wanta do this again.

[wavery]

Wayne ~ I'll be having a look-see at the heads on my GMC this week and if there should be a problem the proceedure (as I understand it) is for me to call the GM owner's service center and state my case.

Let me ask ... are you saying it would be better for me to follow the route you just outlined?



Fly

You may get better results if you have the Service Manager on your side. Going directly to the factory makes some Service Managers feel intimidated. A good Service Manager will be happy to plead your case for you. In the end, it is the dealership that will service your needs. The factory just pays the bill. It's best to have a good working relationship with the dealership, if possible.

If the Service Manager is resistant (which I doubt), just politely ask to have a meeting with the factory rep at the dealership. Remember, the dealership makes a fair profit on warranty repairs. They have every reason to help you if they can. The rep comes in at least once a month and that's part of his job. If the Service Manager is still resistant, write a letter to the local office. List dates, times and people names that you spoke to and ask for a meeting. They will comply.

[wavery]

Well, Just a note: ordered heads today and will rebuild this weekend..OH JOY.

Heads are being shipped 2day air from Mississippi , very hard to find ?? Brand new and ready to install. Will drop the pan tomorrow and clean sludge and take Wayne's suggestion of changing the bearings ( sort of ).I'll check them very well and if necessary will do it. It's been 15 yrs or better since my last rebuild, but other than messing with the FI, its all the same....... to continue

Howz it going???

[joe leister]

I have a 2003 Silverado 4.8L with Castech 706/lr4  heads, How rare have you found the the heads getting a prolific crack vs a head gasket being bad..any help would be appreciated. Mine is losing antifreeze into the heads but not sure why.

:confused: Has it been overheated and if so about how many times?

[oreo57]

UPDATE>>> Ended up changing both heads. The #2-8 side ( right ) had sign of leakage around the cyl. bolts around #2. The cost doing the work myself for both heads NEW and all gaskets was about 1/3rd the dealer quoted ( $3000-3500 )and I have to admit a little more work than expected ( 15 years since my last tear down) . Tear down was 4 hours and reassembly about 10. My loving DW was there during reassembly which was awsome...To you who are asking,  NO sign's of water leakage, no over heating, no power loss,  just sludgey oil and very noisey lifters and rods ( NO OIL PRESSURE ) I'm lucky to catch it in time.If you need more info regarding where to get the heads, the company I purchased from was great...I wont advertise here but send me a PM and I'll give his #.

 
Total Cost $ 1158.00 and some change.
 
Dont Like Chevy's Torque stats though.
 
Wayne..Thanks for the info.
 
Brad...Thanks for reminding me to update
 
GOOD LUCK, the dealer after 80,000 is NO Help

[austinado16]

Nice job.....both in not grenading it, and in doing your own work.  And your times are pretty decent.  That's some tough wrenching.

Whatcha gonna do with the 2 large you just saved?