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intermit low oil psi light and low compression #3 cyclinder

merrillj1

Member
Messages
6
Location
Southern Tier New York
I have a 06 h3 with intermit low oil psi light and low compression #3 cyclinder. It is 30psi. The other cyclinders are all above 150psi. I obviously have the bad head problem and am trying to get the Hummer to warrenty as much of it as possible being it has 74000mi. The thing I don't get is why the intermittent oil light at low idle? Could the rpm be dropping so low at idle the oil pressure pump cant PUMP?
 

Kyle

Well-Known Member
Messages
1,707
Location
Santa Clarita, CA
if the oil pump is mechanical the rpm drop will probably cause it to not pump as fast and will cause the low oil pressure. not 100% sure
 

Reloader

Well-Known Member
Messages
413
Location
Montana a free state
30 psi compression is pretty poor. Obviously a mechanical issue probably a burnt valve requiring head remove and replace. Low oil pressure could be a defective oil pressure sending unit. Needs to be tested with a mechanical guage installed into the sender port on block with engine running. Low end of spec hot should be in area of 15 to 20 psi at idle but could be more or less. Low pressure could be due to plugged oil pickup screen, worn pump assembly or worn engine internals such as engine main and rod bearings. Oil sender problems are not uncommon on GM engines. good luck.
 

4speedfunk

Well-Known Member
Messages
4,250
Location
Tardville
Like you said...you clearly have a bad head/blown head gasket (same results). You might want to check your oil and see if its contaminated. Oil thinned-out by water would allow the bearings to wear at a pretty aggressive rate. This would certainly result in lower than adequate oil pressure. And big money! (bigger than just a head replacement). Low idle could do it too...so don't freak-out just yet. Good luck, and let us know what you find out.

If it looks like the motor is a loss...just junk it and replace it. You can't rebuild it for what a used low-milage one would cost. Maybe upgrade to an 08-09 3.7L?
 

merrillj1

Member
Messages
6
Location
Southern Tier New York
I did cut the oil filter open and found nothing unusual. There was a trace amount of very tiny metal but that's normal. I have an appointment at the stealership Monday. Its a good thing they don't put these engines in aircraft! LOL I let everyone know how it goes.
 

merrillj1

Member
Messages
6
Location
Southern Tier New York
Went to the GM service center. They diagnosed my 06 H3 with a bad cyclinder head. Price to fix $3000.00. Called HUMMER and they took my information and said they would call me back with a possible offer for warrenty. Next day the dealer called me and told me they would warrenty none of it but did give me a coupon for a new vehical. I dont understand, the Colorado/Canyon warrenty was extended to 7 yrs 100000 mi but HUMMER gets nothing for a known defect in the intake valve seats.
 

alrock

El Diablo
Staff member
Messages
10,677
Location
Scottsdale
Sounds like you should keep working with GM for a better deal than that. I suspect that if you searched this forum for cylinder head issues you'd find many that had problems and many that got help from GM.
 

mkmcgreg

Well-Known Member
Messages
196
Location
Carmel
Well being that I unfortunately dealt with all of this today.. The service manager called said the retail price for this fix was $2,300.. I called his bluff, thanks h4o, and he spoke with his rep who was "generous" today and would good faith $1,300 of it and I would have it back tomorrow. I have no idea why a service dept would have a rep but that's the story they gave me. Tell them Hare Chevy in Indy just got this done for a grand. Let me know if I can help.. Other than the $1,000 it was pretty painless for me... I hope
 

merrillj1

Member
Messages
6
Location
Southern Tier New York
Thanks for everybodys help with my cylinder head issue and I am sorry for venting. I really love my h3 and was in disbelief when such a problem happened. Its by far the best vechile I have ever owned. The dealer came down $300.00 to 2700.00 and I will get an extra $3000.00 off my next new car. One side note the service manager told me he is sure the oil pressure problem was directly related to to cylinder head problem. He has seen it happen along with several of the head valve / seat problems. I should of asked him why. Anybody have any thoughts?
 

merrillj1

Member
Messages
6
Location
Southern Tier New York
Thanks for everybodys help with my cylinder head issue and I am sorry for venting. I really love my h3 and was in disbelief when such a problem happened. Its by far the best vechile I have ever owned. The dealer came down $300.00 to 2700.00 and I will get an extra $3000.00 off my next new car. One side note the service manager told me he is sure the oil pressure problem was directly related to to cylinder head problem. He has seen it happen along with several of the head valve / seat problems. I should of asked him why. Anybody have any thoughts?

UPDATE! The service manager called to day and raised his quote to $4100.00. He says both cams and all the cam followers need to be replace. They showed signs of galling in the number 5 cyclinder. I told him to go ahead since the labor is free (they had to swap them over anyway). Evidently I really did have an oil pressure problem. He thought water got into the top of the engine. The only way this could happen (in my opinion) is the head gasket leaked. This is unbelieveable and unacceptable. GM cant make an engine that will last 74,000 mi. Like I said its a good thing they dont put the 3.5L in aircraft. They would be dropping out of the sky left an right.
 

TheGunnyRet

Active Member
Messages
40
Location
MD
5 yr 100k mile which ever comes first. ouch!! Change your plugs as well during all this. I would have them show you the bad parts so you "ACTUALLY" have seen the gail marks on the followers and Cams. JMO
 

Happy Hummer

Well-Known Member
Messages
1,465
Location
Wisconsin
That seems a bit high...You could obtain a rebuilt engine and have it installed for not that much more. Or go with a salvage yard engine and have it reburb out of the H and put it in after tear down and rebuild.
Chris
 
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