Collapsed Lifter

LaMont Owner/Technician Smithville, Ohio Posted   Latest  
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Drivetrain
Propulsion
2008 GMC Sierra 1500 SLE 5.3L (0 LMG) 4-spd (4L60-E)
Low Oil Pressure

This truck has a collapsed intake Lifter on #7 cyl. It also has low oil pressure. The engine does not knock or tick. I verified the low oil pressure with a gauge. I checked the screen under the sender and it was not plugged. It never had an oil pressure problem before the lifter collapsed. My question is: is the low oil pressure the result of the collapsed lifter? Can the oil pressure be leaking out around the lifter somehow? I don't want to replace all of the lifters and still have oil pressure problems. Thanks in advance. 

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Caleb Diagnostician
Mishawaka, Indiana
Caleb Default
 

Is the low oil pressure measured at the sender hole or at the filter housing. If its at the sender that it has low oil pressure its probably the cam bearings. No a collapsed lifter should not cause low oil pressure. Does it also have VVT??

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Rick Technical Support Specialist
Saint Charles, Missouri
Rick Default
 

Could the LOMA (Lifter Oil Management Assembly) be at fault? If lifters are replaced the oil manifold assembly should be replaced too. Check for oil pressure as Caleb stated above.

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Brad Diagnostician
Pullman, Washington
Brad Default
 

The VLOM can cause low pressure at the sender. I have seen in a very few cases where the pressure relief valve in the pan gets stuck open and causes low pressure at the sender. The number two cam bearing can be at fault, usually on higher mileage vehicles. I would hang a pressure gauge at the sender and at the filter and compare the two.

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Douglas Technician
Hermon, Maine
Douglas Default
 

This is spot on. I second this reply,

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LaMont Owner/Technician
Smithville, Ohio
LaMont Default
 

This all happened simultaneously (misfire and low oil pressure message). Truck has around 150 K miles on it. I removed the left cylinder head and checked the cam bearings as well as i could by looking down into the cam through the lifter holes and I couldn't see anything wrong. The question is, would I be able to see a cam bearing that was out of place fairly easily by doing this? Since I didn't…

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LaMont Owner/Technician
Smithville, Ohio
LaMont Default
 

We were planning on replacing the LOMA. I was just wondering if there was no downward pressure on the lifter (because it is collapsed) if the oil pressure could push the lifter up far enough in the bore to let oil escape past the lifter at the bottom.

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Brad Diagnostician
Pullman, Washington
Brad Default
 

This one does not have VVT.

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Raymond Owner/Technician
Binghamton, New York
Raymond Default
 

Do you Spin a cam bearing And if you take notice GM does that sell cam bearings so basically the engine is a paperweight

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Brad Diagnostician
Pullman, Washington
Brad Default
 

So are you saying that everyone of these you see if it has low oil pressure has a bad cam bearing? If so that is poppycock.

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Raymond Owner/Technician
Binghamton, New York
Raymond Default
   

Lol brad apparently you work for Chevrolet do you sell cam bearings!i Doubt it. The Cam bearing next to cylinder number seven rotates forward and out of the journal meanwhile number seven lifter loses oil pressure because it’s all dumping on the other side. Oil pressure will be about 5 to 10 pounds when it started cold and eventually drop to zero if that’s your case junk it. Also you can look…

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Caleb Diagnostician
Mishawaka, Indiana
Caleb Default
 

Raymond I work for a GM dealer. We most definitely sell cam bearings. Especially for the 4.8 5.3 6.0 an 6.2 !!!!

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Raymond Owner/Technician
Binghamton, New York
Raymond Default
 

Ya better check with parts in the am. 5.3 cam bearings!

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Scott Owner
Moreno Valley, California
Scott Default
 

diag​.​net/file/f6yatk6xm… Hmm. The dealer I call has 'em in stock.

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Brad Diagnostician
Pullman, Washington
Brad Default
 

I am curious where you're trying to go with this. We stock cam bearings for these. I installed cam bearings in a older 6.0L this spring. Just because it has low oil pressure doesn't mean it has trashed bearings. The ones I see are high mileage ones 200K plus. And I usually see number two go bad and the most often offender is the high mileage 6.2L. One needs to go through procedures first. The…

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Raymond Owner/Technician
Binghamton, New York
Raymond Default
 

If you could please forward me a part number for the 2008 5.3 I would appreciate it.(cam bearings) - the last time I spoke to GM they had a problem with this motor. I was told once the cam bearing walks out of the journal, the block will not hold the replacement bearing 5.3 only! They could not produce a part # and if we were hellbent on replacing it we should call summit racing. I guess when…

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Scott Owner
Moreno Valley, California
Scott Default
 

Raymond, …

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Raymond Owner/Technician
Binghamton, New York
Raymond Default
 

👍thanks I will inform our local chevy dealer.

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Raymond Owner/Technician
Binghamton, New York
Raymond Default
 

I guess I went a little over the top I apologize! Last year we’re going to rebuild a 5.3 That coughed up a cam bearing. when I called the local GM dealer I was told they did not make them! when I went to the local machine shop, I talked to an old timer(who probably forgot more than I know) and was told that if a cam bearing walked out on a 5.3 it would be close to impossible to get a new one to…

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Robert Diagnostician
Oldsmar, Florida
Robert Default
 

This is irrelevant to the actual issue with the vehicle but I'm going to post it anyways because ... well i think its worth sharing. The professionalism of this site and those who run it and those of us who post here is ( For the most part ) very professional. The "other " site i have been a part of for many many years is completely opposite for the most part. I am so glad i found this site and…

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Allan Instructor
Winnipeg, Manitoba
Allan Default
 

Robert I too cancelled my premium membership after 20 plus years for the same reasons. Too much non professional behaviour, to put it nicely, on “the other site”. Diagnostic Network is far more professional. No need for flame suits here.

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TJ Owner/Technician
Central Square, New York
TJ Default
 

This guys videos go into a good bit of the VLOM issues and collapsed lifters on GM LS truck engines - youtube​.​com/watch?v=pP7I5t…

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LaMont Owner/Technician
Smithville, Ohio
LaMont Default
 

I saw this the other day. Some interesting info. Not sure how the release tool works or how I could make one quickly. Haven't got back on the truck yet. The issue now is that the lifters are on back order from GM and the dealers that have them won't part with them. I'm gun shy about using aftermarket lifters. I don't want to tear it apart till I can get parts for it. Has anyone out there used…

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Matthew Owner/Technician
Orleans, Massachusetts
Matthew Default
 

I have used quality aftermarket AFM lifters several times without any problems. Melling or Sealed Power.

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Gary Technical Support Specialist
Rochester, New York
Gary Default
 

A little help, is the LOMA and the VOLM the same thing. What is there function in the motor, as far as oil pressure.

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Douglas Technician
Hermon, Maine
Douglas Default
 

melling​.​com/wp-content/upl…​.​pdf Quick one page from melling on the Vloam. It's basically the oil manifold in the valley that controls active fuel management AFM Can't say I know what the Loma is, someone else chime in on that one.

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LaMont Owner/Technician
Smithville, Ohio
LaMont Resolution
   

Finally got this one out the door. I decided to replace the AFM lifters on the left bank and the VLOM. The lifters were on back order from GM so after reading Matthew Leonard's post and talking to Tech support at the lifter manufacturer I decided to use aftermarket lifters. I inspected the cam bearings as well as I could while the head was off and the lifters were out and could not see anything…

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