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Replaced Camshaft and lifters...engine light still flashing

ricseay

New Member
Joined
Dec 27, 2015
Messages
8
Long story short.  Had the flashing check engine lights. Codes showed #4 cyl. Mechanic replaced all lifters, spark plugs and #4 coil.  Two weeks later, same engine flashing and code for #4 cyl. Mechanic said lifter was bad again and caused by camshaft. Replaced camshaft, on the way home engine lights start flashing again. Mechanic said to bring it back and he would see what it's doing. Any ideas?

In the past six months, I have replaced throttle body, spark plugs, coil, accelerator pedal, CAT, timing chain, etc.....still have flashing engine lights!!!
2007 Avalanche 5.3
 
What codeswere stored?
 
He's now had my Avalanche for two weeks. Can't figure out why it lost oil pressure after replacing cam and timing chain. He didnt say what codes were thrown this last time. Oil pressure dropped to under 20 and lights started flashing when driving it home after cam was installed. Mechanic now talking about putting in a used motor. He seems to be unable to figure it out. I paid him a lot of money to replace lifters, cam and timing chain. He originally said lifter would fix it, then cam would fix it....now I have paid him over $2K and truck is not fixed.
Just looking for a reason the oil pressure would drop like that after replacing the cam and timing chain. Seems like it has to be related since oil pressure was okay before. Oh, he also replaced the oil pressure switch when he did the cam. Motor doesnt seem to knock but runs bad after lights start flashing.  Frustrated.
 
been reading about the oil filter possibly causing low oil pressure after oil change. Could that be a possible cause for my situation?
 
Oil pressure drops becuase the clearances inside the engine get too large and let the oil pass freely back the pan...

The oil pressure is created by all the passages and gaps and journals the oil is pump to...

So in your case I wonder if cam bearings are too large versus new cam or the guy leftg a part out or does not know the motorand what he was doing?

Too hard to trouble shoot without being there...

Good Luck... and my suggestion... google replacement motors JASPERS and see what they would have charged for replacement motor..
 
I've attached a pic of a cam retainer plate I found on the web (LS1tech.com).  This plate would have to be removed and reinstalled to swap the cam.  Note that someone had indicated the need to inspect the seal.  There is an oil passage between the 2 sides of the engine that this plate becomes a part of, and if the seal fails I'd suspect you'll get low oil pressure.  (We're looking at the back side of the plate in this pic, the side which goes up against the cam and the block.)  Not sure if this is your problem but this is what I connect your low pressure to in regards of the cam swap.
 

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April issue of Chevy Hi Performance mentions a couple items:

http://www.superchevy.com/how-to/engines-drivetrain/1512-check-out-this-useful-ls-small-parts-guide/

There is an oil gallery plug at the front of block behind the front cover.  If you leave it out the engine will not make oil pressure.

A little oil diverter valve located at the back of the block which is essential for the oil pressure circuit.
 
Another issue is when the lifter and cam took a dump if they dump metal debris into the oil pan, it gets sucked up into the oil pump then put thru the filter.  I think the oil pump body is aluminum so metal shavings thru aluminum gall it all up.  All that extra clearance causes a oil pressure to drop.
 
Did the mechanic check the VLOM? The VLOM sends oil through a solenoid to activate the #4 cylinder lifters for AFM. GM has updated this part and is recommended to be replaced when the lifters are replaced. As for the oil pressure I would recommend installing a mechanical gauge where the oil sender is installed to see if the new oil sender is reading correctly. Also have them check the small oil filter located under the oil sender it is a small screen designed to prevent foreign particles getting into the VLOM causing issues with the AFM system. Hope this helps.
 
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