oil circulation to the engine (lifters not getting oil)
#1
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oil circulation to the engine (lifters not getting oil)
I was at a DE this weekend when my turbo gave in the middle of the session. When I drove the car back to the paddock, I noticed a slow oil drip from the turbo. Since the engine starts and run fine, I figured I could drive it home (70 miles) without the turbo. However, about 1/2 mile from the complex, the engine started hesitating and making lifter noise - you know, the familiar tick - tick - tick sound. Long story short, I ended up towing the car to a shop.
*Here is where I need your help!*
The shop believes I have bad lifters - suggesting they take the engine part to check. Ok, I agree the lifters are making noise. At the same time, I believe the lifters are making noise b/c the oil is not getting fed to top of the engine. I'm beginning to wonder if my failed turbo (found out one of the washers broke, and that caused the leak) is the cause of oil starvation up top. My question to you guys... where is the pressure building from? How does the oil get to the lifters? From the turbo or a separate line?
If this is unclear, I apologise... it's kinda tough to explain. Please feel free to email or IM me.. so, I can explain it better.
Right now, the shop is thinking of replacing all the lifter. I have no problem with that if that's the problem, but I don't think that is *the* cause/root of my problem for lifter noise.
Thanks,
Cris
*Here is where I need your help!*
The shop believes I have bad lifters - suggesting they take the engine part to check. Ok, I agree the lifters are making noise. At the same time, I believe the lifters are making noise b/c the oil is not getting fed to top of the engine. I'm beginning to wonder if my failed turbo (found out one of the washers broke, and that caused the leak) is the cause of oil starvation up top. My question to you guys... where is the pressure building from? How does the oil get to the lifters? From the turbo or a separate line?
If this is unclear, I apologise... it's kinda tough to explain. Please feel free to email or IM me.. so, I can explain it better.
Right now, the shop is thinking of replacing all the lifter. I have no problem with that if that's the problem, but I don't think that is *the* cause/root of my problem for lifter noise.
Thanks,
Cris
#2
oil pressure relief valve failure/stuck open in lifter oil galley...
<center><img src="http://pictureposter.audiworld.com/711/prv.jpg"></center><p>
A simple little 10mm hex head spring-loaded check valve that looks like a bolt head with a 4mm hole in its top, usually black in color. Designed to regulate oil pressure to the side-feed lifters by relieving pressure in the lifter oil galleys and subsequently keeps the lifters from over-pressurizing with oil. Relieves/bleeds off ALL oil pressure to the lifters via the center hole if it becomes clogged in the open position or fails. Gets REAL noisy REAL fast when this part lets go or is stuck open!
No serviceable parts inside so must be replaced. Use LocTite 242 (blue) to seal after cleaning female threads in cylinder head of oil w/Q-tip and acetone/laquer thinner. Torque to 18ft lbs.
One in pic is from a 2.8 12V engine and may vary from yours or may be identical.
No guarantees this is the issue but is a perfect puzzle-piece fit to the problem you've described, ie; sudden & simultaneous loss of oil pressure to all lifters. Drive Audi's long enough and you WILL replace one or two of these. I have 4 bad ones lying around.
A simple little 10mm hex head spring-loaded check valve that looks like a bolt head with a 4mm hole in its top, usually black in color. Designed to regulate oil pressure to the side-feed lifters by relieving pressure in the lifter oil galleys and subsequently keeps the lifters from over-pressurizing with oil. Relieves/bleeds off ALL oil pressure to the lifters via the center hole if it becomes clogged in the open position or fails. Gets REAL noisy REAL fast when this part lets go or is stuck open!
No serviceable parts inside so must be replaced. Use LocTite 242 (blue) to seal after cleaning female threads in cylinder head of oil w/Q-tip and acetone/laquer thinner. Torque to 18ft lbs.
One in pic is from a 2.8 12V engine and may vary from yours or may be identical.
No guarantees this is the issue but is a perfect puzzle-piece fit to the problem you've described, ie; sudden & simultaneous loss of oil pressure to all lifters. Drive Audi's long enough and you WILL replace one or two of these. I have 4 bad ones lying around.
#3
I think those are more common on the 5 cylinders & the 12v - V6 engines......
Oil pumps also have an oil pressure relief valve in them, but when they go the oil light comes on. It could also be a low oil pressure problem, would be a good thing to check in this situation regardless.
Here's another thought though. Turbo oil feed is restricted internally, in the turbo. If your turbo has gone bad, in a certain way that has opened that up, the oil pressure to that feed line will be using up a larger portion of the oil pressure in the system. This could have an adverse affect on the lifters, causing an oil starvation to them. Make sense? If the turbo's bad anyway, try plugging that oil feed line & see what happens. Or maybe try replacing the bad turbo first.
Here's another thought though. Turbo oil feed is restricted internally, in the turbo. If your turbo has gone bad, in a certain way that has opened that up, the oil pressure to that feed line will be using up a larger portion of the oil pressure in the system. This could have an adverse affect on the lifters, causing an oil starvation to them. Make sense? If the turbo's bad anyway, try plugging that oil feed line & see what happens. Or maybe try replacing the bad turbo first.
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