Oil pressure woes
08-30-2004, 07:41 AM
#11
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Re: Hows the oil pick-up tube? Maybe cracked, or not seated properly?
Gentlemen,
I have a 93 CS Sport Quattro which I recently rplaced a cylinder head gasket on. The engine started and ran strong for 3 days then I noticed a fluctuation of pressure at the gage. Lower than usual at idle. I replaced the oil and filter which solved the problem for 3 days. While driving in town, it started dropping quite low but was better at higher RPM's. After shutting down, there was zero pressure.
I dropped the pan, removed and checked the pick up tube and oil cooler....appear clean. This is the earlier lubrication configuration. I am at a loss. Any suggestions?
Most appreciated.
I have a 93 CS Sport Quattro which I recently rplaced a cylinder head gasket on. The engine started and ran strong for 3 days then I noticed a fluctuation of pressure at the gage. Lower than usual at idle. I replaced the oil and filter which solved the problem for 3 days. While driving in town, it started dropping quite low but was better at higher RPM's. After shutting down, there was zero pressure.
I dropped the pan, removed and checked the pick up tube and oil cooler....appear clean. This is the earlier lubrication configuration. I am at a loss. Any suggestions?
Most appreciated.
12-23-2015, 12:44 PM
#12
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Completely stumped with the same problem
For those of you who don't know I live with a serious condition (the 12v kind)where I suffer from zero oil pressure on starting the engine after shut down periods exceeding an hour like the pump just will not prime. I've learnt to live with the condition by giving the engine a short blast of revs which brings the pressure up from zero to the full 5 bar. The oil pressure runs perfectly within spec untill the next long shut down.
I've near practically done everything to try and solve the problem including a new oil pump with gaskets, new oil retention valves in the valley pan, new oil pressure valves in the heads and sealed up all joints on the oil pump suction pipe and also thoroughly cleaned the mesh. I've tried all major brands of oil filters and weights of oil.
Anyone know of anything that can cause such a problem?
The problem didn't start overnight but took several months to build up to a every-start occurance.
I know Audi changed the oil pump and relative suction pipe and also moved/incorporated the pressure relief valve and a new 5 bar regulating valve into the upper oil pan in the AFC; looks like a retrofit to the AAH can be achieved with a new pump, pipe, lower oil pan to accomodate the new suction pipe position and pressure valve plate assembly but it's going to be an expensive possible fix but it seems a little coincidental that Audi redesigned these components, like they knew the sort of problem I'm experiencing could be a possibility if they didn't incorporate changes into the V6.
I've near practically done everything to try and solve the problem including a new oil pump with gaskets, new oil retention valves in the valley pan, new oil pressure valves in the heads and sealed up all joints on the oil pump suction pipe and also thoroughly cleaned the mesh. I've tried all major brands of oil filters and weights of oil.
Anyone know of anything that can cause such a problem?
The problem didn't start overnight but took several months to build up to a every-start occurance.
I know Audi changed the oil pump and relative suction pipe and also moved/incorporated the pressure relief valve and a new 5 bar regulating valve into the upper oil pan in the AFC; looks like a retrofit to the AAH can be achieved with a new pump, pipe, lower oil pan to accomodate the new suction pipe position and pressure valve plate assembly but it's going to be an expensive possible fix but it seems a little coincidental that Audi redesigned these components, like they knew the sort of problem I'm experiencing could be a possibility if they didn't incorporate changes into the V6.
When the oil light started coming on at startup, I installed a mechanical gauge on the rear-facing oil pressure port (there was no sensor in it, only a plug) and that's when I observed zero pressure on startup. Gave the throttle a few blips, and the pressure popped right up to 5 bar, and operates normal until you shutdown for an hour or longer.
I have:
removed and replaced the oil pickup/relief pressure plate
inspected the screen (no debris or sludge)
Ran seafoam (wasn't needed, engine is remarkably clean for 160k miles)
replaced oil pressure switch
I'm running a Mann oil filter, always have
no leaks coming from oil system that I can visibly see
Any help would be greatly appreciated at this point.
12-23-2015, 12:53 PM
#13
Sounds like the oil pump is loosing its "prime" after an hour. Weird problem. I've seen on some VAG cars.
Your using the right oil filter..a MANN should be just fine.
If I had that problem I would change the brand and viscosity of oil...maybe something thicker to help the oil pump get going.
What viscosity oil are you using?
Your using the right oil filter..a MANN should be just fine.
If I had that problem I would change the brand and viscosity of oil...maybe something thicker to help the oil pump get going.
What viscosity oil are you using?
12-23-2015, 02:19 PM
#14
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I've tried several different viscosities, 5w-30, 10w-30, 10w-40, Mobil 1 and Castrol Syntec.
It's almost like its sucking air from someplace. I also checked the torque on the bolts for the upper oil pan, and they were fine. With the pickup plate and pan gasket removed, you can see right into the oil pump. The oil only has to suck up about 2-3 inches. I put my bend-a-light up there and inspected the pump, and it looks fine. I have to check my manual and see if there is a gasket between the upper oil pan and block - if there is, it may not be sealing and causing an air leak.
It's almost like its sucking air from someplace. I also checked the torque on the bolts for the upper oil pan, and they were fine. With the pickup plate and pan gasket removed, you can see right into the oil pump. The oil only has to suck up about 2-3 inches. I put my bend-a-light up there and inspected the pump, and it looks fine. I have to check my manual and see if there is a gasket between the upper oil pan and block - if there is, it may not be sealing and causing an air leak.
12-24-2015, 04:55 AM
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I thought about that, but I'm up in Minnesota and we just moved into our winter season. I'm hesitant about putting in a high viscosity oil. However, I am thinking about switching to a conventional oil for a while.
I am now suspecting the gasket between the upper oil pan and block. I picked one up last night, looks like I have a project for this weekend.
I am now suspecting the gasket between the upper oil pan and block. I picked one up last night, looks like I have a project for this weekend.
12-24-2015, 10:09 AM
#17
15w40 wont hurt anything in cold weather..especially above zero. Could be your gasket..could be a bum oil filter with a bad anti-drain back valve...try the 15w40 for a few days rather than throwing parts on the car..you hit all the significant high spots..oil pump and the like.
The oil pump is loosing prime for some reason..and no change after the new pump was installed?
The oil pump is loosing prime for some reason..and no change after the new pump was installed?
Last edited by Rusty Spokes; 12-24-2015 at 10:29 AM.
