Hello everyone,

I have a 93 100 with the 2.8 v6 engine that has no oil pressure. Engine will idle, the lifters sound like they are empty and the engine will not take any throttle whatsoever. Both oil pressure gage and the warning chimes indicate no oil pressure at all. Began by draining oil, dropping the lower pan and checking the pickup screen....no debris, no flaws in the pickup tube. Removed pickup tube and checked that the gears do indeed rotate when crankshaft is rotated.....they do. Pulled oil cooler and flushed out with mineral spirits, seems to flow okay. Buttoned everything back up with new oil and filter (NAPA) and tried it, still have no oil pressure. This car has only 54,000 on the clock, figured it is getting close to needing a timing belt, so removed the belt and tonight I removed the oil pump for inspection. Oil pump looks nearly brand new, I removed the rear cover from the pump and looked at the gears themselves,and they look wonderful. Front seal in the pump looks like new. No cracks or damage to the pump body that I can see. Pulled the pressure relief valve in the pump and it looks good.

When I removed the TB, there was a very light film of oil on the flat side of the belt, nothing apparent on the toothed side (emphasis on LIGHT, as in barely detectable). The only two scenarios I can come up with are that the oil seal is leaking air into the pump causing cavitation, however the seal appearance looks good to me, norubber missing and not chewed up. The second scenario I have is that the pressure relief valve in the cooler is defective, but that one doesn't appear to be removable for inspection (Iunderstand that there are two PR valves, one in the cooler and one in the pump itself),and the cooler flushing indicated good flow characteristics. Therewasn'thardly any oil in the pump itself on removal.

I fix motorcycles for a living and have been wrenching on enginessince the age of 13 (now 34). I have seen some strange engine behaviors and failures in that time but this one has mereally puzzled. If anyone has had a similar problem with a 2.8 v6 please let me know what you found the problem was. On a side note I have had 2 5000s sedans, an 86 and an 87 quattro 5spd, and currently have a 93 V8 quattro with 155,000 which I did the TB on about 8 months ago (FUN).[:'(] The v6 belt was a walk in the park compared to the v8 procedure.

I realize that this is a long post, but am new here and wanted to illustrate what I have done so far.

Lorne S Ulrich

 

check on the oil pressure sending unit it might just be sending a bad signal

 

I just posted a message about a problem of mine I think sounds close to yours. I have a 1995 90s 2.8 V6 with check engine and oil lights on. The motor runs but sounds like the valves are tapping and the motor is just painful to rev. I didn't push it to hard but I took the car for a spin around the shop lot and the engine is just crippled on power and sounds like the head is starving for oil. Its not hard noticing the sludge stuck to the inside of the valve cover. My car only has like 93,xxx miles on it which isnt much really but I'm pretty sure the previous owners neglected to change the oil regularly. Im thinking the oil returns are clogged up since I replaced an oil drain valve under the head between the cyl banks which didn't help. I checked my compression and thats not the issue as I'm sure isn't in your case. You have no oil pressure where as I'm assuming I have low pressure. Did you consider the return lines were clogged or something. Good Luck with your problem and let me know if any of my problems sound familiar or if you have any ideas for what I should do or how to fix this. My next step is probably just stripping the engine apart and cleaning it up because I don't know if the sludge I can see is isolated or has gummed up everything. I've tried products to clean the junk out of the engine but it just can't get at all the buildups.

Thanks,
Chris