Oil Pressure Warning puzzler

Recently, my 2001 VW Passat 4 cylinder turbo sedan started to sometimes set off a warning sound and dashboard message stating that “oil pressure is dangerously low, STOP the engine immediately”. This only happens when I am coming off the freeway and turning sharply and continuously to the right as I go through the 270 degree cloverleaf turn on to the road under the freeway. As soon as I straighten out the steering direction, the light goes out and nothing further happens unless I get into the identical situation. The car has 101,000 miles on it, the oil level is not low, and I notice no other overt problems with the engine. Any ideas? Thank you.

One additional fact. The warning comes on when the car has slowed considerably and I am not accelerating. Actually, I am usually coasting and about to accelerate once I get out of the turn. Thanks.

You MAY have a faulty oil pressure sending unit.

It seems (according to your account) that this strange fault occurs only when the oil is moving to the left side of the oil pan.

When was the last oil/filter change?

Any recent work done on the vehicle?

Last oil and filter change was about six months ago, overdue, no doubt. No recent work done on the car. Thanks.

I think your oil pressure is low. What’s happening is that when you’re driving on the highway, your oil is getting very hot and thinning out, which is fine at higher engine RPM’s because the oil pump is still going fast enough to build up enough pressure to keep the oil light out. When you slow down, though, the pump isn’t able to build up enough pressure and the light will flicker. (Or if its a fancy computerized one, simply come on).

This used to be a pretty common sign of aging in older cars. It’s generally the result of various worn engine internal parts-- usually not the sign of any impending doom, but usually the ushering in of the last part of an engine’s life. If you switch to a higher-viscosity oil, the light will probably go away, but this will just be a cover-up.

I suspect the turning part is irrelevant and that the problem would occur even on a straight off-ramp.

Do you use synthetic motor oil in this engine?

The 1.8T requires this changed every 5000 miles or 6 months whichever first. This engine is very prone to sludging up especially if incorrect motor oil(non-synthetic) is used at extended intervals.

Have your motor oil changed and get this checked out. You may have some sludging causing the low oil pressure during these certain conditions. Go to a versed mechanic in VW for this not a chain place or quicky lube.

Best of luck.

Some follow-up on the problem, which worsened. The oil levels continued to be normal, but the warning light came on more frequently and not just with tight right turns off the freeway. There was also a new rumbling sound that started last night. I got it to a VW dealer this AM and we’ll see what the problem was, but it doesn’t sound good. They will check the oil pump, turbo, etc., and I’ll report back. Thanks for the thoughts, input.

You have a Turbo which you say is over due for an oil change. So what’s the problem???..change the oil. Are you purposely trying to destroy your engine. Turbos are EXTREMELY harsh on oil. Even with Synthetic I wouldn’t go more then 3k miles.