OIL Pressure Problem???

When I went to drive home from lunch today, my oil ight began to flicker at the traffic light. The light turned green, when I got the rev's up, it cam on all the way. I pulled over and checked the oil. The oil is full (as usual). After letting it sit for my lunch hour, the light went away. I just started using synth.-blend oil about 6K ago. Could it be a plugged sensor? This car had a really bad plugged flame trap when I bought it 15K ago. There was a ton of buildup in the vacume lines, which I had to replace. Do oil pumps go bad? It still runs fine and makes no unusual noises. The usual blow-by when you remove the dipstick or oil cap is still there. Its not knocking or running hot. I figured it was a plugged sensor, seeing how the light came on stronger under load or higher RPM's..........

89 GLE N/A w/140K....................

Try reaching behind the alternator and pull the oil sensor light wire away from the alternator. The wires often chafe there and short out. Sensors sometimes go bad also, I just replaced one on my daughters car, it would stay lit all the time.

G-Man said:

Try reaching behind the alternator and pull the oil sensor light wire away from the alternator. The wires often chafe there and short out. Sensors sometimes go bad also, I just replaced one on my daughters car, it would stay lit all the time.

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My alternatior is on the drivers side, which wire is it? There are a few there.....................> I am at work and lacking a Helmes Manual............

UPDATE: I replaced the OP sensor and the oil light is still on. Oil pump or main bearing????????? Any suggestions?

Was it making bad noises when it ran? my 242 makes a distinct rattling noise when the light is on and there is no pressure. hehehe. the valves clack, etc.
I had OP issues on startup of the hulk, it was the wire. Get a multimeter, and set it to ohms and connect it from the blade on the sender switch to ground. Start the car, it should go to zero ohms. If it stays open circuit you have problems.

Nope, sounds like normal. Car runs great, no noise at all at any RPM. I am debating weather to swap oil pumps, or just swap motors (dont really look forward to option #2). Someone said it might be a rod bearing, but I never heard of the B23's doing that. I thought that was a GM deal. But, how often do oil pumps go bad, probably a rarity too..............

I heard the Oil pumps rarely go bad with these cars. iPD says they have never 1 in years........ My mechanic says that they are very good too and rarely need replacing.


Strange........... The same thing happened to me a while back in my 88' 740 Turbo Wagon............. I was driving and all of a sudden the Oil light began flickering. I pulled over, checked the Oil level and color, it was fine. Then I restarted the car and proceeded on my 60 mile drive. On the way home it never came on. Pulled off to the gas station and there was smoke pouring out from underneath my Volvo! Then I looked further and noticed Oil leaking everywhere on my exhaust!


Took it in for service, found out the Rear Main Seal was leaking, Distributor Seal was leaking and the front Crankshaft Seal began leaking a little later...........


When I purchased my Volvo too the Flame Trap was pretty plugged up and Oily. I cleaned it out really well and cleared it. I think it may have been too late though and all the increased Crankcase pressure from the blockage previously had blown most of the seals. Well, after the service the Oil light has never came on again.

This is just my experience and is not to say that this is necessarily your problem though.................

HMMMMMMMM Well, it's not leaking a drop. No smoke, everything looks normal. The car runs great, no funny noises.........nothing unusual but the oil light. I rarely take it past 3K RPM.

Really............ Well, if you have replaced the Sending Unit and cleaned all of the connections with compressed air or something and it's still doing it then it could be an Oil pump or the next thing I would think would be the Main Bearings, which would suck............

Oh yeah, and mine wasn't leaking a drop (I checked after the light was flickering) until I drove 60 miles coming home then Oil was just everywhere underneath the car! I would keep an eye on that anyway, you could be loosing a seal causing loss of pressure at times.


Don't know if this helps but I think at www.thepartsbin.com they have new Oil Pumps for around $100 I think, if I remember correctly. I'm not sure what brand they are but most of the stuff they sell is usually near Volvo spec. I have purchased a few thing from them before and they worked out pretty well.


Good luck with your problem............!

My 244ti has had about the same problem for a couple of months now. I've pulled the oil pump to find the problem, and have not.

I raised my 244ti from the dead in what was functionally a junkyard, and was planning on making it fast before taking it out of there, as in the deal all parts were free. I got it to stage 0, and at this time oil pressure was excellent. When started it'd peg the guage at 5 bar at idle, and as it heated up would gradually settle down to 2 bar or so at idle, and push up to 3-4 bar when revved. I started messing with fuel and boost to get it to good performance at 12-14psi or so. It was fast, fun, and still running great. Then after a few foolish excursions into runaway boost land, I blew some head gaskets, cracked some heads, and was starting over from square 1 repeatedly because of it. Then I was blowing turbos that were already on their way out.

Then at the 6 month mark, I suddenly didn't have as good oil pressure anymore. I had driven the car less than 100 miles since buying it, in which time pressure had gone from perfect to horrible. Now the car would have only 3 bar pressure at idle dead cold, and by the time it heated up it would turn on the light and keep it on at idle. Revving it brings it barely above 2 bar. When under boost, with one of the crappy turbos still in, the pressure would drop even more. Under vacuum at 3,000rpm it'd run 2 bar oil pressure. Under boost it'd start dropping to below 1.5 bar.

So I've pulled the pump and checked it. Clearances seem fine. Then I found an oil pump output seal the was ripped in half in the hole in the block. I figured my problems were over. I replaced the seal. Pressure is the SAME as before.

At this point I still have no idea what the hell the problem is. I'm on my second pressure sender, and still have the same reading, though this sender is used as well. Wiring is fine. No grounds. It f'ing sucks. I'm willing to bet that the whole losing pressure under boost is the big clue as to why this whole thing has happened but I don't know how to figure it out. I've asked for ideas before and got lotsa good stuff, but I'm still up sh!t creek.

damn bro, good luck with that man...................!

Well, in that case you'll have to connect a mechanical guage. that is the only definitive answer then.
I bought a mechanical gauge with a 1/8" npt fitting included for like, 10 bucks or somehting.

UPDATE: There is only 1-3 PSI of pressure..............................on a manual guage..............

Looks like it's time to pull the pump. There is no way in hell you've got that low pressure unless there's something bigtime wrong going on in there. You might have a cracked output tube, blown seals, broken pressure relief spring, or all 3 put together.

There is a way to remove the pump in less than an hour without having to pull the engine or drop the front suspension crossmember. If'n you're going to go that route, I can tell you how.

Isaac said:

Looks like it's time to pull the pump. There is no way in hell you've got that low pressure unless there's something bigtime wrong going on in there. You might have a cracked output tube, blown seals, broken pressure relief spring, or all 3 put together.

There is a way to remove the pump in less than an hour without having to pull the engine or drop the front suspension crossmember. If'n you're going to go that route, I can tell you how.

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Well, I have two options righ now

1. Try to replace the oil pump for $100 and hope thats it.
2. Toss this 240 turbo motor in (under $300) with new turbo and top end. NOTE: I have 2 mitsu. 16G's left over from my DSM in my tool box

See the Brickboard FAQ about oil bypass spring fatigue. Over time, the spring fatigues and allows oil to bypass, reducing pressure. The only solution is a new pump: they do not sell the spring separately, at least to my knowledge.

ORRRRRR, y'all could have the same problem that I suspect. My B21FT transplant has recently had trouble maintaining it's OP as well, much like Isaacs symptoms. I think if I removed my head, I would most likely find my pistons rocking back and forth a bit, and with the recent cold snap, a really bad case of the "blow-bys". My oil pressure is great for, oh, 50 km on the highway right after I change it, and it quickly turns to a watey, gassy smelling mess, leaving my pressure peaked at 2.5 bar

I don't think pumps are generally the issue either, just the extra wear our turbo motors see. You may have lots of oil, but how is it's viscosity? Of course, the runnier my oil gets, the quicker it slips through old seals and whatnot, not to mention getting into the CC- I go through almost a quart a tank right now, on the highway, less in the city. Just waiting for warmer weather to build my B23FT that's currently in pieces....

Well, I am going to try to swap the pump out. If that doesnt cure it, in goes the 5.0 or turbo motor.............

Well, I bought a new Oil Pump on EBAY for $49, in he box. I am going to attempt to do it on my own in a few days. I have a lift and an engine hoist. Anyone have any pointers for me?

This may sound silly, but when's the last time you changed your oil filter, also what brand do you use?