Oil Pressure Light Coming On

[dude65]

Hi all

I've done a search and haven't been able to find anything to explain what's happening to my 01 Cross Country.

About a month ago we got a low oil pressure warning showing up in the dash display. Would only happen at engine idle. Engine sounded fine and continued to run OK. First thing obviously was to check and top up the engine oil. Did that and no change - light still coming on at idle.

Sent to car to the mechanic who cleaned out the sump and replaced the oil pressure switch. He put a pressure gague on the car and found 10 psi at idle and 30+psi when the revs pick up. He ran the car at idle for over an hour without the light coming on. Took the car for a test drive and the light started doing the same thing. Reconnected the pressure gague and found the oil pressure to be fine. That pretty much ruled out a mechanical fault.

The mechanic then sent the car to an auto electrician who tested and checked everything to do with the oil pressure system. He could find no obvious fault. The light didn't come on again and we got the car back from the mechanic. All was good until the next day when the low oil pressure warning came on again. I spoke with the mechanic and we deceided to troubleshoot the thing over the weekend to see if there was any set of criteria/circumstances that caused the light to come on. It never did it again. It just came on the one time and hasn't done it for the last 3 weeks.

Until today.

Same as last time. The car is running fine, plenty of oil and no obvious problems. Warning only shows up when the engine is at idle. Touch the accelerator even a fraction of a mm and the oil pressure warning dissapears.

Volvo tells me they've never had this problem before and in fact they reckon they've never had an oil pressure issue with the Cross Country engine

Any ideas?

[JRL]

Did he replace the oil sump O rings?

[billr99]

VADIS states that the the pressure at 800rpm should be .10MPa or 14.5 PSI and at 4000rpm it should be .35MPa or 50PSI. Your pressure is low coming off the pump. JRL's suggestion would be a good place to start. You could also have a worn pump. How many miles on the engine?

Good luck,

Bill

[dude65]

176 000 kms on the engine. Always been serviced within service book intervals

Oil sump O rings were done. Pressure relief valve was also cleaned and checked. No bearing noises or anything like that. My mechanics words were "the inside of the engine on this car is clean as a whistle". He did everything short of stripping the engine down. He's put the pressure gague on several times and the minimum pressure at idle was only ever 10 psi so not far off your figures Bill. Would you expect a drop of 4/5 psi on an engine with this number of Km's and if so would that be enough to bring up the oil pressur warning?
I just started it this morning and no oil light. I ran it at idel for 10 minutes (didn't rev the engine) and still no light. I'M SURE YOU CAN UNDERSTAND MY FRUSTRATION WITH THIS CAR

Would it be safe to assume that if the light was going to come on it would be more likely to do so when the engine is cold.

[billr99]

176 000 kms on the engine. Always been serviced within service book intervals

Oil sump O rings were done. Pressure relief valve was also cleaned and checked. No bearing noises or anything like that. My mechanics words were "the inside of the engine on this car is clean as a whistle". He did everything short of stripping the engine down. He's put the pressure gague on several times and the minimum pressure at idle was only ever 10 psi so not far off your figures Bill. Would you expect a drop of 4/5 psi on an engine with this number of Km's and if so would that be enough to bring up the oil pressur warning?
I just started it this morning and no oil light. I ran it at idel for 10 minutes (didn't rev the engine) and still no light. I'M SURE YOU CAN UNDERSTAND MY FRUSTRATION WITH THIS CAR

Would it be safe to assume that if the light was going to come on it would be more likely to do so when the engine is cold.
Well, perhaps being where you are at in regard to min. pressure maybe that is close to the activation pressure of the sensor? If you are right at the boundary it might make the light work some times and not others.

My other thought is since these sensors work via resistance I wonder if you might have a wiring fault that is altering the resistance of the signal and the processor is reading it as lower pressure than it really is.

Final idea, the dash processor in these cars can be a bit iffy in its connection to the board it is mounted on. Iffy connections there can cause all kinds of weird activity, especially with the message center and the messages that it shows.

My XC has just over 180K kms and I've have no indications of low oil pressure. On the other hand, I have a dicey dash board and I get things happening like an intermittent high beam indicator, a trip odo that cannot always be reset to 0 and the inability to reliably reset the service indicator.

Hopefully, others can come up with some other ideas, but this is about all I can think of at this point.

Good luck,

Bill

[dude65]

Thanks Bill, I appreciate your responses.

I'm taking the car out today for at least a 60km run so I'll see how it goes. Hopefully I'll have a few answers which I can forward to my mechanic first thing Monday

[Aviator]

Would it be safe to assume that if the light was going to come on it would be more likely to do so when the engine is cold.

No, because your oil pressure is higher when the engine is cold. Once the oil thins out, the oil pressure will drop some.

Dave.

[martinperry]

On mine, it was the seals on the filter feed pipe that runs thru the sump that were disintegrating - once I replaced these, no problems

[Aviator]

it was the seals on the filter feed pipe that runs thru the sump that were disintegrating

I'll second that.

Dave.

[razgaoz]

May be is the quality of the oil. Oil brand, viscosity?

[martinperry]

No, Its the seals!!

[erik]

I had a similar issue on my 01Xc. Mine only showed when I took a left turn at a certain speed. The oil light would come on for a short bit, this was hard to reproduce before volve believed me. After lots of investigation by volvo it was found I had a small crack in the belly pan. the oil Pump pumps the oil into a casted in pipe in the belly pan when turning left this crack just opened enough to loose oil pressure at idle. So in your case it could be the belly pan gasket letting oil through. This happened when my car was still under waranty at about 100K km. now I am at 215k km with some oil consumption since then (1 liter on 7000k) but running fine. The replaced the both the belly pan and oil pump.

So you might want to remove the belly pan and replace this gasket.

Br

Erik

[dude65]

Just had a chat to my mechanic and all seals and gaskets relating to the oil system have been done, including the ones on the filter feed pipe. They were checked first as apparently that's a common problem.

Car has been driven for 2 days now (city driving) without the light coming on. Like I said, when it was coming on it was only for a fraction of a second. I take your point erik and I'm inclined to beleive it's something that's completely randomn and not obvious. It's just a matter of what.

[phmargaret77]

I was reading your story and it is exactly the same issue I have had with my car. We have replaced everything, pump included about a month ago. Today when I was out the light came on again when I pressed the breaks. At first it said low and then it said no oil pressure. I drove home, stopped the car and when I turned it on again the light came back on. Its so frustrating.

[Allen]

Oil filter is clogged.

[Chilled Man]

Oil filter is clogged.

wouldnt a oil change solve that problem / you would have to do one when you replaced any of the seals and I would be suprised any shop would leave the old filter in ... [pico]

[RockitShip]

JRL & MartinPerry may be onto something. Read the description for oil sump O-ring & gasket kit IPD sells:

http://www.ipdusa.com/Volvo-V70XC70-2001-2007/Engine/Engine-Mechanical/Engine-Gaskets/Oil-Sump-O-Ring-&-Gasket-Kit/p-127-379-503-853-3359/

I may try replacing the seals/O-rings along with an AutoRx treatment... follow
their treatment for sludged cars (2x dosage).

Good luck,

[billr99]

I was reading your story and it is exactly the same issue I have had with my car. We have replaced everything, pump included about a month ago. Today when I was out the light came on again when I pressed the breaks. At first it said low and then it said no oil pressure. I drove home, stopped the car and when I turned it on again the light came back on. Its so frustrating.
It would strike me that since you say you have replaced all the mechanically-related bits, assuming you have the correct oil level, and the light comes on when you hit the brakes (have we begun to spell "brakes" differently or is "breaks" an American spelling?), I would look to an electrical problem. On this restart you mention, was it a cold start? That is, was the engine cold? If so that is usually when oil pressure is the highest which would point me back, considering all the work you have done, to something electrical. Have you checked the sensors and wiring associated with oil level and pressure?

Cheers,

Bill

[Allen]

wouldnt a oil change solve that problem / you would have to do one when you replaced any of the seals and I would be suprised any shop would leave the old filter in ... [pico]


Perhaps the oil filter canister is damaged internally, or is sludged up? I wonder if anyone ever cleans out the canister?

[billr99]

Perhaps the oil filter canister is damaged internally, or is sludged up? I wonder if anyone ever cleans out the canister?
I do. There isn't much to the canister and the value in the bottom. Just a spring and a disc valve for the most part. Not that you see much crud at the bottom of it when you change the oil, but you will get a teaspoon or so of pretty dirty oil when you pull out the element. In any case, a quick wipe with a rag and you are good to go.

I doubt in this case with the description of the problem that it is associated with the canister unless the valve is missing and I would wonder how that happened.

Cheers,

Bill

[phmargaret77]

Bill-

Thank you for your post. I am sorry for my "brakes" typo. I found that last night once the car was warmed up, the No Oil Pressure light would come on and stay on only if the car was slowed down or brakes were pushed. As soon as I hit the gas, the warning message and light went away. I have called my mechanic but hope that it is only an electrical problem.

Thank you again. I'll update once I have more information.



It would strike me that since you say you have replaced all the mechanically-related bits, assuming you have the correct oil level, and the light comes on when you hit the brakes (have we begun to spell "brakes" differently or is "breaks" an American spelling?), I would look to an electrical problem. On this restart you mention, was it a cold start? That is, was the engine cold? If so that is usually when oil pressure is the highest which would point me back, considering all the work you have done, to something electrical. Have you checked the sensors and wiring associated with oil level and pressure?

Cheers,

Bill