Engine: B5254: Confusing Oil Pressure Issue

[matt7175]

Hi, i collected a 2001 XC70 2.4 T Auto ocean race a couple of weeks ago and all seemed well. As the tyres were a little low i left car ticking over while i inflated them. When finished i jumped in and set off, a few yards down the road the oil pressure warning came up and i stopped and dipped the oil. Level was fine and all sounded ok so i set off steadily, after a mile or so the 'No oil pressure' warning came up so i stopped, unsure what the problem could be i listened to the engine and all sounded ok until i revved it when there was a whine which i took to be possibly the turbo so i had the car collected by truck and transported to my friendly polish techie.
He has stuck a guage on it and the pressure was around 5 bar when cold dropping to 1.5 bar when warm, there were no noises even when revved and the warning lights did not illuminate. He has recommended changing the oil & filter as the oil looks and smells manky, i think the car has been stood and is low mileage. When i took the oil over to him i started the car and let it warm up, then i drove it around his yard and had it nice and warm for over 15 mins with no signs of any problem.
There is a bill from 2010 for the sump oil seal job but i am still nervous that while he believes there is no further concern with the engine i get half way home ( 40 miles away ) and the warning will come up and i'll destroy the engine as nothing has actually been done to fix the oil pressure. The techie checked something to do with the VVT / camshaft unit as he has replaced some seal up here before but found nothing untoward. I am perplexed, he has only done what i could have done myself but i know little about volvos and didnt want to chance anything with oil pressure.
I have read the many threads re: OP problems but wondered if anyone has had a similar situation and can give any suggestions please ?

[DieselDoNicely]

Oil pressure should not drop unless:

Faulty gauge.
Kink in the oil feed to the sender, if flexible.
Oil leak - you would see it.
Faulty Volvo sender - the part the single wire plugs into from the loom at the front of the engine.

Faulty pump assemble - be it oils seals or just knacked.

DDN

[pacman123]

I had the no oil pressure warning on my S60,took it to local indie,work done was :-engine flush x2,dropped sump and cleaned,replaced pick up pipe,new oil and filter,cost £312,told to take it back after driving for a couple of weeks and have oil and filter changed,no warning after work done..

[Symes]

Agree withe the above advice, flush and change oil and filter as a start - first job on any privately bought motor as far as I'm concerned.

If problems persist, it might be worth looking at the pressure relief valve too incase that's / was sticking.

Hopefully your hunch that it's been standing will be right and fresh oil and fillters will be enough.

[Georgeandkira]

Hello, Seals in the oil pick-up tube are mentioned often. The oil pressure sensor is a known maintenance item. I've changed 4 of them as a shadetree mechanic. That's enough to make it my guess. Elements in "No-Name" spin-on filters can collapse and clog the lubrication system. In our cars the element is more stiffly constructed to begin with because it's shipped and handled directly. I'd change the oil pressure sending unit as a first step given its low cost and the age of the vehicle. Kira

[matt7175]

Originally Posted by pacman123

I had the no oil pressure warning on my S60,took it to local indie,work done was :-engine flush x2,dropped sump and cleaned,replaced pick up pipe,new oil and filter,cost £312,told to take it back after driving for a couple of weeks and have oil and filter changed,no warning after work done..

Volvo are adamant that they should not be engine-flushed and i dont like the thought of it on a higher mileage engine. It is good to hear that some people have sorted it without mega expense though.

[steventoon]

I believe this may be the oil seal o rings that are in the sump. It appears to be a common problem where the light on the dash illuminates then goes off. The seals deteriorate with age and allows oil to be pumped back into the sump rather than around the engine.

Its a sump off job again and replacing the seals.

[XRAY-CHARLIE-TWO]

Yep oil tube pick up oils seals are indeed a common fault

If i where you and the car came from a dealer / garage i`d be taking it back

If you bought it privately then it`s a different kettle of fish

Firstly i`d drop the oil and refil with just some generic brand and some engine flush run for 20 mins at idle and drop it again

Check the colour if it`s coming out black after 20 mins you`ve got plenty of crap in there which needs to be flushed out

So another flush with generic oil and some engine flush and drop again this time change the oil filter as well use a volvo one not some generic no name crap drop / remove the sump and replace the pick up tube o-ring using 2 new o-rings instead of one and refit the tube ensuring it fits tight and compresses the o-rings correctly refit sump

Fill with some descent oil and go for a run to warm the oil up to proper temp keep an eye on the warnings just incase

If the message pops up again then i`d be looking at the pressure sensor and the oil pump

Cheers

stuart

[matt7175]

UPDATE !

The o rings were replaced by volvo 3 years ago and our problem is the other way round in that there is no problem until it is driven.

Sump dropped to find sludge in oil ,strainer blocked and oil passageway completely and solidly blocked with crud. It took a drill to clear the blockage , on bolting everything back up it seemed like all was well until it warned of no oil pressure on test drive.
We decided that a flush was worth the risk and when re-filled with fresh oil it then behaved itself and i collected it and set off on the 40 mile journey home along the M62.
She ran like a dream ( albeit with an occasional whine type noise around 2000rpm when accelerating ) and no warning came up...... until just 2 miles from home the dreaded no oil pressure message came up and i stopped the car sharpish.
I wonder if there is still sludge in the engine and the run eventually dislodged some and it blocked the oil pump strainer, it is fine again when i have restarted the engine. I am toying with the idea of getting a few miles on it and carrying out another flush as i dont want to have to remove the head or anything drastic to get at the remaining sludge.

Additional note: When oil was flushed it had turned the new oil completely black but the oil is now as it should be in colour.

[XRAY-CHARLIE-TWO]

Thanks for your update

I`m thinking possible oil pump failure then mate or pressure sensor failure change the sensor first as it`s the cheapest option if that doesn`t cure it then i`m afraid it`s more than likely the oil pump thats on it`s way out