I guess this is why newbies show up here, something strange going on with car.

Anyhow, I took my Son-in-Law's 2000 V70 2.4 slushbox on a fairly spirited drive to find out how a new set of wheels and tires worked, and the oil pressure light came on. He had changed with some 10w-30 Quaker state a while ago, so I took it home and changed to 5W-40 Delvac 1 (my fleet-wide oil) and after a short drive, the oil pressure light was flashing on and off again, then on continually. It just stayed there as revs went up and down, and then after shutting down for a few minutes, remained off after the subsequent startup.

This is NOT the behavior of an engine with worn bearings or oil pump (only 250,000 kms on it - in exceptionally nice condition with fantastic maint records from PO).

Anyone have any ideas?

BTW: where is the OP switch located? Need to check actual pressure.

What is the source for factory or factory-like workshop manual for this car?

Sorry for the dumbass questions, but I am a VW diesel guy with virtually NO Volvo experience (although I did once own a brick - that is a 245, not building materials).

Thanks for any suggestions forthcoming.

 

Hi and welcome to the forum.

These cars have a history of tossing that light when the car has trouble sucking the oil out of the oil pan. If you drop the pan you will see the oil pick up with either a real hard seal or a seal that is no longer seated properly. Most people simply replace the seal, reinstall the pan and are good to go.

The pan is sealed with anaerobic sealant, strange stuff but not that hard to use. When applied the mating surfaces need to be very clean and dry. Not sure how long the job takes but I think the bulk of it is cleaning the oil pan surfaces.

You would do best with a Google search. Something like "Volvo 850 oil light on" or something like that. It should yield you some good results here or on Matt's Volvo site. Most of us use good DIY instructions that we have written.

On a side note, unless you are in a pretty cold climate, I'd stay away from anything less than 10W-xx. Also, these cars are best served with Volvo or Mann oil filters. They need a good check valve system in the filter to prevent back draining.

Hope that helped.

 

This uses a cartridge filter. There is no check valve.

 

rspi: that all makes perfectly good sense to me. It behaved like something sucking air, but I could not for the life of me imagine how or why. Many thanks for the heads up, hope I can return some useful information or experience in return...

Wait a minute...maybe I can. I was at one time the techy for a lubricant brand owner, and can tell you that a full synth (as in real synth = Group IV and V blend base stocks) 5W-40 is extremely "safe" in replacing some 10W-30 (especially dino) in this or any other engine. In fact, for cold starts (it gets BLOODY cold around here) it gives infinitely superior lubrication. At full operating temp, its nominal viscosity is higher than the 10W-30, but that is far less significant compared with the literal vis at high shear (in bearing journals) and above all the shear stability of the additive package that imparts modified viscosity index to lower VI base lubes (thus my emphasis on Group IV and V base stocks - as they have naturally much higher VI and rely on much less or even NO VII = Viscosity Index Improver - something that can and will "shear down" with time).

BTW: being a VW guy, I am a BIG fan of Mann filters (and I will withhold some of my comments about certain filter brands in case their are children, family members or otherwise easily offended readers on the site).

 

Pretty sure this engine has a spin on, and reasonably sure it is a 2000 model year car. Not sure what you mean by "cartidge", but to me that implies a drop in element.

Could you please tell me what I am missing here?

 

The 2000 does not use a normal spin on filter. It is a cartridge. You remove the housing, remove and replace the filter and reinstall (with new o-ring)

 

I use to live in Japan but I'm not sure what language you are speaking. LOL
I use Mob 1 Full Synthetic 10w-40 right now. Mainly (10W-40) because it get over 100 degrees around here during the summer. I sent a oil sample in to Blackstone Labs to have my oil checked and have the additive levels checked to see how my motor is wearing. I currently have 227,800 on my odo and have been running full synthetic since 189,000. I need to check my e-mail to see if my test was run yesterday.

If you think I should be running some other oil than what I am doing please let me know. You can send me a pm if you'd like. Also, a VW guy told me that there was a place that did FREE oil analysis test. If you know of that place please let me know.

 

You have made an oil choice I would strongly approve. However, most of my fleet is diesel, and we commonly see -40 degree cold starts in the winter, so the Delvac 1 5W-40 I use covers all of those bases.

Mobil was our competitor when I was in the biz, but I use them because a) they make fantastic product and b) they are the company that really spearheaded full synth lubricants back in the '70s and I feel they deserve the respect they have earned from then on.

ES6T: yes, my S-I-L wrote me back a few minutes after I posted letting me know what I saw was the bottom of the canister, not a black Mann spin-on. I will remove the Fram cartridge he put in last change when we get the bits to pull the pan and sort out the sender and pickup.

Is there not a drain back check valve in the filter housing or the circuit in general?

Thanks for the input and advice.