2001 S80 No Engine Oil Pressure at Idle

wildzontar · Post by **wildzontar** » 22 Oct 2013, 11:39

At idle (below 700 RPM), the oil light will come on and "No Oil Pressure, Stop Safely ASAP" or "No Oil Pressure, Stop Engine" will appear in the DIM. When RPM goes above 700 RPM, the light goes out.

Had two garages look at the problem. A third party shop (specialist in Volvos) cleaned out the breather system as well as installing new oil pan O-rings. I thought for sure the O-rings would take care of the problem; they have not. This shop tells me the oil pump is going bad. I later took it to a dealer who gave me even more sobering news and said the engine is shot.

Both have pressure tested with a gauge and both say the idle pressure is barely sufficient despite the light coming on. Dealer says there's no guarantee it won't get worse. Third-party shop got it a bit more pressure after the O-ring change, which makes me feel better, but it's still not enough to keep the light out.

I drove about 800 miles this past week for job interviews without any major incidents, diligently checking the oil before I got back on the road. No leaks. In addition, I was getting oil bubbles on the dipstick prior to the O-ring change; that appears to have either gone away or was really cut back as I don't really see the bubbles anymore. Pressure is still bad, though.

Oil light switch was already replaced. Currently at 210,000 miles.

What I'm wondering is, who sounds more right? They're both expensive repairs so I'd like to know which one is more likely to get it (or if it can be something else). I generally am not inclined to believe the dealer as they love their money, but I could be wrong.

difflock54 · Post by **difflock54** » 22 Oct 2013, 19:55

What grade of oil are you running the motor on ?
If the oil pressure sensor is working properly and as replaced one can presumeably assume so, I'd do a compression test to assess the motors general condition.
If she passes a compression test then my money is on the oil pump being stuffed.
Is she using a lot of oil or any signs of blue smoke?

Post by **boosted5cyl** » 29 Oct 2013, 14:23

Oil pump failures are very, very rarely the cause of low oil pressure. The biggest cause, short of obvious things like leaks, wrong viscosity oil or clogged pickup tube is in fact excessively worn main and or rod bearings.

You could try a higher viscosity oil, it would mask the problem but still better than spinning a bearing. What viscosity are you running? How is the pressure when the motor is cold?

wildzontar · Post by **wildzontar** » 30 Oct 2013, 20:16

boosted5cyl wrote:Oil pump failures are very, very rarely the cause of low oil pressure. The biggest cause, short of obvious things like leaks, wrong viscosity oil or clogged pickup tube is in fact excessively worn main and or rod bearings.

You could try a higher viscosity oil, it would mask the problem but still better than spinning a bearing. What viscosity are you running? How is the pressure when the motor is cold?

I use 10w-30 in Pennsylvania mid-atlantic climate (cold winters, hot summers). On a cold start, the light does not come on (and the pressure is good). It takes about 15 minutes of driving or running the engine before the light comes on, and only at or below 700RPMs.

I'm pretty sure the pickup tube was cleaned when the O-ring job was done. No leaks.

If the problem is the bearings, are either replaceable or does this require replacement of the entire engine?

difflock54 · Post by **difflock54** » 30 Oct 2013, 20:58

The fact your oil is gradually thinning as it heats up and oil pressure becomes too low after about 15 minutes of running seems to point to low compressions. Worn piston rings or bores.
Have you done both hot and cold compression tests yet?
Other than that the oil pump seems the likely culprit.
Running higher viscocity oil say 15w-30 or 10w-40 in a worn engine may boost your oil pressure enough to keep your oil warning light off for a while but isnt really a fix.

Post by **jimmy57** » 30 Oct 2013, 22:08

The oil distribution uses the groove in main bearing shell as the duct for oil. When mains wear it can cause a loss that leads to what you are seeing.
The dealer has likely had a car with a spun main bearing that required a new engine. The aluminum block opening for the mains is damaged beyond repair if bearing spins.
This could be fixed but the only way to know is to do some significant engine disassembly.

frothberg · Post by **frothberg** » 31 Oct 2013, 19:24

I have a 2002 s60 2.4T with this exact problem. Is it dangerous to drive if the "no oil pressure" light goes off as soon the rpms are greater then idle?

difflock54 · Post by **difflock54** » 31 Oct 2013, 19:49

frothberg wrote:I have a 2002 s60 2.4T with this exact problem. Is it dangerous to drive if the "no oil pressure" light goes off as soon the rpms are greater then idle?

Assuming your oil pressure sensor is working correctly then the oil light going out above idle indicates an improvement in pressure which is a positive.
The question remains though, why is the pressure less than generally required and what is the reason?
What quality is your oil filter and is it due for replacement perhaps. Low quality filters break down a bit and would affect oil flow if badly clogged.
Otherwise a worn out oil pump as stated previously in earlier posts.

Post by **boosted5cyl** » 31 Oct 2013, 21:51

Yeah I would hope the pickup tube was cleaned when it was apart. Motor is probably just getting worn. You can try a higher viscosity oil like mentioned but for the most part disregard the first number (one followed with a w) as that corresponds to cold viscosity, the second number refers to warm viscosity at 212F. There's some crossover but its teeny.

So in short, you could try 10W-40 and see if it helps. With our cars I have been running xW-x+10 since they have higher miles on them. In the case of the XC90 and the S80 specifically I have been running Rotella T6 5W-40. Again the oil wont be a fix but then again it'll probably still be good for 10 or 20K miles which isn't so bad. Since we first got our S80 (35K miles ago), especially after we first got it, I dont know how many times the oil pressure light has come on due to various oil leaks in the car over that time. I'm not talking about just at idle either!! Despite all that abuse, the motor still runs OK. My point here is that while not desirable, the low oil pressure warning light appearing doesn't mean that your motor is necessarily going to just pack in soon.. I'll also add that the pressure in the S80 is good, it just dropped a lot in the past with the rapidly sinking oil levels.

I think getting a good xW-40 oil in there may help prolong your motor until you are ready to move to another car. Its probably not worth the time and money to investigate things any deeper.

wildzontar · Post by **wildzontar** » 03 Nov 2013, 21:04

boosted5cyl wrote:I think getting a good xW-40 oil in there may help prolong your motor until you are ready to move to another car. Its probably not worth the time and money to investigate things any deeper.

Yeah, judging by everything I read in this thread, it may be time to throw in the towel. If the engine has to be torn apart to find the source, that may run more than just a new engine which already isn't worth it. I always try to keep cars as long as I could do so I may change out the oil pump as one last repair, as well as use some thicker oil.

Two guys already told me the pressure is "okay" for now so even though the light comes on at idle, I don't think it's doing anything more than just wearing out quicker. I don't even know when that'll finally come to a head, but it could be a while. Volvos are tough once saw an engine go ten full minutes on liquid glass during that dumb Cash for Clunkers disabling thing.