Volvo S80 V8 cold start puff of blue smoke

Jackazz · Post by **Jackazz** » 24 Mar 2018, 03:13

Hello!

I'm facing a rather curious problem.
I recently started noticing a puff blue smoke followed by grayish smoke coming from tail pipe when the engine has been sitting for a certain amount of time. The smoke disappears after the engine warms up and is not at all persistent while driving. I also cannot smell any burining oil.
I also recently had engine oil changed (0w30 Castrol Edge Titanium) and noticed yesterday, that the oil level was above max (about 0,5 cm higher).
While the engine was overfilled with oil (i had no idea) i swapped my winter wheels to summer wheels by jacking up one side, changing wheels, then repeat on the other side. I noticed that the smoking started after that.

Could it be that the mixture of overfilling the engine with too much oil + tilting the car to one side might have caused the oil to go to places it should'nt be? Is there any possible damages this could have done to the engine?
I have already drained the excess oil and the oil level is now normal (a little bit below max).

I know that the main cause of blue smoke is due to buring oil. And the cold engine blue smoke puff generally indicates to valve seals to be worn. But could it be possible that it is caused by overfilling the engine?

The car has done 136k miles and it's a 2008 model.
It starts fine, runs fine.

Here's a video:
(In this video, the engine has been standing for like 2 hours)
https://youtu.be/wOyxugnLN2I

Sorry if some of my text is not understandable - english is not my first language.

bugeye · Post by **bugeye** » 25 Mar 2018, 17:34

I have looked at your start up video. My 2007 S80 V8 with ~ 82,000 miles does not exhibit smoke even if it sits unused for weeks. I use Mobil 1 or Pennzoil Ultra/Platinum 0W-40. I doubt a slight overfill or slight side to side jacking would cause the start up smoke. Perhaps try a synthetic high mileage oil. Watch if the oil changes darker quickly as an indication of cleaning engine deposits. My engine oil stays translucent in the 5000 mile change interval.

Jackazz · Post by **Jackazz** » 26 Mar 2018, 04:26

Thanks for the reply!
I will have diagnostics ran on the car soon. People suggested that the smoke might indicate that the engine is running rich at cold starts. Maybe a temp sensor or something has failed. I started noticing that the car, when idling cold and giving it a little gas, stutters a bit. I also felt a slight stutter while driving it when the engine hadn't been warmed up yet.
Worth to point out: Car occasionally throws a P0193 code (Fuel Rail Pressure Sensor Circuit High Input). So maybe these things are connected. We'll see.

Post by **oragex** » 26 Mar 2018, 05:13

I would try to remove some oil, really simple, warm the engine a little bit, no more than 2-3 minutes, just ot have the oil fluid but not hot, then turn off and insert a long plastic tube by the dipstick hole. May try to pass it underneath the bumper somewhere. Then suck in until the oil flows near the opening and let drain about 1 liter. The tube must sit really low to the ground at your end. If you need to suck it again don't let oil touch your lips, it's carcinogenic. Then check the level again.

If the engine had mineral oil, switching to synthetic may start consuming oil, I'd keep an eye on it weekly.

The 0W-30 is an excellent oil for cold climates (cold winters) although perhaps not the best choice for 'racing' the engine.

Also, once the oil level is correct, I'd try revving the engine a little bit. The oil might have got past the piston rings and too much into the ring grooves, if it turns into sludge in the groove the rings may start sticking (just a theory).

Jackazz · Post by **Jackazz** » 26 Mar 2018, 13:47

Yeah, i drained about 1l of oil already before making this thread. Also drove and revved the car after that yet it still smokes when starting it cold.
Gonna point out that the smoking started overnight. Just like bam, in the morning, when starting the car, it stuttered a bit and smoked. Just for a while, then the engine started idling fine and smoke disappeared.
Got diagnostics booked for tomorrow. Hopefully i get some answers. Will let you guys know.

Post by **oragex** » 26 Mar 2018, 13:52

I'd also test the PCV while there, hopefully it didn't affect it (the high oil level)

Jackazz · Post by **Jackazz** » 26 Mar 2018, 14:10

I was planning on getting that checked also as i also suspected that the high oil level might have affected that. Thanks tho!

Jackazz · Post by **Jackazz** » 27 Mar 2018, 06:55

So i just got back from the diagnotics. Turns out that the fuel rail pressure sensor has occasionally sent faulty reading - so this needs replacing, but the mechanics stated that the smoking is not caused by that sensor being faulty, as there was oil on the spark plugs.
They think its probably due the overfilling the engine with oil. They suggested that i drive the car for atleast 500 km to see if the smoking disappears. If it doesn't, then we'll probably look into the valve stem seals. But as for now, i'll replace the fuel rail pressure sensor and keep driving. Hopefully the smoking will disappear.

Jackazz · Post by **Jackazz** » 29 Mar 2018, 11:24

I replaced the fuel rail pressure sensor today. Had to remove throttle body for better access and i found that it was pretty oily. Gave it a good clean. Im gonna check tomorrow, if the smoking has gone any better and i'll let you know.

Post by **SuperHerman** » 29 Mar 2018, 19:18

What you describe points towards aging valve stem seals. How many spark plugs had oil on them? Has the car ever been run low on oil?

The oil system is closed from below by the piston rings and above by the valve stem seals. It is possible that the extra oil increased oil pressure which slips up from the rings (doubtful but theoretically possible) or from above through the valve stem seals. What doesn't make sense is if it is coming from below through the rings it would ALWAYS smoke and from above after it is sitting and off.

Your car is too young and has too few miles for failing valve stem seals, but that is what it sounds like.

The main danger of over filling the oil is pressure blowing out seals and/or oil cavitation or aeration. Basically the oil is frothed and looses its ability to lubricate and kills the engine.