Julian
My 850R has had oil smoke issues for a while now. I have replaced the turbo which didn't fix it. I'm thinking it's likely the valve stem seals, as others on this forum have mentioned.
Whilst getting my rego check today, the mechanic said he believes it's much more likely the PCV system, as he has done many of those on volvos but has never seen one requiring new valve stem seals. I would think many old cars would require valve stem seals, but before I write his comments off I thought I'd check that I'm testing PCV operation correctly and definitively.
I get no smoke from the oil dipstick when I lift it with a hot and running engine. A balloon over the oil cap hole doesn't inflate with a hot, running engine, even if I rev it. It just kinda does small amplitude pulses. Is it possible that my car could pass both these simple tests but still have a blocked pcv system? For what it's worth, the previous owner claims to have done the pcv job.
If valve stem seals, since it's a pain in the ass to do the job, has anyone tried those oil additives intended to rejuvenate seals? On this last point, please only comment if you have first hand experience of them working or causing harm- I understand many people have a negative opinion of them without ever having tried them (me included!) But it'd be good to hear from people who've actually used them.
carnut222
BREAKING NEWS: SNAKE OIL SALESMAN also sells snake oil seal rejuvenation fluid! ;)
Julian
As mentioned, would be good to hear from people who have used them and can comment on whether or not they work. Mechanic guy I spoke to today said he's seen success with them before. Trying to get a good cross section of actual experience.
Philia_Bear
Pcv on an 850r... Very possible it has re clogged again
3 years or 60000km can frequently be the life of them
It can also be clogged in a way that oil is draining into the intake more than it is draining back into the block
Valve stem seals are dam rare unless highly overheated or run low on oil for extended time
I'd do the pcv again cause cheap before ever thinking about the stem seals....
Exception... if car is now over 300,000km the stem seals could be worn out...
Have used oil additives, the only ones I have ever seen do anything are cleaners and friction/viscosity modifiers anything else is snake oil
Julian
My car has 180,000km and at least in the time I've had it has not been overheated, but having said that there are several people in this forum who believe the turbo cars commonly harden their valve stem seals and that mine may need replacement.
Are there any other pcv tests that could show whether mine needs doing? Or is it a matter of just pulling it apart?
I'll read up on a tutorial about how to do the pcv job, but does it require new parts or just cleaning/adjustment?
Philia_Bear
Frequently the hoses from the pcv box to the intake are effed and need to be replaced
The pcv box is honestly cheaper to replace than clean
There is no adjustment just clean and or replace
Uro parts are fine for this and are cheaply sourced from rockauto as uro stuff always ships from the one warehouse
Julian
I checked out the hoses etc today and at least from what I can see they all look ok. There are normal screw type hose clamps on all of them rather than those oem type which may indicate that it's been done.
I took the plastic spark plug cover off and there is some oil pooled on the top of the valve cover as shown. This may just be from me spilling some when refilling in the past, or could it be coming from somewhere it shouldn't? It seems to be more localised around the breather hose but I guess they'd where the oil cap is too. I pulled the hose in there off at the head end and it's not blocked or anything.
As mentioned, since it seems to pass the "smoke out the dipstick" and "glove over the filler cap" tests and these hoses look ok I'm a bit reluctant to go pulling off the intake manifold etc when there's sort of no indication that the pcv system has any issues. But the rego check mechanic seemed to think that smoke from exhaust at idle is indicative of oil getting past the turbo seals, and since I have a brand new turbo, that it's likely improper pressure relief.
Ex850R
Filler cap seal been done?
Mechanics recommended new one every oil change.
Can get viton ones which last longer.
Julian
Looking back into this again to address my exhaust smoke/oil consumption.
Just to clarify, is it possible that I could have no oil dipstick smoke, and no pressure in the glove over the oil filler test yet still have a pcv system in need of service?
Ex850R
As bear said above, yes.....
It's not hard to do.
Julian
Yeah ok, just wanted to check as I wasn't sure if the comment on the oil draining to manifold was conforming that.
Also interesting to note that most sources list 100,000 km as being the life of a fresh pcv system. Mine won't have done that much, but I guess it's been a few years.
Ex850R
You can't trust sources when the car is driven in differing circumstances by different drivers with wildly varying degrees of how well they service the oil and filter.
Replace all the system, it's cheap insurance from blowing cam, rear main sales...
850AWD
Check cylinder compression, pcv sounds fine. Head gasket could have leak, could have fried a ring. But probably stem seal. Compression test will give an idea before tearing it down. Its hard to remove the valve spring without head off or the right tools. Put a catch on to relieve blow-by buildup pressure in high psi ( vent to atmosphere ).
Julian
Thanks for the input. I have checked cylinder compression and all cylinders were within spec. What about my symptoms make you think that pcv is unlikely?
I have heard differing opinions on my issue, and since all of the solutions require a reasonable amount of work it has sort of put me off trying to sort it out (especially after replacing the turbo chra and it not being the problem...)
Ghettobird
Smokey?
Do the valve stem seal test:
Idle for 10 minutes, then bring the car up to 3500rpm and hold. If said seals are on their way out, you should see a bit of smoke.
My car with 300,000 Kms needed seals big time
I've seen cars with 200K that were just as bad.
Do a leakdown test, my R needing a bottom end has fantastic compression, but atrocious leakdown past the rings. Is the smoke when engine braking after closing the throttle?
Whats your oil level like?
Is it overfull?
Julian
I haven't noticed smoke under closed throttle when compression braking, but I'd also probably be unlikely to notice this any way since it would be behind me.
If I idle for a while then rev high, I get smoke. Similarly on startup I often get a cloud of smoke. I notice a strong smell when reversing with windows open sometimes, presumably burning oil.
I'm also not over filling oil.
Ghettobird
Valve stem seals then, Id be fairly confident if you can guarantee its not the turbo
Julian
Yeah turbo is brand new. Might bite the bullet and pull the head, do head gasket and valve stem seals. Tempted to just drop the head somewhere to have them do the seals so I don't need to start pulling the hydraulic lifters apart.
I suppose the pcv would be easy to do whilst head was off, but would also save $150 if I just did it after the head work in the event that I still had a smoke issue.
Oh, also I often get smoke under hard acceleration.
850AWD
Pcv could be clogged and blow-by escaping somewhere else. Check pcv hose input at intake for buildup. Check intake pipe turbo side for excessive oil. Is there oil in piping after turbo? Is the pcv heater working?
https://ozvolvo.org/discussion/comment/143547#Comment_143547
Julian
I do remember that at least with the old turbo, if I wiped my finger inside the pipe from the turbo to intercooler that I would get a layer of oil on it but was never sure what was normal