Julian
Hi guys,
My 1996 850R has very high oil consumption (at a guess I might go from top dipstick line to bottom line in 6 weeks daily driving or so). I suspected the pcv system, even though the previous owner said it had been overhauled before i bought the car a year ago. I don't get any smoke coming from dipstick when hot and running, and don't get any positive pressure inflating a balloon/glove over either the dipstick tube or open filler cap. I do however get smoke from the filler cap when i first open it after it has been running. Is this normal or could it still be indicative of a pcv issue?
I get smoke from the exhaust upon acceleration if i have been sitting at lights, which i wouldn't have thought would be a pcv thing either. My car has about 175 000 km on it. Do our engines wear out their valve stem seals over these kind of distances, or is it more likely to be worn out turbo?
Pretty keen to get this problem sorted since synthetic oil isn't cheap! In using fully synthetic nulon at the moment.
Philia_Bear
Rings or valve stems or turbo are shot
If no pressure then the pcv is fine
Julian
Ok, hopefully not rings. Would a compression check give this away? Or can rings leak oil long before they show up as being worn in a compression check?
nickm
Turbo cars kill seals through the extra heat. I just changed the Valve stem seal in my 850r they were rock hard and allowing a little too much oil into the combustion chamber.
I was finding it blew smoke on a cold start. Or after I added oil.
I would also suspect your turbo
Run a compression test check how much oil is in your intercooler too.
Ex850R
Actually Nick mentioning the intercooler is something that most forget.
I have pulled apart 3 P80 turbo intercooler setups recently and yes, oil is in the hoses and the cooler so I gave the cooler a good chemical flush.
Julian
Ok thanks for the advice. I'll do a compression test since I have the tool, and check the intercooler out too. So i suppose it's likely that if i have good compression and not too much oil present in the intercooler that its the valve stem seals?
To replace these, did you have to remove the whole head or was it possible to just take the valve cover off and cams out and get to things like that? I haven't had to disassemble hydraulic lifters before so not too sure what's involved or what special tools may be required. Is it the sort of thing that people typically just take the head into a cylinder head shop to get done?
Ex850R
As a matter of interest, what oil are you using?
nickm
I just did this job. If you are doing it pull the head. I ended up doing this.
It can be done without but it is back breaking work and you need a specific style of valve spring compressor and compressed air sparkplug thingy. If you drop a collet you will swear...
.I was not happy with the leak down of the valves so I pulled the head.
Julian
Ok, so I did a compression check today and all cylinders were well within spec. Looks like the next steps are checking turbo and valve stem seals.
I pulled the pipe from turbo to intercooler off, and there was a bit of oil on the walls of it. When I wiped my finger inside it, it came out pretty oily and black. Is this normal or is any oil here a bad sign?
nickm
Is it smoking at extended idle?
Top it up with oil does it blow smoke when you start it?
Julian
I have mainly noticed oil in exhaust if I accelerate really hard or if I've been idling for a while then accelerate. I guess either turbo or valve stem seals could cause those symptoms
nickm
Sounds more like a turbo.
Turbos also leak on the exhaust side. If you leave the car idling for about 5 mins after you have fully warmed it up. It will start to puff as the oil builds. But it smells different to fully burnt oil.
If you top it up with oil when the engine is cold. You are poring a lot of oil around the stem seals some will leak in and on a cold start it will blow smoke.
Julian
Hmm, now I think of it maybe it did blow oil after I last topped it up. I'll have to check at next topup. I'll test what happens if I let the car warm up and continue to idle, ie:check if it starts smoking. Cheers
Ghettobird
At the age the car is, it dosnt matter if youve done 100,000 or 300,000
Im doing my valvestem seals as we speak, 320,000 and the car did exactly as you say
Extended idle and acceleration would puff blue smoke
Start after expended period of time and she would puff blue smoke
Car was on its 3rd turbo, last was a known good 16t with 170,000 on it and never gave me any issues
Rings are HIGHLY unlikely, my compression was perfect across the board on an unopened 320,000 km old motor
nickm
Yep .. I have replaced nearly every seal in the motor.
jagardh
I had the same issue with my R. It was the valve stem seals. I changed them without pulling the head.
Julian
Ok, so I'm looking at valve stem seals on eBay trying to find a set of 20. I noticed, looking at a couple of different brands, that the same part seems to fit a bunch of different vehicles from different manufacturers.
I previously had a 1991 saab 900 aero, and it looks like some sellers list the same part to fit the 900 as the 850. As it turns out I have 2 new sets of 16 valve stem seals for the saab still sitting around in their boxes from probably 4 years ago, I think they are Victor Reinz brand. I'm almost hesitant to believe they'll actually fit (seems too coincidental...), and see that some sellers only list their parts as fitting the 850.
Anyone know much about valve stem seal compatibility?
Ghettobird
I have a set of 20 Elring valvestem seals for sale if your interested?
I bought them in a kit to rebuild my head, but I doubled up