Hey guys, I just picked up a 95 850 turbo wagon Its got right at 170k on it so its no spring chicken but its in very nice shape for its age and seeing as how I traded my gas guzzling. F150 that I only had $1500 I don't think I did to bad anyway.... I drove the car almost an hour home last night and it ran great lots of power and smooth running. Well today my dad came over to check it out and i started it up and let it sit and idle well after about 5 minutes of idling it started lightly smoking grayish/white smoke but once I rev it up it goes away pretty quickly the big problem is is that now after the smoking started it is now skipping/misfiring. I noticed after it started smoking and I could smell oil and the car was now running rough. Has anyone had problems with plugs fouling? Because when I start pulling plug wires off on 4 of the cylinders the engine changes sound when I remove the wire from the plug but on one of the cylinders when I remove the wire it doesn't change the sound of the engine at all.. Im pretty sure the wire is good because it has spark(stuck a small screw driver in the end of the wire and saw/heard it sparking).... The previous owner said he recently replaced the turbo along with the plugs, plug wires and distributor cap and they do all look pretty new... But I just have a feeling that whatever is causing it to burn oil and smoke some is also causing it to foul a plug ( if that is indeed what happened ) so hopefully I can get that fixed as well

 

Compression test would the next order of business...

 

Well, a 18 year old car will have some issues, here are my thoughts.

1. Smoking after idling a few minutes usually mean that the valve stem seals are hard and leaking. You can try switching to high mileage oil to see if it can swell the seals but they are likely so hard that nothing short of changing them will help. If you are not ready to do that, you may want to avoid letting the car sit idling because that's when the oil slips by the seals and runs down the valves and gets into the combustion chamber and burns through the exhaust. Please don't get me wrong, oil is doing that anyway but burning off at a much fast rate than it does while sitting at low RPM's.
You should also know that this is likely the #1 cause of burnt valves, oil deposits sitting at the bottom of the valves and cooking on them after the car has been shut off. After doing this over months the deposits stops the valves from seating properly and will cause leaks and burns (chips the valve). A buddy of mine who is an awesome mechanic usually gives his motors a quick rev right before he turns them off. I believe he's trying to knock the oil off the valve before he turns the car off to prevent this build up.

2. The oil in the chamber can cause the plugs to foul pretty fast so try not to let it idle much. You can pull the plugs and brush them off with a wire brush, make sure they are gaped at 0.0028 and put them back in.
These cars do not like after market parts so it would be a good idea to use Volvo parts unless an experienced Volvo guy tells you it's ok to use something else.

NOTE: It is NOT a good idea to touch anything under the hood with the car running. That's a good way to get knocked on your ***. The only exception is if you are going to have someone standing by with a video camera/phone rolling so they can post it and we can get a good laugh.

3. There is a slight chance that the turbo or you have a vacuum problem that is causing the smoke. Check and make sure all of your vacuum elbows are in good condition and connected, especially on turbo models.

4. If cleaning up the spark plug will not let it fire again, you may have a burnt valve all the sudden, highly unlikely but a compression test will tell you for sure. You can use these instructions to do the compression test.
Compression Test - Volvo S70 GLT, 1998

5. Read the NEW 850 OWNER thread. It's worth it's letters in GOLD.

6. Check the PCV system and if you can't tell if it's been replaced within the past 3 years put that on top of your list of things to do. A clogged PCV can cause leaks and blowback.

 

BTW, my car smokes if I let it sit idle for several minutes. I plan to do my valve stem seals soon. Along with NA cams and whatever else is needed with the cams out.

 

Oh, I remember now... all that oil blowing through the exhaust will foul out the o2 sensors and cat.

 

Ok, so I tried cleaning the plug and then when that didnt fix anything replacing it with a new plug and its still skipping/misfiring, and when you pull the plug back out you can tell its not firing... its got a set of "max power" wires on it which are a super cheap parts store wires so I'm going to try and replace it with a good set of oem quality wires and see if that might be the problem but as of now I'm still at a loss seeing as it ran great on the way home and then after starting it up the next day its running like crap

 

What were the results of the compression check? I would not go throwing parts at it until you do what gdog recommended.

 

Yeah, I was hoping for an easy fix and well its just not meant to be I guess . Seeing as after going and buying a compression tester today and checking it I had a whopping 0 psi on the cylnder I have been having the misfire on.

 

That would be sad but I'd do a compression test if cleaning the plug didn't get it to fire. Was there fuel in the chamber and on the plug?

 

Ouch! My guess would be a burnt valve. Had the car been sitting up?

Did you wet it and check it again?

 

Put about an ounce of oil down there and see if it builds any pressure. If not, you'll need to pull the head and have it rebuilt.

Head Removal and Installation, Volvo 850 / S70 Turbo B5234T, B5254T, Head gasket replacement, valve replacement.

 

0 psi compression means burnt/bent/broken valve; no amount of oil is going to bring it up. Sorry dude, but it's overhaul time.

Unless (this is very unlikely so don't get your hopes up) this car has been sitting for quite a long time and the valve is just stuck open a bit (from carbon buildup on valve stem)? If this were the case I would expect considerable valve train noise.

 

With zero compression you don't have many options. There is a small chance it's had terrible maintenance and the rings seized in the piston or a valve jammed in a guide.

If you're really reading zero you likely have a valve stuck wide open because even with the rings not seating they should still have some contact and provide for some compression. Or a valve spring broke on your way home ??

Other than starting to pull the head and physically inspecting the valve train the only cheap, easy mechanic in a can option I can think of is running a can of Seafoam into the intake through a small vacuum hose. You don't want much going in at a time as you want it to coat the valves stem and hopefully get wicked up between the valve stem and guide. They also make an aerosol top end cleaner with a "straw" that sprays itself into the intake flow.

The idea of an ounce of oil in the cylinder would give you an idea if it's rings or valves as the oil would help boost the compression is it was rings but usually will not if it's a valve.

If you had a compressor you could use it to blow air into the cylinder once you're brought it around to TDC on compression and then it's just a matter of listening to the intake, exhaust or oil fill to find out what is hissing. The leak down tool you can get as a loaner at most part stores.

I know you also said you purchased a compression tester already but it is also something you can get as a loaner tool from most parts stores.

 

I got around 160-175 psi on the other 4 cylinders and then on the bad one it wouldnt even move the needle on the gauge .... This was supposed to be something a little nicer to drive than my 240 wagon you know, newer , more power , less problems ,etc..... Seems like the ol 240 wins again haha



Oh yeah I tried seafoam as I have used it with some positive results on some of my other junk/projects I have dragged to the house over the years , and it didnt help. So it looks like whenever i can actually get time to do anything to it we will pull the head and see what kinda damage it has

 

When you get to the problem, please let us know what it turns out to be.

 

There are a few youtube video's about laping the valves on a Volvo S70. So you can do it yourself. The nead shouldn't need to go to the shop for decking unless you just want to have them rebuild the head. That would likely cost you about $275 if they don't have to shave it.

 

I'm gonna have he head gone thru by a reputable shop just for piece of mind, I have a buddy who can do just the valves but if I'm gonna have it that far apart I want to make sure there's nothing else hiding I need to worry about.. Going to buy a new pcv kit,along with the ipd Intake gasket, new timing belt, water pump, etc.... Anyhting else I can do to up the performance a little bit while I have it apart?

 

Lots of stuff you can do to a 95 855 Turbo; ck out ARD Tuning for starters.

But if it were me, I would want to make sure the bottom end is sound before I start cranking it up...

 

Ordered a crap ton of parts from IPD last night.... headgasket kit, new headbolts, their turbo control valve and heavy duty cbv, phelonic intake spacer, cam timing tool, performance wire set, new pcv kit, timing belt kit with water pump and handful of other things... Hopefully I will get to tear it down in the next few weeks... Want to get everything straight so I can order my tunes from ARD like I had originally planned when I bought the car lol

 

Since you have that and want to toss in a tune, you might want to toss in a set of NA cams. You can get a set from a junk yard. If you don't have access to one, I have a set, PM me. From what I have read, they change your torque curve and give you more torque sooner. Most guys say it's the best low cost performance upgrade you can make.