1979-1993 & 94 Conv [Subscribe to Daily Digest] |
[Main C900 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Re: what are drivability symptoms of bad rings/pistons? Posted by Ari [Email] (#2847) [Profile/Gallery] (more from Ari) on Mon, 19 May 2008 09:25:45 In Reply to: what are drivability symptoms of bad rings/pistons?, Austin Underwood, Mon, 19 May 2008 07:40:57 Members do not see ads below this line. - Help Keep This Site Online - Signup |
I'm always amazed at how long an engine can run when it's in bad shape.
With bad rings/scored cylinders, you'll get the blowby you're seeing. This basically drops the compression ratio, so the low end performance will suffer. The high end won't be great, either.
The blowby will pressurize the crankcase, so that's what's pushing the oil out of the distributor cap. That'll push more oil past the PCV and into the intake, further reducing power and generally oiling things up.
What can you do? Not much, other than palliative care. You can't fix rings without removing pistons. You can go to a thicker oil, as it will provide some measure of sealing, but not much. You want to change the oil more frequently - all that hot gas and combustion by-products blowing into the crankcase are degrading the oil quickly. I'd go to 2K oil changes, max. More frequent is better. Also check your spark plugs - they may gum up sooner, because of the oil getting pushed back into the intake. Once a week or so, pull off the big air intake hose, open the throttle plate, and wipe things out with a lint-free cloth.
How long will the engine run this way? Probably a lot longer than you'd think. If a ring has broken, it may at some point come apart and that cylinder will really lose power. But then again, you could limp along like this for another 10K miles. It won't be pretty and it won't be fast, but it'll probably keep running.
posted by 192.249....
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.