Riick

My 93 Civic stalled as it does sometimes, but after trying to start it a few times, smoke came out the air intake smelling like burned rubber. This was accompanied by what sounded like something floppy being stuck into a fan blade. I'm concerned I'll destroy the engine if I try starting it again (assuming it's not already destroyed). What should I check for?

Background: I had the timing belt replaced a few hundred miles ago. No performance issues related to that, although there has been a bit of a whining sound at certain engine speeds. I also suspect this car has had a small head gasket leak for years although chemical tests show nothing. It's been running fine over the past few days.

ezone

Whir sound ever since the timing belt got changed COULD mean it is too tight.

Smoke from the intake can happen when the engine rolls backwards a little bit after cranking it.

Riick

I am no longer positive the smoke originated from the air intake because the air filter is neither charred nor sooty. A decent amount of smoke was seeping out from the closed hood and I waited for it clear before investigating. By the time I looked all I could see was some smoke drifting out the air intake, which is why I thought that was the source.

I am pretty sure the engine compartment is not supposed to fill up with smoke and that the engine is not supposed to make that sound. What should I do to diagnose this? Could I do engine damage by trying to start it again?

ezone

Got oil leaks? Any oil that can get onto the exhaust can make quite a lot of smoke.

Riick

I don't think I have oil leaks, and it smelled more like burning rubber than burning oil. Also keep in mind the exhaust manifold had cooled down some before the smoke occurred, because I had been trying to restart it for about 15 or 20 minutes. I'll keep your idea in mind though...

I haven't found anything burned, melted, or charred, but obviously SOMETHING caught fire. I'm planning to look under the distributor cap and also maybe behind the timing belt cover (a nuisance to remove though). Where else should I look? Is there a risk of damaging the engine if I try to start it again?

ezone

Maybe something is rubbing, or a belt/pulley issue like a seized pulley or accessory, that would cause a belt to burn. A separated harmonic balancer, a slipping belt, etc.

You could turn it over with a wrench and watch, but you may need to run it to figure it out.

Riick

Alternator and compressor belts looked OK. Can't check the harmonic balancer until Wednesday. Harmonic balancer is possible because recently I've been redlining the engine for a few seconds after it warms up. This somehow keeps it from bucking but it must be hell on the balancer!

That loud growling or tire-hitting-fan-blades noise it made when it smoked makes me concerned about the valves. That is why I am reluctant to turn it over. Should I be? I'm really disliking not having a car...

ezone

I don't think you are going to find any noise if there is no noise to hear.
I don't think you will see smoke if there is no smoke to see.

I think you will have to run it in order to figure this out.

Have you pulled the timing cover and inspected in there yet? If the timing belt lets go, there will be serious damage. If it is ok, then it is probably safe to run briefly.



Taking stuff apart without having any idea what you are looking for seems pointless.

Riick

I started it up after verifying that the timing belt looked good and the harmonic oscillator was on solidly. No smoke, and it ran as well as it usually does after sitting for so many days. I am completely baffled as to what caught fire and why it didn't happen today. If it happens again I will post again. Thank you very much for your help ezone!