: Catasrophic engine failure?
Greetings Saab fans and other Saab drivers,
I had a nasty incident this evening with my 1989 9000S (2.0L, 5-speed, 125k miles).
Car started and ran normally, but shortly after I was underway, I heard a loud screeching not unlike that of a loose belt. Initially, the noise coincided with engine revs to 1500-2000 or so, then quickly became constant. Fearing further damage, I shut down the engine and pushed the car back home. I also detected a strong odor unlike I've ever experienced. I believe the odor was not of burning fluids (oil, fuel, coolant, etc) or plastic or rubber. I did not find any smoke.
Lacking light, I was unable to perform even a cursory underhood inspection. Both belts appeared intact.
Any ideas as to what I might be into? Please feel free to ask for further details.
Thanks in advance for your time!
You might have suffered a bearing failure on something on one of the belts, and the friction was burning the belt or other parts. Perhaps start it and watch/listen carefully for any noise/vibration. Use a piece of hose to listen for bearing noise, although what you describe must be a complete seizure.
See my post in the Lounge, 'Hot Warp (Speed) on Autobahn'. I recently had a belt idler bearing seize, but unfortunately was passing a 155mph limited BMW at the time...:o
Sorry to hear about your loss. Good thing you had a spare head laying around. Good luck with the rebuild!
Thanks for the the quick reply. The noise did remind me of a bearing failure. At the time of the incident, the engine had only been running for a couple of minutes, revs never exceeded 2.5K, no warning lights illuminated, and as I said, I shut it down pretty quickly
I am a little hesitant to restart the car. It seemed to be running smoothly when I shut it down. If there is indeed a bearing failure / seize, would it be safe to run the engine briefly? Are there some conditions under which is is NOT adviseable to run the engine?
The noise is LOUD. I won't need a hose to hear it clearly, but might no be able to isolate it, especially if I am only running the engine briefly.
The worst would be if the timing chain has failed, then it is not good to even crank the engine. You may smash valves just turning it over, but if you drove it for even 30 seconds w/ the noise I suppose whatever is going to happen has already done so.
If it is belt related, the worst is that you have no water pump, and I can tell you the sequence is overheat, head gasket fails, warp head (I stopped there) and finally distort cylinder shapes/bugger block.
Might be prudent to remove the belt to check all the bearings there. If they all check OK it might be something worse, consider pulling the cam cover to look inside at the chain.
i would advise against running your engine whilst listening because if the problem is as kev suggested a seized bearing on the belt there is a possibility of the belt breaking and coursing injury if you have your head in the area
Do not run the engine... get it to your mechanic! My 9000 did the loud scream and stink in Feb and it turned out to be just a bad belt tightener that decided to loosen up... if the engine was running smoothly when you shut down there is hope! it may be 'just' a belt tightener and belt or an AC Compressor, or power steering pump going south. All cheaper than an engine rebuild.
24-05-05, 07:16 PM
The harmonic balancer on the crankshaft nose is a known weakness on the older engines. The two steel pieces are separated by a rubber ring (the "balancer" part) which can fail to grip one piece or the other. Normally you get a lot of warning when this puppy is about to fail as you get an early morning squeal especially when the temp is very cold. However, they also fail catastrophically.
The squealing sound is caused by the steel running freely on the rubber ring. The crankshaft fails to drive any of the accessories because the driven component is slipping on the drive component.
Cheap to fix and the good news is SAAB updated this part so it doesn;t fail as often.
Other thing it might be is the belt tensioner bearing or idler bearing on the serpentine belt. if this fails you usually lose the belt however.
24-05-05, 10:49 PM
Mine did the same when the AC compressor seized up (the screech) and the belt started to burn (the stink & smoke). I cut the belt off and its been OK (except hotter in the cabin for some reason) ever since. I hope your fix is as easy.
25-05-05, 02:00 AM
I would concur with the bearing failure. Especially coupled with the strange smell.
What kind of accident was it? What might have been damaged?
But I would say don't run the engine without finding out what the deal it.
25-05-05, 04:32 AM
Seized alternator? That happened to me, and sounds pretty similar. Although most things seizing would make that sort of noise. Was the smell err, electrical?
Thanks for the observations!
I have an appointment a reputable Saab mech on Tuesday of next week. I will leave the car as-is until then.
I'll let you know what I find.