What is causing the "clunking" sound (chain jumping?) on my 1989 Saab 900 Turbo when I accelerate really fast?
Answers:
Its usually drive shafts on these early Saab 900
Could be a bunch of things. Transmission maybe? lose belt? Just have it checked out, usually when a vehicle gets to the "thumping" phase its time to call out the big wigs.
it must be your car belt
Are you sure it's not you're waste gate popping? If not that, wheel bearings? Drive shaft yokes? Wobble stuff about, you'll find it.
If it sounds like a rattling noise coming from the engine & it is only when you accelerate fairly hard it is what is called "pinking".
It is the sympton of incorrect combustion, it can be caused by incorrect ignition timing (unlikely on modern cars), incorrect fuel, weak air/fuel mixture or carbon build in the cylinders & on the valves. It needs to be taken to a garage as specialist equipment is required to rectify all/any of the possible faults.
so many possibility of clunks from a car engine, unlikely to be chain jumping a cog tho.
If the noise happens at low engine speeds and you accelerate hard it could be pinking, try buying a higher octane petrol such as BP Ultimate,
If engine speeds are higher and there is just one clunk it could be a variety of things such as an engine mount or exhaust. You need to go though a number of options and have a passenger listen out for you as you drive, notice what gear you are in and whether the noise comes from the gearbox or the engine or even the wheels, see if you can produce the same noise when the car is still with the bonnet up, good luck
The easiest thing to try first would be to change the type of fuel you're using. Try to use a higher octane fuel.
Is it an automatic?
They have a reputation for a lot of problems.
The answers post by the user, for information only, UKQnA.com does not guarantee the right.