vibration

Hi!

What could be the cause of my 944's vibration? It is pretty much the same in idle or in gear, notable increasing when i shift down before making the turn or just slowing it down by shifting down the gear.

people (not 944 specialists) advise to change the gearbox mounts. The engine mounts seem to be ok, althought this also could be a problem.

what would be the cost of replacing gerabox mount (and how many mounts are there??)

thanks a lot,
Mindaugas

dont worry its not the gear box its the 3rd rod bearing on that cam shaft, this is very common with 944's i am currantly rebuilding my 944 with my dad because the rod bearing went out it'd be best to replace all the berings just incase. a rod bearing set runs about $100 if you take it to a porsche specilist it'll cost about $2,000 im replaceing it myself and its also a chance to replace my timeing belt and rebuild my engine with stronger parts so i can supercharge it and give it a lil extra juice with nos :)


good luck with your 944

How many miles are on you car? I seriously doubt that it is the rod bearings. They make a VERY distinct sound when they let go (like a train wreck followed by a very poorly running engine). If it was, then it would already be too late and you would be looking at a full engine rebuild.
The most common problem that I have seen for vibration issues is the motor mounts. These can be changed by yourself, if you have the time. Plan on at least 3-4 days of downtime. It would also be a good idea to get the timing checked by a good mechanic that has experience with 944's. Sometimes the timing belt will slip a notch if it's loose.
You may also want to check the balance/alignment of the wheels. This could also cause some serious vibration.

you metioned that you only hear it when you down shift this means that the engine is running at a higher rpm in a lower gear this makes a rattaling noise you should start you car and pop the hood let it idle and then open the throttle body to increase the rpm you will hear a slight ticking and then a notcking around down in the engine if so then your looking at a worn rod bearing you should stop driveing the car because it the bearing goes then you have to get the crank shaft machined down