chris-sti

Hi guys,

I have a wrx sti version 3, and over the last 500 miles or so its developed a series of problems thats leading me to believe its a mount of somekind... firstly the most noticeable thing is its now near impossible to pull away without the engine juddering to the point i have to dip the clutch back in. also unless i match the revs when changing down, its judders sometimes so much, it feels as though the engine is about to fly off the mounts. secondly when you start it up, there is a knock from something hitting the inside of the bonnet (i think) around where the afm sits. thirdly sometimes the clutch cable/gearbox mechanism squeaks... sometimes it doesnt, this also comes with a very slight change in biting point. and last but not least, the juddering, and going over bumps is accompanied by a knock from the same area as where the last knock was coming from (afm/top inner wing), which i can also feel through the clutch pedal, along with a few other vibrations one of which being in sync with the cylinders firing.


I have a pit so ive been under there, all mounts seem fine and cant see anything obviously loose. when started with the bonnet up, the original knock is gone but nothing looks like its been hitting the underside of the bonnet. I have a 4 plate paddle clutch with 15k and an unusually high biting point (never bothered me). Ive had a good search over the forum but didnt really find anything as specific as this! I have good mechanical experience, but im a total scoob noob!

duncatr

iTrader: (18)

I'd start by checking the engine stabiliser bar. Its locatod at the rear of the engine bay, where your oe Top Mount Intercooler was.
Then check the 2 engine mounts under the engine.
Then look at the gearbox mount.

If they are all fine then you can dig further.

Judder can be caused by the flywheel but not the way you describe it.
This can only be fixed by skimming the flywheel.

tonyrally

sounds like an engine mounting to me get under with a small opry bar an have a pry about u never know lol regards

chris-sti

thanks guys, the engine stabilzer bar is fine, as is the 2 bottom mounts (only look a few years old at most), gearbox mounts seem tight (although i cant see the one that is covered by the exhaust, but seems tight).

The first knock on startup is nothing to worry about, im 99% sure it is the air filter hitting the bonnet. the 2nd knock is still worrying me, i can feel it through the accelerator pedal and i would usually associate it with suspension, but that all seems fine also. Im going to get under it again later and grab a few pictures.

hux309

Just curious do you run an fmic if so did you leave the original ic mounts on?

chris-sti

the guy before fitted the fmic, not too sure if the original mounts are still on there, what am i looking for? you think it may be the source of the problem?