I have done a bit of a search but can't find what I need and kind of need back to basics advice. I have a 2004 WRX that now has 105,000 miles on the clock. I am looking to get it remapped to around 300bhp soon but I am concerned about possible engine failure.


What sort of checks I can do before actually going for the remap to determine if the engine seems sound. I am guessing that a compression test on each cylinder would be a good idea? Anything else?


The other issue is when I got the car at approx 80,000 miles I had no history with it. I had the cambelt changed when I got it and have done oil changes but nothing else major. Are the valves supposed to be checked at certain intervals and is this a major job?


thanks

 

Checking the valve clearances is not a major job but will become a MAJOR job if they need altering as on my bugeye the cams need to be removed to change the shims.

 

Do most people not check/reshim the valves, I just can't find many threads about this type of thing?

 

Most valve clearances are done when the engine has major work carried out on it eg: head gaskets or engine 're build.
WRX outer shims can be done 'in situ' but STI under bucket or selective bucket type require camshaft removal to adjust the clearance.
N/A Engines with screw and locknut adjusters are a doddle to do

 

So if you were me would you say don't worry about it and just have the remap. Or should I check clearances and then decide?


Is this a DIY job or is it best to leave it to a professional garage. I've reshimmed my 450cc 4 stroke Yamaha bike and dismantled and rebuilt a 4 stroke quad engine but not done much work on cars or Subarus.


Would a garage charge hundreds for this kind of job, is it a more major job than a cambelt change?

 

Bigger than doing a cambelt change but if they need doing getting the cambelt changed at the same time won't add much labour as the cambelt, cam pulleys need to be removed to remove the camshafts.