Group Captain Smudger

I have a 97P turbo, 50K, minor mods (bb, ITG), run on NUL and I've recently noticed a weird "tappetty" noise coming from the vicinity of the engine-bay (reminds me a bit of my air-cooled Jap bikes). Sometimes the noise continues for several seconds after the ignition is switched off as if something is still "spinning". However it's only occasionally that the noise is heard on start-up; it's usually noticed at the end of shortish runs (5mile/15 mins). Have not noticed any deterioration in performance. Can't be symptoms of piston slap can it? And should I be worried?

clubby

Groupcaptainsmudger

I had two Imprezas that both got piston slap, and what you describe doesnt sound like piston slsp to me. They usually get it everytime you cold start the engine, and it goes away as the engine warms up. I gather if it's not dealt with it can remain when the engine is warm, but it doesnt sound like your problem.

scooby_si

I may get corrected but my understaning of piston slap was it was more prevelant when starting from cold not after turning off mine is also a MY97 in a similar vain & it does make sum noise after u turn it off which i've never worried about & haven't had any reason to worry but there maybe more experts out there who can shed sum light on wot it is but i just put it down to stuff cooling down etc
Si

scooby_si

but i woodnt wana run on NL & i'd be tempted to get sumin to check for "plinking" such as a knock link
Si

Dan B

(cough} TURBO {cough}

DreXeL

If it goes 'ticky-ticky-ticky' it's probably the boost solenoid, that's normal AFAIK, it should be coming from the right hand side of the engine from the drivers point of veiw.

scooby_si

lol @ the turbo comment even if he duz use carp fuel i'm sure he dont red line it before turning off
Si

Dan B

Your car only uses the turbo at the red line does it....? What else can be spinning in the engine after the ignition is turned off?

I wasn't taking the pi55 besides, not letting the car idle before turing off isn't the only way a turbo could get knackered.

scooby_si

my head usually spins after i've been getting the best out me turbo at the red line Only kidding m8y but i think the noise has already been highlighted as nowt to worry about, which i no from past experiance can be incorrect since we aint there listening to it but it doesn't sould like owt to worry about from the description
Si

Imprezive

i agree wi Drexel, it sounds awfly like the boost solonoid,
mine clics for approx 2 secs, occasionaly when ya turn of. it dont
do this all the time though, just after its been warmed up then, turnd of and re-started, have been told the root cause is idle control valve sending wrong signal,so the ecu continues to run the solonoid when you switch of.

Dont know if this helps, but my little contributiion neway,
B.

Group Captain Smudger

Thanks for your comments - they all help. "Spinning" was probably the wrong word to use but the noise is unsettling, "As in what the bloody hell is that"? And it's not after thrashing it either as the last road to my abode is up a mega steep hill so no chance to go above 30 for about 800yds.