Right, now before I start I appreciate that rattles can be any number of things and without hearing in person it a diagnosis is pure speculation.

Background –

1. Car has engine swap, jumps from ej20 to ej25.
2. Injectors are changed and uprated
3. Car has running in map put on by Bob Rawle to allow me to use it and check that nothing untoward happens and covers 1500 or so miles like this.
4. 2nd map goes on and car goes like stink, asked Bob to run car at about 80% of potential as I want some longevity from it.
Runs awesome for 200-300 miles then starts to rattle, I take it to large reputable garage nr me (Sumo Power) and they suspect it is the turbo which is confirmed after they send it away for inspection.
So I decide against going for the £1800 new VF43 straight from Subaru themselves and get one from the members for sale section here which has been checked by reputable source and is A-ok.
2nd Turbo has now been fitted to the car and garage tells me the noise is worse than before and is definitely coming from the turbo, they are checking this with a stethoscope.

After this long winded explanation my question is;

Is there some obscure foible within the Impreza’s engine that’ll cause a rattle to sound like its coming from the turbo?

Thoughts / ideas / help greatly appreciated...

 

Up-pipe and downpipe heat shields often rattle if you've got an old classic, but I don't know what car you've got. I'd imagine the garage would have eliminated these though.

 

I have just had a heatshield welded up allbeit on a newage, when I first heard the noise on hard acceleration I thought under-bonnet - turbo?

Take it to a specialist, my local heard it even when I couldn't and straight away 99%ed it as heatshield - took off the undertray, had a tap here and there, welded a couple of spots. I drive away - silence..

 

Its a Newage car, rattle is easily heard on tick over not so much when being driven but then wind noise, engine noise probably jst drowns it out.

 

Get them to take off the undertray and check all the heat shields there. Might just cure it.

After the guy checked mine by knocking them to see which were loose we took it off the lift, started it up and I could very easily hear it on tickover. Sounded nasty.

 

When you turn off the ignition does the rattle become very audible as the engine comes to a stop, then disappears as the engine stops movement? when you are driving at low speed 15-20 mph and in either 2-3 with engine slightly labouring, can you hear the rattle?

 

i have a 2001 bugeye what has had similar issues! i was told my turbo was the problem changed it noise still there, so was then advised it sounds like my downpipe, so changed that for a full stainless sports cat system (downpipe back) noise still there, after reading more threads on here im sure it has to be the up pipe, but guys at work seem to think it could be big ends going!! mine rattles/clunks at idle or if i gently blip throttle to 1500 rpm as revs go up noise stops then when the revs drop rattle starts!! any thoughts

 

Morning,

No it stays constant (like a mild, then occationally deep, rattle/knock) whether on tick over or when being rev'd gently by hand, it stops when the engine stops and I can't hear it from the cabin when driving in any gear.

 

Is there anyway you could post up a short vid of the rattle. It might give the lads a bit more to go on.

 

Alas no, car is 40 odd miles from me in Rye.

At this rate I'll be picking it up and nursing it home at the end of the week so could get one up for the wkend