funny noises

[mikey2]

Now the car is actually running properly again, theres a few other things i want to sort out.
Firstly, when i back off the acclerator i get a funny noise, kinda like a high pitch rattle, its in tune with the exhaust as it makes the noise at the same time as the exhaust is popping and farting, goes away when i dip the clutch, but i dont think its the clutch.

Secondly, and importantly, its lagging like a b*tch, running 1.1bar on an esl board, but not hitting 1.1 until nearly 5.5k. The boost rises to 0.6 quick enough, but then it really holds back until 5k ish and it rises properly from there.
I will try and do a video of it today so you can see what its doing.

Its started to occasionally missfire now too, mostly when just changing gear at low revs, but occasionally does it when i am accelerating hard.

I know the drivers side exhaust header is leaking slightly, i can hear a tap, i have tried tightening it, but am scared of overdoing it and snapping the stud, it wouldnt be the first time!!!!

Any ideas would be great! the shopping list so far is a pair of rocker gaskets, exhaust gaskets for header to block, header to up pipe and header to header (standard 2 peice header)


Thanks Mike

[RobEvo5]

Sound like the nightmare continues.

Posted on other, but sounds like coil packs could be the cause of several issues. Missfire and holding back defo sounds like coil packs, and could even be affecting what you think is lag (that might be electrical).

WRX should be on full boost by about 4K, and with and ESL map this should be reduced if mapped properly. So something is definately wrong.

Leaking header will cause lag as gasses are escaping before the turbine which will affect spool, but check the uppipe from the headers. These have a flex joint and they rust and blow badly. They are covered by a heatshield so not visably easy to see. By Every early classic I have had had a blow in the uppipe.

Dont over tighten the bolt in the headers it will strip the thread in the block. Don't get cheap gaskets they are crap. Get OEM 3 ply metal subaru ones and torque up the bolts.

Problem from memory is you have to undo the upipe which is bolted to the turbo in order to get enough drop on the headers to get past the studs and slide out the old gaskets.

[mikey2]

These are the manifold gaskets i was looking at, either
http://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWAX:IT

Or

http://cgi.ebay.co.uk/Subaru-Impreza...item2553dff4db

I know which one i would prefer, but i also know which ones are already one there, and they are blowing. However, some numpty has crossed one of the header bolts, so i wouldnt be surprised if thats the reason its blowing and has damaged the gasket in the process!!

I intend to change the header gasket, the header to up pipe and up pipe to turbo, hopefully i wont need to change the header to header gasket, i think the studs will come out without too much trouble. meaning i can slide the gasket out without dropping the manifold.

I did wonder if the threads would strip, so i was careful when i tightened it up the other day, but as mentioned the bolt had been cross threaded so wasnt even touching the header, i used a washer and spring washer to take up the gap.
I will check the flexi, and i might even change the header and up pipe to something shiney, depends how many pennies i can find!

[mikey2]

This is the video, hopefully it will work, its not the greatest as it was dark, will try and get one in the daytime tomorro.

[RobEvo5]

Dont bother with the £10 ones IMO, they are just gasket material cut to shape. The TSL ones are the same as OEM subaru use and are several thin layers of metal that can take up any tollerances in the flatness of materials. And are metal so the material won't be the failing factor.

When you use the proper ones, there is a very satisying crunching noise as they do up. If you have a cross thread in one of the header bolts you are going to be fighting with it so the better gasket might pay dividends.

I do fear though it will never seal if the bolt/thread in the block has been torn. Dare I say it, you might have to think about tapping a new/larger thread.

Also be careful if you think about using longer/different bolts to overcome this problem. If the bolt is too long and you over tighten it, it will tear through the block and into the sump. There isn't much material (aluminium) between where the end of the bolt stops and the inner sump chamber.

When you remove the header to block studs, I had a few where the nut came undone but the it left stud in the block, and the stud would not come out. Therefore I had to drop the headers enough, to get past the stud to then slide out the gasket. But hopefully your studs will come out complete.

I originally used the cheap gaskets on one of my scoobs and they never sealed right, so took them out and replaced with the TSL / OEM subaru ones.

[mikey2]

I will be careful with the header bolts, i suspected that the heads were aluminium so i was careful. I will get the better ones. Thanks