New year - More air leaks?

[Dr H]

As some of you will know (as I've gone on and on about it ) I have an air leak somewhere that I am currently living with and waiting for the Samcos to give me an excuse to pull everything to bits.

Recently something that seems a bit like a leak has reared it head and I was wondering if anyone knew what it mght be.

After a high speed run (145 up hill on private roads of course ) my car has strated to make a rasping noise when cold. At low revs I can hear it but it seems to go when the engine is hot. Also when coming to a stop the revs dip to about 450-500 and then bounce back up before settling at tickover. This too seems to go when fully warmed up.

Any ideas could the high speed run have done anything?

Cheers

[martinjs]

Have you done the mark H intercooler mod yet leigh?

[Dr H]

@ Martin

Yeah did that mod a while back.

It sounds like something's blowing slightly. I'll check the exhaust, is there anything under the bonnet that is prone to blowing. Exhaust gasket or something similar?

[newsh]

Exhaust manifold leaks do that, louder when cold and quieter when hot.
I have a leak on my ur at the mo between the turbo hotside output and the downpipe flange. Sounds just as you describe. On the S2 this might confuse the Lamda at low rpm. A cracked manifold would also do it, urs are prone to this.

[APNess]

Happy new year Leigh - take it you didn't go skiing

You've checked the dump valve yeah?

I'm having a garage built on Tuesday so if you want when the samcos arrive we can have a 'not getting piss wet through fitting session' inside and I'll lend you my valuable expertise...

'I'm sure this pipe went on there - no, I don't know why it's not fitting now, but I have these spare screws, clips, pipes, hoses and stuff from my car u can use. Then we'll figure why my car won't go either.'

I expect that will boost your confidence.

One other thing... at 145mph I'll bet it was hard making sure the pipe was stoked up....

Again, happy new year - he's hoping new year brings us both improved cars :S

PJ

[Dr H]

Originally posted by newsh
Exhaust manifold leaks do that, louder when cold and quieter when hot.
I have a leak on my ur at the mo between the turbo hotside output and the downpipe flange. Sounds just as you describe. On the S2 this might confuse the Lamda at low rpm. A cracked manifold would also do it, urs are prone to this.

Oh cr@p don't say that! So how would I go about deciding if it was this then. I'll check all the bolts on the turbo and wastegate to the exhaust first though. It wasn't as bad today but it was there and the idle was a little up and down but only occasionally.

[Dr H]

@APness

Paul - Happy new year to you too mate. Not due to go snowboarding until Feb - still on at the moment.

I think I'll check everything when the Samcos get here unless it gets worse. Mind you the leak is so bad that now by 3000 rpm at WOT in 6th I'm only at about 0.9 bar .

Just found out that a friend of mine (female) has a garage with a small pit that she never uses and says that I can have a key if I like - to the garage that is and not her house

But a joint Samco fitting session could be a great idea as we can learn from each others mistakes. Just need to see if I have some horrible problem with the rasping noise first

Oh yeah...........145 mph with a pipe is bad, I've got Dutch Shag all over my slippers :eek2:

[newsh]

Sorry to scare you
If it's a manifold or turbo leak you should hear it by opening the bonnet when it's cold. Try to listen for the rasping noise and where it's coming from, use a short piece of garden hose as a stethoscope and have a poke around the exhaust side of the engine to locate any strange noises.
I actually found the source of my leak by removing the right hand headlight and putting my hand in a feeling around for the draft.

On the other hand it could be that the airleak is getting worse and the noise is getting louder, or a loose heatshield rattling.

[Dr H]

Cheers John

I'll have a look later on or maybe in the morning.

[Dr H]

Just been investigating and it sounds like the exhaust somewhere at the front. Maybe before the cats, I'll have to try and get under it and have a look.

Would an exhaust leak cause problems with both tickover and fuelling? Seems to be a bit rich when cold (is this normal until the lambda heats up?)

Also seems to smoke a bit when very cold - but I guess that could be steam and it's so cold that it takes a while for it to evaporate can't tell as it's a bit dark out there. Did 110 miles today and didn't see any smoke come to think of it.

Whilst I'm on the subject my car seems to produce a hell of a lot of steam before it heats up properly when it is very cold out. Is this normal seems to produce miles more than other cars I see.