Head back on ... lumpy idle etc

[JH32]

After blowing a head gasket, we've replaced everything and put it all back together.

Started the car up ... it runs ok but its a bit lumpy and there's no white smoke anymore! woohoO! Could the lumpy idle be contributed to not having set the crank angle sensor position correctly? ie. the timing is out?

Also there's a whirring noise coming from the cambelt ... does that mean it's too tight?

Cheers!

[muffas 180]

Yep chances are the belt is too tight. If its a new belt chances are it will make noise any way. Give it a while and see if the noise gradualy goes away.

Lumpy idle could be possibly a tooth out, or ignition timing. It could be many other things too.

Michael...

[Bl4cK32]

What? You tell him the belt is off, then say "Give it a while".....:confused:

[JH32]

How do you know if the belt is a tooth out?

[JH32]

Ok I've loosened off the cam belt and then retightened the tensioner, and the whirring noise has gone away Cheers for that!

Now to the other problem which I feel is quite alarming. It still sounds like it's "missing", even when I rev it, the engine sounds like its only running on 5 cylinders even though I'm sure all 6 are firing. The alarming part is that after I turned the car off and removed the radiator cap, the coolant spurted out. Isnt that the sign of a blown head gasket? :D

[DCIEVE]

was the coolant bled of air properly before this happened, if not itll spray everywhere if the coolant is even remotely warm, as i found out last time i tried to bleed the coolant from there, whoops. just do it from the little attatchment on the inlet manifold and check it again

cant help with your other problems tho

do you know what caused the head gasket to fail in the first place?

[gtrken]

Ok I've loosened off the cam belt and then retightened the tensioner, and the whirring noise has gone away Cheers for that!

Now to the other problem which I feel is quite alarming. It still sounds like it's "missing", even when I rev it, the engine sounds like its only running on 5 cylinders even though I'm sure all 6 are firing. The alarming part is that after I turned the car off and removed the radiator cap, the coolant spurted out. Isnt that the sign of a blown head gasket? :D

James, try taking the cap off while the engine is running . Be careful as it will be hot and what you are looking for is constant bubbling in the water as it passes the filler neck. Most cars will blow water out immediately after you stop the engine.

Are you sure it's missing above idle ? Missing at idle means you probably have an airleak.

Try spraying some crc or contact cleaner , once again be careful as it is flammmable, around the intake manifold and injectors. If the revs rise then that usually means it's drawing in air and running lean at that cylinder.

Cheers

Ken

[Cubes]

Bleed both the inlet plenum and the little bung that is teed from the heater hoses against the firewall.

With regards to lumpy idle due to a tooth being out.

Mine was a tooth out on the crank. It didn't appear to idle lumpy however it was more gutless down low. There was a noticible gain in the low rpm torque when it was all set right.

[Steve]

Man, life isnt fair:( I have HKS step 1 cams and (apart from hunting when its in the mood) it sounds like normal when it idles.

All that money spent and no lumpy idle, you just change a gasket and you get lumpy idle - there is no justice:p

[EnricoPalazzo]

my idle is lumpy steve, jealous??? Hehe why does it sound like it does? BOOSTD and i wer thinkin about it, he reckons head portin?

[JimX]

Like Joel I had my exhaust cam wheel one tooth off and idle was completely normal, and there was no missing even in upper revs. The car just died in the arse power-wise above 4000rpm (so it must have been the opposite direction to Joel). Being one tooth off isn't a guaranteed way to make the engine miss, although I'm sure it's possible. Look for other things too.

[JH32]

Cheers guys for the replies

Ken the revs dont rise and fall ... its just sounds very .... WRX like. But the car doesn't seem to move around like if a spark plug wasn't working :confused:

[compnerd]

check for air leaks @ all the inlet fittings ,listen for vaccum sounds from a hose incorrectly fitted,get someone with a co2 tester to check carbon dioxide levels in cooling system,this will tell you for sure if the new head gasket is sealing correctly,if you unplug 1 injector @ a time you can usualy iscolate which cylinder it is ,if it is only 1 cylinder!did you get the head milled when you replaced the gasket!

[adam 32]

1 tooth is a big step on the std RB20 cam gears

if its 1 tooth out then youd notice alot more than a lumpy idle

id be thinking along the same lines as ken - an air leak somewhere. theres alot of hoses that have to come off in order for the head to come off, just make sure youve got them all connected properly and there arent any small cracks in them. (alot of the hoses on the firewall side of the head needed replacing on mine as they were worn out from age and heat exposure)