cherry red exhaust manifold
 

I just changed oil in supercharger (by removing it). I have a 2004 Mini S, I put it back together & I have an irrattic idel ,& the exhaust manifold gets red hot, anyone have any clues to what I did wrong?

First off, welcome to the forum. Sorry that your first post had to be an issue like this.

No engine codes? Will the car drive ok despite the rough idle? I'd recheck the s/c vacuum line and the intercooler boots. Did you get new gaskets for the s/c to manifold and s/c to intercooler horn contact points? Perhaps this is it.

I do not know if these things would cause the red hot exhaust, but the could certainly cause the rough idle. Hopefully someone who works on these cars for a living will be able to chime in with some ideas. I also moved the thread for more exposure.

Glowing exhaust manifold is a sign of excessive EGT's, generally meaning you're running very rich...

Not sure if this might help you, but when I went about replacing my clutch several years ago, after we put everything back together, I had a similar situation. After some diagnosis, we discovered the boots for the IC were not sealing properly and caused a leak.

GotMINI

Wouldn't cherry red exhaust manifold (high EGTs) mean your running too lean?

Yes higher EGT's are more comon on cars running lean. Unless it is injecting so much fuel that it is still burning in the exahust system.

As for the OP's problem, make sure to re check all your work. Outside of that I am clueless of the cause.:confused: Sorry.

Not saying your wrong but, I've never heard of being too rich causing high EGT's.

Here's the scenario. A rich mixture and a small exhaust manifold leak. All the extra fuel gets burned in the manifold when oxygen is drawn in through the leak.

For the EGT to be so high that the manifold glows red, that would take a really lean condition. On my kart the piston melted before the manifold started to glow.

Rich

Sorry all, just got done with a diesel course and my mind slipped. Complete correct. Gasoline engine w/ glowing headers = lean. Diesel engine with glowing headers = rich.

Apologies.

I use to race a 1275 Midget in F/P. Tube headers would glow red and EGTs were fine. However, with the oem Mini cast header glowing red, I agree the EGTs would have to be off the scale.

Are you still having this issue ?

I had the same problem when rebuilding my engine.

While reading this thread, I saw that someone mentioned the supercharger and had an idea that the bypass valve was not working.

Correct! Connected bypass vacuum valve to supercharger and I got nice idle and brown exhaust again :thumbsup: