exhaust glowing red - BMW Forum

wes325i · 02-11-2007, 10:53 AM

i bought a 325ise e30 not knowing if it runs or not so we tried it and it ran but the exhaust was glowing red at high rpm so we stripped the head down replaced all the gaskets filters plugs and pumps banged it all back togwether and its running sweet but the exhaust is still glowing red anyone got any suggestions

german-speed-demon · 02-11-2007, 11:26 AM

drop the muffler, sounds like it might be partially plugged?

nukeduster · 02-11-2007, 03:13 PM

If you have a pyrometer hit the exhaust before and after the cat.. if the exhaust is hotter AFTER the cat the cat is fine, if its cold then the cat is plugged..

the reverse is true for the muffler section

Starmavin · 02-15-2007, 07:16 PM

Quote:

Originally Posted by wes325i

i bought a 325ise e30 not knowing if it runs or not so we tried it and it ran but the exhaust was glowing red at high rpm so we stripped the head down replaced all the gaskets filters plugs and pumps banged it all back togwether and its running sweet but the exhaust is still glowing red anyone got any suggestions

Are you blowing out any black smoke during revs?

fastshivy · 02-15-2007, 09:22 PM

Hey starmavin...what will the black smoke tell you? Just curious..retarded timing can cause these issues too, but that is reaching. I like the cat idea, an infrared thermometer will tell a story.

www.e30Parts.com · 02-16-2007, 09:19 PM

Your plugged - probably the Cat. Sometimes that honeycomb breaks up and can cause restrictions. Unbolt the muffler and the cat and bang the hell' outta them on the concrete floor - see what goodies you might have in there? Dead mouse, cat, jimma hoffa?

Good luck.:lol:

Starmavin · 02-17-2007, 01:11 AM

Actually black smoke will tell if you are running too rich.

fastshivy · 02-17-2007, 09:48 AM

Yes, but I am not sure how that ties in to the exhaust glowing red. Seems like that would do the opposite?

used:

Starmavin · 02-17-2007, 04:54 PM

It will cause the cat to burn it off, and glow red. If its like that for too long it'll kill the cat.

fastshivy · 02-17-2007, 07:50 PM

Gotch ya.. I thought he was referring to the exhaust manifold, makes sense now.
Thanks

Starmavin · 02-18-2007, 11:43 AM

Your manifold is glowing? Do you have full power? Sounds as if your cam timing is off a tooth or so and is letting combustion exit too early. Was the head shaved more than .020?

wes325i · 02-22-2007, 03:21 PM

my head has been shaved alot but the car has no cat a garage put a 320 head gasket in and the engine locked and ever since my manifold has glowed red

german-speed-demon · 02-22-2007, 04:30 PM

sounds like the timing is off a bit.

Starmavin · 02-22-2007, 04:31 PM

If your head has been shaved a lot, your cam timing is off. I'm not sure if they sell a block shim for the m20 but that is most likely your problem. When you have the head cut too far, the cam timing will be off a few degrees. This will cause your problem.

fastshivy · 02-23-2007, 06:36 AM

I am just thinking out loud here. If the head was shaved alot theoretically you would retard the cam timing slightly...??? The tensioner would then compensate for the extra slack. It seems like you might move the torque curve around a bit, but is this really causing any problems? Could there be a water flow problem through the head? Are the head gaskets identical for the 320 and 325?
Can you move the ignition timing around a bit on this particular car, to see how it affects the "glow"?
One last thought...it could be a girl car and we simply do not understand it!