OK, here's the deal, I dropped a new motor in my Jeep about 2K miles ago... been running great, all of a sudded it starts over heating and has a funky exhaust noise, so I get it home, pop the hood and the ******* exhaust manifold is glowing bright red. No cats, older exhaust. What do you guys think? My first thought was plugged exhaust, is that even likely, could be a rich fuel mixture too, pushing fire into the manifold rather than gas.



I don't quite get it, this is one thing I haven't seen before and it pissing me off any help would be appreciated.



Thanks.

 

dunno but sounds lean to me..really lean and detonating... check ur plugs for signs of detonation...

 

Lean or rich? I was thinking rich, but why would it start now?



Thanks

 

I am wondering if it could be a stuck choke. I just don'e get it, I have never seen anything like it, bright red header, you wouldn't beleive it unless you saw it, when I opened the hood I actually thought a light was on.

 

Saw something just like that in my friends Toyota truck- it turned out to be no more than a bad thermostat- check the easy **** first I always say.

 

Yea I would check that except I took the thermostat out when I switched to electric fans and they are coming on just fine, but that does bring another thought about, could be a clogged heater core, although I know the coolant does cycle because I can cool the motor via shutdown, let fans run, then cycle cool water through.



Thanks!!!!

 

well bout the other stuff, i have no idea, cooling system can be a bitch. but if you are running rich, then you will be backfiring, and you can hear coming out the exhaust...if you run the engine lean, it will run REALLY hot, and might even detonate...but then again im aint no mechanic..=)

 

I'm thinking it might be a stuck choke, not give it enough air to acutally afterfire...???

 

Definately pull all the plugs and check them closely. Leave them where you can see which cylinder they came out of. If its to lean, all the plugs will be gray and burned up, if to rich, they will be all goupy.

If it was running to rich you would notice a back fire, especially when shutting it down. A gasket could have slipped and blocked some of the exhaust flow since you installed a new motor.

Good luck.

 

Yea I am going to pull the plugs as soon as I get the whole unpacking mess somewhat done with!