manifolds suck - Toyota Nation Forum : Toyota Car and Truck Forums

flynnagain · 10-21-2003, 08:42 AM

i have a 1992 corolla, i have my second exhaust manifold in it and its the second time it had cracked in half. i was wondering why it is doing this. i also considered buying a header if there are any even made for this model. are there? if so where can i find one?
its a 1992 corolla dx DOHC 1.6L if that helps

***Chris Corolla S*** · 10-21-2003, 10:43 AM

Quote:

Originally posted by flynnagain
its the second time it had cracked in half. i was wondering why it is doing this. i also considered buying a header if there are any even made for this model.

Sounds like excessive heat. Are you missing the manifold heat shield?

Your engine is the 4A-FE, I think pacesetter might make a header for it.

4Aaron GE · 10-21-2003, 12:44 PM

HP Racing (or something like that) also makes a header for the 4A-F as well.

flynnagain · 10-21-2003, 01:45 PM

it is a year old manifold, it has a heat shield. i think its just because of too much compression at high rpm's. i am on the interstate about every other day for a half an hour at a time. i dunno.

***Chris Corolla S*** · 10-21-2003, 03:00 PM

No, there is something wrong with your car, running on the highway all day long should be fine. Maybe a sensor needs to be replaced? I had a problem on my '84 Camry where the exhaust manifold was always getting warped. I went through gaskets all the time. Something to do with excessive heat there as well, I never figured it out...

Deep · 10-21-2003, 03:26 PM

Yeah, how well is your car running? High exhaust gas temps are an indication that your car is running lean. Did you advance your timing by any chance? If the temp of the mani gets too high and is exposed to water, it will likely crack or warp. Same deal with brake rotors.

1owner · 10-22-2003, 09:50 PM

By any chance do you leave late for work in the morning? Jumping in and driving away with a cold engine, then putting the boots to it on an extended high-speed highway run can also do nasty things to a manifold (and other things!) Just a thought.
A lean mixture or a misfiring plug can also overheat things.

neil85AE86 · 10-27-2003, 12:29 PM

I'll put my money on a lean condition. Your injectors could be fouled and dirty, your fuel pump could be on it's last legs, you could have faulty sensors. Any of the above could cause your ECU to go into 'safe' mode, which would retard the timing, as well as try to enrich the fuel mixture. Timing retard will also cause excess heat.

I'd recommend you get your car in to a Toyota dealer ASAP.

Neil