90 4A-FE Exhaust Donut Issue

[xxgmsmgxx89]

Hi, my 90 DX exhaust gasket keeps blowing out...i had it fixed about 3 times in the past 3 months, the last repair has been holding up...

it's still loud, but not like it used to be (lol). I think it's because the OEM manifold flange that connects to the down pipe is warped, not allowig the bolts to fully tighten on the studs, allowing a gap between the mani and the pipe. you can feel the exhaust rushing out at this seam under the hood. it's not bad, is it? as far as codes/O2 sensor/NYS Inspection, correct? I kinda just want to take it off completely so I can run open mani...he he he

[eage8]

Originally Posted by xxgmsmgxx89

Hi, my 90 DX exhaust gasket keeps blowing out...i had it fixed about 3 times in the past 3 months, the last repair has been holding up...

it's still loud, but not like it used to be (lol). I think it's because the OEM manifold flange that connects to the down pipe is warped, not allowig the bolts to fully tighten on the studs, allowing a gap between the mani and the pipe. you can feel the exhaust rushing out at this seam under the hood. it's not bad, is it? as far as codes/O2 sensor/NYS Inspection, correct? I kinda just want to take it off completely so I can run open mani...he he he

if you run open manifold your car will sound like a 20 year old dump truck... ask me how I know.

why don't you just have the exhaust shop put a new flange on the front pipe?

[xxgmsmgxx89]

he he he i know ALL about the dump truck sound...apparantly uv had it happen? i love the exhaust burble when you let off the throttle lol that really makes me happy

id rather do things the cheapest way possible, as this IS a 90 Corolla. however, the most recent repair has held up, I think it might be the huge amounts of thread loc they used. he told me they heated up the flange with a torch and tightened it up, so the flange kinda bends back to original form. still is a little gapped though.

i think ill leave it...

[boopie]

Try puting some thermal wrap around it. JB weld also.

[xxgmsmgxx89]

hmm...

the guy I bought the car from in February gave me the info for the dealership that did the most recent work on the car (besides the time I fixed the donut and the rad. hoses at the same time, i've done no work on this car as far as fixing things is concerned). I went to Penn Toyota in Greenvale, NY and requested a copy of the receipt for the work done at "27,500 miles". They replaced the exhaust gasket as well as the timing chain, water pump, and some other things. I think I'll go back and complain, and say I've had this thing fixed numerous times since they worked on it. maybe they'll fix it free?

[teamyoda]

you should just take it to a grinding shop. they would resurface it so the flatness would be dead nuts. +/- .000 you wouldn't have any warpage problems or leaks. are all your mani bolts in? because sometimes the heat makes them corrode and fall off and or strip

[Ghostyman]

Originally Posted by boopie

Try puting some thermal wrap around it. JB weld also.

Thermal wrap will make it retain more heat... and JB Weld is only good to 500 degf. Matter of fact, JB Co specifically says not to use JB Weld on exhausts.


If the most recent repair holds, I'd leave it as is. Otherwise, the cheapest way to resurface them is with a belt sander. Depending on how warped it is, a good coat of ultra copper RTV might seal it up for you.

IMO, the car sounds best with the manifold completely removed and the exhaust spitting directly out the cylinder into the radiator.