ncmn

my story is that i've had my 84 gs in storage since october. i've occasionally gone and started it up and driven it around the lot, but obviously no serious driving (not out of 2nd gear).

usually i find there is backfire, sometimes white puffs of smoke (very light, very short duration -looks like condensation clouds). initially all is as usual, but i happen to look under the car checking for any accumulation of fluid from leakage. i see none. instead i see glowing red hot pipes -like you see when a poker comes out of the fire. immediately turn off the engine. rush to consult the haynes. looks like it's the area of the exhaust pipe around the thermal reactor.

unless i didn't open my eyes before, i don't recall the car burning this hot underneath. i know the rx7 pumps out a lot of heat, but is this normal? particularly when it hasn't been started on a regular basis? could it be a difference in the temperature of the pipe vs. exhaust? should i relax or should i begin to save up funds for a major repair?

thanks in advance.
norman ng

JIMMY54

iTrader: (2)

Your Car may be really running lean which is very bad and your cat my be clogged also.... It could be one or both of those things IMO

phatcat

one of my friends had this happen to him, and it was because of a clogged cat. he punched it through and that stopped. his car has isn't an rx-7, it's a 200sx, but the exact same thing happened.

peejay

Many people report glowing headers at IDLE. (It's supposed to be really cool looking, you can apparently see the exhaust pulses moving through the pipes) At night, if it's really dark, I can detect a very dull red glow at idle from the headers.

I know you don't have headers, but if you don't have heat shields you will see glowing! Especially if you have converters as they retain heat, and burning off all of those excess HC's generates a ton more. (BTW if you have converters, you don't have a thermal reactor, just a normal exhaust manifold. Mazda stopped selling thermal-reactor equipped rotaries after the '80 model year)

FWIW, my exhaust system turned blue from the engine to the middle of the midpipe after a track day, so it must have been glowing from the engine to the middle of the midpipe

ncmn

sounds like either lean or clogged or normal behaviour (??) are my choices.

i'm going to pull the spark plugs and crawl under the car very soon to see if i can begin to understand the problem.

the car seemed to drive well for the brief period before being put away. i'm sure this NEVER happened before. a mechanic friend of mine suggested that maybe the o2 sensor gave out. is this possible in this situation?

i had the oil/fuel filter/plugs and associated wires changed less than 100 km ago. dumped in some MMO as endorsed by members on this site.

i'm frightened and frustrated and nervous. but i believe this car-n-me will have a positive life experience.

thanks to all who reply.
norman ng

Felix Wankel

12A's don't have an O2 sensor. Get a hammer and tap on the converters to see if they make noise. If they do, ditch them. For that matter, ditch them anyway (screw the environment).

I have a nice exhaust system for sale that'll fix your problems

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Pele

iTrader: (28)

You shameless bastard. :p



If your catalytic converters are indeed bad and you have emissions requirements in your area, Gut the first two small cats by jambing a screw driver down em and grinding up all the crap. First one has probably already fallen apart anyhow and gotten clogged up in the second. Remove the third, big one and chuck it. Replace with a new one from Bonez, Random Tech, or another supplier.

New cats do the job of all three old ones and flow better.

speckamp

I can vouch for the Bonez cat system. It bolts in perfectly and while the noise level is up a touch from stock, it's extremely mellow. The car responds better, and when I took the OEM cats off they were SHOT, and that was with only 83000 miles on them. If you still have cats and you're experiencing glowing pipes, then I'm betting they've deteriorated and clogged.

If you don't need to keep the car emissions legal. Straight pipe

--matt