Hi Everyone, The headers on my '83 Mondial QV are running hotter than I believe they should. Does anyone know what the normal temperature for one of these headers is? At night, I can see the rear header glowing dull red through the holes/cracks in the heat shield. Can't see it during the day, so it's a very dull glow, but I don't think this is normal. I suspect the car is running lean. Birdman
I've seen the same thing on my GT4 when it is dark after a "spirited" drive. I've been concerened also, but I've also never had a car where the headers are wrapped to keep them warm, and this is my first mid-engine car (less air flow to keep them cool). The first time I saw this I immediately bought a new timing light with an advance knob to check full advance, but it checked out ok. I suspect the wrap makes this "normal." I sure hope so!
same here except more sever....glowing red at idle, it's so bad I'm afraid to drive it so it sits there...please help me get back in and drive. I'm out of ideas
Mine never did that. Even at standard tuning the K-jet is lean, so if it is off a bit that might do it - or more likely, summer blend or ethanol gas which runs much leaner. In the Digi/Microplex cars I really doubt the ignition is the problem as there is nothing to get out of adjustment -each side runs or it doesn't. Although I am very biased, I would get an A/F meter and tune the K-jet to around A/F of 13.2 or so, instead on the over 14 value that the factory CO numbers translate to. That way you will have more power and a safety margin. There are different cause and effects depending on just how hot the exhaust is getting and where. This is excerpted from a concurrent thread:
i would suspect a leaky injector causing excess fuel in the exhaust which is burning in the tubes, causing the glow. at idle and low speeds the fuel is in there to cook / and burn, where as at higher rpm, the rate of flow through there keeps things "normal" . there was a 308 here that did that for years on one bank, and it was found to be vacuum leaks at the throttle shafts ( carb car) . the car was tuned so rich to run at idle that the excess fuel was causing the pipes to glow red at low rpm and idle. driving it hard made them cooler and "normal" looking. the owner was fanatical with his laser temp sensor, i will see if he took any notes of the temps he saw under normal conditions. ps, none of our older cars are required to have cats anymore here, if that matters. most of the old exotic cars here are barely driven 3000 miles a year anyway.
