heat spike

**undecided** · 01-17-2010

okay so i just did an ac delete on my car because the compressor broke.
when i took it for a drive i did a launch from a dig and at about 90mph i noticed the engine temp was at 210 which is unusually high for my car.
when i let off the temp dropped back down to about 180 in about 10 secs.
when i pulled into the driveway i opened the hood and the headers where cherry red and glowing.
my brother and friend took it for a drive immediatly after and it did not have the same problem.
normally i would think is was a fluke but since the headers where glowing it worries me. any info?

p.s. it was only one of the front three pipes. the one on the driver side

any and all help would be appreciated
thanks

**matt5112** · 01-17-2010

the glowing sounds like it'd be your cat.

After doing that, I'd pull the plug and check to see how its doing.

**kfish** · 01-17-2010

it wouldnt be the cat if just one exhaust port was glowing. sounds like somethings goin on with the cylinder. but i agree pull the plug and check stuff out.

**bronzemist02** · 01-17-2010

^ I'd try that first too. Couldn't the thermostat do that too if it wasn't working at all because the fans wouldn't come on when they were supposed to? Fuse for the fans could do the same thing too if it was blown.

**kfish** · 01-17-2010

if the thermostat was stuck shut, he would over heat big time. if it was stuck open it wouldn't ever get warm.

**matt5112** · 01-17-2010

its a $10-20 part that will probably have to be replaced anyways.

If you want to test it, pull it and put it in a pot and boil the water and use a thermometer to confirm the open temp.

Its slightly less time consuming to just replace it.

When you're moving above say 50 KM/h, the cooling fans don't really all that much.

Also, bleed the cooling system.

Air pockets could have caused that.

**bronzemist02** · 01-17-2010

Originally Posted by kfish

if the thermostat was stuck shut, he would over heat big time. if it was stuck open it wouldn't ever get warm.

Ok. Thanks. Just thought i'd ask because I wasn't quite sure about it and thought it may relate to this somehow. If the fans weren't coming on at all too the car would overheat fairly quickly when under that much stress too. He said he accelerated from a dig to 90mph (i'm assuming hard acceleration).

**matt5112** · 01-17-2010

the speed would have been enough to pull the temp down due to airflow through the rad,

but that would only happen if hte t-stat was open, so i think its safe to assume its okay.

**bronzemist02** · 01-17-2010

Ok. Didn't think of that. Thanks for helping me clarify some things.

**undecided** · 01-17-2010

thanks aton guys ill check those things out and inform ya if it works or not

**UR LOSN** · 01-18-2010

any updates? are any hoses close to the headers?

**badbrad** · 01-18-2010

when the a/c works your fan runs. u deleted the a/c so the fan may not be running. computer tells other fan to kick on around what 200*??? u need a tuner or tune to cut the fans on according to the t-stat..i believe i may be somewhat right.....i'd still check the cat/exhaust stuff to for sh!ts and giggles. almost blew up the mustang when the cat clogged... post resluts

**undecided** · 01-19-2010

the plugs are all clean but i think im gonna replace them soon anyways

im back in my dorm room and the car is at home so i wont be able to do anything on it till this weekend

**blowfishRus6** · 01-19-2010

my fans dont turn on till 225* its winter time, dont really need the fans, and i dont consider 210 to be running hot at all. blocks like to be ran hot. there more efficent then.

as far as your issuie, i dont really have a clue

**badbrad** · 01-19-2010

i would think the cat or an air pocket, but not plugs, oh well...

**blowfishRus6** · 01-19-2010

air pockets will cause heat spikes like that.

i just let the car get up to operating temps, crack the radiator cap for a few mins, let it bleed the air out, then cap it back up.

you dont even need fans if you have a properly working coolent system. well maybe on a 100* day sittin in traffic, but even then it should not OVER heat, just run hot.

**agrazela** · 01-19-2010

Glowing red exhaust manifold usually means either plugged cat (as said), running too-retarded timing or poor valve seating (allows unburnt fuel to combust in exhaust manifold), or running too lean (just gets too hot).

As was said, since it's only one pipe, it's likely not a cat (or for that matter, timing) issue. I guess it could be a bad injector on that cylinder causing leanness, but then you said the problem went away?

(Injectors can have intermittent issues, of course)

And since it did "go away", it's probably not a valve issue.

I'm with those who think it was an air pocket/bubble in the coolant jacket in the head, and it's probably OK (burped itself) now.

But do burp it, keep an eye on it, and keep an eye on that cylinder's injector. If you see redness on that cyl again, switch injectors around and see if the problem follows.