Orange Glowing Exhaust Manifolds

[corning_d3]

Icepick, your timing sounds pretty well dead on. Anything as old as '87 that still has 15-16" of vacuum is in good shape. Are you 100% positive there is no exhaust restriction? Maybe a birds nest?

[Icepick]

Originally Posted by corning_d3

Icepick, your timing sounds pretty well dead on. Anything as old as '87 that still has 15-16" of vacuum is in good shape. Are you 100% positive there is no exhaust restriction? Maybe a birds nest?

I am now 100% positive! I just got finished driving my neighbors crazy.

I decided to remove the exhaust pipe at the rear manifold (directly below the O2 Sensor). Basically open exhaust. Loud as hell, but after suffering through 10 minutes of 2000 + rpms, the exhaust manifolds started to glow.

I'm starting to think that this might be normal maybe?!?!?? Maybe never noticed this before. Afterall, the exhaust manifolds are kind of thin steel, not cast.

Sure would be nice if someone else with the same year car and 3.0 L engine would rev their engine to 2000 rpms for about 10 minutes to see what happens to their manifolds.

Calling all cars, calling all cars..............Anyone with a '87 - 3.0L engine!! Please rev your engines to about 2000~2500 RPMs for about 5~10 minutes and tell me what happens to your exhaust manifolds.

I am going nuts.........................

[grfnkl]

I can reassure you that they don't glow being reved at 2,000 rpm, ours never glowed like that. The last time we drove ours, i had to look under the hood due to a trans leak, at night, and everything was normal with no glow.

I have an idea, it's a bit of a longshot, but i guess it could be possible... The exhaust manifold itself, maybe breaking down the metal maybe getting thinner, with all the exhaust heat coming through, it's going to heat up much faster and hotter.... Would anyone else care to agree or disagree with me on this?

[Icepick]

Originally Posted by grfnkl

I can reassure you that they don't glow being reved at 2,000 rpm, ours never glowed like that. The last time we drove ours, i had to look under the hood due to a trans leak, at night, and everything was normal with no glow.

I have an idea, it's a bit of a longshot, but i guess it could be possible... The exhaust manifold itself, maybe breaking down the metal maybe getting thinner, with all the exhaust heat coming through, it's going to heat up much faster and hotter.... Would anyone else care to agree or disagree with me on this?

I drove the car on a highway that gradually climbs. I have kept the engine at ~2500 RPMs and driven about a mile at night. I pulled off to the side and quickly opened the hood to find a very low glow. I also drove up a steep hill full throttle for about three blocks, and quickly pulled over and opened the hood to find a slite glowing manifold. In both instances, it cooled really quick (about 20 seconds or less).

If I wasn't really looking for the glow, I would probably miss it entirely, especially if I take a bit longer to open the hood and look in, or if I wasn't looking for it specifically.

The only time I can get the manifolds glowing hot red/orange is while standing in front of the car reving engine. I still hope someone with a '87 - 3.0L will stand in front of their car and rev it to ~2500 RPMs for about ~10 minutes and tell me what happens.

I kind of like your theory on the metal getting thinner, and it heating up faster and hotter, but I really don't know what to think about it........You would think that if it is thinner, it would crack or break, or develope an exhaust leak?!?!

[gravis2000]

What kind of fuel are you running? I would get a emissions test done on it to make sure you are not running to lean. Just a thought.

[corning_d3]

His exhaust readings indicated a rich mixture. I wonder if the exhaust valves aren't opening too early. Does that engine have a timing belt or chain?

[gravis2000]

There is also the possibilty that the mainfolds are cracked and the exhaust is going out of these cracks and super heating the manifolds.