Smoke from glove box?

[rayconstruction]

Hey everyone, Im new to the forum here but I have a 96 Chevy 2500 with a 6.5 and on my way up some mountain passes this weekend I had a scary problem. After a few minutes of high rpms going up a 6% grade, smoke started coming out from behind the glove box. I stopped and so did the smoke. I looked behind the glove box and couldnt find anything burned or the source of the smoke. Sure enough on the next pass same thing but this time I kept going to see what would happen. As soon as I reached the summit and started down the other side the smoke stopped and all was well. Any ideas?

[rapidoxidationman]

Look closely at the firewall in the engine compartment; doesn't the exhaust run from (or to?) the turbo in that vicinity? If the wall is getting heat from there you could be cooking the insulation on the inside.

[Robyn]

I would agree.

On a hard pull the turbo down pipe gets VERY Hot and is in close proximity to the fllor and the firewall.

Take a look at the firewall in and out to see whats up.

The only thing behind the glove box is the computer, and if its smoking there will certainly be other issues :eek:


Robyn

[rayconstruction]

So, can Insulate the pipe to prevent this or just live with it?

[DmaxMaverick]

Blanket the firewall or shield the pipe, don't "wrap" it. It often helps (turbo performance) to insulate the plumbing before the turbine (crossover), but not recommended after the turbine, such as the downpipe.

As Robyn said, the only engine related component behind the glove box is the ECM. If it's smoking, you have bigger fish to fry, so to speak. The problem almost certainly has to be the radiant heat from the turbine/downpipe, being load related. The smoke could be the paint, tape, wires, plastic HVAC ducting, or anything attached/close to the cab-side of the firewall, burning off as the heat increases. The odor of the smoke should be an indication of what's burning. If you don't know now, I don't suggest repeating it to find out (where there's smoke, there's fire). Get in there and look.

[greatwhite]

Your downpipe shouldn't be getting that hot.

Do you have an egt gauge installed?

If you pull in mountainous terrain, you need one installed.

Most limit egt's to around 1100 F, although a few short bursts to 1200 f won't really hurt anything.

How was your engine coolant temperatures?

These two things can indicate a lot about your truck and how it is working on a hard pull.

If you're smoking the insulation on the firewall, I'm willing to bet your EGT's were well over 1200F....not good.

Was the truck smoking black heavily out the exhaust?

This can indicate a turbo/wastegate/control problem and will drive your egt's (exhaust temps) through the roof. A boost gauge is a good thing to throw on too as it allows you to monitor the turbo system and how it's working.

There are several ways to help your 6.5 pull better in the mountains. It ranges from a recalibrate PCM to bigger exhaust to cooling system improvement to different turbo's and any combination of said parts thereof...

Of course, if you only tow in the mountains occasionally and the truck works fine for you the rest of the time you can just throw on an EGT gauge to help keep the engine alive and just accept going a little slower up the mountains....