Engine/Transmission (1998.5 - 2002) Exhaust Manifold "Blue"?

[IWeiny]

For starters, I am totaly stock 99 24v, for now... I know this has been asked but most of the posts are about having some BOM affect EGT, I am wondering about a stock 24v.



I was changing the oil last night and I noticed that the Exhaust Manifold has a sort of blueish tint to it. I wonder to myself, is towing in OD at about 1700-1800 RPM making the EGT too high? I don't know. I only today ordered my guages...



I also just got SLIGHTLY bigger tires. I am talking 3mph at 60. So the RPMs are a BIT lower but not really that much. We also just got a camper so we have about 3000# more weight than before but have only been on 2 weekend trips.



The engine was warm as I had been driving it that day. I would be really surprised if I cooked anything but now that I have made the decision to keep this truck I want to make sure... Can't wait for that EGT guage.



Ira

 

[krs]

In a way, you've got it wrong. Much of the modifying that people do is done to help the motor pull hard without damaging temperatures. They usually increase power but that will let the engine do more work with less effort. The effort translates into exhaust temperatures. Read the stuff from bombers who pull RVs and see that they talk about temperatures more than about most other things engine related.



So if it were my truck I don't think that I'd tow at all, particularly with a heavy camper aboard, until I had a gauge on what is happening.



The 24 valve engine makes it's best torque at higher RPM than a 12 valve does and the revs you've mentioned are too low for best use of your engine under load. Shift down, or out of OD, and get them up to 2200 -2400. It's designed for it and somewhere I saw something saying that Cummins would or should void a warranty if it were shown that an engine were used as you describe. I can't point you to that statement but it was likely right here on this site.



I'm pretty sure that if you've got a blue cool exhaust manifold you've had a cherry red one sometime while running. Next step is piston meltdown, a catastophic event.

 

[LSMITH]

I think it may have something to do with materials. My 99 has a blue manifold too and never sees high EGT's, it has been a year since it was over 1300 for example. I have never really had much rust on the manifold either where trucks that work a lot harder than mine are rusted up heavily.



Is this the blue color you are talking about?#ad

 

[keimmmo]

I too have the blue manifold. I too was concerned that it was due to high heat. But, I have now put on gauges!



I have NEVER been over 1250* and have been over 1150* for only a matter of seconds at a time. I cruise at about 900* empty. I tow a 35 foot travel trailer and load it without mercy! I live in the mountains of central Mexico and tow the trailer through those mountains. Hey, these trucks are made to WORK! Treat them with some common sence and they will last forever!



Steve

 

[IWeiny]

Yea that photo is similar. It is hard to tell for sure. I think I will try and keep the RPM's high. I am also stopping by the scales to get a better idea of how much weight I really have.



Thanks,

Ira

 

[jrandol]

I'l tell ya with my stock HY and no bombs I could get my truck hot, like 1300 degrees with no load. My manifold is pretty blued as well. I went for an HX35 and life is good now. You can pickup up a non PDR HX35 for pretty cheap, wouldnt hurt. I lost a little low end boost but it kicks harder once boost comes on.



Jeff

 

[JJW_ND]

No problem.

If it is blue you have barely burned the paint off. What color is the clear coated cool side fo the turbo? If it is very yellow you have made some heat.



I just looked at one of your 2001 ETH 6sp with 65K miles. This truck has had the dog ***** towed out of it. Total stock but towed most of its miles fast interstate driving or towing in mountains of MT and WY. Grosses 20K all the time.



The hot side of the turbo and 90% of the exhaust manifold are redish, whiteish, and rusty. The head has areas that look like this.



This truck runs great and I would guess and I would exect zero engine problems related to heat! It is hardly broke in yet!



They are made to run. You cant do that without a load!



jjw

ND