High altitude smoke

[DHenry]

I was driving home unloaded from Breckenridge to Boulder CO yesterday in my new ride (ODO <1500) enjoying the Cummins' performance going up the West side of I-70 into Eisenhower Tunnel (long >5mi, steep, high altitude 10000-11000' pull). At about 10500' (estimated looking at a topo) I was about to fly past two trucks in the slow lane, both towing, and looked to be going about 35-40 mph. I only really took notice because the lead truck was blowing huge clouds of black smoke . I figured I was coming up on an older diesel, but while passing, I saw that it was a dually Duramax. On his butt (his buddy perhaps) was a late model PSD running clean. Both appeared to be towing similar (identical?) loads. Our speed differential was so large that I didn't have time to get a good look (was concentrating on ID'ing the trucks), but I'd guess the loads to be in the 5K-10k range. After seeing that, I checked every truck I saw pulling a load, and most were running pretty clean.



I know a BOMB'ed truck will smoke pretty good, but then a BOMB'ed truck pulls faster up that grade. I don't expect you guys to be Duramax experts and I guess this isn't really a Duramax issue. It's more of a general diesel issue, but I'm trying to understand what would be wrong to cause a newer ECM-controlled diesel to smoke this badly. A turbo helps to a large extent at these altitudes with the thin air. Would a dirty air filter cause it? Is there some way to drive it (other than lugging) that would cause it? There are probably too many factors to get a good explanation. I'll be making this run frequently now, and just want to be sure that I treat my engine right.

 

[jwdeeming]

A CTD sure makes the Eisenhower run a lot more fun, doesn't it?



I don't know what was wrong with the Duramax yiou saw, but it may have been a function of how heavy his load was combined with how he was driving.



My '01 (not bombed, but BAHF and 4" exhaust) runs clean unless some joker fails to get out of the way and I have to back out of the turbo. At that altitude, it will blow a solid cloud of smoke until the turbo spools back up.



I've ordered some DDIIs - my frequent trips up that same route, sometimes pulling a horse trailer are what kept me from going to IIIs. Reports here on the TDR make me think the EGTs and smoke would be pretty outrageous if I went to IIIs.



According to my GPS, the west port of the tunnel is between 11000 and 11100 feet.



How do you like your '02? I sure wouldn't mind a full-on crew cab, but I just couldn't get used to what they did to the looks of that front end... .



JimD

 

[DHenry]

Originally posted by jwdeeming

A CTD sure makes the Eisenhower run a lot more fun, doesn't it?

You bet! Man, that Cummins is a horse!

I don't know what was wrong with the Duramax yiou saw, but it may have been a function of how heavy his load was combined with how he was driving.



My '01 (not bombed, but BAHF and 4" exhaust) runs clean unless some joker fails to get out of the way and I have to back out of the turbo. At that altitude, it will blow a solid cloud of smoke until the turbo spools back up.

I would have figured that he had the Allison (but no way to know for sure) and that it would have kept his RPM's up, so maybe he had a manual and wasn't gonna shift it.

...

How do you like your '02? I sure wouldn't mind a full-on crew cab, but I just couldn't get used to what they did to the looks of that front end... .

My '02 does not have the new body style. DC isn't going to the new body style on the 2500's and 3500's until 2003. I wanted a crew cab too, but wasn't willing to buy non-Cummins, and wasn't going to wait until 2004 or 2005 (I never buy the first year of a "new" model). Anyway, I love my CTD. It's the first one I've had and not likely to be the last .

 

[klenger]

These trucks are awsome in the mountains around here. I pull a 10,000 5er and have never noticed excessive smoke. I drove the west side of Eisenhower over 50 MPH pulling the 5er. The truck had less than 1000 miles on it.

 

[roadranger]

That DuraDud probably had boost problems- not enough air to burn the fuel.



I drove a U-haul Ford moving van up that hill once, and it was laying down a smoke screen like a destroyer- it didn't HAVE a turbocharger.



That Eisenhower Tunnel pull sure makes the Cummins shine! I pull that loaded to 18,000 GCW, cruise set at 65 MPH (and holding), 22 psi boost, and 1200* EGT, all the way up with a clean pipe.



I run an Edge EZ, and have to keep it at setting #2 at these altitudes to keep down the smoke a bit while upshifting. It'll still smoke out a rice burner alongside till the boost catches up.