tfergus777

My Ram 3500 blows black smoke. Fuel pressure to injectors is 96-98%. All injectors firing fine. This weekend I pulled my 5th wheel and noticed the exhaust was cleaner at 2000 RPM and I was at 65 -70 mph. If traffic forced me to drop my speed below 60 mph, I was back to smoking again. My research leads me to believe I have excess fuel not being used. Will removing the Cat help increase air flow and help burn off unused fuel? Seems going Cat-less is a popular idea on the web. Will this hurt towing power?

CLICKBANGBANG

What truck/ trans and mods? How many miles? What RPMs does it smoke and how many pounds of boost? What are your EGTs when it smokes and after?

Dropping the CAT doesn't get you a ton of flow unless you're pushing big power.

tfergus777

It is a 2006 Dodge 3500 w/automatic transmission. Not sure what EGT is? On flat highway, it smokes at 55 mph / 1500 rpm pulling a load until I get my speed up. Once I hit 65 -70 mph @ 200 + rpms, it clears out on flat ground. I hit a hill and it shifts down and the smoke rolls. This is with a heavy trailer and speed drops to 55 up the hill. The Dodge Dealership ran diagnostic and said fuel pressure for each injector was great. Shut down each injector to test and all were good. They said the Turbo was working and they could find no reason for the smoke. Flashed the ECM to factory just to make sure. No evidence of a computer upgrade. Lots of power. Does not miss or stall . Lots of black soot on rear panel and everything I tow. Please help!

reddodge225

I have an 06, but mine is not stock so of course it's going to smoke. My dad used to have an 07 with the 5.9 and automatic. His was always stock and would roll the smoke if you got on it at all. Dealership said everything was fine and didn't know of anything to do. My advice would probably be adapt and get used to it, or trade it in. It seems that this is a pretty common thing and nobody really has any answers.

Dieselbuilder

It still sounds like air restriction hows your air cleaner is the turbo makeing boost? is the turbo slow to respond ( turbo lag )???

michael/edge

i would expect it smoke under load at that speed. its just grabbing 4th gear and with low rpms your running your exhaust temp high with low rpms. once you hit that 60 mph you rpms are built up and egts are lower....

rockcrawler304

EGT = Exhaust Gas Temperature.
When you say heavy trailer, how heavy is it? What grade hills are you towing in? Being all stock it sounds fairly normal because of turbo lag like said above.
Lots of soot can be different for different people. Every friend of mine with a Dodge diesel has soot on the rear panel or bumper whether stock or modded.
Instead of going to the dealer try to find a good reputable diesel shop. Most dealers are not very good with diesels. If the starscan tool doesn't tell them anything is wrong they have no idea where to look!! Very few dealers have a REAL diesel tech.

Spooler

If you had guages it would be easier to diagnose. You could have a boost leak on one of the CAC pipes or somewhere in the charge air system. If you have low boost, you will get smoke.

totalloser

First thing I'd look for is preturbo exhaust leak. A leaking exhaust manifold will leak out pressure that would drive the turbo. Check all preturbo exhaust bolts for tightness and look for cracks on the exhaust manifold.

You should NOT be smoking steadily. Turbo lag will make for some smoke until the turbo catches up-a second or two at most. You are not getting adequate air flow from the turbo. Often boost leaks are somewhat noisy, but exhaust leaks can be sneaky because a diesel is inherently loud.