Engine/Transmission (1998.5 - 2002) High EGT Black Smoke and Running Warmer than Normal

[KBrennan]

Ok, Here is the problem.



EGT is running about 200 degrees higher than normal and I am producing more black smoke than normal. It gets wores when pulling the fith wheel od 12klbs. Engine temp was also higher but part of that was due to the ambiant air temp was 90 and altitude was 6600 feet.



What I have found:



IAT sensor was covered in an oily black residue. Have not been able to inspect the MAP sensor because I do not have the right socket.



I am cleaning the old IAT but have ordered a new one and it should be here Tuesday.



Am I on the right track and is there anything else i should be looking at? Bost under heavy load is between 20 and 30 lbs.





What is installed on the truck



PF 100 fuel pump and filter

Banks Auto Tune with exhaust brake and 4 inch pipe (Stinger Pachage)

S&B Air filter and box



VP 44, turbo and injectors are all original with 151K miles

 

[AH64ID]

You boost seems good, but is it normal? A boost leak is the first thing that came to mind.

 

[KBrennan]

For as long as I have had it the boost looked in the right range for the amount of load and throtle applied.

 

[AH64ID]

What condition is the air filter in?

 

[KBrennan]

Was cleaned about a thousand miles ago. It is still very clean. I pulled the MAP out it was also full of the black oily substance, All are cleaned and back in. Started up and took a run around the block. It did seem to coll down faster and even went below 300 degrees. That has not happened in a long time. Next run will be with the A/C on max and driving at 70 mph but no load.

 

[Joe Mc]

Even though boost numbers are normal as stated, check for leaks @: boots, turbo outlet elbow, compressor to bearing/shaft assy, inter-cooler, intake horn, etc. It may be fine until the point where the boost is most needed and then leak enough to get hot and smoke show without noticeable boost gage drop.

 

[DSeamans]

Sensors

FYI, The e-brakes are known for sooting up the sensors and they do need to be cleaned fairly often. If I'm towing, I clean mine every 20k - 25k miles. It makes a big difference.



Dave

 

[KBrennan]

I have also heard that the injectors can get gummed up and start having spray pattern issues causing hot spots and high EGTs. Cleaners help but can only do so much. I got a good deal (I think it was a good deal) on a set of Bosch Marine injectors also known as Rv 275 injectors for $382 including delivery. They should be here Thursday. If I can get the time or get the shop to do it I will get them in before the weekend. If anything I should get a little better MPG .

 

[Houser]

yep Injectors

Injectors were my choice.

with 150k your probably due for a new set. I replaced mine with rv275s at 80k and it really made a difference. Now I get black smoke because I have bigger injectors and a smarty. oh yea and a Banks quick Turbo, which didnt really reduce the smoke that much but makes it easier to get away from.

I do get better mpg and a it runs a little quieter too. I'm Sick. :{Oo.



Mike

Palmer, Ak

 

[AH64ID]

FYI, The e-brakes are known for sooting up the sensors and they do need to be cleaned fairly often. If I'm towing, I clean mine every 20k - 25k miles. It makes a big difference.



Dave

While this is true on the 6. 7 with EGR... it should have zero effect on a non-EGR issue... The EB is on the exhaust side, and there is no mixing on 5. 9's.

 

[KBrennan]

While this is true on the 6. 7 with EGR... it should have zero effect on a non-EGR issue... The EB is on the exhaust side, and there is no mixing on 5. 9's.

What would cause the black oil stuff that was all over the sensors. I have heard this about EBs for some time now, beofre the 6. 7s were out.

 

[AH64ID]

What would cause the black oil stuff that was all over the sensors. I have heard this about EBs for some time now, beofre the 6. 7s were out.

Would have to be an issue with the turbo seal. . I have an EB and zero residue, soot, etc in my intake or on my sensors. The turbo must be allowing the EB pressure to bleed from the exhaust side to the intake side? Or your bearing is leaking oil into the intake on the turbo.



I have only ever heard of EB's sooting up the oil, never the intake.

 

[KBrennan]

Oh great, now I am looking at rebuilding/replacing the turbo $$$$$$$$$$$ the well is running dry quickly.

 

[AH64ID]

Oh great, now I am looking at rebuilding/replacing the turbo $$$$$$$$$$$ the well is running dry quickly.

If it takes you 20-25K miles to notice a difference its probably not worth looking at... And that's just a guess, it by no means you have an issue.

 

[KBrennan]

If it takes you 20-25K miles to notice a difference its probably not worth looking at... And that's just a guess, it by no means you have an issue.

I just got notice from UPS that the new injectors I ordered arived in Albq this morning. Maybe I will luck out and they will deliver today. I might as well start researching Turbo Replacement options. It is one of the easiest parts to replace but also one of the more expensive parts.

 

[PC12Driver]

While this is true on the 6. 7 with EGR... it should have zero effect on a non-EGR issue... The EB is on the exhaust side, and there is no mixing on 5. 9's.

Not true. Because of valve overlap (intake and exhaust valves open at the same time), there is enough backpressure to reverse the flow in the head for a brief moment and put a little squirt of exhaust into the intake with the IAT and MAP. Like DSeamans said, dirty sensors with an exhaust brake are pretty common.

 

[KBrennan]

I gues I could pull the inlet boot to the intercooler and see if it has the same oil black stuff. If it does that would tell me it came from the turbo and if not then I am ok, I think

 

[AH64ID]

Not true. Because of valve overlap (intake and exhaust valves open at the same time), there is enough backpressure to reverse the flow in the head for a brief moment and put a little squirt of exhaust into the intake with the IAT and MAP. Like DSeamans said, dirty sensors with an exhaust brake are pretty common.

Interesting, I didn't think there was much, if any, overlap from exhaust to intake on force induction motors... Even still, the exhaust should be free of soot as there is no fuel going thru the injectors, and no fuel means no combustion means no soot. Overlap occurs on NA motors to get the vacuum effect of the exhaust pulling the intake in. . But on a motor where DP is greater than boost (even if not by much) you won't get a flow effect. .



I will add this, I just changed cams and I have noticed that my IAT's go up about 10* when the EB is on. I never noticed this before the cam. . but you know how you watch things after major changes. I presume its from the airflow stopping with the EB on and the intake air spends more time in the manifold and can absorb engine heat. . If the exhaust was spitting back enough to get soot/exhaust in the intake then i would expect to see a much larger jump than 10* considering EGT's are in the 400+ range with the EB on. Also the IAT's only jump about 10*, and it doesn't seem to matter if I have 30psi of back-pressure or 55psi, still only a 10*ish rise.



Not saying your wrong, I just didn't think turbo diesel cams were ground with an exhaust to intake overlap.

I gues I could pull the inlet boot to the intercooler and see if it has the same oil black stuff. If it does that would tell me it came from the turbo and if not then I am ok, I think

Thats what I was thinking.



I just changed my intake horn about 6K miles ago, and the stock one (40K miles with an EB) had zero residue on it.

 

[PC12Driver]

Interesting, I didn't think there was much, if any, overlap from exhaust to intake on force induction motors... Even still, the exhaust should be free of soot as there is no fuel going thru the injectors, and no fuel means no combustion means no soot. Overlap occurs on NA motors to get the vacuum effect of the exhaust pulling the intake in. . But on a motor where DP is greater than boost (even if not by much) you won't get a flow effect. .

Ever adjust your valves? You'll see the overlap.



I think you'll find some level of overlap on any piston-driven engine. Using the inertia of the exiting relatively higher-mass exhaust gas to help pull in a fresh air charge is more efficient than stopping the flow and restarting it. Even in a boosted engine, the exiting exhaust gas creates a relatively lower pressure inside the cylinder to help pull in the air charge and purge the spent gasses (or creates less of a restiction for them to enter anyway).



As far as the no soot thing, you are correct: in normal exhaust brake deceleration soot would be minimal or nonexistant. But as the engine nears idle and the fueling starts to ramp up again, or if idling with the EB on, there will be soot.



Your IAT increase after the cam install is a pretty cool observation. The aftermarket cams I looked into did increase overlap, and that is probably what you're seeing. I've also read about less boost and a less effective exhaust brake after a cam install, but that was from a company that didn't make cams, so take that for what it's worth. I didn't notice any change in either. What did you use to read the IAT?

 

[KBrennan]

Ever adjust your valves? You'll see the overlap.



I think you'll find some level of overlap on any piston-driven engine. Using the inertia of the exiting relatively higher-mass exhaust gas to help pull in a fresh air charge is more efficient than stopping the flow and restarting it. Even in a boosted engine, the exiting exhaust gas creates a relatively lower pressure inside the cylinder to help pull in the air charge and purge the spent gasses (or creates less of a restiction for them to enter anyway).



As far as the no soot thing, you are correct: in normal exhaust brake deceleration soot would be minimal or nonexistant. But as the engine nears idle and the fueling starts to ramp up again, or if idling with the EB on, there will be soot.



Your IAT increase after the cam install is a pretty cool observation. The aftermarket cams I looked into did increase overlap, and that is probably what you're seeing. I've also read about less boost and a less effective exhaust brake after a cam install, but that was from a company that didn't make cams, so take that for what it's worth. I didn't notice any change in either. What did you use to read the IAT?

I know with the Banks Brake it automatically kicks in when ever you start a cold engine and throttle voltage is at idle. It does that so it will not stick from lack of use. Some of the older styles would gum up if you didn't use them periodically. The minute I add any throttle it cuts out. Makes a heck of a noise when engaged sitting in the driveway. It is like a very loud hissing sound. Banks claims this also helps in a quicker warm up in cold weahter.