6.5TD Running Rough Warm

[patterson]

I have a '97 C2500 with the 6.5 TD engine. Recently I have been having problems with it. When the engine is cold it runs and starts perfect, but when it gets warm it runs very rough on idle with alot of smoke and sometime stalls.

When you take off from a stop light with the engine warm it will throw a huge cloud of blueish white smoke and them will clear up and run great instantly. On wet pavement it will chirp the tires sometimes when it quits smoking and starts running right.

The first sign of it running wrong was that it stalled when I was braking down a hill and the SES light came on has stayed on since.

I took it to a friend and he read the codes for me, the stored codes were: P0236, P0216, and P1214. The guy that read the codes did not know much about diesels.

I decided that because it runs good when it is cold and no good when it is warm that it could have something to do with the coolant temp sensor. I unplugged the temp sensor and the problem went away. I replaced the coolant temp sensor and I still have the same running issue with it plugged in. The truck runs perfect with the coolant temp sensor unplugged except for always being on high idle and the tranny shifts different.

Any ideas? Does GM sell good service manuals for these trucks?

Matthew

[Barry Nave]

For now
PO236 Turbo Boost
PO216 Injection Timing Control Circuit
P1214 Injection Pump Timing Offset

[charliepeterson]

GM doesn't make shop manuals. You can get them from Helm Inc. on line. IIRC about $120.00.
With the truck running try to move the waste gate rod at the turbo. If you can the issue is in this delivery circuit, either vacuum or electronic. The solenoid can fail due to heat.
Make sure the three hold down nuts are tight on the back of the injection pump to the gear train housing. If you can find someone with a Tech II scanner try to re-time the injection pump. Maybe the injection pump codes will go away.

[6.2L Driver]

hello

you should like your having the same problems as I am. Howerver i dont get any codes with my truck yet. but symptoms are simmilar. On a slow acceleration from the light I get lots of smoke and a stumble, but on a fast acceleration all is fine, no smoke.

It seems to be that 1200 to 1500 rpm range. once though that things are better. If I'm in overdrive slow to about 90KM/Hr. then accelerate but not enought to kick down a gear, the truck will smoke again, and also feel very choppy, like there engine is cutting in and out. I have been to the GM shop but they dont know anything is seems but they will sure take your $97 and hour and tincker away

[Barry Nave]

Also I take it you have no Boost Gauge?
This would help alot. The FSD can a will set these codes also even though the Eng. seems to run fine. Check out the search on boost,wastgate solenoid and make sure all is working in this area. This for the two of you guys ;)

[patterson]

No, no boost gauge. I checked and found that there was hardly any vacuum at the wastegate. Worked back to the vacuum solenoid and found that the supply line to the solenoid was only getting 5 inches of vacuum insteat of the 20 or so expected. I have ordered a vacuum pump. I have had vacuum pump go out before and usually the symptoms were alot of black smoke at full throttle and low power.

I will check around with some mechanics I know to see if any have the Tech II scanner and retime the IP. Would the stepper motor being bad cause these codes? Thanks for all the help so far.

[patterson]

I replaced the vacuum pump today. Now the wastegate is being pulled closed like it should be. Power is improved, but I still have the same problem when the engine is idling warm it smokes alot and runs rough and often stalls and is difficult to get restarted. This problem goes away when the temperature sensor on the crossover tube is unplugged.

I haven't been able to find someone to retime yet. I suspect that my running problem is injection timing related, but I am not familiar enough with these engines to know how the computer controls the injection timing. So if anyone can explain that it would be great.

Thanks for the help so far.

[Barry Nave]

#1 Jim B. Has what is called Feature Articles and Product Reviews.
My frist issue dates from 1997 through 2003.
Have some issues that I should be getting ordered.
In the 1999 Articles it explains the 1994-1999 DSG Injection Timing, Checking and Timing procedure.
The 2001 talks about the Stanadyne DS4 Electronic Fuel Inj. Pump.
About the DS pump,the basic componets of the pump,Basic electrical circuitry and rebuilding by Gomer's Diesel.
I injoy seeing these type of questions yet have a hard time explaning it in a short answer when Jim has done it so well in the Articles.

They are like the DP bible for our trucks ;)
Much info, lots to learn, good reading. A must for DIYSelfer's ;)