Engine/Transmission (1994 - 1998) Poor Performance & White-Gray Smoke

[BTanzini]

Here we go-I have had problems with the performance of my truck for a while now and when I did a valve adjustment about 2 months ago the truck run fine started better, but now I am noticing a white-gray residue build up on the conner of the bumper directly behind the exhaust pipe and the truck is running like crap. On my way back from town today I thought I might have developed a bad head gasket, my RPM seem to be higher then they should be and it feels like my power has dropped off. I replaced the overflow valve about 4000 mi ago. Any suggestions from anyone shot of getting reed of it? Any help is appreciated. Thanks in advance.

I just recently reconnected the pre-heater filter because when it was cold 30 degrees out (thats cold here in central Texas) and I started the truck with a little pedal it would blow all kinds of smoke, white, blue, gray and tend to want to stall out.

 

[Missouri Mule]

Could be the p7100 going out.

You could trying and adjusting your idle speed higher for cold weather starts.

 

[BTanzini]

Missouri Mule,I tried that a couple days ago. What makes you say P7100 ? When cold after short idle time runs fairly good when hot runs bad. Thanks

 

[KYOUNG]

what is your fuel pressure after the fuel filter???

 

[DonFitzwater]

Try testing for combustion gas in the oil and most certainly do a fuel pressure check at the P7100 inlet. Have you lost power when your engine is up to temp? Maybe check your timing if possible? I've had a few issues like that but they all turned out to be fuel supply problems in the past. Good luck and let us know what fixes it!

 

[BigPapa]

Timing slipped?



Scott

 

[BTanzini]

KYOUNG, DFitzwater, BigPapa I had a fuel press gauge on a couple months ago until it started leaking and at time it was a healthy 33 PSI running down road and 28 PSI at idle at fuel filter out port. I thought of timing myself but I don't feel it is that I may be wrong and I'm not ruling that out for sure. I down loaded an article last nite on pump timing and low and be hold at the top of the page it said White Smoke Thermostat might be stuck open. On my way to town today i watched my temp gauge and saw that it was sticking open, the engine did not warm up for about 15 miles of driving, then the gauge started going up scale, and on the way home it did the same thing. So I have to replace Thermostat tomarow and I will keep every one posted. Hope that's all it is. Thanks Guys

 

[BigPapa]

Don't know what your air temp is there in TX but it's been as low as 10* here in TN a couple of mornings this week. Had the truck plugged up all night and it started fine but still it took me driving @10 miles before the coolant got warm enough for some heat in the cab and @15 miles for it to get warm enough for the thermostat to open up. I found that if I ran the HVAC on recirculate it didn't take quite as long but it still took a while.



The moral of the story is that you may not have a thermostat problem at all, it's just that it takes a while when it's really cold for the old Cummins to warm up.



Scott

 

[BTanzini]

BigPapa, It has been what I call cold at my age here 22-30 range but nothing like New York where I'm from. It has been cold here in the past and it has never taken more then 6-8 miles to warm above 140 in the past warm or cold weather. Thanks

 

[Missouri Mule]

When the p7100 is going it can blow different colors of smoke but other things can cause smoke also.

Hope it is your thermostat.

 

[Vaughn MacKenzie]

I would start by going over the fuel system to be sure there are no leaks, and service the prefilter. Remove the fuel heater and check it for leaks too. Check the return line. It could be you're pulling air into your fuel, so start by ruling that out.

My '98 takes a long time to warm up, got down to 40 last night & still took ~4 miles before the temp gauge began to rise.

 

[BTanzini]

Vaughn MacKenzie, I did every thing you mentioned a couple months ago and just recently reconnected the pre-filter heater which seemed to help some on start up, It starts right up, it just runs like crap untill it idles for alittle while,30-60 seconds. I have always had a slight problem with the idle especaley in the summer when I use the A/C, it drags the Idle way done and I have to increase the idle about 100 rpm every year, so it could very well be the pump.

 

[BTanzini]

OK guys replaced Thermostat and truck seems to run much better, have not noticed any smoke but it has warmed up also

70 degrees. I'll tell better next cold spell, also temp gauge does not fluctuate anymore. Will keep posted. Thanks

 

[RedRamer]

Was that Dodge thermostat or a parts dealer one?

I replaced my radiator a few years ago and had all sorts of problems with the filler cap not sitting on the thingamajig in the rad hole cause it was lower than stock.

Wonder if there's a diff with thermostats?

 

[BTanzini]

RedRamer, The T-STAT was a Cummins product.