Checking exhaust temp with temp gun??

[erobb]

Howdy folks,

Long time subscriber but I don't get on here much.

This past spring I ran across an 04.5 2500 Quad Cab, automatic, short bed, 4x4 with only 91000 miles and in excellent condition overall, it seemed to have been garaged all of it's life. I purchased it, as my old 98.5 regular cab had 385,000 miles on it.

When I was test driving the truck before purchase I thought it may have a slight miss at idle but I was so glad to have found a low mileage one that I purchased it anyway. I have driven the truck almost everyday since then, it now has 110,000 miles and I just changed the oil this morning. I changed all fluids and filters as soon as I purchased it this spring.

I have tried to diagnose the slight miss at idle and have had 2 diesel shops listen to the truck, both recommended Stanadyne injector cleaner to me and I have run 2 of the medium sized bottles through the truck that say they treat 100 gallons, so about 6 tanks total. It seems to have helped some but in general the slight miss is no better or worse. I have no white smoke on start up, the engine is not making oil, I checked it just before I drained it, and it was about halfway down on the cross hatch area on the stick in 5000 miles. The truck does blow black smoke fairly bad when I stand on it, but again, I drive it mostly highway miles, and rarely pull anything anymore, at least not anything very heavy.

This morning, just for giggles, after a short run to drop my daughter off at school, I remembered I had a temp gun in my tool box. So I took a reading at each port on the exhaust manifold, with engine idling and up to full temp on the temp gauge. #1 cylinder was at 175, while all the other cylinders were at 235 or within a couple degrees of each other.

Should I suspect the #1 injector of being bad or going bad, not spraying like it should, or is it just a fluke and not a good way to check anything? I know I should just take the truck to a diesel shop and leave my credit card on file with them, but i don't think I want to pour a pile of money in this truck. It's low mileage and in very good shape, but I really don't need a 3/4 ton any more, my business has changed, and I have sold my skid loader.

I would be willing to try an injector if it makes the condition better, but I don't feel the truck runs bad enough to justify spending $2500 for an entire set of injectors plus diagnostic fees, I will just trade the truck off on a 1/2 ton first and use that money to outfit the new truck as needed.

Any advice?? Thanks

 

[BILTIT]

Try running 1L of cheap non-synthetic atf in a full tank. Helped clear up some of my slight miss/cold lope.

 

[erobb]

I forgot to mention in my previous post that I ran a couple tanks with just straight diesel, winter blend here. But I just filled up yesterday and I had some Lucas injector cleaner on hand, my wife's old Mercedes diesel loves the stuff, makes it run smoother and quieter. So I put some of that in this tankful, I haven't driven it much yet, less than 100 miles, but it does seem to be slightly better, not sure if it's just lubing up the injectors better or what. I have also thought to try some Marvel Mystery oil in a couple tanks before I purchase any major components.

Also, I went ahead and test drove a left over 2015 Ram 1500 Hemi this afternoon, not sure I want a ecodiesel, heard too many horror stories, and it was OK but not great, I mean it's a nice truck but somehow not what I expected. Plus they low balled me on my trade, after the salesman couldn't stop talking about how hard a low mileage Cummins without all the emissions garbage was to find. I can get $5000 more out of it by selling it outright. And I guarantee as soon as I put it on craigslist my phone will start ringing, since my dealer doesn't seem to want to play ball I guess I will just keep the truck and try to figure out the slight miss thing and be happy. After all I owe way less on it than a new one, and the problem is only slightly annoying.

 

[AH64ID]

#1 being colder could mean an issue or it could be colder from it's location on the engine. It gets the coldest ambient air over it.

A cylinder contribution test is the best way to tell which has to be done with a DRBIII or other scan tool.

Have the valves had their 100K mile adjustment?

You will probably have a hard time finding a reputable shop that will replace just one injector, as when one is failing the others aren't far behind.

The black smoke is probably residual soot that builds up in the exhaust during long periods of light use. The increased temperature and flow of a good romp will clean out the exhaust.

If you really want to give the injectors a good cleaning then I would put a double dose of your favorite non-alcohol fuel injector cleaner in the tank and hook up to some good weight and hit the hills. The high pressure and duration from sustained load will do a much better job cleaning things out.

Try running 1L of cheap non-synthetic atf in a full tank. Helped clear up some of my slight miss/cold lope.

Please, please, please DO NOT do this!!!

Modern ATF is a HORRIBLE idea for putting into a fuel tank. ATF is designed NOT to burn and can leave deposits that does more harm than good. Run something that is designed to be burned and put into fuel.

 

[BILTIT]

I realize this is not a good thing (theoretically), but many are having good results by doing it as a last ditch effort when nothing else has worked.

 

[erobb]

Yes I did the 100k valve adjustment myself, did it a couple times on my 98.5 as well, there were several valves that needed adjustment, I ended up doing the job twice as I still one one clacking after I did it the first time, so the valve cover came back off and I double checked everything.

I was going to leave the ATF as a last resort. The Lucas injector cleaner seems to be helping, seemed like it was running better today, although the outside temp was about 15 degrees warmer today as well, so not sure what is helping the most.

I romped on it a few times in the last couple days and I notice the black smoke under hard acceleration is getting much better.

I just missed a road trip where a buddy of mine went 2 states away to tow his college age son's car back home after it broke down on him at school. He drove his old bombed out Ford van with bald tires, and no heat. I didn't find out he went until he was already back home, I gave him some crap told him he should have given me a call, my truck needs a good long road trip with a broke down Toyota in tow.