More truck engine problems


Sep 6, 2006
central Florida
More truck engine problems/ solutions

I just need to blow off and vent some frustration here. My truck has been down for 3 of the last 4 weeks and I've deposited $1100 in my bank account in the last 30 days. I have 3 guys who still owe me money from a week and a half ago. I've spent over $2600 with 2 mechanics and a towing company in the last month and it still runs like shit. I'm hoping it will keep running well enough to get through the next 3 days because I have a 3 day job and I need the funds before I can put the truck back in the shop again.

So far I've had all the fuel lines changed, primary and secondary fuel filters have been changed 3x, the aftermarket Raycor water separator was deemed redundant and too small for that motor and bypassed, the auxiliary fuel heater was bypassed, all 8 fuel injectors were replaced (at $110 each plus overnight freight). I've also added a couple bottles of fuel conditioner/ cetane booster and one bottle of sludge dissolver in the last few weeks.

Today I brought the truck home and drained the main fuel tank, strained the fuel and put it back in the truck. I got a little bit of crud out of the bottom of the tank but not much, considering the tank is 18+ years old. The fuel was a bit darker than I expected it to be but no signs of water or sludge. It's still missing and sputtering under load, although there's no big clouds of blue (fuel) smoke any more since the injectors were changed.
My old roomy used to say, "If it's mechanical, it's gonna break." :X

Sorry to hear you are going through that.
Everything's good on the air side? No animals living in there or nothing? Filter's serviced/new?
What Suishy said, plus have they done a compression test and a fuel pressure test?
Deisel is pretty simple, air, fuel under pressure, and compression.
Short of a valvetrain problem, sounds like they have checked all the simple stuff!!
Sorry Brian, been there, it SUCKS!!!!!
That sucks Skwerl. Those Raycor water separators are made about 5 miles from me. I'm doing a job next week for a machinist that works there, I"ll tell him "you suck"! JK, I don't know what else you can do except that was the motor warmed up when they adjusted the injectors? I understand that this is necessary as the adjustment changes when the motor warms up. Going on with what Squishy said I'm also assuming that they adjusted the valves when they did the injectors. Also just because the injectors are reconditioned doesn't mean that something isn't wrong with one or more of them. I'm gathering from what you said that the motor idles OK but when put under load it starts missing. Mine does the opposite, at idle I can detect a miss but it disappears when you rev it up. I'm also thinking that something could be wrong with the linkage that steps up the injectors and/or something wrong with the transfer pump. The mechanic was probably thihking of all of these things in his dreams last night. Good luck.
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Andy, I will take your advice and insist on fuel pressure and compression tests when I bring it back in. Silly me, I just assumed that a diesel specialist with over 30 years experience would do that without being told. It sucks that I have to instruct them on how to diagnose the problem.

And unfortunately the old guy is kind of sloppy as well. There's at least 2-3 hose clamps missing (I just finished paying for all new fuel lines and clamps 2 weeks ago) and he put the fan belts on the wrong pulleys so they weren't running true. I have no idea what else he may have forgotten or screwed up but unfortunately I don't have a lot of choices for Detriot diesel mechanics around here. :cry:
Damn man that sounds like a lousy place to be with those mechanics. I'd be flipping if clamps and stuff like belts on the wrong pulleys and what not. That's like paying to create future problems. Make a list of everything you've found/thought of and take it back in with the truck. If they get offended oh well, you need to make a living with this rig things need to be done properly. Man I hope it all works out for ya.

I'll send some of my positive vibes and good luck out towards your truck, that will surely work ;)
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Brian, Does that engine by chance have a governor on it?

Yes. It's an electronic governor and not adjustable or servicable. It was only used on the last year or two of production for the 8.2, prior to that they had a mechanical governor.
Brian, just a guess here but does the truck have a turbo on it??? If it is there is a good chance it has what is called an aftercooler or some dumb thing like that. This after cooler is tied into your air intake system through the turbo, diesels run better with cold air being pumped into the intake. The aftercooler gets clogged with crap inside of it and will cut down the amount air that the engine can take in.

If you have one and if is similar to the one on my Cummings diesel chipper it sits on top the engine looks like a box with a petcock valve on it and some hoses going over to your turbo. It also has coolant in it which is how it is able to make air intake cooler or colder than the outside air as it is recirculated through the turbo back through the intake system.

Hopes this makes a little sense?? Just giving you a different place to look for a problem. I had this aftercooler problem before with the same chipper and have to change or clean it again soon as my chipper is running, but not as good as it could. Sounds similar to your problem. It is very easy for this problem to be confused with a fuel delivery problem it can get so bad the machine will quit and not restart. I found this out the hard way and to the tune of $600 to have a new one installed plus the mechanic's time.
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No, Steve, mine's a turbo. I've never noticed any cool air intake for the turbo though, unless it's cast into the intake manifold. Huge air filter cannister sits on top of the intake and the turbo sits back behind it, wedged under the firewall.
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Only $59K (asking price) and I can buy this and not worry about the old blue tank any more. Anybody wanna loan me $15K until I can sell my old truck?
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Excuse me. Did the air filter cost a fortune? The engine that my buddy gave me is a turbocharged version and it doesn't have an intercooler. The air goes from the turbo right up and around into the manifold.
I'm becoming more afraid of my truck ending up like yours and purchased a Cat 3208 with 120 hours on it a couple of days ago.
What year is your current truck? Did you try to get codes out of it? Turning the key on and off 3 times will display a series of numbers. When my International with a Detroit Diesel was getting hard to start, I got some codes and called the dealer. The lead mechanic there told me I had a bad cam sensor. I changed it and no problems for over a year. That is probably NOT your problem, but the truck codes may help you to pin point your problem.
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It's an '89 with mechanical gauges, Wesley.

I might have to make a road trip later this month and go look at that other truck. I'll beg, borrow and whore myself out in order to scrape together the funds if it's in top shape.
If I'm not mistaken Brians truck has a GMC engine?? If that is true it must have a scavenging air blower to run at all.In addition all that prior being true,those Jimmy engine even though they have a blower are classified as natural aspirated.

Generally speaking if the engine is blowing white smoke one of several things might be awry.Low fuel pressure ,could be caused by a screwed up fuel transfer pump.Low injecter pressure which is the main injecter pump or low engine compression.

Then too if this truck had been wrenched on by a good mechanic all these things should have been checked already I would have thought.
Brian, good luck with it. Surely in the Orlando metro area, there has got to be a good mechanic. Where is the one for sale?
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Sorry Al, it's an 8.2 Detroit turbo. I've never heard of a 'GMC' diesel, they have used motors from external sources for as long as I've been around. GMC, Ford and International have all used motors from Detroit Diesel at one point or another. I've heard GMC went to the Detroit 8.2 in the 80's when Caterpillar went on strike. In 1990 GMC went back to using the Cat 3208 which they are still using to this day.

Gigi, the one I'm looking at is in Alabama. I suspect it might be a Katrina flood victim, it's too new and too low mileage for it to be sold otherwise.