I just recently inherited a 99 f250 4x4 7.3L diesel. I've never owned a diesel and know nothing about them. All my past experience working on vehicles is with gas engines.

The truck runs fine around town. The other day I was running it on the interstate at around 70 mph, and it ran fine for about 30 minutes. Then white smoke started coming out the tailpipe, it gradually was losing power and running real rough. I pulled off the interstate and took some back highway roads back to the house, and it continued to run rough until I got home. Drove it around town yesterday, and it ran fine again.

The previous owner had the same problem when he had it, but the mechanic he took it to to get it fixed could never duplicate the problem. They did replace one of the injectors and the fuel heating relay. Anyone have any suggestions on what this could be. I would guess fuel filter, or junk/condensation in the bottom of the tank, but I would imagine that would be the first thing a mechanic would check. Also, they must have checked the injectors if they replaced one. Any other suggestions?

 

Welcome to FTE.

You have a very good truck there and this should be an easy fix as soon as we track it down. How does it start up? Do you have any codes? Are you able to check for codes? Have you checked your oil level? these trucks hold 15 qts.

As for the white smoke, it seems to me that you are burning oil (don't worry, these trucks should burn a qt or so every 3-5,000 miles). On these trucks, you need oil pressure to open up the injectors to get diesel into the cylinders. My guess would be that you have some o-rings that are failing at one or more injectors and that it is leting oil into the cylinder(s) and that you are loosing oil pressure and that is shutting down the injectors and you are starving for fuel. This is very fixable and can be done cheaply if you are able to do it your self.

Some more guys/gals will come along with some more input for you on how to look into this and/or give more suggestions.

 

I'd suggest you start by cleaning the screens inside the fuel tank.

 

Kinda what I was thinking!

 

Has the truck been sitting not being used for any length of time ? How many miles are on it ?

 

The truck starts up just fine. No problems there. I believe the mechanics couldn't get it to read any codes when they had it. Oil level looks good and oil looks clean, but think the mechanic changed the oil when they had it.

Yeah, doing some searching on this site, sounds like the o-ring problem on the injectors is a common problem, so thought of that. Also, my father-in-law has the exact same truck, and acts like you have to really know what your doing to work on a diesel. I have a good bit of experience working on my jeep wrangler and suzuki samurai gas engine vehicles. Basically have done a lot to them based on the knowledge I acquired by chatting with the guys on the jeep and samurai websites. Do y'all think I have the skills necessary to tackle this problem myself, or is my father-in-law correct and I shouldn't mess with it. I really don't have much money to throw at this truck right now as i'm out of work, so i'd much rather do it myself. It seems to me that diesel mechanics are pretty darn expensive.

 

I think the truck did sit up for a few months, but the gas in it isn't that old as I know it was filled up within the last month. It has around 250K on it. My brother-in-law who I got it from used it mainly to tow boats around the US, so most of those miles were highway miles.

 

You do have the skills and we are here to walk you through it step by step. You will come to love your truck and work on your truck. We will get some more ideas and see where to start. Diesel mechanics are darned expensive, that is why there is this form, to keep you from getting screwed and to show you how easy it is to get going again. We all started somewhere and there is a vast amount of knowlege on this forum to walk you through this question and the ones that come up later.

 

I would lean more toward a fuel restriction issue in the tank. Three are fine screens that can get clogged up. I would recommend doing the in tank mod: Welcome to guzzle's In-tank Hutch Mod Web Page

 

That is what I figured. I didn't know a thing about working on cars when I bought my first jeep. I was tired of getting ripped off every time I took it to the mechanic, and with the help of guys on the jeep sites, I was able to do many mods and repairs myself. Same thing when I bought my samurai. So don't think I will have a problem fixing this truck with the right direction.

Yeah, i'm excited about this truck and plan on driving it for a very long time. I've heard great things about this engine's long life, so I plan on getting at least another 100K out of it and hopefully more. My father-in-law has over 400K on his.

I'm gonna find out from the mechanic who worked on it what all he did/checked. He is out of town and won't be back until next Monday. After I talk to him, I'll get back on here and post what I find out and that may eliminate some things to try and fix it. Hopefully, I can get started on it a week from tommorrow. Want to get this problem fixed and then I will try and tackle other issues (4x4 not working, hubs frozen).

Thanks for all the responses and y'all look out for this post next week when I find out more info.

 

Just another word of encouragement, these things look pretty intimidating but when you really start working on them you'll realize they are just another machine. If you done work on other vehicles you will be able to figure this one out. FTE has some of friendliest help on the net, post the questions and break out the wrenches!

 

We can help you get this fixed too.

 

so what was the out come ? did you get it fixed? sounds like a injector going bad!

 

You should check the slop in the turbo shaft, white smoke is in some situations of a turbo that needs to be rebuilt, correct me if Im wrong fellas...
Welcome to FTE

 

I have been slammed at work, so decided to take it back to the Ford Dealership. Finally, got the truck back from the shop yesterday. Had them drop the tank again just to make sure it was clean. They said they found some gunk in the two cylinder like filters that are above the sock on the pickup tube(at least I think that's where he said they were). Said the sock looked fine. He said they usually don't check those filters(don't know why), so that may be why they missed it the first time. Anyways, it seems to be running fine now. If it messes up again, I'll probably try to tackle the problem myself. The mechanic said the next thing he would look at if it messed up again was the pump on the fuel rail. Said it looked fairly new but was an aftermarket pump and said he has seen problems with those when they get hot, although he said they usually blow the fuse so you shut down completely. Hopefully, though the problem is fixed.