Not long after getting a new tranny from the dealership in Mojave, CA ($3,700) my truck ('99 PSD 4X4, 7.3) is having drastic power loss problems. It's probably just a coincedence, but anyway. I was coming back from driving on about a 2 hour trip, the engine had a hard time maintaining speed. Instead of doing 65 mph, I'm lucky to do 40 -45 with the same RPM (2,000ish) and it does this the next 15 miles back home. The engine seems out of rhythm or something. So I take it to the dealership and they diagnose ($145) that it's nothing in the computer or whtaever they check and say the fuel filter needs changing and that that's the problem. ..So I do that. And same exact problem occurs. But, once again, it's after a nearly 3 hour drive where the truck seems fine and then I start having the same problem. Only this time I've got an ATV in the bed and I'm going over a few hills. I can barely do 15-18 mph at 1,500 RPM and same kind of hesitation as it tries to go. Does better on the downhills getting up to 50ish but the last 15 miles it's doing this kind of thing.
I don't think it's the tranny, because it does seem to engage, and doesn't feel like the traditional tranny slip. And I really don't feel like taking back to the same dealership again. DOES ANYONE HAVE ANY IDEAS? I NEED MY TRUCK FOR WORK.
And I don't think it's bad diesel, because I get it from a high traffic/turnover in Mojave. And it's done it on two separate tanks from 2 different places.
Any help is appreciated.
Thanks

 

watch the exhaust when it does this. kinda sounds like a turbo problem. is the waste gate sticking? make sure all the fuel lines and filter are secure with no leaks. i had problems with the prv in the oil resivor for the injection. dealer ship wanted around $1000.00 to replace what ended up being a $30.00 seal kit. (that i installed)

 

First, does the engine SOUND like it's still making "normal" horsepower?

If not, I'd find out what the fuel pressure is during these "bouts". There's an adapter that's cheap from one of the sponsors that you can fit to a pressure gauge to find out.

If the filter is new, and the pressure drops off anyway, I'd suspect the screen at the pump's inlet is getting clogged. Kwik had this happen to him.

If that's not it, you might try back-blowing the fuel line into the tank to see if the screen in the bottom of the tank is getting clogged, but this is kinda' rare.

There's a start, but here's another angle:

You didn't tell us why you had a new tranny put in. I wonder if this is related.

Could it be the dreaded bypass stuck open? Did you get any filtration put into the tranny cooler lines when the trans was replaced? Maybe the cooler is clogged from pieces of the old trans. You may be just burnin' the new one up, and you're feeling it slipping!

Is this the engine not making power, or the power not getting to the wheels?

Pop

 

How old is the oil & is it FULL ?....

 

If it coincided with the tranny replacement perhaps they "bumped" an up pipe and caused an exhaust leak and the turbo cant spool up. Or there is a major boost leak in the intercooler piping.

 

Well, the dealership said the turbo checked outo fine and otherwise couldn't find anything wrong.
As far as the tranny, it grabs and is not slipping so bad like the old one did.
The strange thing, like I said before is that it seems to work great for about an hour or two and then starts to have the problem. Although the last time I drove it it seemed like it was starting to do it again right from the start. But I haven't driven it for a week now, because I wasn't sure what I am going to do.
I guess I should take the new fuel filter out and take a look around?
As far as oil, it's synthetic and it's about 5,000 miles old. ...but it should be able to last 10-15 no?

 

Only if you're running bypass filtration. I would go no more than 6 or 7k on syn otherwise. You also will need to be sending samples off for an OA when stretching oil changes that far.

I look at it this way -- I spend $50 for a dino change, or $75 for syn (Rotella in both cases). I can stretch it a little with the syn, but beyond that, I'm spending $25-$30 for OAs. Might as well run fresh oil after 5-7k and be done with it, IMHO.

Joe

 

You definitely have a tranny problem. At the very least, your TC is not locking up like it should. At 2000 rpm you should be going 65 mph (4.10 diff ) or 71 mph (3.73 diff) and if you're not doing these mph at 2000 rpm the tranny is the problem, not the engine. I would've come to the same conclusion even if I didn't know that you'd just had an obviously defective tranny installed!

 

well it might seem like UVC harness having issues with connections?? no????? its an 99 right? so do you get any SES light coming on? thats where i would start looking.. does it smoke when it happens? or maybe you have fuel delivery problem, like pump going bad or the fuel pump reset switch burned up the wires, take the passenger side kick panel off and see if all the wires look perfect, and than you might have to pop the Valve Covers off, ..... just my 0.02

 

rough idle if connections bad or injectors plus very hard start. if rpm's up then yes trannie. but lube the waste gate, the attached dohickey to the turbo. it only has to stick a little, which it will do with no real pattern, for a huge power loss. when the truck starts to do it take a carful listen to the whistle from the turbo. does it sound the same?
these trucks through codes as soon as theres a real problem, have you had it on a good scanner. ive worked on a few of these that had sticky waste gates. the tell tale sign is the black heavier than normal exhaust out the rear. plus they have almost no power. its simple to lube it up with never seize around all the pivoting spots. simple to try. it may not be the problem but its almost a free fix if it is the problem.

 

One question, if it is the tranny, why does it seem to be fine for a while ..up to two hours, and then start having problems? Wouldn't it have problems a lot sooner than that?
..also, about lubing the waste gate.. ..where and what is that exactly?
..and as far as the codes being thrown out.. ..dealership said there weren't any.
Also, the tranny is under warrantee, but if the dealership would refuse to admit there's a problem with it, then it's a big waste of a guarantee!!
Also, I can take the truck to ANY ford dealership and they must honor thte tranny warantee, correct?

 

on the back of the turbo there is a mechanical body that has an arm comming out of it to an accuator. if those pivot points seize they keep the truck from building turbo boost and these engine fall on their face without it.

 

Why wouldn't you be asking this same question no matter what you thought the problem was? Why would the engine be fine for 2 hours and then have problems?

The 4R100 tranny has a lock-up torque converter (TC) clutch that's supposed to lock and stay locked at normal road speed. With the TC locked it's just like having a manual tranny in that there's a direct connection from the fly wheel to the rear wheels. Since your original post mentioned 65 mph at 2000 rpm, I'm assuming you've got a 4.10 diff, because those are the correct mph vs rpm #'s for that ratio. If your tach says 2000 rpm and your Speedo doesn't say 65 mph, then either the Speedo is malfunctioning or the tranny is. I conclude that at the very least you've got a TC lock up problem, but I wouldn't be surprised if there were other tranny issues as well involving slippage. The only way you can be doing 2000 rpm in 4th and not be doing 65 mph is if something in the drive line is slipping!

It's not unheard of for a newly rebuilt tranny to have a problem with the TC not properly locking up. If I recall correctly, this happened to strokin_it7.3 after he had his tranny rebuilt by the famous Brian at BTS, and they had to pull his tranny an install another hydraulic valve that controls the TC lock up function. So if it happens to one of the best tranny guys around, can you expect anything less from a Ford rebuild?

 

i agree, after you check the easy things that dont cost you any money. it's not just your lock up though. the no codes is the only thing that leads me to believe that its a turbo issue. if your slipping that bad in the tranie there should be some code. you have to take into account the tire size for rpm at speed in lock up.
make sure of your engine rpm when this happens. but again i agree that the tranie needs to be looked at. but once you slip a tranie that bad they usually dont work good again. no matter what the time. i t could be something to do with the shift cable/solenoids.

 

I'll make it as clear as I possibly can, this is my last attempt. With the TC locked you have in effect a solid shaft between the engine and the rear wheels. If you turn the input end of a shaft one turn and the output end doesn't go one turn, I'd say the shafts broke or slipping. 65=2000 for a 4.10 diff and stock tires, 71=2000 for a 3.73 diff!