Can you solve this riddle?!? NOBODY else can! PLEASE HELP ME!

This is one for the ages. Ok, at 80,000 miles, tranny goes out. I get a rebuilt. 10 DAYS later, that one goes out! They tried to say it was the differential, but I called the Better Business on them, and got it fixed. Ok, flash forward 2 years. Now, I was starting my new job, and driving around town, and the engine was hot. I was getting on the freeway, and couldn’t accelerate over 50mph! The tachometer would spike wildly, it was like I had zero transmission, nothing ‘grabbing’ if you will.

I took it in to the a**holes who repaired it the first time the next day, and just followed my gut and said screw you. My girl was following me back home, and it ran fine and normal. Even took it out on the highway, no problem. Drove it 70mph and ran fine. So I took it to a locally owned shop. This guy hooked it up to a computer analyzer, we took it out on the road, and he beat the hell out of my transmission! It tested 100% good! The only thing he found, was a rough shift at low speeds, but that’s it. He said with your V8, 5.4 Triton, you should be lighting up the tires when I punch it, but it’s just like a dog when I hit the gas. He thought it might me the catalytic converter. Guy never charged me a cent!

So, next week (truck is still running ok, but want to find out the issue), I took it in to our local mechanic. He tested it for over an hour, and said my catalytic converter is just fine. I explained the symptoms, so he went back and tested it some more. Well, he said the computer shows that it was missing, but that was about it. He recommended to start with the simplest fix first. A tune up. Which, not simple nor cheap. $450 for the tune up.

I hadn’t had the tune up done yet. We were coming home from the Indy 500 the other day, and of course, it’s hot out, and you sit forever in traffic. Well, same thing happened again on the way home. We actually had to pull over on the highway because we couldn’t get going past 50mph.

Can ANYONE solve this? I have been unemployed for the past 2 years, and I’m just starting a job that doesn’t pay much, but need my truck. So I’m willing to pay for the repair, but I just want the RIGHT repair, and not several “guess” repairs. Oh, and there was no Check Engine light ever, no smells, no leaking, nothing. All guages were fine at all times and still are. I appreciate any and all advice.

Thank you!

They’ve been checking your engine operation and your tranny operation…all in the shop and while not under heat-creating stress.

I think it’s time to check your tranny cooling system…which in your case is probably built into the radiator. I’m guessing that because (1) you alluded to the engine overheating and (2) a bad tranny cooling system will fry even a new tranny in short order…and your symptoms fit.

Oh, yeah, I specifically wonder of your tranny cooler is leaking into your radiator and/or vica-versa.

Oh, and I’m assuming you have an automatic.

Sounds like your truck is going into a limp home mode in order to protect the expensive parts.

Here’s what you might want to do:

Install an additional transmission fluid cooler.
It sounds like whenever the truck is getting really hot, the temp sensor in the transmission is telling the computer to limit power in order to protect the transmission from burning up.

Does the truck run better when cold, and then get worse when hot?

Have you ever had the spark plugs changed?

Buy a set and change them yourself, if you’ve got the tools and the know how.
It will save you most of that $450.


Well, I may have mis-spoke. My engine isn’t ‘over heating’. All gauges are normal. It’s only when the engine is “hot”, being driven for a while. But, I like your diagnosis! I appreciate it. I will be going back to my local mechanic and pass along what you said. Oh, and yes, sorry, I have an automatic.

Don’t know what happened to my post, but I think you are RIGHT on the button! I don’t have tools, and have a bad back, so I can’t do it myself. But, that wouldn’t affect my problem would it? Headind down to the mechanic now and tell him what both of you said. Thanks SO MUCH to both of you and I’ll let you know the results!


The transmission has a temp sensor, you can monitor the temp while driving to see if it overheats. The problem is trying to get it to act up while you have a scanner hooked up to monitor the temp.

I wouldn’t rule out a restricted converter. I have seen converters where the catalyst inside of the case breaks apart and moves around. Sometimes it moves and restricts the exhaust causing a problem like you are having. You can check for a broken catalyst by banging on the converter with a rubber mallet, listen for a rattle coming from inside of the case. If there is a rattle then the catalyst has broken apart.

Yep Willey, I had my catalytic converter tested, and it tested fine. Now, I just got back from the transmission shop. He told me to drive it around until it got hot and acted up, which I did. I went by the shop, he hooked up his analyzer and off we went. Now, it has never thrown a “check engine” light or an overdrive light ever, all gauages are normal, nothing overheating, no leaking, smoke, smells, etc.

I explained to him it only does it when it’s warm, and especially when driving on an incline. I drove a short distance, and thank GOD, it happened! It immediatley heard it, and said it’s not grabbing 4th, and could possibly be a band, servo, but would need to drop the pan and get in to take a look. These are very trusted mechanics, well respected, and have tested my truck twice now, and have yet to charge me a cent.

So, I did mention to him about the sensor, and he agreed it ‘sounds right’, but it would have thrown an error code, which no codes whatever are being read. He is baffled, but definatley heard the rpm’s rev up while the truck would not accelerate. He thinks it’s just the 4th gear band, but doesn’t know for sure.

At this point, I’m going to make arrangements to drop it off so he can have it for the day and get inside and see what he can find out and we’ll have to go from there.

I will keep everyone posted, and I sincerely appreciate all the feedback!



For me I need the "extras’ to be omitted from the post. As I understand it the symptons are, limited acceleration, and an scanner indication of a misfire but no check engine lights for any issue. We are dealing with a F-150 with the 5.4, what year? (I want to look up TSB’s).

Please list the items and services that 450.00 will buy you. The term “tune up” should be removed from all sources.Also could you please report what testing procedure was use to give the catalytic converter a clean bill of health?

Don’t know what you mean by ‘extras’, nor the "tune up should be removed’ bit. It’s a 2002, 5.4, V8 Triton.

Don’t know the name of the machine he tested my truck with. He had it on nearly 90 minutes testing several things to eliminate what it could be.

“Extras” are the stuff about the BBB (and similar “cluttering”) info and “tune up” means nothing today. We need to know what will be done for 450.00 (in order to say “go” or “no go”) and we need to know how the cat. was determined to be 'good".

It only happens on an incline?
You probably should have mentioned this earlier.

I wonder if when the transmission was replaced, that they failed to give the proper dipstick with the car, and you are running with too low of a fluid level.

When you go on an incline, the fluid level drops enough, that its no longer doing what it needs to do, and is overheating, causing the temp sensor to be unhappy.


I’m in agreement with oldschool that a lot of information needs to be provided in order to sort all of this out and the term “tune up” is a bit of a misnomer.
That term really should have been dead and buried with any vehicle that uses a DIS, or distributorless ignition system.