I took my truck on the highway for the first time to stretch its legs and we got only 60 miles.

As I was driving up a hill the engine note changed and it started "chugging" and loosing power. I saw the temperature was creeping up above 105 degree c and I pulled over onto the hard shoulder.

There was smoke everywhere! and oil (seemed to be engine oil colour) underneath. When I started it again after cooling - engine started and sounded fine, but when I put it in gear there was no power. The engine would rev OK but no forward or backward motion. BUT it looked like engine oil which does not make sense to me.

Can you help diagnosing what the problem is. I will

1. Check the engine oil level (if this is low problem probably main rear seal?)
2. Check for white oil in the engine oil (to see if its the head gasket)
3. check C-6 auto box ATF level (if low probably its front pump brokeon)

What else should I look for? I have little experience with this kind of problem / esp on these trucks (first I've owned). What would you look for first if you had these sypmtoms.

Other info There is no oil spillage /leak at the front of the engine. 86 F150 with 460CI / C6 / NP208

Can torque converters fail catestrophically? What colour is their fluid

Hope you guys can help I feel sick as after working on the truck all summer to return to road worthy condition its failed majorly on our first fun trip.

 

transmission fluid is normally red, but in the case of a smoked tranny, it's more like coffee..

trans fluid level?
blown/leaking cooler line would be my first guess, blowing fluid on the exhaust

 

Ill check this ASAP back in a minutes

 

OK - Oil is missing from the auto box as you guessed.

I checked the cooler lines and these are OK. Perhaps the atuomatic fluid overheated and puked out of the front of the case. Can this happen?

I'm going to fill the auto box back up and see what happens.

 

"I'm going to fill the auto box back up and see what happens."

Actually ... is this a good idea??

Tranny ATF fluid is 1 month old - should be red but the oil that has leaked is brown. Very strange. Does it change colour if it overheats?

 

The fluid does turn brown when it overheats. It will probably be brown if you just changed the filter, but did not change all the fluid in the tranny.

What does the truck look like underneath. The best troubleshooting tool you have is a good light and your eyes. If there is oil all over the place, then wipe it all off with a rag, fill the tranny back up and get it running, and then get under there with a light and look for a leak.

There are a lot of things going on in a vehicle. Don't believe the TV shows. It's a rare thing to rebuild a vehicle and it not need an adjustment here and there or have a leak somewhere.

 

Right just had a go at this.

Seems the transmission oil has overheated and puked the fluid all out.

Someone has fitted an aftermarket oil cooler which I presumed to be sufficient (but it is behind the bumper with no direct airflow or fan assist). I think the transmission just got too hot.

I dont know how it got out thogh. The dipstick / engine area is clean. Could you suggest place for me to look?

Tomorrow I'm going to steam clean the underside, start it and run for a while. If I'm satisfied its not leaking I'll do a short drive and check the level. I'm going to get a gearbox and x-fer case temperature sensor for the dash.

Should the transmission be flushed after its oil has overheated and turned brown?

I use Dexron III ATF fluid (C6 transmission and NP208).

 

By the way I feel sorry for the person that was behind me there is oil EVERYWHERE on the underside

 

Yes, get all the fluid out. Take the inspection cover off the flywheel/flexplate area, and then turn the engine by hand till a drain plug comes around that is in the torque convertor. Take this plug out and drain the fluid, and then pull the tranny pan off and drain the fluid there, and check for any metal or bad things in the pan. Put the pan back on and go get about 14 quarts of fluid. I think it takes about 12 or 13 to fill it.

You should not be using just the tranny cooler. You should also be using the cooler in the radiator. The aux cooler and the radiator cooler should be hooked in series.

 

Thank you for your advice!

I will hook the radiator cooler up (new radiator just installed!) and plumb this in series with my transmission cooler, which I will add a fan to.

The current cooler is connected using fuel hose. Is this ok?

I'm going to get tepm guages for the transmission and x-fer case. What is their standard operating temperature range?

Im starting to think this trucks last owner is a fool

 

I have never had a tranny temp guage, but I would assume since the cooler is in the radiator, that somewhere around 195 degrees would be the expected temp, maybe a little higher. I have used fuel hose with no problems. I have wondered why though, they give you such thick hose in the cooler kits.

 

I got to the bottom of this problem - no damage really

I fushed all the Transmission fluid out
Mounted the trans cooler in a better location (behind front grille).
Installed fan on transmission cooler.
Ran transmission oil also through my BRAND NEW HEAVY DUTY water radiators oil cooler section
Removed W/C mounted fan. I have a 3000CFM fan on the engine radiator (after idling at 100 degrees water temperature, turn fan on, hits 70 degrees in 2 minutes).

The transmission oil line now looks like this:

Transmission -> Engine radiator oil cooler -> Dedicated oil cooler -> Tran oil temp sensor -> transmission

I think the transmission basically massively overheated, perhaps even boiled!!!

There is a slight problem that I'm leaking ATF - I suspect the transmission rear seal is leaking, and pressurising the transfer case (NP208) which seem to be leaking all the way around.

Not too bothered as it probably only needs topping every 500 miles. I'm thinking of putting an easy access pipe onto the ATF fluid line.

Keep on rollin ........ 42" TSL's forever.

 

The reason for such thick hose is fire prevention. You should never use fuel hose! If at all posible, hard lines should be used at all times.

Rubber fuel hose will fail over time, the tranny fluid sprays all over the engine compartment and on the exhaust manifolds/headers. The result is an engine fire.

I've seen this first hand and it's not pretty. We were sitting on the side of the highway watching my buddy's nearly new Chevy truck burn to the ground from using a rubber hose on a tranny cooler.

 

AH

Shall have to look into getting some braided cables made up

That said, my fluid should always be less than 100 degrees C

N