V10 Triton losing power

[Fishbreath69]

Originally Posted by twinboat

The occorance isn't intermittent. If you read the OPs post, it happens under heavy load while climbing a hill.

That says gas filter.

Actually it is intermittent, only happened twice, both were long hills no run and in first gear. Any other hill that I can keep my momentum it's perfectly fine, no issues what so ever.

[Waiter21]

Are you watching engine temperature on these climbs, What is the temperature???

ALSO - Verify that you do have an integral transmission cooler in the regular radiator. Look on the bottom of the radiator and see if the transmission cooling lines go into it. On early V10 F53, it didn't, I'm not sure about the E350/450 ??

Do you hear the fan clutch kicking in. This WOOSH sound will sound like a 747 taking off.. I don't think your going into engine overtemp limp mode, but its possible.

NOTE - A significant source of transmission heat is the torque converter slipping. The torque converter will unlock and slip when its shifting gears and also some throttle movements. One way to reduce this is to manually downshift and hold a speed / rpm / gear that doesn't require full throttle..

On my F53, I make hard climbs with the trans manually shifted in 2nd and even 1st. When in 2nd, I can hold 4000 rpm and about 45 mph. In 1st, its 4000 rpm and about 25 mph. Keep the rpms up there.. on the V10, rpms are your friend.

You have the same engine I have, the non-pi (Performance Improvement) V10. So you'r only able to put out 275hp, but you need to be turning rpm to do it...

[Fishbreath69]

Originally Posted by Waiter21

Are you watching engine temperature on these climbs, What is the temperature???

ALSO - Verify that you do have an integral transmission cooler in the regular radiator. Look on the bottom of the radiator and see if the transmission cooling lines go into it. On early V10 F53, it didn't, I'm not sure about the E350/450 ??

Do you hear the fan clutch kicking in. This WOOSH sound will sound like a 747 taking off.. I don't think your going into engine overtemp limp mode, but its possible.

NOTE - A significant source of transmission heat is the torque converter slipping. The torque converter will unlock and slip when its shifting gears and also some throttle movements. One way to reduce this is to manually downshift and hold a speed / rpm / gear that doesn't require full throttle..

On my F53, I make hard climbs with the trans manually shifted in 2nd and even 1st. When in 2nd, I can hold 4000 rpm and about 45 mph. In 1st, its 4000 rpm and about 25 mph. Keep the rpms up there.. on the V10, rpms are your friend.

You have the same engine I have, the non-pi (Performance Improvement) V10. So you'r only able to put out 275hp, but you need to be turning rpm to do it...

I do keep a close eye on the engine temp, always in the normal range, never gets hot. It had 2 tranny coolers before, the integrated one in the coolant rad and a small secondary one, I have since installed a third larger aux cooler. Yes the fan kicks in, scared the crap out of me the first few times it did. I also do manually shift the transmission, keeping the revs up.

I dont think that it's going into limp mode as theres no additional codes, and it also recovers so quickly. I believe it's a heat issue, hopefully the extra cooler helps, but now I can at least keep an eye on the tranny temp and actually see what's going on. Im going to change the fuel filter and find the source of the lean codes today hopefully.

[Waiter21]

Im going to change the fuel filter and find the source of the lean codes today hopefully.

Very good. It sounds like your cooling system is acting normally.


If you have an integral transmission cooler in the engine radiator, I'd say you are probably OK with trans temp, unless your bypass valve is stuck and its limiting the trans fluid to the cooler. There is a test for this. You also have a gauge now, so you can keep an eye on it. (pressure bypass leaks and doesn't send enough fluid to the coolers)

I don't think the weird shift TSB applies to you, its for F53 PCM. (grounding wires were sending noise as the vehicle speed signal and confusing the transmission as to what gear it should be in)

When was the last time you did a tranny filter change and flush? I flushed mine last fall when I changed the filter. It takes about 5 gallons to do a complete flush. I use Valvoline ATF Synthetic in my 4R100. It cost about $18 a gallon at Walmart.

F53 Transmission filter change and flush – 1999 Southwind 35S


Its possible the fuel filter could be limiting you. If its never been changed, it would be good to do it anyway...