Hey new to forum, need some help. I need to know what this line is, had a bad smelling brown liquid in it
03 5.4 4x4

 

And your truck is what year and which engine? Are both pics rotated 90 degrees left? Looks like a coolant hose to me.

 

Yep, would also say this is a coolant hose.

 

2003 5.4 lariat 4x4 auto trans...and yeah sorry theyre both rotated left 90 degrees. I was thinking something tranny related though, fluid was brown and stinky (could be burnt tranny fluid). Wouldnt coolant be a sweeter smell and blue or green?

 

And its the one with writing on it just to clarify it

 

It's definitely a coolant line and not transmission related. You probably just have rust in the coolant system causing the antifreeze to turn brown. Would be a good idea to do a flush.

 

Ok thanks guys, gonna do a coolant system flush. Might flush trans too for good meausre as its a new truck to me. Check out my truck in the show it off page too gonna post some pics there

 

You may have a leak in the trans cooler inside the radiator, getting trans fluid into the coolant. How does the coolant look and smell?

 

Sorry for sounding so knewbish, so f150s have a stock trans cooler integrated in the coolant system? I havent checked the coolant system. The trans dipstick lookes brownish and smells burnt like the line. Almost like clean diff fluid but not as bad. But wayyyyy overfilled. I havent checked the coolant but i will tomorrow for sure

 

If the trans fluid is brown and smells burnt, your trans is on its last legs. You made a mistake buying it.

Trans fluid level is checked with the engine and trans warmed up, idling in Park. If the coolant is brown, you have a problem there too.

 

Brown and burnt smelling transmission fluid is definitely not a good sign, as GLC said. Does the transmission seem to be shifting properly? How many miles on the truck? I guess it's always possible that it's just never had a fluid change and the fluid has broke down and not doing it's job lubricating. More than likely though you have some bad internal parts causing friction/heat.

 

I think the idea of a small leak in trans cooler is spot on. Checked coolant and its a match to the color and smell. 88k miles on it. Optimistic its not a burnt trans because its shifting fine. Going to put stop leak in, drain and fill both systems and throw some stop leak in again and hopefully that fixes it.

 

I used stop leak one time and it ruined the radiator, be careful with the stop leak.

 

Do NOT use stop leak - replace the radiator and get both the transmission and cooling system flushed. Stop leak will NOT work for this kind of leak. If you look around you may be able to find a radiator for 100 bucks.