Went for my first real shakedown run of the truck after it being rebuilt and sitting for awhile. Truck started great and seemed to run fine (albeit slower than I remember), but every time I shifted from 3rd to 4th I notice a puff of shift smoke coming from the exhaust. Was not present the entire time I was driving, only between those gears. The engine was completely rebuilt with a new head and everything. After driving I looked at the engine and don't see any signs of coolant leak. I will check levels once it cools off, but does anyone have other ideas of what could cause this? I'm thinking it could be something with the trans since it only happened shifting.

 

Only between third and fourth is strange none at start up Automatic??

I could think lots of condensation from sitting hot days cooler nights but that would be at start up.

Leaking coolant into the engine would be all the time.

I would think engine mounts and transmission mounts are good no twisting of the engine causing anything to flex and leak coolant into the engine.

Interesting ??

 

It is a manual and yeah it's not constant. Only a puff when shifting. Could low trans fluid or something cause it?

 

Nothing like that. It’s combustion related from where you take your foot off the gas to shift.

 

Defective valve guide or valve seal? I know you said it got a new head but it is chinese made right? I've found the quality with damn near everything chinese made to be pretty hit or miss (often miss).

 

I'll have to go back and see which head I got (giggity). It's been awhile since I've bought everything and done the work. A lot of stuff came from lce, some stuff came from rockauto. It might be worth adding that there is a rhythmic tick when the trucks idling. Could this possibly also be valves? Could be lifters too. Finally to the point where I can get this thing dialed it.

 

I am hoping Lifter was a slip?

Was the head complete with all new valves?

Do a leak down test a valve might not be seating correct.

 

Yes new valves. Everything in the engine is brand new.

 

Thing is it can take time for rings to seat! A new Engine needs some break in time.

Give it sometime since everything is new . A compression or leak down test at this point might not support the true condition

As long as it gets no worse !!

Keep an eye on the coolant and oil levels

 

10-4. I checked after that first drive and all fluids are spot on, didn't look discolored or anything either. Drove it for about 60 miles. Although my temp gauge wasn't working, everything seemed to stay very cool.