Hey guys i have an '87 gxl that i did an engine swap on. the swap was from my old car that got wrecked but its drive-train was good so i took it out. The new car had an engine with blown coolant seals which is why i did the swap. The engine i put in is fine, the problem is with the exhaust. i test started the car a few times without an exhaust on it, it would do the normal smoke on start up then disappear. but once i put the exhaust back on (from the engine that had blown coolant seals) the smoke will not dissipate. I know the seals in the swapped engine are fine and im hoping it is just the exhaust. anything helps thanks.

 

white smoke is water/coolant/steam burning. So it is a possibility that there is water In the exhaust. But you are in Colorado and its cold so it could just be steam from the fuel burning. you say it will not go away there is a possibility the seals are gone. so put the old exhaust back on and see if it still smokes. if yes cold or bad seals if no the condensation in the exhaust. Is it thick or just noticeable?

 

It's not uncommon for it to take a bit of time for the coolant left over in the exhaust to burn out. If the seals were very bad on the previous engine the exhaust being loaded with liquid coolant wouldn't be that surprising.

Happens a lot with head gasket jobs on piston engines where the exhaust will still smoke for a good 20 minutes after repair.

 

It can take a 20 mile drive to get all of the old coolant burnt out f the exhaust.especially in cold weather

 

i had one car that never stopped smoking, the exhaust had to be pitched out because it wouldn't quit after 5 hours of smoking. you can try drilling a hole in the bottom of the mufflers and weld them up after it stops, this may work a little better.

 

I put the exhaust from my other car on it and it no longer smokes. I am having trouble passing emissions though. The vacuum solenoid that has the blue dot on it broke and i cannot find a replacement one for the model year. can i use one from an fd on an fc or just any old vacuum switching solenoid?

 

all those solenoids are basically the same only they have a color designating the reference to a connector.
If you grab any other one off a rack regardless of color just switch it out.

 

I went to get the emissions tested and they said i could not be tested because the car smoked too much. there was no abnormal amount of smoke, only the small amount that there is upon every start up. is there anyway to keep this from happening?