1989 5.0 GT smoke out tail pipe issue.

Hi im new to the thread and recently purchased my first 5.0, the car sat in a garage since 2004 has a 120k miles one owner, and since then ive got it running. The issue im having is smoke out of the tail pipes but intermittently. It never smokes on a cold start the the times it does do it is when im driving at normal rpms for a long distance come to a stop, and once stopped the smoke will roll out for 10 to 15 seconds then disappear, some times its quite a bit. Since it started smoking, Ive done a compression test to all cylinders along with a leak down test and all cylinders were fine. I also went ahead and replaced valve seals thinking that was the issue along with pcv valve, but no change. I do pull a thermactor code but for the first valve off the smog pump. Not sure if that's the issue. Everything is basically stock besides, off road x pipe with cat delete, bbk headers, bbk air intake and Msd cap rotor and plug wires. The engine seems to run fine no hesitation or weird idling. The smoke is white in color and smells of fuel/oil. Any ideas would be appreciated Thanks.

90sickfox said:

Fuel ( generally ) makes black smoke. With compression test you can cross out headgasket... unless it's a very small leak.

Have you lost any coolant ? The throttle body spacer can leak putting coolant into the intake. It can cause mysterious white smoke. This has happened to me and a couple other guys. You can remove the bbk intake pipe and look in the throttle body. If its leaking you should see evidence of it....or you can pressure test the coolant system.

Click to expand...

Hey sorry for the late response i looked inside the throttle bisy and no sign of coolant, i also went ahead and pressure tested the system wich hels 16 psi steady for 20 min. Still having the issue any help would be appreciated! Thanks.