I was sitting in a parking lot on the phone and my friend tells me that my exhaust is really starting to spit out white smoke it wasnt real thick but a decent amount was coming out at idle i started freeking checked my oil and coolant and everything nothings really changed so i started to drive home and it stopped hasnt done it since. it only did it for about 20 mins. Im guessing the headgasket is about to be needing a change and when i turn my truck of i hear a slight knock for a few seconds its like a slight click click click doese it about 5 times then stop is that normal? never really noticed it till lately?

 

Was it cool or moist out? Did you just start the truck? Probably just moisture from the tail pipe. Normal. The click click is the sound of the exhaust contracting as it cools right after you shut the truck.

 

no it had been running for probably about 10 minutes prior to the smoke

 

oh and i doubt it was cool or moist i live in vegas last anykind of rain we saw was about a month ago