When i crank up the car, it pushes out a purple-dark smoke, is that bad gaskets? or what? and sometimes it backfires after letting off the throttle? are these problems related and or how can they be fixed? Thanks.

 

Smoke on start-up is almost always due to bad valve stem seals.

 

well, the smoke on startup should be bad valve stem seals...not too hard to replace and can easily be done by even a novice mechanic...and the "backfiring"...are you sure its not just the exhaust popping? if you have an aftermarket exhaust...or hell, a worn out stock exhaust, then you will get popping out the exhaust for lack of backpressure...if it IS literally backfiring, we will need to know what the specs are on your motor to make a diagnosis (carb, TBI, TPI? any mods done...just general specs)...btw, WELCOME to the site!!

Josh

 

I would say that most likely if you are getting smoke on the startup it would be the valve stem seals - most likely the exhaust. As other have said, this is a fairly simple repair assuming you have the right tools. I would explain how to do this for you but you would probably get more from a service manual, especially one that has pictures. As far as the backfiring, are you sure this is not just your exhaust popping? That is fairly common. (not good, but common.) Does the car have any other drivability issues: loss of power, abnormally high/low coolant temp, trouble starting?

 

NO the car runs and drives great, it is the L98 350 engine. Where exactly are the valve stem seals located? and the backfire or 'popping' may be the exhaust, it is the stock exhaust that came on the car...p.s. this info is very enlightening thank you all.

 

Also the car seems to use a lot of coolant...