Hey guys. I dont get under this topic much... but I have a quick question. My brother has a 91 Nissan 300ZX nonturbo. Last time he drove it, he raced a Porsche on a highway... and supposebly kept up. He has intake, headers, full exhaust... Anyway, that night he saw smoke coming out the back and out of the hood. We have no idea what it is. We drove it today, to see whats up, but it is not nearly as fast as it used to be. He doesnt pick up as fast. To me, I would say spark plugs and maybe a air leak. What do you guys think it is?

 

Possibly head gasket. Do a compression test. You may have a coolant leak that would cause a white smoke when heated up.

Was it a boxter by any chance?

 

Yeah it was a Boxter.

Anyway, the guy at a shop I go to said it could be the catalytic converter.

And also Sebba, how can I do a compression test?

 

I highly doubt its a cat because you would feel more power and not less. You will get a little more emissions if your cat is bad and it wont start as good but it wont cause those kind of things.

You can buy a compression tester and you just hook it into the spark plug socket and crank over the engine. I think you should be getting someware around 175psi but i could be wrong.

Also what colour is the smoke? Im still willing to bet its a head gasket.

Boxter = slow POS

 

Yeah Boxters are POS. They are slow.

Anyway, the guy at the garage said that the 'cat' could be clogged.

Anyway, I am going to tell him to do that compression test and let you know if you were right. But is that just going to solve the smoke problem? We can still turn on the car and drive it, but we can go as fast as it use to be. It drives fine. Is that head gasket going to fix that too you think Sebba?

 

The reason for smoke is something burning in the combustion chamber that shouldnt be there. After running it hard and then it smoking would be logical for it to be the head gasket. That would explain why the car is sluggish because its burning something it shouldnt be. I would also check the condition of the spark plugs. Check the cheap option first lol.

Is this a thick white smoke? Blue smoke? Does the smoke smell or anything?

The clogged cat still would not cause alot of smoke.

 

do you hear a clanking noise? nah its not an air leak...and by any chance can you get good light and look around the block and see if you see a lot of oil build up anywhere it does sound like a head gasket...and a head gasket going would produce that smoke and the power loss due to not as much compression and runnign way too lean....

 

THanks guys. I guess we are going to check out the head gasket and spark plugs. Thanks for your help. Appreciate it.

 

Burning all that crap has probly fouled your plugs up

 

Hey guys. We found out what it was. You guys wont believe it, but it was the spark plug coil wire. It was loose.