View Full Version : Blue Smoke

12-28-2001, 05:30 PM
recently, under full throttle only, i've been getting blue smoke out the exhaust. it never used to do this until i replaced the spark plugs, cap and rotor. i think there was a leak in cyl #4, could the better spark actually ignite the oil more? the car has 183,000 miles on it. i guess i should be lucky my car has lasted this long, but exactly how serious is the blue smoke, and how much longer will my motor last before a rebuild?

i got a digital camera for xmas and when taking videos of the exhaust, it was even more noticable.
or http://whateverjames.com/240SX/HKSsportR2.mov

12-28-2001, 06:31 PM
James, first of all I just wanna say what's up...I'm from Champaign, Illinois...we should meet up sometime.

About the oil burning. First of all, does it occur all the time or just at start up (and a short while afterwards)? If that's the case, it's probably just some worn out valve guides. These can be replaced, but I've never done it. Might be hard. I don't know. Check the FSM, and if it's hard, just leave it. Worn guides aren't a big deal...just keep an eye on the oil level.

If the oil burning is all the time, do a compression leak-down test. I've never done one of these either, but a mechanic will know how. Or, for an easy test, check the compression like normal (with a compression tester screwed into each spark plug hole in succession). After you get those numbers, pour a capful of oil in the spark plug hole and do the test again. If the numbers go up, your rings on that cylinder are shot. Not necessarily a reason to buy a new engine tomorrow, but this is not something that will go away. You could try Engine Restore or something like that, but that's a band-aid fix and something I would only do if I was planning on trashing the engine in the long run.

Do those checks and then get back to us (me).


12-28-2001, 07:32 PM
yes changing the valve guides is very difficult. You have to heat the head to 248-284 deg. Ferinheit, the you have to use a press, then ream the hole, then heat it up and press the new ones in. It is alot of work, and i will have to do it soon myself so.......i am not looking forward to it.