slidekin Posted July 23, 2005 Share Posted July 23, 2005 A few months ago I bought a 92 sc400 with 125k on it. Now it smokes from the tail pipes and runs super rough and crapy. I took it to my mechanic and he said I will have to replace or rebuild the engine. Sounds a little extreme to me. I heard it could be the rings or the valve guides from him and other shops. Still way to expensive. I looked on this site and found that other people with this similar problem have had problems with the coils and it seemed to work for them. But I dont see how that could cause smoking from the tail pipes, and that awful gas smell that comes from them. Please HELP I think it s to dangerous to drive so its been sitting in my garage for about a month. Quote Link to comment Share on other sites More sharing options...
Sadistic Posted July 23, 2005 Share Posted July 23, 2005 If it's smoking, I would say that it's probably burning oil somewhere. If something needs to be replaced, or rebuilt it should be done. Even if it's expensive. There could be other things, but if multiple mechanics are saying the same thing, and they've done diagnostics to figure this out. I would have to say go with what they suggest. Quote Link to comment Share on other sites More sharing options...
texsn95 Posted July 23, 2005 Share Posted July 23, 2005 What color smoke? White = coolant, blue = oil, black = pig rich. Oh and find a new mechanic if they can't even explain why an engine swap is needed Quote Link to comment Share on other sites More sharing options...
slidekin Posted July 23, 2005 Author Share Posted July 23, 2005 As for the first response, they didnt do anything but guess. To find out what is wrong they would have to take the engine apart. That alone is the most expensive part. I have only taken it to two mechanics, in addition to Lexus. The first mechanic said there is a 20% compression loss on all cylynders. And took a guess as to what is happening. I replaces the spark plugs and there is wet oil on one ind the threading and dry on another above the seal line. Also there seems to be oil leaking from the rear main seal. The smoke coming from the tail pipe is white. Which = coolant but why?They have explained why engine swap is needed, b/c its cheaper to replace it tan rebuild Any other suggestions? Coils? Quote Link to comment Share on other sites More sharing options...
Sadistic Posted July 23, 2005 Share Posted July 23, 2005 Do an oil change on your car. Drain the oil and see if it's frothy, and smells like coolant. Or if you can get a good enough look at it under your oil cap, go for it. It almost sounds like head gasket is starting to go between. That could explain the white smoke. The oil on your plugs (if I read it right) sounds like the valve cover gasket. Quote Link to comment Share on other sites More sharing options...
texsn95 Posted July 24, 2005 Share Posted July 24, 2005 As for the first response, they didnt do anything but guess. To find out what is wrong they would have to take the engine apart. That alone is the most expensive part. I have only taken it to two mechanics, in addition to Lexus. The first mechanic said there is a 20% compression loss on all cylynders. ← So he did a leakdown test then? That's different and more involved than just a compression test, which just shows xxxpsi. Whichever one he did, it helps to have the numbers, then you can compare to spec. Quote Link to comment Share on other sites More sharing options...
jzz30 Posted July 25, 2005 Share Posted July 25, 2005 um did the car run rough all of a sudden? and that smoke does it smell like gas? if these 2 things match then i think 99% that its your coil primary or secondary but you should just chnage both, they range from 75-100bucks from the dealer. if you keep on running like this you will overheat and damage your cats. your oil leak maybe a different case but the plugs are probably just wet with fuel. Quote Link to comment Share on other sites More sharing options...
texsn95 Posted July 25, 2005 Share Posted July 25, 2005 Oil on the spark plug threads are indicative of worn valve guides and/or seals. If they're really bad you'll get a puff of blue smoke on startup. It's not throwing a check engine light? Quote Link to comment Share on other sites More sharing options...
SKperformance Posted July 25, 2005 Share Posted July 25, 2005 Oil on the thread is from an oil leak form a valve cover usually. As oil doesn't leak on a plugs thread unless the head is cracked. Oil on the tips only is a problem but not on the threads. Quote Link to comment Share on other sites More sharing options...
texsn95 Posted July 25, 2005 Share Posted July 25, 2005 Oil on the thread is from an oil leak form a valve cover usually.As oil doesn't leak on a plugs thread unless the head is cracked. Oil on the tips only is a problem but not on the threads. ← Ar, forgot about the valve cover. What I mentioned is common on the pushrod V8s I'm familiar with, but perhaps not with these <_< Quote Link to comment Share on other sites More sharing options...
slidekin Posted July 26, 2005 Author Share Posted July 26, 2005 Oil on the thread is from an oil leak form a valve cover usually.As oil doesn't leak on a plugs thread unless the head is cracked. Oil on the tips only is a problem but not on the threads. ← So what your saying is that my head is cracked since there is oil on the threads. :o Quote Link to comment Share on other sites More sharing options...
slidekin Posted July 26, 2005 Author Share Posted July 26, 2005 um did the car run rough all of a sudden? and that smoke does it smell like gas? if these 2 things match then i think 99% that its your coil primary or secondary but you should just chnage both, they range from 75-100bucks from the dealer. if you keep on running like this you will overheat and damage your cats. your oil leak maybe a different case but the plugs are probably just wet with fuel. ← I like this idea. Is it hard to do yourself?? Any computer reconfig after? Quote Link to comment Share on other sites More sharing options...
jzz30 Posted July 27, 2005 Share Posted July 27, 2005 not hard to do at all you dont even have to disconnect the battery, no computer reconfig. Quote Link to comment Share on other sites More sharing options...
slidekin Posted August 6, 2005 Author Share Posted August 6, 2005 So what exactly do I ask for when I go to Lexus and get the coils. I know there is a diffrent name for them. And how would I find out how to install. Thanks for the help Quote Link to comment Share on other sites More sharing options...
jzz30 Posted August 7, 2005 Share Posted August 7, 2005 just ask for the ignition coils. and its fairly simple to replace you just have to look for them. one is on the driver's side bank of the engine and the other is in the middle of the V you will see coil wires coming out. but make sure first that you smell raw fuel coming out of the exhaust Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.