A 92' sc300 with 105,000 miles, leaks a little oil, but now it idles low in low rpm and when you get into higher rpm range, it lacks power and starts blowing smoke out the tailpipes, so much you can't see a car right behind you. Anyone know what the problem could be or had something similar to???
Please help
Please :

 

What color smoke?

I found this information and posted it on a prior thread a few months ago.... may be useful:

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Exactly what color is the smoke? Here's a good diagnostic FAQ I found with a quick google search...

From http://www.salemboysauto.com/faqs/faq-38.htm:

Black, blue, white or grey smoke from the tailpipe!

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Black smoke is raw gasoline burning. A rich condition can be the cause by a heavy or mis adjusted float, a choke stuck shut, a bad oxygen sensor, a bad map sensor, a bad fuel pressure regulator, a plugged up air filter or a bad injector. Typically, if you only get black smoke first thing in the morning, it has to do with the choke or the fuel enrichment portion of your fuel injection system. If you get black smoke all the time, get it fixed NOW. If you don’t, you run the risk of wiping out the catalytic convertor and doubling your repair bill.

Blue smoke is oil burning. The tailpipe will either smoke all the time or just once, first thing in the morning. If you get blue smoke all the time, that is a sign of impeding doom. That is the first sign of the beginning of the end. Broken rings, bad pistons, damaged cylinder walls, all high dollar items.

On the other hand, if all you get is a puff or two first thing in the morning and never again throughout the day, then your problem is probably bad value guides or value guide seals. It will cost between $350-800 to replace the seals, $750-1,500 to replace the guides and seals. I always tell my customers, wait until you begin to see other symptoms of this oil usage. Wait until you start fouling plugs, wait until the oil consumption is greater than one quart every 1,000 miles. And never assume that seals alone will totally fix this problem, if the engine has 100k miles plus.

Grey smoke can really be black or blue. You can usually tell which is it by the smell or by matching other symptoms you have to the color of the smoke is easier. Others will say blue is blue and all other is really grey to black and I would agree.

White smoke is either the transmission shift modulator is bad and allowing the engine to suck and burn transmission fluid (repair costs under $100) or it’s really, really bad. White smoke could also be coolant or antifreeze that is either leaking, or being forced into the combustion chambers and being burned. The exhaust will look wet and have a sweet smell to it. A bad head gasket (75% of the time), a broken head (15% of the time) or a broken cylinder wall (10% of the time) will be the reason your engine is burning coolant or antifreeze. The repairs start at $400 and go to $4,000.

 

this is a VERY good reference because recently my car has been spittin' out white smoke even after the car has properly heated up..

thanks you you i can properly diagnose what the problem is....

 

The smoke is grey-blue

 

Check your water level first. If its low, thats a blown headgasket.

Also, that much blue/grey smoke on any car with only 105,000 miles on it is extremely bad, let alone a Lexus. Does the car run ok otherwise?

 

I recently had lots of thick blue smoke coming from my tailpipes. Plus a smell of burnt oil.

Turned out to be blown rings on two of the pistons. Car idled fine.

 

the car only smokes when the overdrive in engaged and the is in first or second gear.
any thoughts??????

 

more than likey the OD button has nothing to do with it at all, and it's visible in lower gears because you're not going as fast.......the faster you go, the harder it is to see the smoke usually, and the wind will knock it down out of view of your sideview/rearview mirrors.........

sounds like rings to me, but sometimes the valve stem seals can allow enough oil by to cause this, although they normally show up as really smoky start ups more than anything.......

during winter, people will confuse steam with smoke too because they literally just get paranoid and expect something bad to happen.........certain weather conditions can cause your car to "steam smoke" for a lot longer than normal........temp, humidity, temp of your exhaust, etc

 

Are you sure the smoke is coming from the exhaust?? I know that may be a silly question, but sometimes something can drip on the header/exhaust when high speed or high RPM's which translates into high pressures. You have tranny fluid, coolant, oil etc. which all can produce tons of smoke when dropped onto a very hot exhaust pipe........


Dan

 

all fluids are fine, but if i don't engage the overdrive around 50mph, it starts to smoke until the engine gets back down to idle speeds??? it doesn't really happen any more though. could it have been too much oil???

 

whats the problem?? mine also throws smoke at 5000-7000 rpm when i put in neutral or push on highway it throws out grey smoke why ??