Lexus Repair: smoke from ex. pipe, oil smoke, american engines


Question
I just purchased a 99' GS 400 with 94k miles from a dealer (not lexus). I just noticed a fair amount of oil smoke comming from the tail pipe when I  started it this morning.  I think I may have made a mistake w/this car. Can I assume valve guides need to be replaced? I have removed the heads from several american engines; 350 chevy,3.8 gm v6. Is this a very complicated job? How much would a machine shop charge to redo these heads. Thank You  Very Worried!

Answer
Mark,

Thanks for the question.

The bad news is that something will have to be done to fix the oil smoke from the exhaust.  It may be a relatively minor repair, or it may involve quite a bit of engine work.

The good news is that this engine is practically bulletproof, and can take a lot of punishment before it gives out.  For this engine to be smoking, means that by all probability, the owner (owners) before you didn't do any regular maintenance on the engine.

The problem could be as simple as replacing the valve guide seals (if the engine smokes mostly after it has been idling for a while and then is revved up), or as complicated as a complete disassembly to fix an engine with oil gelling (sludging), along with a good cleaning, inspection and refreshing.

The best place to start would be to remove the valve cover, and look to see how much oil gel is present in and around the camshaft area.

If there is a bunch of gel and gunk built up, the entire engine should be disassembled, checked, and refreshed with new bearings and whatever else is worn or damaged.

If the engine doesn't show signs of sludge, run a compression test.  If the compression tests ok, then you may be able to get by with just valve stem seals.  This is especially true if you remove one of the seals and see that it is cracked or brittle.

The engine itself is actually easier than a V8 or V6 to work on, so based on your experience, you shouldn't have too much trouble.  I would suggest, however, that you invest in a factory repair manual and follow it carefully.

In any event, this is certainly not the end of the world.  The GS300 engine is relatively easy to rebuild and should be well worth the time and effort it will take.  

As far as the machine shop prices, you'll have to find out what is needed first, and then ask around for estimates.  The labor time and shop rates vary tremendously across the country, so that part you'll have to ask around about.

Hope that helps.

Leonard