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  #16  
Old 01-23-2007, 08:45 AM
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Join Date: Aug 2006
Location: Houston, TX
Posts: 450
Don't think its Transmission or Brake Fluid

Others may challenge this assertion (I could be wrong), but engines that are burning transmission and/or brake fluid usually put out the most smoke during rapid deceleration, when the engine vacuum is highest, not during rapid acceleration when the engine vacuum is lowest.

Reason - the aforementioned fluids are pulled into the engine via vacuum - vacuum to power the power brakes, and vacuum to send a signal to the transmission modulator. In either case, testing for this problem is generally as simple as removing the vacuum hose (for the brakes, at the booster if possible - for the transmission, at the intake) and checking for the presence of the related fluid.

If you're new to this car, do you know it's previous owner, and/or their driving habits? Given the age of the vehicle, it's possible that lethargic driving over the years has resulted in an engine with a lot of combustion chamber deposits. If the smoke you're seeing is "pure white", then it's likely coolant or transmission fluid. If the smoke is more "hazy - gray", then possibly it's just upper engine deposits being burned off via your "italian tune-up".

There's a simple test to see if you've got a leaking headgasket - a device that will check for the presence of combustion gasses in the radiator fluid - any competent mechanic shop should have such a device.

For transmission issues (and again, I refer to my original assertion that transmission fluid isn't your problem), there are only 3 places that transmission fluid can "disappear" to -
1) Outside - leaking things on the transmission - seals, hoses, connections, etc.
2) Engine intake via damaged modulator diaphragm.
3) Engine cooling system via ruptured transmission heat exchanger, which is inside the radiator.
Transmissions don't have combustion, so they can't burn fluid. A severely slipping transmission might generate enough heat to vaporize some fluid, but you indicated your is shifting properly, so we can discount this as a possibility.

For condition 1 - you should see evidence of this under the car. Try placing a fresh piece of cardboard under the vehicle @ night.

For condition 2 - look under the car (will need ramps or jack stands), find the transmission modulator - just guessing that it will be on the driver's side of the tranny, towards the front of the housing. There'll be a small plastic hose attached to it that routes upwards towards the engine. If the small hose is attached to a device that also has a large cable, that's the upshift controller, not the modulator, look for a single hose.
If you can pull the hose loose at the transmission without breaking it or anything else (old cars have old, brittle plastic), take a Q-Tip and pull ALL of the cotton off the end. Needs to be a Q-Tip with a cardboard stem, not plastic. Use that cardboard stick to probe the hose and the nipple it attaches to. If you find red fluid - there's a leak in the diaphragm of the modulator. You can also test the other end of this hose where it connects to the intake, but as long as you're up under the car.....

For condition 3 - you should see evidence of this in the radiator overflow bottle.

If all of the foregoing tests yield no results - try using an top-engine cleaner. I've used Seafoam before with good results. It's available at your local Autozone, comes in a white metal can with red lettering. I've not tried it on my MB, so you might post a question about using this product before attempting it. I drive cars HARD and Seafoam got crud out of my 32V V8 Lincoln's motor - resulted in a much improved idle.

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  #17  
Old 02-14-2007, 01:21 PM
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I'm a chicken
 
Join Date: Sep 2006
Location: SAN ANTONIO, TEXAS
Posts: 1,148
Thanks for the info. I will try these tests when I get a chance. As of today I need to bleed the brakes as I replaced a caliper last night and this morning I developed a nice fuel leak at the fuel filter. And then I have to fix my windows as they do not toll up all the way anymore. Sigh. It seems I'm working every weekend to fix something on this car. Can't wait til I just can enjoy the ride without worrying about another problem. Luckily nothing major so far.

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