Here's a puzzler

liamket · Post by **liamket** » 28 Aug 2006, 22:18

1995 850 Turbo Wagon, 150,000 miles, very well maintained thoughout the years, one owner...

Last week i replaced the upper motor mount bushing and in the process i loosened several of the metal bands that hold different sections of hose together. Upon completing the job, i tightened all the bands except for one apparently. Over the weekend I was driving on route 80 in PA. I was passing someone up a hill and went to give the car a little more gas when it died. All power was lost, every warning light was flashing on and off, the engine was unresponsive. I immediately put it in neutral and pulled off to the side of the freeway. my immediate thought was that i had completely burned through the clutch. About 10 seconds after the engine gave out, a very acrid burning smell came through the air vents (burning plastic/rubber). So i stared at the engine for a while trying to figure out what might have happened. I started the car but it could barely idle and when i tried to move it forward and a little farther from the road, the engine stalled.

So i keep staring and i finally see what is wrong. One of the metal bands that holds the sections of tubing together had slipped the the pipe had separated. To the best of my knowledge, this was the lower turbo intake pipe. it runs from the intercooler, up between the airfilter and the engine, over the corner of the engine and down into the back closest to the firewall. I reconnected it and everything seemed fine.

However, i wonder what damage might have been done to the car. I smelled something burning and now there is a small bit of smoke that comes from that end of the engine, even when idling. does anyone know if i might have burned a seal or a gasket or even how the intercooler system works? Any help would be appreciated.

Liam

Post by **MadeInJapan** » 29 Aug 2006, 06:28

Take the throttle cover off and see if something else is loose in there or another hose (thinking throttle position sensor hose) has gotten slightly damaged. Without the cooled air blowing through the inake, unmetered air that wasn't cooled entered your throttle, thus possible melting rubber. Anyway, it's worth a look and may answer your questions. Also in your writing, the hint was there that there is still smoke on that side of the engine- I definitely suspect a hole and a leak. Anyway, good luck with this and please keep us updated.

Post by **robert213** » 29 Aug 2006, 08:42

Located just after your air filter box, you will find the air flow meter sensor. Air is sucked at turbo inlet and is pushed at turbo outlet. Air under boost flows to the front of engine compartment, thru the intercooler (think of it as a radiator for air instead of for liquid), and back to your throttle body. The accelerator pedal opens the butter-fly plate to control air flow into your engine.

Whenever the amount of air measured by the air flow meter is different that the actual amount going into the throttle body, the ECU will become confused. It will open/close injectors per what was measured by the air flow meter. If there is an air leak anywhere between air flow meter and throttle body, your engine will not run correctly.

If the air leak caused your engine to run rich -- lots of black smoke out of the exhaust -- the only damage is that some unburnt fuel has seeped down into the oil pan. Drain-and-refill with fresh oil (and oil filter) for piece of mind.

If the air leak caused your engine to run lean -- not enough fuel to cool engine combusion process, engine starts bucking -- it possible that you may have burnt a valve, but I really doubt it.

In either case, replace hoses between air filter box, turbo, intercooler, and throttle body for piece of mind. Also, small vacuum hoses around throttle body may need to be replaced. (Perform search on SAMCO and StylinMotors).