Hi all,

My used Japanese import 2003 model Mitsubishi Grandis suffered automatic transmission oil cooler failure a few months ago, and because the vehicle is not supported or sold in Botswana, the repairshop I sent it to recommended replacing the unit with one built into a bigger custom radiator as opposed to ordering the original thing from Japan and having to wait for over a month for it to arrive! Because certain Mitsubishi models use the same technology, I accepted the idea and let then modify and re-route the piping. The failure of the transmission oil cooler had caused mixing of radiator coolant and automatic transmission fluid, introducing weird transmission behaviour - so I had the system flushed and took the opportunity to have timing belts, cylinderhead gaskets and a few other things done to preempt any other problems that could have arose in the near future.

When the car was delivered to me I noticed immediately that it wasn't running as smoothly as before with the automatic transmission making violent gear changes once in a while and the engine running perceptively hotter than I remembered it (After a while I could even see a slight discolouration of the headlamp glass as affected by the temperature! I was assured that the transmission would calm down after a few more oil changes and that the temperature was not abnormal since the gauge was operable and reporting normal temperatures.

Almost a month of discontented driving later, the vehicle mysteriously lost coolant and overheated - hitting the red zone and stalling on me! I called the repair shop to take it back in and they "discovered" a failed thermostat stuck in the closed position, and found also that the cylinder head gasket and oil scraper rings had been damaged as a result of the overheating. I ordered new parts for both the cylinder head and the engine, including a set of new piston rings straight from Japan.

The cylinder head was measured, machined as necessary and reassembled. The engine was put together and the car prepared for a road test before they could hand it over to me. It was during the road test that the mechanics reported intense clouds of blue smoke arbitrarily issuing from the exhaust, and specifically under hard acceleration.

Back at the workshop they removed the cylinder head and discovered engine oil in the combustion chambers of the last two pistons to the left of the transverse mounted engine, fouling the spark plugs. The cylinder head valve guides were tested and found to be fine. The pistons, their rings and the bore were also inspected, measured and found to be fine!

Is anyone familiar enough with the 4G69 SOHC 2.4l mivec engine as found in this car, to know what might be causing this? Please HELP!!!