Questions and Answers
A Hot Transmission
Q. Transmission on my 1994 Cutlass Convertible seems to overheat depending on outside temperature and will not shift into overdrive. During summer months transmission down shifts into third after in town driving or about fifty miles on highway at speeds over 70 mph; has not occurred during winter.
Local dealer / garage do NOT know what problem is. I had to recreate and still no guarantee they can fix?? 1994 Cutlass Supreme Convertible, V-6 w/ DOHC, 63,000 miles, Automatic, A/C, Cruise control.
I have the oil changed regularly and had ATF changed about 6 months ago (no help). Dealer has checked electronics multiple times (diagnostics only check for current flow ??). Their current strategy is to go into the transmission and replace solenoids with no guarantee of success. Before we do this, should I consider an oil cooler? Just yesterday morning, drove 65 miles in cool weather (65 to 70 degrees) without occurrence.
NOTES: Water pump recently replaced (was loosing coolant). Engine temperature rises slightly when slow in town driving. In my opinion there is excessive heat from under car after stopping.
Thanks,
RobertA. That transmission might already have a fluid cooler on it. It seems there was a problem with the cooler becoming slightly clogged and that it needed a flush to get it back up to specs. There was a TSB 99-07-30-017 issued 9/99 on the procedure for checking the flow rate and proper flushing. I quote from the bulletin:
GM studies indicate that plugged or restricted transmission oil coolers and pipes cause insufficient transmission lubrication and elevated operating temperatures which can lead to premature transmission wear-out. Many cases could have been prevented by following published procedures for transmission oil cooler flushing and flow checking. This procedure includes flushing and flow checking the auxiliary transmission oil cooler, if equipped.
If your car is not equipped with a transmission fluid cooler I would have the cooler in the radiator flushed out and see if there is any improvement. If there isn't, then an auxiliary cooler can be installed.
Additional Information provided courtesy of ALLDATA
