Mr. Spock

OH OH , i need some serious and fast help here people , or do I ? I have been noticing that when i driv eemy 1993 GM around town ( i keep my gear selctor in D and the O/D is on ) i have noticed a small bit of vibration in the car recently as i slow down and bring the car to a stop . In fact , when the car is FULLY stoped like at a traffic light , the car is almost sound like it is going to stall but it does not . I have at that time placed that car in PARK and let the engine idle until the light changes and there was no problembut this sound / feeling is worrrying me a bit . I have also noticed twice now that as i want to accelorate from a slow speed to a higher one , i have noticed a sound that sonded like the pin ging one may get from low octain fuel but this only happened twice and only as i was about to accelorate . I thought i heard a sound that was sort of like one that wouild be heard as if there was no oil in the engine but a check of the dipstick showed proper oil level . The trany oil to is at the correct leevel and is a nice red color , no browning .

If anyone has any ideas or suggestions , please tell me as i am not crazy about spending huge bucks for a new trany ... if indeed that is what it is . I do NOT use this car as a tow vehicle at all .

spock

Mr. Spock

OK , i have done a small amount of test driving to try and better understand an describe what is happening . One note is that this is only happening during city driving conditions .

I have tried to drive various conditions to see what was happening and here is what i have found . While driving in the CITY under varying speeds and conditions . I may have to slow down from a higher speed andn if i am to once again accelorate to a higher speed , it seems as if the transmission is still in the higher gear such as it would be in if i was driving at the higher speed . In other words , i drive at higher speed , slow right down and again pick up speed . What is happening is that as i slow down , the trany does not appear to be downshifting as fast as i would think it should and then , when i again accelorate , it is lugging because it is now in too high a gear for the speed of the moment .

I have tried a few things to see a out of this and what i found i had to do that worked was to quickly step on the gas as the car slows down ever so slightly and then the trany is finding the correct gear to be in for the speed being traveled at . I am also not using the OD function in the city now .

My theory is that what is happening is that the trany is simply shifting gears as it sences the revs go up as i drive but because of the nature of city driving , it is continuously up and down shifting , lugging the motor and giving the false impression that something is wrong but it is infact not a serious issue . AM I RIGHT in my theory and of not , what else can it be ?

spock

BlueSteel

First off, let me assure you, you are crazy..... Don't worry, I'm crazy too, Crown Vics and Grans tens to do that to people. I suggest you take your car to a shop and have them run a dianostics on it. 1993 has a computer brain for the transmission (I beleive in 1992 they came out with the EOD), it'll tell you whats wrong. Also, does this happen all the time or just when the car warms up?

__________________
Blue Anodized Steel
The Apocalypse is coming, are you ready?

Morella

Does this vehicle have a modulator valve? There are classic symptoms of vacuum leak or bad modulator diaphragm.