: Leaking Transmission fluid and High Idle in Park and Neutral

04-03-11, 07:05 PM
I have a 1989 Cadillac Brougham. I brought it not to long ago and it runs fine except for the fact that when it is in park and neutral it idles high and when I put it in drive and reverse it idles fine and rides like a dream but on the other hand it is leaking transmission fluid badly I jacked the car up and got up under there and it seems that it is leaking slow from right behind the oil pan but I really just need some help so I dont have to keep going to autozone for transmission fluid 1-2 times a week. Hopefully save a few buck on gas with this high idling. ANYBODY WITH ANY HELP OR ADVICE PLEASE LET ME KNOW ASAP....... It is leaking from behind the oil pan could it be aa clogged or bad transmission filter/screen?

04-03-11, 09:53 PM
The leak might just be the pan gasket. You could first check and see if it's tight enough, sometimes the bolts loosen up. Don't do them too tight, and work out from the middle. Gasket is most likely shot though, so a new one might do the trick. On the idle, does it appear that anything is binding? I had high idle on mine too, it was a combination of things. I had to lube certain areas of the linkage, extend the linkage, and still had to add an additional throttle return spring to get to to settle down. Yours might have a control though, something that is intended to regulate idle, either electrical or vacuum. I had something like this on my '90 DeVille, don't know how it is on the RWDs of that era. That's a carbureted 307 if I'm not mistaken, and I don't think they had the same sort of electronics as the 4.5. Check linkage, throttle return binding, spring pressure, that sort of thing.

04-03-11, 11:26 PM
It sounds like you're leaking from the front main seal in your tranny. Thats too bad because you'll have to remove the tranny to replace it. There is nothing you can do to slow it down, just find somebody to help you one weekend and get to it. Nothing special needed but those tranny lines can be fun. If your car is rusty on the bottom, it gets nasty. The idle issue could be a number of things...idle control motor on the carb, linkage, stuck butterfly, all in your head(jk), stuck choke... More than likely, its related to the carb.

04-04-11, 10:50 AM
Have you tried kicking down the idle? The engine is supposed to idle high for 30 seconds after a cold start, but then you need to manually kick the idle down. To do this you jab the throttle pedal to the floor, once, and release it quickly. Sometimes on my car, if I don't do this, the idle will return to high when I shift back into park.

If you have tired this and it hasn't worked, then there may be something wrong with the Fast Idle Cam. I believe the linkage for the fast idle cam is on the passenger side of the carburettor. Lubricate that linkage and then check to see if it is changing position.

The Idle control motor is on the driver's side of the engine. You can see if you take the air cleaner off (it should have an arm going up to the throttle linage). If I'm not mistaken, screwing the arm out will cause the idle to lower (I don't recommend do this adjustment unless you know what you're doing).