HELP!! Urgent 3100 issues

[N2Oldsmobile]

My car has developed a severe idle problem. It's extremely pronounced when it's cold. On startup, if idles at 1500 rpm then at times will climb to 2000. It drops to just above 1000 in drive, and it really slams into it. Its at the point where its not idling, it will actually pull itself along. This brings me to the second half of the issue. It's overheating my tranny really badly. I got off the highway yesterday and lost overdrive. It just stays in third. Tranny fluid is full. I just put a cooler in a week ago, but I don't think its that because the issue started like 4 days after I put it in. The tranny had a fresh rebuild a year ago too. I'm thinking the idle might be blown intake manifold gaskets and I'm praying I didn't cook my tranny.. Any suggestions? Please help.

[eliteweapons]

Are you getting any trouble codes?? What tranasaxle is in it the 4t60e? You might want to check for some shorted wires first. The trans shouldn't overheat from an idle issue it sounds like as line pressure issue. The 4t60e is electronicly controlled and that may also cause an idle issue if it is engaging overdrive.

[rx191]

i ran into this problem on a grand prix i worked on. grab a scann tool and look at teh tps voltage if it is too high the computer will think the throttle is open and will raise the idle and cause the problem you are talking about. anything over 2% will cause an idle problem

[no_doz]

also check your throttle, because sometimes there is a screw that will hold your throttle at a certain position, & if thats adjusted wrong well, you know...

[tractorman]

Check for vacuum leaks- that'll make 'em idle too high. Look for broken/loose hoses and such, but here's a trick to see if your intake or throttle body gaskets have a leak. Get some starting fluid- like you use for diesels when it's cold. Run the car at an idle and spray it around. If there's a leak, it'll suck the starting fluid in and you'll hear the engine rev. Find out exactly where you have to spray to make it rev, and you've found your leak.

Could you have knocked loose or broken a vacuum line when putting that cooler on?

[JMo60]

i would check the vaccume line that goes from the intake to the trans modulator, that would give the trans issues, as well as make it idle high