New member! I've been poking around here since I bought my Bonneville, and now I gots a problem, so, first post! You guys seem well informed, hopefully I can get a little info...
I have a '95 Bonneville, naturally aspirated, 90k miles. 4T60E transmission. Here'* my dilemma:
Bought this car a few weeks ago. Drove it around, seemed ok, took it on a 300 mile trip. Car went great for about 100 miles. Then overdrive quit. I later found out that the TCC wasn't working either, but we'll get to that... After playing around, I figured it was a heat thing, and decided to check the fluid and filter. Bought a new filter and fluid, take it home, start to drain it- and it sure looks like Type F is coming out of this thing. So I get it all drained out, new filter, Dextron III back in, and suddenly the old beast is a much smoother car. Shifts into 2nd are smooth, no longer causing whiplash, ha, and overall is just smoother and most shifts are unnoticeable.
I start doing a little research, and I find out this car has a TCC. So I start checking it out- still appears that the TCC isn't working. So I pull out my scanner, and I have a code P0740. Search around, can't find any definitive info on that. So I go live info, take her for a drive and I find that the TCC solenoid is engaging. However, the converter never locks. RPM'* never drop, and the tool says it'* not engaging. When I first started looking at the problem, I thought it might be the solenoid, but that'* engaging.
I've searched around here, but I'm not entirely sure what I'm looking for at this point, I'm really little more than a back yard mechanic. What could be my problem here? What can I do to test things? Any help would be greatly appreciated. Obviously I'm buying a 15 year old car here, I'm not exactly looking to drop a ton of money at a shop