'90 300zx Auto Transmission Problem.

[Aaron2355]

My 300zx started to overheat the other day when plastic radiator cracked in half (why would anybody make a plastic top for a radiator?) I had radiator replaced and changed oil and transmission fluid but since then I think I have major problems. First the overdrive is whinning whem engaged. Second, when I turn off the OD and am driving in 3rd gear, if I lift off of the accelarator it drops to idle and coasts. When I give it gas again, gently, it revs up until it catches the transmission and drives great. It still pulls strong and shifts great but I'm afraid I'm in for some money! Is there anything electrical that could cause this or strictly mechanical? I checked the fluid levels and they are fine. Thanks for your help.

[Q45tech]

Is this the original 1990 [16+ years old] RE4R01A transmission? Never heard of one lasting this long.

[Aaron2355]

I don't know if it is the original transmission or not. I bought car about 6 months ago. It does have 190,000 on it but runs great other than current issue.

[inquisitorof240]

when you changed the fluid,what color was it and did it have an odor?

[inquisitorof240]

If you have AIM, instant message me at CarFanaticDavid and I'll see if I can help you a bit more

[Aaron2355]

I didn't change the fluid. Normally I would but I had to have the car towed to a garage and I just let them replace radiator and all fluids. I don't have AIM but any help would be much appreciated. A friend told me that the same thing happened on his camero (transmission disengaging while coasting) and it was just a module but I cannot find info on any such module for 300zx. Thanks

[inquisitorof240]

I had radiator replaced and changed oil and transmission fluid but since then I think I have major problems.

I was under the impression that you had. Check it and then tell me what color it is. If it has an odor or texture, describe them to me please. I'll try to help. Also, it may not be an electrical problem. If the fluid is black and gritty and smells burnt then you should rebuild your trans. I'm unsure how many miles it has on it but also check for leaky gaskets as low fluid level may not be able to maintain sufficient pressure at lower RPM to hold the gear. Also, if the trans is elecronically controlled, check the shift solenoids for proper operation. This may be difficult but it may be easy. I have been workig w/ american trannys so I am unsure how these Nissan transmissions are designed. If all else fails, have a certified technichian hook it up to a scan tool and pull the Diagnostic Trouble Codes (DTCs) and see where yo can go from there. Oh yeah, usually the solenoids make a noise (depending on the car) and may be heard if the solenoids are external. The easiest thing by far to check is the fluid so start there.

P. S. Oh, BTW, I am having roughly the same problem w/ my chrysler. Yeah, its a MOPAR but its reliable. Over 100K on it and just now giving me probs.


Modified by inquisitorof240 at 9:52 PM 8/2/2006