R50 Terrano auto issue.

[nickmcdonald]

Evening all. I'm having an issue with my auto trans. Vehicle in question is a 1996 Nissan Terrano, QD32eti. Cruising at 100kmh, it normally sits at 2100rpm...just purring along. Lately though, it sits up at 2400-2500rpm, which is a noticeable increase in a diesel! After about 15km's down the motorway, you'll feel it finally come right and 'shift' into operating normally. Is this the torque converter locking up?

If anyone has any insight into this particular issue, sing out! Cheers.

[BlakeNZ]

yeah, you have correctly identified that it's not locking up the torque convertor as early as it should/used to. Sometimes i think it is a faulty sensor(for instance, it won't lock up till the computer sees a certain operating temp-not sure if this is an engine coolant temp, or trans fluid temp). Other times i think that trans wear is a contributing factor.
My Mistral (same auto trans as you) has done this on occasion recently.

[nickmcdonald]

Ahhh I see. I have heard that from factory they don't lock up the torque converter until something reaches a certain temp. I guess its always gotten up to temp quick enough that I've never noticed it until now, when its faulty. She's coming up 300,000km's, so a bit of wear is expected I'm going to give it a birthday at 300k, which will include a transmission service, so maybe they can shed some light on it. Cheers!

[scratcher]

i fitted a after market trans cooler inline with the rad cooler and now takes three times as long to drop into lockup so most likely temp related

[mudsurfv6]

I had a 130 surf that did that, first start of the day, the colder the day the longer it took, really cold days could be 10+ minutes of driving. Turn it off then start again while still warm it was fine.

[nickmcdonald]

Yeah, I think so. Talked to a few people who know their way around an auto, and apparently it only locks up the torque converter once up to temp. Fitting a trans cooler would definitely cause this to take longer, as well as cold weather.

[johnny262]

I have a funny feeling that Jatco transmissions have a relative temp sensor deep inside the box that can cause delayed lockup like this, hopefully someone can chime in on this