Weird Renix Trans Problem

Ok, so a couple of days before Christmas I was driving along the highway and suddenly smelled something like burning plastic. My initial thought was a wire or something burnt up on the heater core, so I pulled over. Couldn't find anything wrong. I took back off down the highway. Pretty soon the cabin starts to fill with smoke, pretty badly. Pull over, look under the car and see trans fluid spewing out like a firehose. Tranny cooler line had popped loose and thats where the fluid was comin out. The smoke was coming from it hitting the exhaust and burning (good thing I didn't have a fire - and of course this was the one trip out of a thousand I left my extinguisher at home.) After much cussing, I was able to get the line popped back in, and topped it off with ATF. No dice, O-Ring and quick connect must have been blown out too - new fluid drained right out.

Had to have her towed to the nearest shop. When the shop got back to me, they said they replaced the quick connects and o-rings on both lines and topped up with fluid, but could no longer get it to turn over (even with a new batt.) Asked me if "I had any ideas" First thing that made me a lil unsure about this shop. I called back and they said "they let it sit in the shop overnight and now it cranks fine."

I don't hear anything back for a couple days so I call. Guy says that they can get the Jeep to go about a block, then it stops moving. They can "let it cool down" and it'll go another block or so before dying. He thinks that the trans suffered some internal damage and probably will need to be replaced.

My feeling is either A) sensor problem (could be CPS - but the car never die - they say it stops and won't move in any gear.) The odd temperature thing - leaving it in the shop overnight to crank - letting it "cool" then it makes me lean in this direction.

Could also be B) They are correct, and trans suffered internal damage (either causing or CAUSED BY the trans cooler leak.) What makes me think this may not be correct is for one, it still moves. Short distances, but it moves. I would think a burnt up trans wouldn't move at all. Also, I never FULLY lost fluid with the engine running. I pulled over pretty much immediately. Also, the trans has been the only damn part to ever work right. Shifts smooth, etc.

Last option is C) Before all this happened, I was having problems with my NSS and/or shift linkage. Sometimes it would only start in neutral, or I'd have to shift back and forth between park and neutral to get it to start. Sometimes while driving it would shift itself into neutral, and I'd have to pop it back into drive manually. (Note it did this about five mins before the trans cooler line popped.)

Any thoughts? Right now the shop is offering to look around to find me a trans, just thought I would pick your brains here first. Really don't think the shop is trying to rip me off - they're a lil Mom and Pop place and have only charged me $63 bucks so far - the price of the quick connects and new battery. I just am not sure of their technical knowledge, but I'm not a mechanic by any means, so who knows.

Edit - I should add that this fall I replaced both the IACV and TPS, so probably not those sensors.

Does the shop know about the NSS? I would be concerned about all that fluid spaying everthing. It does not evaporate readily. I wonder if the cool down is really a "drying out" or draining. Starting it up might cause more fluid fluid flow due to thermal expansion causing a short. I know this is a hairy and crazy option, but cause of failures could be more obscure.

If the engine does not die, (isn't that the case?) that safely eliminates the crank sensor as a culprit. This is not an NSS issue either for the reason that the NSS issue you were suffering just gave you trouble in getting it to crank.

But if the vehicle remains running and fails to move after warming up, considering what happened to it, then it is highly likely that the tranny is fried. A good tech. should be able to tell if the tranny is causing this. If I were you, I'd like to see it first hand...

There are some tests that could be run (see FSM) to confirm the tranny which might be a good idea to run before swapping.

But looking at good old "cause and effect", the lack of fluid probably did some internal damage.

overflow said:

...After much cussing, I was able to get the line popped back in, and topped it off with ATF. No dice, O-Ring and quick connect must have been blown out too - new fluid drained right out....

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Yeah, when the Quick disco goes, the o-rings and spacer usually blow right out of there too. If you're out on the road, the best thing to do is cut the hose and clamp it.

overflow said:

...I called back and they said "they let it sit in the shop overnight and now it cranks fine."

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Oh, that ALWAYS works...it's a time/space thing.

overflow said:

I don't hear anything back for a couple days so I call. Guy says that they can get the Jeep to go about a block, then it stops moving.... They can "let it cool down" and it'll go another block or so before dying. He thinks that the trans suffered some internal damage and probably will need to be replaced.

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This sounds like your torque converter is either empty (not enough ATF or there is in fact damage to it). The trans should take somewhere around 8 qts. including the Torque coverter. Just drain and fill is about four quarts, but if it spewed out under pressure, it likely needs the 8, or a least 6 qts.

overflow said:

My feeling is either A) sensor problem (could be CPS - but the car never die - they say it stops and won't move in any gear.)...

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CPS would not allow the car to "run, but not move. It either runs and moves or not, generally.

overflow said:

The odd temperature thing - leaving it in the shop overnight to crank - letting it "cool" then it makes me lean in this direction.

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Meh!

overflow said:

Could also be B) They are correct, and trans suffered internal damage (either causing or CAUSED BY the trans cooler leak.) What makes me think this may not be correct is for one, it still moves. Short distances, but it moves. I would think a burnt up trans wouldn't move at all. Also, I never FULLY lost fluid with the engine running. I pulled over pretty much immediately. Also, the trans has been the only damn part to ever work right. Shifts smooth, etc.

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Internal damage did not cause the quick disco to pop off. Quick discos are iffy at best. All mine are cut, flared, barbed and clamped. 0% failure rate (unless the hose itself blows).

overflow said:

Last option is C) Before all this happened, I was having problems with my NSS and/or shift linkage. Sometimes it would only start in neutral, or I'd have to shift back and forth between park and neutral to get it to start. Sometimes while driving it would shift itself into neutral, and I'd have to pop it back into drive manually. (Note it did this about five mins before the trans cooler line popped.)

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If it has ANYTHING to do with the NSS it would just be an adjustment issue. Coincidence?

overflow said:

Any thoughts? Right now the shop is offering to look around to find me a trans, just thought I would pick your brains here first. Really don't think the shop is trying to rip me off - they're a lil Mom and Pop place and have only charged me $63 bucks so far - the price of the quick connects and new battery. I just am not sure of their technical knowledge, but I'm not a mechanic by any means, so who knows.

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Someone on here knows, wait for their response.

overflow said:

Edit - I should add that this fall I replaced both the IACV and TPS, so probably not those sensors.

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A sensor will not make your hose pop off.

ParadiseXJ said:

Quick discos are iffy at best. All mine are cut, flared, barbed and clamped. 0% failure rate (unless the hose itself blows).

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The newer updated ones use a 4 prong internal metal clip as opposed to the early 2 prong plastic clips. No problem with the new ones.

sjx40250 said:

Does the shop know about the NSS? I would be concerned about all that fluid spaying everthing. It does not evaporate readily. I wonder if the cool down is really a "drying out" or draining. Starting it up might cause more fluid fluid flow due to thermal expansion causing a short. I know this is a hairy and crazy option, but cause of failures could be more obscure.

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I suggested it may be the NSS when I called back and gave them "ideas" of why it might not start. They were quick to dismiss it when it cranked after sitting in the shop overnight though.

I am going to go look at it this weekend - unfortunately it's a good hour from my house so I won't be able to do much. Any ideas on quick things I can check before having them put in a new tranny?

There is some formal testing per factory service manual that can be done; unsure as to what capabilities or equipment the shop your xj is at has.

I'd get in it and drive it. If the tranny binds up in a block and doesn't move the vehicle any longer, I think you probably know the answer.

birchlakeXJ said:

I'd get in it and drive it. If the tranny binds up in a block and doesn't move the vehicle any longer, I think you probably know the answer.

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Basically yes. I had had one AW4 smoke on a friend and I helped him replace it with a junkyard one I got.

As has been mentioned on the board here before if the trans still acts up with the trans contoller unplugged then it's probably time for a new/used one.