Strange limp mode - related to low transmission fluid ?

UFO · **Posted:** Mon Sep 24, 2012 12:16 pm

I've got a leak in my transmission cooler, and I need to get an external cooler to fix it, since I don't have the resources to put in a new radiator that will likely develop the issue again.

I checked the fluid level before a short trip yesterday, and it did not show on the stick, so I added a pint and went to pick up a passenger before the trip. After I picked him up, and hit the road, the engine started misfiring badly with no power and slipping transmission. I parked and checked the running engine, it sounded like it was only running on 2 cylinders. I re-checked the tranny fluid level, but having recently added fluid, the stick was coated the whole way up. I went and added the rest of the quart and shut the engine down.

I then restarted it, and it ran great. Drove where I needed to go and back with no further issues. I still need to pull the codes, if there are any, since the CEL was on before with P0299 (which I assume is the MAP sensor because I have plenty of boost).

Is this a transmission-induced limp mode from low fluid?

Randy B · **Posted:** Mon Sep 24, 2012 8:03 pm

From you stating at idle it was idling rough, How many miles since your last fuel filter replacement? Could it have gotten some air in the fuel to make it run rough? I could see the trans shudder or slipping because of low fluid. But with the idling rough makes me think fuel. But then again it could have been the trans issue that put it in limp mode, Just my :2cents:

Mine went into limp mode once and could never figure out why.

UFO · **Posted:** Tue Sep 25, 2012 1:27 pm

I replaced the fuel filter last winter with the upgraded fuel head. Very strange that it cleared up immediately on restart.

Another curious difference before this happened is they way I was driving. I normally drive an automatic VW TDI, and shift into neutral while rolling (saves fuel in some circumstances), and I was doing this a little bit with the CRD. I stopped shifting into neutral after the restart, and the rough running mode has not re-occurred.

Randy B · **Posted:** Wed Sep 26, 2012 10:14 am

That could have done it. The filter was just a thought. Hope that was all it was

Sir Sam · **Posted:** Wed Sep 26, 2012 12:15 pm

slightly OT here is my cooler that I installed, it was like $60 from orielly and came with all the hose I needed to install, though some longer bits would have been nice.

UFO · **Posted:** Wed Sep 26, 2012 3:35 pm

I really appreciate the pictures Sam, that's where I'm going next with the Jeep.

UFO · **Posted:** Mon Oct 22, 2012 3:14 pm

Installed the tranny cooler yesterday, pretty easy actually, so that should be the end of the major leak. This transmission seems very in-sensitive to fluid levels, unlike my old Mercedes diesel, so I am very much in doubt that the screwed up limp mode was due to the fluid level.

I think I just confused the poor computer by shifting in and out of D on the fly. I will not do that any more.

Strange limp mode - related to low transmission fluid ?

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