Trans problem: last call for help
 

Hi,

I am new to this forum. I tried the diesel mailing list but could not get adequate reponses for my transmission problem with a 87 190D 2.5. Hoping for better luck here. Anyway, the symptoms are as such: When I first start up the car, it will go into reverse or drive just fine. Good acceleration, shifts fine as it has always been. But no more than a minute later, it will lose all power. I have to keep the revs very high to keep it at a mere 20mph and the glow plug light will come on too, and if I come to a full stop, the car will not move, as much as I keep the rpm high. My only remedy at that point is to shut off the engine and wait a few minutes, then restart. But that only allows me to get the car moving at a crawling pace back to the parking lot.

I have checked the trans fluid and the level seems fine. Fluid and filter changed 6mths ago. I checked the kickdown switch too and it is not sticking, although I am not sure how smooth it has to be. It takes some effort to push down the switch. I checked as many of the vacuum lines as I could. Vacuum at pump is to spec, 700mbar; good vacuum at amplifier; vacuum control valve is somewhat lower at 300 mbar than the required 400mbar. Is there other vacuum lines I should check? I took a look at the EGR valve and it was completely sealed with inches of gunk, not surprising after 350K miles. I cleaned out as much as I could and I could actually hear the turbo spooling now. But that did not fix my transimission problem.

Any help or ideas would be greatly greatly appreciated. I don't want to give up on this car just yet.

Yen

It is not a diesel specific problem but here goes.

What is the condition of the fluid? Just because you filled it up 6 months ago doesn't mean the fluid is not burnt. Just because it was OK 6 months ago doesn't mean the tranny isn't shot. So, one more time, baby. Drop the pan and be careful about it. That way we can see if there are metal flecks at the bottom of the pan. If so, your tranny might be going out.

This may be a dumb question, but are you really sure that its a trans problem?

Your description would lead me to look elsewhere.

I'm not but looking at the fluid and pan is one way to see if there is something wrong there and then I would think he could take it from there

Where would you loook? Just curious and trying to learn

I can drain the transmission fluid when I find the time next weekend. The trans was rebuilt 30K miles ago, but that is no guarantee on the transmission's condition.

Sounds exactly like a clogged fuel filter to me.

Sounds like a fuel starvation problem to me. Check your filters, I bet you have an algae attack and the filters are clogged. Same experience I had.

How much fuel is in the fuel tank right now? I bet it isn't full.

OK fellows.

If he can "keep the revs very high" and the vehicle will only go 20 mph, it's not a fuel starvation issue. Now, if he can't get it to rev, that's a different story. So, I conclude that it's not fuel filters.

If it drives perfectly fine for the first minute and then won't move, it sounds like the fluid must be very low in the trans. Just enough to engage the clutches until all the fluid is distributed and the pan runs dry??


How have you checked the fluid? With the engine shut off? Or, with it running? This could provide some insight.

Remember my "loss of power....Briefly thread.."

a fuel restriction does act like this.....even though my problem was the shut off solenoid was artificially partially restricting fuel due ot a restriction in the crankcase ventilation.

A set of filters are cheap......low or high trans fluid won't keep the engine from reving...or making enough power to go more than 20 MPH.....

low fluid would lead to trans slipping and being way too free to rev...due to slipping clutches..

The canister filter will hold enough fuel to let it go for brief periods at more than idle, the inability to feep up with fuel consumption would leed to the power loss......

$15 will prove thats not the issue. Of course checking the trans fluid of course cost nothing but I bet its fine.

No way. If you have a fuel restriction, you will not have the vehicle display high revs and not go anywhere. Your problem was that you lost power and could not get the revs to allow the vehicle to move above 55 mph, IIRC.

This one has revs but won't go over 20.

I agree that fuel filters will rule it out, just in case "high revs" are not all that high.

I would concur with that. The problem sounds like it might involve a failure to downshift. Have you tried manually downshifting when the problem occurs?

I have extra sets of fuel filters and I would give that a shot. FYI, I did run a can of diesel purge maybe 6mths ago and changed both filters afterwards but I might have had a bad batch of diesel afterwards. My problem with checking the trans fluid accurately now is the car could not be moved enough to warm the fluid up to temp, so how could I be sure? And does anyone have an answer to the glow plug light coming on while driving? The glow plugs are working I know. I have no problems starting the car in winter, even though it might take at least two cycles when it is 5F outside.

High revs I was talking about was 3000 rpm; the engine sounded like that was the limit at that point. I did try to downshift manually to no avail. It would not even go into reverse from a stop.

With the transmission cold, where is the fluid level on the dipstick? (Idling in neutral.)

New fuel filters won't solve that problem.