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-   -   Another Tranny Problem (https://www.subaru-svx.net/forum/showthread.php?t=44526)

pylon500 04-28-2008 07:24 AM

Another Tranny Problem
 
Hi Guys, Been a long time away (Moving and building a new house :)), and have slowly been building up some odd problems with my '92.
The most recent (and important?) is after first start up, when selecting D or R, I get a sudden judder, sometimes a minute wheelspin, and the engine stalls. :mad:
If I hold a bit of gas (1500~2000) and select a gear, after about the 4th stall, :eek: the juddering goes away and the car drives normally.
I'm assuming I have a problem with the TC locking up at start?
Plenty of fluid in the box and still reasonably red.
All subsequent starts, selections and changes while driving are OK.

Next fault is with my climate control.....
Every now and then while driving along, I would hear a beep and see that the climate control had selected the outside temperature momentarily :confused:
Sometimes it would alternate between the setting and OAT repeatedly which would get very annoying.
Then the climate control setting would start beeping down to the lowest setting and stay there, if I tried to reset it, it would just beep down again :mad:
The other day when it started beeping, I looked at it to find it was now going to the highest setting! Fortunately my heater core is disconnected as it has a leak :(

Oh yeah, that's another problem :o
I've read the posts on replacing the core, and I'm not looking forward to that one!!

An interesting note on the climate control, about a year ago I noticed that when I turn the lights on, the P at the end of TEMP stays bright, about a month ago the M would stay bright as well.
In fact I think last week the E was also bright.

I was having a problem with the headlight fuse blowing, but that turned out to be a loose wire in my trailer plug.

I'm also hearing some exhaust gas noise under the 480k klm engine, but cannot find a leak around the manifolds and suspect a burnt valve?

Most of this may not be too important as I have another engine and tranny (160k klm) to swap, but reading those posts, I now see I've got a JDM front cut, and will have to do all the speedo mods :(

So, any ideas on the tranny lock up problem, are any of the other problems likely to be related?

Arthur.

svxistentialist 04-28-2008 08:32 AM

Hello Arthur

Good to see you back, you have been a busy lad! ;)

Regards your transmission, you may be perfectly correct in your assessment.

Possible causes of stalling are given as "valve sticking", "poor engine performance" and last but not least "lock-up clutch seized"

The fact that it does not give a problem when running for a while could be down to the oil getting warmer and thinner.

With your climate control, what is happening there is an age related problem. It seems to be common in Japan, and the only known cure is to replace the unit, not too cheap of a solution.

Two of my cars were doing the same sort of madness, either bleeping all the way up to the highest level, or else down to the coolest setting. No science to it. The outside temp thing blips annoyingly as well.

I have discovered a solution, but I don't know how temporary it might be; you need to blitz the car interior with heat, and have the aircon working so that the humidity and dampness from inside the car is all soaked up.

We discovered this driving home from Oxford with Jersey Girl [good job it was winter.;) ] As soon as the car was warm and dry inside, the aircon started to work as normal.

In your case you have the heater bypassed, right? This means your interior is getting cold and damp. This dampness is affecting the aircon computer, and setting the logic circuits askew.

You should fix the heater core first. Then when you heat up and dry out the interior, if the aircon goes back to normal, you are laughing.

If it doesn't, you will have to find a good s/h one, or fix the one you have. I suspect the problem is caused by poor and intermittent solder connections in the circuitry. It would be worthwhile opening the unit up for a look. An electronics shop could solder up any bad contacts you identify.

Joe

oab_au 04-28-2008 06:31 PM

Hi Arthur, moved to Taree yet?
Well it does look like the lock-up clutch is jamming. This will be because some of the lining has flacked off to jam it. Some of these bits may have traveled down to the cooler and have lodged there also. So give it a clean when you do the transmission change. Swapping the speed sensor is not a big job to do before you fit it, the holes are already drilled and tapped.

Can't help with. the AC, except that I have scans of the system and the code procedure in my old locker here:
http://www.subaru-svx.net/photos/user.php?oab_au|35851

It may give you a clue to the problem.
Harvey.

Trevor 04-29-2008 06:39 AM

Greetings Arthur,

I note that you have been advised that the lockup clutch is jamming because some of the lining has flaked off to jam it and that therefore a transmission change is inevitable. A costly first off analysis. Logically would a jammed clutch consistently clear, in the way you have described?

Lock up operation is controlled by solenoid valve “B” which is a normally closed, and is opened to drain at a 95% duty cycle in order to fully engage lock up. Lock up release occurs when the solenoid valve receives a duty cycle of 5% or less, whereupon the valve is closed to drain and full lock up release pressure is applied.

Control of the solenoid is dependent on the TCU and when in first gear or reverse, i.e. when you are getting a shudder, the solenoid should receive a only a 5% pulse modulated duty cycle and there should be no lock up.

As you start with a lock up condition this could be due to solenoid “B” not closing properly or having a worn or fouled seat, any leak to be overridden immediately full transmission line pressure is available.

The solenoid could well record a fault code at start up and you should first off run a test. However the test should not be taken as definitive as the system has limitations which depend on solenoid armature movement and the electrical circuit both of which may be OK.

Importantly the solenoid involved is accessible without removing the transmission, being part of the valve body. The message I have is to investigate fully before writing off the transmission. ;)

Trevor.


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