Questions and Answers
Chugging Subaru Legacy Wagon
Q. Sir; Let me first say that I appreciate the fact that you and About.com have provided this great resource for those of us who work on our own vehicles, for whatever reason.
Now the hard part... About two weeks ago, my sister's medium-mileage 1992 Subaru Legacy wagon with an A/T started to occasionally "chug" and die at very low speeds. I am about 600 miles away from her and can only rely on her verbal descriptions for troubleshooting.
She says that when she slows to a stop, it feels and sounds NOT like the engine is just running rough and dying, and MORE LIKE slowing to a stop in a manual transmission car without depressing the clutch (sort of an overloaded surging sound). It is now occurring with increasing frequency as time passes.
When it operates normally, it drives as it always has, but once it starts doing this, the problem will continue at every stop as long as the car is driven. She states that she can get in the car the next morning and it will usually be fine, at least for a while. The symptoms generally begin while she is driving, and it was unclear if they had ever started from a first-of-the-day cold start.
Ambient temperatures at which this has happened have ranged from about 70F to 30F. After it dies, it will then start and run fine in park or in neutral, but as soon as she puts it into Drive, the engine bogs down and dies. She has had know other transmission or general vehicle problems that I am aware of except a slow leaking left front tire that she insists on only refilling when it is dangerously low.
Most of her trips are less than five miles and she is a fairly conservative driver. I have suggested that she check the transmission fluid for quantity and a burnt smell, and try manually shifting into first or second gear as she slows to the appropriate speed, but have not heard the results of this yet.
I will be traveling home at the end of this week to take a look and perhaps get the DTC codes, but any head start you could give me would be greatly appreciated. I trust that if this email is published anywhere, that you will remove any personal contact information.
Thank you very much for your assistance,
JohnA. Rest assured John, I never use personal information anywhere on my site unless given written permission to do so. The furthest I'll go is to use a first name.
The first thing I would suggest before looking for any transmission problem is to change the transmission fluid and filter. A lot of times this will correct a transmission problem.
One problem this transmission was prone to was a bad ground for the transmission control unit. The cure for this was to clean the existing ground by removing the grounding bolt and cleaning the wire terminal, seating surface and bolt. In addition Subaru wants a second ground wire added by splicing a wire into the factory ground wire and grounding the new wire to a different location.
Having done that, and the problem is still present, then it is most likely the Lockup Torque Converter is not releasing fully. In this case there should be a code for the TCC solenoid or circuit.
That's about all you can do external to the transmission. All the other possible causes would be internal and should be diagnosed by a competent transmission shop.
Additional Information provided courtesy of ALLDATA
