4l60e won't go into reverse when cold

[lesmore49]

I have a 1997 Chev. Astro with the 4.3 Vortec V6 and 4l60e automatic transmission. I have had this vehicle since new and generally it works well, except for a tranny problem, which started about 11 months ago. I have 143,000 km (around 90 thousand miles) on the odometer.

 

In Jan./04 the temperature went down to about - 41 degrees celsius (which would also be about -41 fahrenheit when it gets that low) . I am from the Canadian prairies so it does get this cold on occasion.

 

I had left my van out for about 6 hours in this weather and had not been able to plug in the engine block heater.

 

I put the van into reverse and it would not engage reverse until the van idled for about 5 minutes.

During the spring, summer and fall months when the temp. is about 10 degrees to 40 degress celsius (50- 95 fahrenheit) there is no problem. I get into the van, fire it up and put it in reverse and it engages reverse right away.

 

But during winter months whenever the temperature goes below -10 degrees celsius (about -15 degrees fahrenheit) I have to let the van idle and warm up for about 5 minutes or so. It will then engage reverse.

 

If I don't let it idle for 5 minutes or so, it will not engage reverse, until the warm up has taken place.

 

Any ideas what the problem would be? I have heard that these GM electronic transmissions sometimes have solenoids that may act up and cause a problem?

[chevroletmb]

could be a bad seal that leaks fluid when the seal is cold but once the fluid warms up the seal expands and seals allowing transmission to engauge reverse

[hercman]

Those are pretty cold temps and would expect that to be normal. If it operates fine after a warm up then I see no problem. I've seen ATF coagulate at 0*F That stuff gets pretty thick and has a hard time gettin through the filter.

[lesmore49]

Those are pretty cold temps and would expect that to be normal.  If it operates fine after a warm up then I see no problem.  I've seen ATF coagulate at 0*F That stuff gets pretty thick and has a hard time gettin through the filter.

 

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I appreciate the replies, both from hercman and my fellow prairie dweller from Calgary.

I never had a problem engaging reverse right away until that fateful and cold winter day, so I thought it might be a solenoid or an internal seal.

 

If it is a seal , as suggested from the member from Calgary, do you think it will deteriorate over time and continued cold temperatures until it finally will not engage reverse? Would a faulty seal mean a complete overhaul or just a replaced seal? If I continue to operate it does anybody know if I will do more damage?

 

I think hercman's view about cold making fluids coagulate makes one think about the current advice manufacturer's provide to consumers. Manufacturer's during the past # of years suggest that you warm machinery up as little as possible, that driving will warm up faster. Less fuel consumption, better for the enviroment, etc.

 

This maybe the case, but driving warms a machine by putting it under a load, perhaps an unnecessary load when the temp dips down very low.

 

It used to be (20-30 years ago) that accepted practice in a cold climate was to warm up a vehicle for a few minutes before putting it in gear. I think I will return to warming up vehicles in cold conditions before driving off.

[chevroletmb]

If it is a seal , as suggested from the member from Calgary, do you think it will deteriorate over time and continued cold temperatures until it finally will not engage reverse? Would a faulty seal mean a complete overhaul or just a replaced seal? If I continue to operate it does anybody know if I will do more damage?

 

well i really don't think i seal will fix itself, will it get worse? probably but when? who knows. once you get into a transmission looking for a bad seal i don't know a tranny guy who wouldn;t insist on an overhaul. all new seals and clutches

if your gonna go that far you might as well overhawl it so it's reliable and 3 months later your not digging into the tranny looking for another problem or bad seal.

[hercman]

Current thoughts are with the computer controlled fuel injected motors a traditional warm up is not needed. Yes your car gives off more emissions while idling cold and you are burning more fuel as well. The enviromentalists are willing to sacrifce the longevity of your motor for the enviroment. Remember for proper lubrication and proper operation you should warm up your vehicle before you put any kind of load on it. At a minimun the first start up of the day you should let the motor idle for a couple minutes to ensure the engine is recieving enough oil to lub things up. As for the seal being bad or going bad. Freezing temps will cause rubber seals to harden and shrink slightly and operating them in that condition can destroy said seals. It is possible once they warm up to function properly as I believe you have experienced.

 

 

And oh by the way -41* is downright cold. The C-130s that operate in Antartica do not shut down their engines when they fly to the south pole because the outside air temps are too cold to get the engines restarted.

[lesmore49]

Current thoughts are with the computer controlled fuel injected motors a traditional warm up is not needed.  Yes your car gives off more emissions while idling cold and you are burning more fuel as well.  The enviromentalists are willing to sacrifce the longevity of your motor for the enviroment.  Remember for proper lubrication and proper operation you should warm up your vehicle before you put any kind of load on it.  At a minimun the first start up of the day you should let the motor idle for a couple minutes to ensure the engine is recieving enough oil to lub things up.  As for the seal being bad or going bad.  Freezing temps will cause rubber seals to harden and shrink slightly and operating them in that condition can destroy said seals.  It is possible once they warm up to function properly as I believe you have experienced.

 

 

And oh by the way -41* is downright cold.  The C-130s that operate in Antartica do not shut down their engines when they fly to the south pole because the outside air temps are too cold to get the engines restarted.

 

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I have to agree with hercman. I think that the advice that manufacturers have been giving the public is more based on what is politically correct then good engine durability practice. Starting up and driving off immediately in extremely cold conditions, ie; -15 F, is not good engine practice, in my view.

I'm sure many of the engineers at the different auto companies wince when they see the ' advice' given out to consumers.