Delayed shifting when cold, yes I know its normal but.....

[thegipper]

Ok so recently my 97 V6 will not shift out of 1st gear until the engine temp reaches approximately 120 degrees (temp reading via Ultra gauge). It is clearly in 1st as I can only go about 25mph and I'm at 4k rpm. From everything I've read it normally won't shift past 2nd until it warms up, mine, all of a sudden, won't shift out of 1st until it warms up???

It never did this before. Occasionally, in the past, when it was really cold out (in the teens) it wouldn't shift into third for about two blocks but it would at least be in 2nd gear. This is what I thought was normal and has been talked about on here numerous times.

The weather now is in the 40's in the morning and it won't shift out of 1st gear even if I manually put it in 2nd.

OD off or ECT doesn't change anything.

Once it is warmed up, everything shifts like normal and the transmission acts 100% normal. I can park it, let it sit for awhile and it will still be fine. It is only when it has sat overnight and got "cold".

Fluid levels are spot on, fluid is brand new (replaced a couple months ago).

So, what gives? Is something goofy with whatever system tells the tranny not to shift until it reaches a certain temperature? Can a shift solenoid be going bad but not throwing a code? If so, why would it only act up when cold?

No CEL although recently I do get a random "Pending P0301" every couple weeks. Truck otherwise drives, runs and shifts excellent.

 

[Tinigunner11]

I know very little about transmissions so hopefully someone else will chime in. But how many miles are on your truck? It could possibly be that your torque converter is starting to fail.

 

[thegipper]

About 212k miles. I would think if the TC was failing the symptoms would show up more often and not just during cold starts. I am no tranny expert either though.

 

[thegipper]

Going to try disconnecting the battery for 15 minutes and see of that changes anything. This one has me stumped.

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[mtbtim]

Maybe it's the shift solenoid. [MENTION=115590]StreetCreeper[/MENTION] has replaced solenoids before and could probably give you come advice.

 

[AntleredRuin]

A bit off topic, and I understand that the 4k RPMs was accidental, but do be careful about that high of RPM until the engine warms up.

I know, I know, there have been threads galore about driving before the engine warms up, and there have been differing viewpoints, etc, but that seems very excessive to me. Even if it shifted to 2nd, that's still a pretty high RPM at 120F.
The dummy gauge on the dash doesn't even register yet at 120F.

High revs at cold startup are the leading cause of mechanical wear on an engine.
Same goes for a tranny, and the tranny warms up slower than the engine, especially if a tranny cooler is installed to bypass the radiator. I'd think that could even potentially be a cause for your tranny issue, if this has been a consistent driving pattern.



Now, all that being said, how is your tranny 'kickdown' cable? Any slack, or too tight?

Not sure if at all helpful, but the 2nd Gen Rav4 has a chronic tranny issue directly related to the ECM (same board for both the engine and tranny). A few solder joints get old and brittle and don't connect well at cold startup. This causes the tranny to either not shift when cold, or to slip between 1st and 2nd. Once warm, works just fine. Anyone have an opinion on this? Not sure if the 4runner ECM is the same way.

 

[thegipper]

Kick down cable is good, not too tight or loose.

Engine temp is being measured off of my Ultra gauge not the unreliable coolant temp gauge on the dash. I also almost never rev it to 4k, I drive like an old lady especially since these 3rd gens have zero power anyway. The 4k rpm was only noticed because it wasn't shifting, I immediately slowed down until it warmed up. Again, once it warms up (120deg +) it drives 100% normal in every regard like normal.

I was thinking it may be the solenoids also but I hate to just throw parts without diagnosing it a bit more. Again, no CEL lights but maybe they can be bad and not throw a CEL?

In the mean time, I am just going to let it warm up in park until it hits that 120ish mark.

Disconnecting the battery didn't change anything. I did drain out some fluid as it was a bit overfilled.

 

[jgue467]

....
In the mean time, I am just going to let it warm up in park until it hits that 120ish mark.
...

That's what I would do. Doesn't take long, mine will warm up to 120 in 6 blocks. :cowboy:

 

[pauldub]

You can check the resistance on the solenoids. Find the pinout in the FSM.

 

[thegipper]

Just went out and checked it again. Engine temp was 88 degrees and again, it wouldn't shift out of 1st and this time it shifted into 2nd and so on after it was at about 110 degrees.

The next test I want to do is start it when its been sitting over night and let it reach full operating temperature then put it in drive and see if it stays in 1st. If it shifts normal, then I know its related to engine temp.

If it still acts up, then its something in the transmission.

This is so weird....

 

[thegipper]

I forgot to mention, when it is stuck in first when cold, if I let off the gas and let it coast for a few seconds and give it gas again, the engine just revs (like it is slipping) until i reach the rpm appropriate for the speed i am going. Once it "catches back up" it will continue to rev and increase in speed like normal. I hope that makes sense.

Once it is warmed up and shifting normal again, if I manually put it in first gear, it stays locked in 1st gear and the rpm stays consistent with the speed i am going like normal.

 

[gamefreakgc]

I forgot to mention, when it is stuck in first when cold, if I let off the gas and let it coast for a few seconds and give it gas again, the engine just revs (like it is slipping) until i reach the rpm appropriate for the speed i am going. Once it "catches back up" it will continue to rev and increase in speed like normal. I hope that makes sense.

Once it is warmed up and shifting normal again, if I manually put it in first gear, it stays locked in 1st gear and the rpm stays consistent with the speed i am going like normal.

That is not normal operation. Have you ever opened up the valve body at any point in time?

I ask because I have, and I assembled it back together wrong. A check ball was out of place and it had that symptom, except through all gears.

It most definitely sounds like either your engine is not reading temperatures correctly (engine coolant temp sensor?) and holding the gear or your transmission is showing the first signs of an eventual failure.

 

[LittleCaesar]

What fluid are you using by chance?

I do know that the solenoids can fail and still not throw a code but can be ohmed out to be checked for correct operation.

TPS ever been changed?

I will say that when I changed out my ECT sensor years ago due to being OCD sensor anal, and drove the 4runner for the first time afterwards, I didn't need to wait for the coolant to reach 130F to shift into 3rd. I was elated. Unfortunately it has not ever allowed me to do such again.

 

[thegipper]

TPS has never been changed or touched.

Valve body has never been touched.

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[thegipper]

I'm using some fleet farm brand (mystik) tranny fluid that is compatible

I also had the pan off a couple months ago to clean the filter. Fluid looked brand new still and there wasn't any metal shavings or anything in the pan at all.

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[LittleCaesar]

I don't think it is the solenoids. Only having dealt with other ones in other trannys (GM mostly), when they are ready to die the symptoms are not relative to the fluid temp.

I would guess something electrical, maybe even the ECU.

 

[thegipper]

That is what I'm thinking. Or maybe something in the valve body?

Not sure what to do...

 

[mtbtim]

I'm using some fleet farm brand (mystik) tranny fluid that is compatible

I also had the pan off a couple months ago to clean the filter. Fluid looked brand new still and there wasn't any metal shavings or anything in the pan at all.

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Hmmm, you said clean the filter and not replace. I wonder if the cork gaskets on the filter aren't getting a very good seal against the valve body until the trans warms up and the gasket gets a little more pliable. Might be a long shot but I think I'd drop the pan again and put a new filter on there.

 

[T4R2014]

I'm using some fleet farm brand (mystik) tranny fluid that is compatible

Get a name brand fluid in there. Like Castrol IMV. I used cheap fluid for a week to flush out some old fluid and it was the worst shift quality I had.

 

[AntleredRuin]

I don't think it is the solenoids. Only having dealt with other ones in other trannys (GM mostly), when they are ready to die the symptoms are not relative to the fluid temp.

I would guess something electrical, maybe even the ECU.

That's the same symptom as my 2nd Gen Rav4 issue that I mentioned, which was the ECU. Where is the 4runner tranny ECU located? Is it the same board as the engine?
Maybe find a junkyard with a decent return policy and grab an ECU.

Get a name brand fluid in there. Like Castrol IMV. I used cheap fluid for a week to flush out some old fluid and it was the worst shift quality I had.

Even walmart (Supertech) brand is probably better than a 'bulk' fleet fluid.

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