Transmission problem?

[Oldgamer]

Hi guys,

I know I should to do at least some "homework" before posting here, but just can't keep it until tomorrow.

It's happening yesterday around midnight on a way home from my sister's birthday party. Right before Outerbridge Cr was stop and go traffic (as usual). A little later, still before the bridge, I noticed unusual noise (my window was down) and engine hesitation. I noticed that when I depress the gas pedal RPMs goes high but car speed barely raise. So, I touch the gas pedal just a bit, to try not to make a slip and get home. Without stopping I tried to check brake pedal position just in case. I didn't get any computer messages. I didn't stop the engine, turn computer on, read the codes, but nothing was current. Code P036 and P044 were in history. I drove home as carefull as possible (I was just around 5 miles from home). I tried to change gears to 3rd and 2nd but didn't noticed a difference. What I noticed that was unusual sound and that transmission behaved like there was no VCC lock. When I put car into garage it was around midnight, I was dressed up and didn't try to check anything. I know, it's no excuse for forgetting to check transmission fluid level at least. And I know I checked it a long time ago and it was more on a low side. But how come I didn't check it yesterday right away? Can't excuse myself. I hope I didn't toast my transmission (no computer codes related to transmission), don't want even to think about it. I Hope it's just a low transmission fluid level, but that noise... It's driving me crazy.

Engine runs stable in idle.

Tomorrow I will be at home all day and try to do everything you guys tell me to do.

I don't think it is related to the problem some how, but just in case... I filled around 12 gallons of gas the same day.

[adallak]

oldgamer, here is what Guru recommends:

The easy and quick way to determine if the Viscous Converter Clutch is locking up is to drive along at highway speeds when you would be sure the VCC was locking up. Hold the throttle steady with your right foot...even crowd it slightly to add a little more load on the drivetrain. With your left foot LIGHTLY depress the brake pedal just enough to activate the brake interlock switches. Keep your right foot steady on the throttle when you do this. You should feel the VCC disengage when you depress the brake pedal and you should see the RPM jump 100 RPM or so on the tach. The VCC solenoid is fed voltage thru the brake interlock switch so when you interupt the circuit with your foot on the brake pedal it will cause the VCC to disengage.

The Torque Converter Clutch in the 4T80E has a viscous coupling in it (hence the Viscous Converter Clutch name) to smooth the power delivery to eliminate chuggle and roughness instead of the normal solid connection of a TCC. There will always be a bit of slip or creep to the lockup with the VCC as per the design intent so it is never a solid lockup.

The PCM controls the shift points, downshifts and such so it is unlikely that the shift points are changing. Perhaps you are simply feeling the additional AC load in hot weather or something like that..??

[Oldgamer]

adallak,

The slippage is so bad, I can't even drive higher than 30-45 miles, cause RPMs goes high even if I depress the gas pedal just a bit higher than a touch.

No A/C was on on the time that happening. Earlier in the same day cars ran just fine even with A/C on.

[Ranger]

Are you sure it's slippage and not stuck in 2nd gear (shift solenoid)?

[Oldgamer]

Thanks for response to everyone.

I'm pretty sure, cause if it was stuck in 2nd gear, the car speed will increase accordingly RPM's but that not happened. In reality, when I barely touch a gas pedal and there are no much torque, the RPM increase slow and speed increase the same way, but if I accelerate even a little harder, then RPM jumps (but not like it's shifting) and speed actually getting even slower, like transmission got almost disconnected. So, to keep it going I pressed gas only a little bit, trying to avoid a slippage as much as possible. When I drove downhill, there engine was breaking a lot.

I believe if transmission was locked in a 2nd gear, it will accelerate just fine up to the shifting point.

[Oldgamer]

At one point I even thought that problem is related to fuel delivery. I remember that once when I got run out of gas the simptoms where such, that first thing I thought was "I got a tranny problem". But back there simptoms where kinda different (it was like transmission hesitates to upshift, and no unusual noise).

But again, now I'm very surprised there are no computer codes or warning at all.

[Oldgamer]

Ok. This is update:

1. I checked transmission fluid level the way it should be and it's normal. (Started the engine and did everything by manual). Didn't notice any unusual noises when I shifted gears.

2. When I shut engine off I noticed strange sound from Cruise control area. It was not too loud scrubbing sound reminding scrubbing sound like you cleanning something following tickle-tackle sound. It was right after I shut engine off.

3. I started engine again and tried to drive car from the garage and around the block. It was just fine even when I accelerated hard. Then when I was back to my garage and stoped before entering garage "it" happened again. I shift to rear, drive, any gear and it wasn't move and I didn't feel that "grabbing" when I shifted.

4. I stopped engine for 1-2 second, no more and started engine again. And it was fine! I put car in a garage.

5. Couple minutes ago I started engine to check level again (something was confusing me) and then I tried to shift. It was fine first minute and then again no engaging at all. Stopped the engine and restarted. It was fine again. And, yes, when I was still seated in the car I heard again that strange sound.

6. Now I checked PCM data PD01, PD10-12, PD71-77, PD81-82. Everything was Ok at first. PD73 (sleepage speed) was around idle speed when I applied brake in a drive position and around 25-40 in a park position. Then, after minute or two I noticed that when I shift gears I can't hear any click, nothing. I checked PD73 in a drive position again and it was around 60, like in a park position. Stopped and restarted and sure enough gears were fine.

I hope somebody can give me advice what I should check now.

[adallak]

The linkage from the gas pedal to the throttle body... any restrictions? Same with servo? I think there is rather an easy mechanical problem.

[Oldgamer]

The linkage is fine, because when I accelerate, RPMs rose fine. Transmission behave like it's in neutral. I very confused I didn't get any computer codes

[Oldgamer]

I hope it's an easy mechanical problem, but more I analyse, more I got upset.

[Oldgamer]

Another update:

I noticed that when fault exist PD073 code (switch position) shows 111 wich is for gear 2, no matter what gear I shift to, even parking. But in the same time despite that "virtually" it looks like neutral. I gues cruise control noise not related at all, I think it's normal and I didn't noticed it before, because of hood was closed.

[Scotty]

I would drop the pan and see what I see.... messy job but usually very telling, Mike

[Oldgamer]

Mike, I think I'll do that next weekend. What I afraid of is that if I'll drop the pan I didn't notice anything wrong, specially because fault not presents right after engine start. It's possible I will see some partickles, though. I try to collect as much info as I can now. I always believed that transmission is a "bulletproof" up to 100K at least, and look what happened.

May be Guru have something to say about these simptoms? I feel like I gave a lot of info for some analysis...

[Scotty]

I have to agree your symptoms are very odd, that you could restart it and its fine?!?! That is why I suggested that you drop the pan, if you have clutch material in the pan, it could intermittantly block, clog passages or your filter (just a guess). Again you don't have any codes?

[Oldgamer]

I don't have any codes. And as soon I restart it's fine for some short period of time, like couple minutes. I start thinking, that difference is just changing transmission oil level after start.

P.S. No, it doesn't sound right, cause I restart right after stop, in no time. May be something with the brake switch? I'm going to brake my head

[Oldgamer]

Anybody?

Can't see my baby sitting in a garage like this...

[adallak]

Anybody?

Can't see my baby sitting in a garage like this...

I do not know if these are syptoms of bad shift solenoids. As scotty suggested i would perform an autopsy and would have two new solenoids handy in case they indeed need replacement. If the old ones look OK ... well I would refill the tranny with fresh ATF and clean it up. It never hurts.

[Oldgamer]

When I was watching code PD073 (gear position) I noticed that right after engine start it was fine for couple minutes (showing correct code for any position), then it "flashes" a bit wrong code, and a bit later it started to show only code 111 (gear 2), doesn't matter what gear I shift to. And transmission became disconnected, like in neutral.

Before weekend I have some time. To drop a pan I should have a new seal at least.

[KHE]

When I was watching code PD073 (gear position) I noticed that right after engine start it was fine for couple minutes (showing correct code for any position), then it "flashes" a bit wrong code, and a bit later it started to show only code 111 (gear 2), doesn't matter what gear I shift to. And transmission became disconnected, like in neutral.

Before weekend I have some time. To drop a pan I should have a new seal at least.

Check the shift cables and the PRNDL switch on top of the trans. That could be the problem.

[Oldgamer]

Thanks, I will.

I can see them when I open the hood?

[adallak]

Thanks, I will.

I can see them when I open the hood?

This is your switch.

[Oldgamer]

Thanks, the picture is better than any words.

[Oldgamer]

guys, I got a hope.

More I think about problem, more I believe it's a PRNDL switch' fault or something related to it.

Computer gets information of gear position (PD071) from the switch, not from transmission. So in my case, doesn't matter what, switch SHOULD show correct code despite of real position or fault of transmission.

So I will inspect mechanical and electrical thing related to switch and switch itself before I do anything with transmission itself.

Thanks.

[adallak]

guys, I got a hope.

More I think about problem, more I believe it's a PRNDL switch' fault or something related to it.

Computer gets information of gear position (PD071) from the switch, not from transmission. So in my case, doesn't matter what, switch SHOULD show correct code despite of real position or fault of transmission.

So I will inspect mechanical and electrical thing related to switch and switch itself before I do anything with transmission itself.

Thanks.

There is a procedure of adjusting the switch (if it is not bad). It is easy one, but usually one needs adjustment when one cannot start the car in P and have to put in N. Try it, you have to losen the switch and insert a drill bit into some hole...

[Oldgamer]

I realized, that Transaxle Pressure Switch and PRNDL switch are different things, so cause of a problem is not a PRNDL Switch, but something else. Whole fault seems really strange to me, because transmision works everytime fine after shut engine off and restarting it, even after just 3-4 seconds. I noticed that fault happened sooner if I rev the engine. And when fault is there Transaxle Pressure Switch shows me data PD71 111, whitch means "gear 2", doesn't matter of manual shift position. So, may be it related to oil pumps or oil moving inside of transaxle. I don't know. Not getting any computer codes.I just don't feel right to open transmision without having enough of info. I'm not sure I'll see anything wrong in there because after every restart it works fine. Sure I can see some debris or something like that.

I hoped Bbobinsky have somesthing to say, any clue or tip.