Possible Transmission Problems??

[camsing23]

Hi everyone,

I have been searching the forums and reading for a couple of hours, and can't find anything yet that describes the same problem I'm having. I fear that I may have the radiator/tranny contamination problems that so many have described on here, but the problem just started last night so I haven't had a chance to check for it. Also, the symptoms I have don't seem the same.

To start, it's a 2005 Frontier Nismo 4x4, auto, V-6 with about 106k miles.

When I take off from a stop, I have very little power/acceleration. It runs in the 2000 - 2500 RPM range and sounds like it is laboring, but it just takes forever to get up to speed. Once I hit about 20 mph, it accelerates fine, but it stays in higher RPMs than it should, seeming like it won't shift. When I started it back up later, it took off just fine on my first start, but after about 2 seconds of acceleration I heard a THUMP and it lost the acceleration and went back to very slow acceleration.

Does anyone have any ideas or suggestions? I'm a little afraid to even drive it to a shop with all of the cost and issues I've read about.

Also, if it makes any difference, I just had to have the oil cooler seal replaced just a few days before this happened.

I appreciate any and all feedback.

Thanks!

[05Fronty4x]

I'm not sure what to say, but this doesn't sound good.

It's easy to check for contamination, just pop the radiator cap and coolant reservoir cap and take a look inside (with everything cold of course). Snap some pics of what you find and post them up if you'd like, but it's usually pretty obvious if you have some serious contamination, which will look like a frothy milk-shake. If you cant see well into the coolant reservoir, stick something like a screwdriver down in it and pull it out, if it's covered with anything that looks like frothy beer foam it's time to have your tranny pulled and inspected.

[JB'sFrontier]

I believe 05fronty is right about this one

[Mandangalo]

I'd check the level of the tranny fluid as well. Maybe it wasn't topped off enough?

Is it throwing codes?

[GRN ENVY]

Sounds to me as if your torque converter is not engaging, disengaging properly. Change the fluid. If you have any material in the fluid, get it to a shop to go though it immediately. Any material in the fluid can cause damage to the clutch packs in the transmission, which will then cause slippage and eventually failure. Change out your fluid see if that helps if not, re-build time.

[camsing23]

So the seemingly good news is that it doesn't look like I have the "strawberry milkshake" so many people are talking about. I did seem to be running low on coolant though.

I checked the tran fluid and I'm pretty sure I'm good on that.

So I went to the nearest Auto Zone and had the codes run. Here is what it pulled up:

P1757 & P1759 (Same explanation, I'm assuming left and right?):
Front Brake Solenoid Valve.
Probable Cause:
1-Open or short circuit condition
2-Poor electrical connection
3-Faulty front brake solenoid valve

P0420:
Catalyst Efficiency low - Bank 1
Explanation: The oxygen sensors monitor the Catalytic Converters ability to store oxygen
Probable Cause:
1-Catalytic converter defective (failure possible due to # 2, 3, or 4)
2-Engine misfire or running condition
3-Large vacuum leak
4-Engine oil leakage into exhaust-valve guide seals, piston rings.

That's what I've got so far. It's a little tough to do much right now since I go to work in the dark and get home in the dark. I read a little bit about a transmission "safe mode" and it almos seems a little like that. I need to read up a bit more on that.

I appreciate the replies so far and look forward to hearing anything else anyone can offer.

Thanks!

[05Fronty4x]

Originally Posted by camsing23

That's what I've got so far. It's a little tough to do much right now since I go to work in the dark and get home in the dark. I read a little bit about a transmission "safe mode" and it almos seems a little like that. I need to read up a bit more on that.

If your transmission were in limp mode it would lock you in second gear. Accelerating from a stop would be kind of sluggish, but you should know if this is what happened because it would never shift gears. No matter what forward position your selector is in you would always be in 2nd, and reverse wouldn't work. The other thing is that the one time I experienced limp mode, I shut the truck off for 15 minutes or so, and everything was fine when I started it back up. I don't know if there is any "condition" that would put the tranny in limp mode indefinitely (assuming this issue you are having has been consistent).

Limp mode is all computer related. It is a "mode" the truck puts itself in as a failsafe if the transmission is overheating (I'm sure there are other things that cause it too) and what you have described sounds like there may be some mechanical issues.

Above all, it's hard to say exactly what's going on. The computer system and how it's tied to the complex inner-workings of the auto tranny is well...complex. The AT service manual alone could be the course material for a full length college class.

[Mandangalo]

I'd start to look into the cats as well. They may be partially plugged

[plankk]

Since one of the codes refers to the brake and he mentions it labors til 20mphs. Could it be possible that something is afoot with the ABS and possibly it is locking down until he reaches 20mph and then releases to allow normal operation?

[bassman]

My truck acted exactly like you describe the day my battery died. Of course I knew it was going bad, the 3 times I started it before replacing it it barely turned the engine over enough to fire. But on my way to Sear's to get a new battery, it had VERY sluggish acceleration, stayed in gear too long and needed high RPM's to move. I though my transmission had crapped on me, but a new batter got rid of everything.

When I had the contamination issue, I got hard shifting and a BAD shudder ever 30 miles or so. That was 47k miles ago, and so far doing about 10 drain and re-fills on the transmission it hasn't failed yet. Still keeping my fingers crossed though.