Help Please! Bogging down on highway!

LARRY70GS wrote:

You might have a problem with the torque converter clutch. Very difficult to tell over the internet. What I am saying is that even with no SES light, the computer will keep count on the misfire history of each cylinder. All you need to do is hook up a scan tool and look at the misfire history. Takes 5 minutes max. Each coil fires 2 cylinders, 1-4, 2-5, and 6-3. If you see misfires on 2 companion cylinders, it could be a coil pack. If it is one cylinder, a wire/plug issue. If it misfires, it does it under load. Putting it in neutral removes the load. Your mechanic needs to diagnose this if you can't.

That makes a lot of sense, I'm getting tie rods done tomorrow, Ill ask the mechanic to check for misfires then.

Green-irwinman wrote:

I read a little about these trannies on a couple other forums, about othe people having problems with the pcs. How difficult a part is this to replace?

It's not something I want to do! It involves opening the transmission case, which is possible but not easy in the car. Depending on the general condition of the transmission, a flush _may_ resolve it, or _may_ make it worse. I do NOT like flushing in these transmissions. I'd rather drop the pan and put in a drain plug, then for the next couple of oil changes, just drain and refill the pan at the same time.

A transmission shop may be able to replace the PCS without removing it from the car. It's worth trying a clean filter and some fresh fluid first.

Alright, I tried the brake trick again, and after a couple taps, thw shuddering stopped. This indicates the Torque Converter clutch right?

Yes, it could be TCC lock-up is slipping from a worn clutch. This happened to mine. Manually shifted in 3rd gear at between 27-60 mph, apply at least 1/2 throttle (or tap the brake) and TCC should release; pulsing will go away as long as you hold the throttle on.

If this were an ignition issue, the opposite would occur - you would see more pulsation with 1/2 or more throttle, and less with light throttle.

Another test is to manually shift into 2nd gear. TCC will never lock-up in 2nd, so the pulsation will stop.

Hmm, ok. What would be the fix for such a thing? I dont have the experience to take apart a tranny, nor the money to have it taken care of by a Proffesional.
If the fluid was recently flushed, and replaced with a poor quality fluid, would that make a difference? The Fluid looks nice and clean, like I said before. It would not surprise me to find out the last owner flushed it. A mechanic suggested an additive, he seems pretty sure it would take care of the problem in a couple hundred miles. Is there such a thing?

If this is in fact the TC clutch going bad, the fluid condition won't matter because it's an electromagnetic coupling. I'd be very surprised if any additive can fix the issue - again assuming it really is the TCC that's bad and not something else. Sometimes things can seem worse than they are. Without actually driving your car I can't be sure.

There are only two ways I know of to fix a bad TCC:

1) pull the transmission and replace the TC clutch. It would make sense at this point to just rebuild the entire transmission, imo. You're going to pay someone $500-1000 just to pull it.

2) can also tune out the TCC lock-up function from the PCM with the right equipment (tuning software). A 3800 specialist (like deekster) should be able to do this for a reasonable fee. The result is the pulsation stops because the clutch is turned off at all times. If you go this route, you must install a heavy duty transmission cooler to deal with the extra heat. Otherwise your torque converter won't last long and then you'll need to rebuild. I also recommend a trans temp gauge to monitor.

Understand your freeway economy will drop a significant 5-10 MPG without the TCC lock-up. Otherwise the car will drive just like it used to. The throttle will actually be more responsive in 3rd and 4th gears without TCC (you'll accelerate more quickly on the freeway with less pedal effort).

If you can find someone to tune your PCM, you would know for sure what the problem is, and if the tuning fix will correct it. Worst case, you can revert back to to your old program and you're only out the cost of a tune.

AA is right on here - I can disable the TCC lockup and it will never engage again. This will save you some money short term (cheaper than a rebuild!) but long term you have some other things to address and you MPG will suffer a little.

Optionally, a full transmission fluid change may make the difference. The pressure control solenoid and torque converter solenoids are very similar, and both are very sensitive to dirty fluid or 'crud' broken loose from flushing. That's one of the reasons I don't like flushing these transmissions. I know too many people who have had problems with one or the other solenoid after a flush.

Changing the fluid a few times may clear it up. In the meantime, I could turn off the TCC engagement altogether.

Keep in mind trans fluid changes aren't cheap. I think last I priced Dexron VI it was $7/qt. You'll need 5 qt for a change, which is only half of the 10 qt capacity.

Maybe I'm missing something, but I don't see how it helps to change the fluid. Mine never recovered after probably 5-6 changes. The way I understand, the pulsing you feel means the clutch is energizing, but slipping, indicating the linings are worn away. If there were a clog in the valve body, causing the TCC to not lock-up, I could see how a fluid change could help there. In that case there should be a DTC code, but no pulsing.

I think a good first step would be to scan for codes and turn off the TCC lock-up function. If this fixes the issue, install a trans cooler in spring ($100) and see how it goes. One caveat: I've noticed TCC cannot be turned off during cruise control activation. As a result, I no longer use my cruise. Maybe deekster knows how to tune it out, but I could never get it to work.

Scanned for codes yesterday, and came back with a long shift. It seem the TCC is going. It sucks, but I think I have to let go of the car before the problem worsens.
I really appreciate all the help Ive gotten from everyone.

It seems obvious the previous owner knew of the issue, since you just picked up the car last week. In good conscience, you can only expect to sell the car at a loss, since it now needs $1500-2000 in work. This being the case, it would be difficult to give away the car with a dieing transmission. I need to ask: why not spend the money and fix the car to drive (or re-sell)?

If I could dig up the money to fix this car, i would. Its just that I lack the resources to get the problem fixed. Everything else about the vehicle Is great, and if the tranny WERE fixed this car would be set for years. Ill shop around just to see.

Joe, hate to break it to you, but...... you gotta get it fixed.

you see, anyone with a Riv can join this club... but there's only one way of leaving and it's not going to be easy...

Alright then, let's discuss trannys! I presume the most sensible thing is to have to thing pulled, and rebuilt. Alternately I could just get the TCc replaced, but it seems silly to take the whole thing out and only replace the bad part.
I could also get another transmission, correct? Several other vehicles use this same model, so it shouldn't be too hars to find one. The problem I see with that is I won't know the history of the new one, and risk running into the same problem or worse.
The last option is to purchase a rebuilt transmission. which just seems silly to me, as I'm only having problems with the TCc.
Did I miss anything?

You could keep your trans in the car and have the TCC deactivated. deekster caddy can do this for a reasonable fee. Only thing you have to do is have a trans cooler installed before it gets warm.

I had your issue in early 2010 and have put over 60k miles on my car since I deactivated TCC lock-up. I get about 16.5 MPG in town and up to 26 MPG on the freeway. My current average is 20.1 MPG.

Green-irwinman wrote:

Alright then, let's discuss trannys! I presume the most sensible thing is to have to thing pulled, and rebuilt. Alternately I could just get the TCc replaced, but it seems silly to take the whole thing out and only replace the bad part.
I could also get another transmission, correct? Several other vehicles use this same model, so it shouldn't be too hars to find one. The problem I see with that is I won't know the history of the new one, and risk running into the same problem or worse.
The last option is to purchase a rebuilt transmission. which just seems silly to me, as I'm only having problems with the TCc.
Did I miss anything?

Consider getting a junkyard transmission from a large yard that sells to the auto repair trade, so they can sell you one that's already been overhauled (there are ways to tell).

If we disable the TCC, it's also a troubleshooting step for you - if your problems go away, either the torque converter or TCC solenoid is bad. Replacing either of those will be cheaper than a full transmission rebuild. Or you may choose to leave it that way and the transmission will last an additional 3 years/whatever until you save up your money for a full rebuild.

If your problems remain, you know it needs a rebuild.

Green-irwinman wrote:

Alright then, let's discuss trannys!

Trannies kinda scare me..

You think Itll last up to three years? I could save enough for a rebuild by midsummer, I think, and worse case scenario, it craps out and Ive already got money for a down payment, along with a trade in, haha.

IF it's the torque converter clutch, and we disable the lockup, and your problems clear up, then install a cooler and you have bought yourself some time, yes maybe a couple years. Then we know you need either the solenoid or the entire converter replaced. The car will drive 'normally' to anyone else, only you would really know the difference other than that it seems to work fine...

But IF we disable the TCC clutch lockup and you still have problems, there's only one other thing I can try and that is to increase shift pressures. Again, a temporary bandaid over other problems, and you'll know the transmission needs to be pulled and serviced.

If just the TCC is bad, the rest of your transmission could in theory last forever, as long as you keep the fluid cooled. Only things the TCC does is increase MPG and help cool the TC in OD. It's not even used at all in 1st & 2nd gears.

Mine is showing no signs of failing anytime soon. I'm not that gentle on it, either.

Bad news guys. I love this car. It is an absolute joy to drive. I'm by no means old, but I've owned my fair share of cars, this is the ninth in five years actually. And it takes the cake. I had an old notchback cutlass that didn't even come to close to the combination of fun and elegance this car brings.
So, I keeping it! I'll get the transmission fixed or rebuilt or whatever needs to be done. Again, thanks for the help

awesome! Good decision!

Good for you! I replaced my transmission with a junkyard one. Set me back 1K.

is that for the parts and labor? It works well I'm assuming!

Good news everyone! I madr a giant mistake when diagnosing, and as it turns out the traction control is grabbing on! ive never been so happy to have something wrong with my car, haha.