Major Transmission/Torque Converter Problems

[Ardan]

Hello again, its me! Bear with me while I type a lot, but I just thought i'd share this problem with everyone and get their thoughts on it. Basically, I noticed that when I would be accelerating 2 weeks ago from a complete stop, I would feel it slip. I took my foot off of the pedal when i'd hear the engine race like I just slipped it into neutral or something. When i'd push the pedal back down, it wouldn't have a problem. At the time, I just thought it was some weird fluke thing, but I took note of it on the computer here that it occurred (so that I wouldn't forget it).

The next week, it had issues going into 2nd gear if you're accelerated at a decent pace (we aren't talking with the pedal halfway to the floor or anything, either), but then I noticed something. If you really leave the pedal on lightly, it will shift gears like it has no problems and slowly go up in speed, but once you push it down a little (like, say, if you're passing someone), it goes nowhere, the engine races and it slips considerably. What also happens is you feel a loud shuddering sound as you try to. The shudder will ONLY occur in that situation...never from a stop position. If you're cruising at 10mph and push the pedal down, it will vibrate. The TPS sensor was faulty, too, so we replaced that and it seems to vibrate less and slip more, lol. I've been trying to piece this together before I take the parts in for service. I live close to the place, Master Transmission, and actually live close to where I work so I can afford to. After the TPS sensor was fixed, the Service Engine Soon light came on and stayed on, so we're going to disconnect the battery for a little bit to clear that out and see if it comes back tonight.

What makes me curious about this is that the fluid level was a little low (but not dangerously low), but the fluid looked and smelled normal. It shifted and ran just fine before it happened. This is also a rebuilt transmission that was installed into this car about 26,000 miles ago...i'm a little concerned as to how it could have a problem, especially when they said it would probably outlast the car! They are very professional, and are definitely the best in the area so I have already ruled out some kind of incompetence that my friends assumed when I told them.

On a side note, you can hear a constant squeak (slow and constant like its squeaking to a 4/4 beat in a slow song) that is very quiet, and the car has always rattled when accelerating. I don't know when that happened (long time ago), but it seemed to run excellent so I always ignored the rattle. I don't know how to explain that rattle, but it doesn't sound like two metal pieces hitting each other...actually it kind of sounds like the fan hitting the radiator and you can only hear that at lower speeds (it also eventually goes away as you go up in speed). Of course, the fan is not hitting it...thats just how I would characterize the sound.

To cut down on cost, we're going to hoist the engine out and bring the transmission and the torque converter up to Master Transmission (they were okay with that, too) for repairs. They said they are pretty certain it is a repair and that the transmission probably isn't broken completely. Other people say that, before bringing it up there, we should closely inspect the torque converter. If the torque converter is having problems or is faulty in some way, can that cause the slippage condition I mentioned? The slippage is also really major...its like you're trying to drag race on a sheet of ice or something. The shudder makes just about everything vibrate inside the car, so I am not driving it until I get it fixed. We have completely disassembled and reassembled a 3.1L Cutlass V6 (not this car, but another one), so if anyone has any ideas that I could do a visual inspection of before taking the two parts in for service, let me know!

Enjoy the week!

[GTP Dad]

Before doing anything drive the car to the tranny shop and have the computer scanned with a trans capable scanner. You may find that the problem is major but it could be minor too. Rather than pull the engine, at least at this point, the scan may tell you what needs to be done and it may be repairable in the car without pulling the engine and transmission. This sounds like the pressure control solenoid is going bad. That is why it shifts eratically. A scan will tell you what is actually happening before a major teardown.

[Ardan]

Good idea, I didn't even think of that. I was going to inquire about that for tomorrow (tomorrow as in August 10th) until I found out that someone else already brought it up to them. They were vague, but they said that when they did a road test, the EGR valve set a code that went off and on occaisonally. One thing of note was that the Transaxle Range Switch (PRNDL) code was set in there the entire time they drove it. I was told that he told her that the moment he turned the car on with the tester connected, it popped right up and stayed the entire time. He cleared all the codes out and it came right back up again. However, the SES light was never on, which it is now (and things have changed dramatically).

We cleared everything out with a battery disconnect tonight and the Service Engine Soon light came back on, so I called up a buddy and borrowed his scanner. He has a pretty slick 'Auto X-Ray' scanner that pretty much covers all bases in regards to which vehicles it scans and he lets me use it when I have troubles. However, we couldn't seem to get it to give us what DTCs were set this time, so I am thinking of having them scan it again for me to help me out here (especially since it is free).

So all I have to go on, at least from the 1st scan with out the SES light on, is that the PRDNL/Trans Range Switch indicated a problem to their scanner the entire time it was connected and popped back in when the DTCs were cleared. Any thoughts on that? He did a quick check of the various components (sounds like he was checking the vacuum hoses and whatnot) inside the engine and told her that he was very confused as to why it is having the problems he observed when driving it. Maybe things will be more evident this time around :P. She was impossibly vague, but I know who she was talking about and he told her that he is 100% sure that it is repairable and that the transmission probably won't need any major overhauling of any kind. So that is encouraging, but it is a bit discouraging that a very knowledgeable mechanic that has worked on transmissions for as long as he has is a bit baffled to the point of being really curious as to what went wrong :P.

Thanks for the tip on the solenoid, we will keep that in mind. If I do have to pull the transmission and converter out, at least we're going to be the ones pulling out the engine to get at it . I can imagine the labor charge just to get at it in that confounded engine would be significant. I'm so glad that they don't mind if we do that part of it ourselves...IF it needs to be pulled out, that is.

I'll let you know what we find out tomorrow, and if your suggestion leads to a resolution!

[GTP Dad]

If this guy is confused you may want a second opinion before doing anything. As for the SES light have them check the speed sensor in the transmission. It is a cheap fix and can cause a lot of issues especially since the TPS was bad. Sometimes when this sensor goes bad it will cause erratic shifting and drivability issues. Also check to make sure the TPS you put in is within specification. There was one member that went through three of them before he got one that was good. It is possible that the one you put on is malfunctioning.

[Ardan]

The throttle position sensor was bringing up the SES light, so we checked it out and the little notch that clicks in and holds it in place was broken, thus the connector was loose or something. We took it to a pretty huge GM dealer nearby and they were able to help us get that fixed. That went away now .

We knew him personally so we asked if he could check things out, so he hooked up a connector to it. He said the PRNDL Switch keeps bringing up a DTC and also the EGR Valve and IAC Valve come up and go away, which he said can be an indicator of a problematic PRNDL switch. I told him what the guy at Master Transmission checked and he said that, while he doesn't specialize in transmissions, they concurred that he really didn't check anything. Just like you suggested, he said they have *got* (he was emphasizing that) to check out the pressure control solenoid and the other sensors involved.

I don't work on Saturday so we are going to finally investigate further. I'm going to buy that PRNDL switch (which seems to have multiple names, apparently) and we're going to switch them out just to get that out of the way and see what that helps. We're going to do some electrical tests of what we can and other diagnostic procedures that aren't too hard just so we can rule things out and say we did what we could. If it still isn't solved, i'm going to call around to two nearby shops that do Transmission work and see what they would charge to examine my transmission problem for me. If it all magically goes away (i'm doubting that, but you never know) then I will proclaim the good news .