Hey guys,

I'm having some trouble with my 2004 TL (AT, 196k miles), and I'm trying to diagnose the issue.

When accelerating at a normal pace, the car shutters a bit near the middle-top of 3rd gear. Always in the same spot, and doesn't seem to act up under harder acceleration.

I was originally thinking that it was the transmission, which is notorious on these TL's, but my symptoms don't seem similar to the other transmission failure threads. It never really slips out of gear or misses the shift. I also originally thought that it was the shift from 3rd to 4th where it was acting up, but it will still do it in the middle-top of 3rd even if I switch to "manual mode" and let it stay in 3rd.

The shuttering feels a little bit like a spark plug failure that I had on a previous vehicle that needed a tune up, but seems too consistent in the rpm and gear range for that. And I would think that I'd eventually get a mis-fire code.

For now, I'm going forward with the transmission guess and ordered replacement 3rd and 4th gear pressure switches just as a shot in the dark. Would appreciate any other ideas.

Thanks,
John

 

I'll say transmission/converter. You hit the same RPM in first and second, no problem, but in third there is a shutter.
I thought I'd do a little research after I posted:
https://acurazine.com/forums/problem...hudder-639089/

 

Yeah sounds like the torque converter lock up clutch. Is it at low rpm? Have you changed the fluid lately?

 

Thanks for the link. I was hoping to find something more recent, because all of those issues were covered under warranty. At this point, I don't have a free pass to let the techs at the dealership poke around.

 

I have not. This has been a long-standing issue for me. I'm not the first owner, and can't find an Acura dealer that can verify that the fluid was ever changed prior to my purchase. This is significant because every mechanic I've spoken to about doing a flush tells me that changing the fluid at my mileage, if it wasn't changed before 100k miles, would likely be catastrophic.

Not sure what to do. The car drives pretty well otherwise, but I'm sure that the shutter is a bad omen of things to come. New transmission would set me back about $4k, and the car is probably worth about $6k.

 

How long have you owned it for mileage wise? I would say if the fluid is not burnt looking/smelling and still is some shade of red, doing a few drain and fills would be a good idea. Flushing these trans thru a machine is a no no. You can get a case of DW-1 and do a 3qt change..as simple as an oil change. Drive it for a while and see how it goes. Maybe put a few hundred miles or so on. If all seems ok, then do another 3qt change and drive it some more. Repeat one time if all is still ok. It all depends on the health of your trans but I don't think following this method will be too risky

 

Sorry for the delay. Just going to post both updates since I didn't get around to posting the first.

Update 1: Bit the bullet and did a 3qt change in November. ATF was almost black. Re-filled with Castrol Z1. Wanted to give the transmission a little time to get used to it, so drove it a bit. Shudder was still there. Someone on one of these related threads (who could have just been an employee of that company) recommended "Mr. Tranny's". It was cheap, so tried that. I think the the "original shudder" (repeated detailed description below) has gone away for now, but the car still seems to have a general uneasiness about it. It's tough to tell though. I could just be hyper-sensitive at this point, and the roads in Wilmington, NC suck, but it still seems to shudder randomly at different rpm and gear ranges.

Update 2: My TL just rolled over 200k over Christmas. Should count my blessings that the transmission has lasted this long, considering all the old posts I've read of guys that had to replace theirs under warranty.

After driving about 1k miles, did another 3qt change last night. ATF was still pretty dark, darker than I expected after 1k miles.

Like I said before, the very specific original shudder seems to be gone, but general hesitation still seems to go on randomly at different points.

Just to explain the original shudder again in detail: mid-top of 3rd gear, just before shift point, under low throttle, for about 1-2 seconds, felt similar to a cylinder misfire. Just a little power hesitation and shake, but noticeable enough that my wife would always point it out when riding with me. Did not seem to be the kind of slipping that I'd see in videos where the rpms jump like the car goes from drive to neutral for a second, like I've seen with bad clutch.

Anyway, just wanted to keep updating because people sometimes come on here, post a problem, then forget about their thread when it ends up being solved.

Next up, driving it another 1k and reporting back, another 3qt ATF drain and fill, and maybe switching out the 3rd and 4th gear pressure switches. I order the parts for this a while back, but have been reluctant to go ahead and do it for two reasons. 1. I saw a post where someone screwed up the wire grounds or something and tripped a code by doing it, and 2. I haven't seen a thread where someone actually had a similar problem, swapped the switches, and it actually fixed it.

Sorry about the novel. More to come...

 

Also want to add a question. I had originally ruled out things like spark plugs and cv axles because the shudder was so specific with regard to gear, amount of throttle, and rpm range. Not that it's more random, should I start down that road again?

I doubt that a cv axle is bad. Boots look fine, and an outer joint issue would likely make some noise.

That leaves spark plugs and wires. My question is, if a mis-fire from an old plug were bad enough to cause shuddering here and there, wouldn't it trip a code? In other words, what minimum amount of mis-fire does trip a code? I ask because I had a 4Runner a few years ago that shuddered due to a bad plug, but did it for a couple of weeks before I took it in. It actually didn't generate a code until, luckily, the day that I was able to successfully replicate the shudder with the tech present. Half the time, these guys are worthless if they don't have a code to go by.

Thanks again,
J