mynameisjacob

This is the outline I wrote for my dealer's service adviser. I think it may be a torque converter that is beginning to fail? I thought I'd run this by the Acurazine wizards. What do you guys think? Surely all symptoms cannot be linked to one ailment... but you never know. Listed in order of seriousness or most bothersome:



2010 ACURA TL SH-AWD w/24,000 miles.


SYMPTOMS (All on auto transmission, no paddle shift):

1. On braking and coasting to a stop, car lurches just before making full stop, followed by mechanical whirling/winding down noise audible from inside cabin.

2. General hard up/down shifts at low speeds (and presumably earlier gears) below 30-35 MPH. ATF was drained and refilled (repeated 3 times for virtual flush) 3 weeks ago by Acura dealership. Made difference on first day (smoother shifts and no lurch just before stop) but symptoms reappeared after 2-3 days.

3. During cruising and coasting, light pressure to throttle intermittently causes a vibration throughout car. This is hard to reproduce and I can't identify exactly what RPM/speed or gear this occurs. It is a deep, boomy/bassy rumbling and grinding sound throughout the car. It disappears once I speed up or apply more throttle.

5. On initial car startup (after sitting in lot for more than a day) and shifting from PARK to REVERSE/DRIVE... the car jerks and a loud clacking noise is heard. Generally, shifting to and from PARK is rough and lurches the whole vehicle.

6. On high throttle acceleration from stop, a metallic "tin can rattling/clanking" noise can be heard. There is also a general hissing, whistling noise coming from car but not too loud. Sound is magnified when driving through a block with sound bouncing off walls and parked cars.

7. Very poor gas mileage. I am averaging approx. 270 miles per tank (18.5 gal) for 14.5 mpg with mix city and long island highway driving.


I suspect damaged torque converter. Acura records indicate the PCM flash of new Torque Converter software (TSB 12-029) was conducted November, 2012. Can damage have already occured? Does TC need replacement?

HeartTLs

iTrader: (5)

The whirling, whistling noise was a very distinct propeller shaft issue in my 09'.

jim_c

It's not possible to diagnose over the phone or internet :-)
but it sounds like you might have a problem with the converter's lockup function. An auto trans car nowadays has a lockup converter which means the engine/flywheel are locked to the trans input shaft above a certain speed, say maybe 35 mph in high gear. This is controlled by the computer and the valve body/electronics but the lockup is actually a clutch inside the converter itself. i.e. there is a mechanical connection once you are through the lower gears. If the lockup does not disengage when you slow down, the car will chug like a standard trans car when you forget to put in the clutch pedal as you come to a stop. If the lockup is on when the trans tries to shift, the shifts will be very harsh. You can normally run an auto trans car in gear at a stop without stalling the engine because there is (should be) no mechanical connection between the engine and the trans input. Just a fluid connection, thus the term "slushbox". Lockups converters came in way back in the early '80's for better fuel economy at highway speeds. They should have it figured out by now.

mynameisjacob

^-- Wizard right here

Thanks!

Tonyware

A three or four drain and refill of the tranny oil may fix all that. Flushing the tranny oil cooler from all the crap in it may do wonders. I did both after the CPU update and have no issues anymore. Our transmissions are oil-pressure driven mostly, so the correct oil quality throughout the entire system is very important.

jim_c

It is true that clean oil is a very good thing, and a fluid change may "cure" minor issues, but if you have a real technical problem it will not be fixed by changing the ATF.
Problems on a low mileage vehicle are almost always related to electronics of some type. In the old days, before everything was controlled by chips, most problems were caused by abuse, overheating, or lack of maintenance. Nowadays (is that a word?) transmission problems are caused by switches or transistors or circuits or programs, i.e. "electronics".
Still, change your (expensive) atf regularly and don't do dumb things that cause overheating.

mynameisjacob

UPDATE: Spoke to an extremely knowledgeable service advisor at rallye acura. He reviewed the symptoms and gave an initial assessment that he suspects the software controlling the torque converter lockup clutch needs to be flashed to an even NEWER version than what was specified in TSB 12-029.

Interestingly, there have been subsequent updates to the software issued to dealers AFTER the TSB... and dealers have been updating this software on clients' who return with complaints. I am scheduled to take the car back next Tues, have them plug in, verify software version and flash to the newer version and hope that it resolves the issues.

jim_c

Oil pressure in an automatic trans is used to operate the valves in the valve body, the governor, etc., and for lubrication. The oil must be very clean because even minor grit can interfere with the operation of the valves which are very precisely machined. Oil pressure also operates the clutches which determine which "gear" you are in. But the transmission of energy (power) through the transmission (transaxle) is still mechanical, from the input shaft through the planetary gearsets to the output shaft. The transmission will not operate without oil pressure, it will forever be in neutral without oil pressure. The first thing to check for any transmission problem is proper oil level.

iamdk72986

Sorry, was reading two threads at the same time. Mynameisjacob, which service advisor did you speak to at Rallye? I've dealt with Chad and Chris. This way I know who to look for as I have the exact same symptoms.

iamdk72986

Moderators, can I get this post and the previous one deleted? Don't know which mod to contact. Thanks.

bugfam4

iTrader: (1)

I have the same car as the OP (exact car, with 72K) and am/have been experiencing the same issues, except for the whiring/winding down. I do, ocassionally experience the "tin can rattling/clanking" noise when in stop and go traffic and go to acclerate when the car is coasting.

I bought the car certified and it has a 100K powertrain on it. I took the car back to Courtesy Acura to have it checked out and they said it was the fuel I use?? I have always put HO fuel in the car. Sounds like crap excuse to me.

I want to make sure and have this addressed/resolved while still under warranty.

Should I go to a different dealer and have them look at it? Should I "press harder" with Courtesy?

I respect my fellow "Ziners" advice.

Would also apprecate any update the OP might have in fixing his issues?

mynameisjacob

Sorry no updates yet. Did a software upgrade but issues remain.

The tin can rattling/clanking noise could be a loose heatshield... or something hollow and metallic that may be rubbing against each other. I get this initially upon startup but it disappears after prolonged driving which may suggest its tied to heat and thermal expansion. Maybe get the car up on a lift and start clanking on the exhaust pipes and heat shield for any loose bolts?