2006 Acura TL
3.2 L V6
42,000 Miles
I have around 42,000 miles on my 2006 Acura TL with a 6-speed manual transmission. It has been a few days since I last drove my car and today I started noticing mild difficultly accelerating in first gear, it was like there was a drag on the car, similar to taking off with the parking brake still engaged. It seemed like the car just did not want to move starting out in first gear, it was like pressing on the gas and getting a 1/4 of the response. The drag was not very noticeable in the other gears while accelerating, mostly just first gear when I was starting from a stop or near stop with the clutch pushed in at idle. There were also weird rpm drops when I pressed in the clutch. It seems the tach dropped lower than I remember it typically dropping for idle as well as hanging/bouncing at different rpm levels that I have not seen before. Usually there is only one hang I notice which I believe is done for rev matching.
I also noticed a mild rough abnormal idle which proceeded to get really bad....all within about 20 miles of mainly city driving. As I pulled into my driveway my car was idling really rough, loud, sputtering, shaking, and on the verge of dying (dash lights going on and off). The only thing that helped me get up my driveway in first gear was pressing in the clutch and revving a little for a higher rpm, then releasing. My car was sputtering, and dying, then coming back alive with the application of gas in neutral (clutch depressed). The very loud idle sounded almost like when the engine turns over but won't start. At a higher rpm around 3,000 - 4,000 the rough idle dissipated and the car seemed *almost* normal. It died several times and I kept restarting it and giving a little gas to keep the rpm up high enough to limp it into the garage. At higher rpm such as driving on the freeway, and in gears other than first it seemed okay but I can't be sure because it was finally at its absolute worst as I arrived home. I also noticed an egg odor after I exited the freeway that I believe came from my car, but I have smelled that before so it may not be relevant.
It seems that the low rpm, which is running lower than usual at idle is causing my car to die. However, I have no clue why this is happening and why my engine sounds like it is going to blow up. It truly sounds awful.
I don't drive my car hard...sometimes a little spirited, but mostly average and I have never hit a wrong gear i.e. aiming for 4th and hitting 2nd.
I also use premium fuel, 91 octane here in California as required/recommended by Acura.
Edited to add:
I have only done the maintenance required according to the driver information system. I have not changed spark plugs or timing belt. I believe I had the air filters changed and I have had all of the oil changes completed at the appropriate intervals.
I have had the clutch master cylinder and battery replaced under warranty.
Thank you for any help and information!