I have a 2006 Acura TSX Automatic and I'm beginning to wonder whether the car may be starting to have mechanical failures?

It doesn't start amazingly -- very slow (4 cranks) and when it does turn over, it sounds very weak at first -- at least on some mornings (like today, even though it was 65F and in the garage!) It can't be the battery -- that is fairly new (replaced in July). Our 2013 Chevrolet Avalanche turns over quick!

I am also getting very poor MPGs... when I purchased the car, the reading was 25.4mpg (and the lady lived in the city). I live in the suburbs and I am getting 21mpg... and my average speed is about 50mph except 25mph in my neighborhood. I don't run the A/C or heat, though I have been running the heated seats on some mornings.

I was at one point getting 24-25 mpg, so I'm not sure what happened. I haven't changed my way of driving or anything. I don't run premium gas, however, I run mid-grade. I'm not sure whether that affects anything though, and I ran mid-grade when I was getting 24-25.

Finally, I have also noticed odd noises (a loud thumping sound) when turning left... It doesn't always happen, but when it does, the noise is very noticeable. I can't really tell where the noise is coming from, but maybe the suspension? I do have another noise, but that comes from the front-passenger seat (does anyone know how to fix that noise? It's a small knocking/thump noise when turning, not the same as the other loud noise though).

 

Sounds like spark plugs and a n Injector cleaning, a right side CV Axle, and a bad mount on the passenger seat

4 cents for you

 

do I need to replace the spark plugs? What do the spark plugs do and what problems are they causing for me?

and as for the right side CV axle... what makes you say that? I was reading that you notice this when it starts shaking... my car doesn't shake (except when idling... another problem)

BTW, I have 63,000 miles on my TSX. I didn't have any problems with my Escalade until I hit 200,000, but that was the rear axle ;o

 

BTW, mid-grade is a rip-off. TSX calls for premium. Here's the math:

Station gets a shipment of gasoline...two types, premium (we'll say 91 octane...place where premium is high as getting screwed more) and regular (87 octane). So how do they make mid-grade (assume 89 octane)? They pump a half gallon of regular and a half gallon of premium for every gallon, averaging 89 octane, voila, mid-grade.

Here's the nasty bit, many stations stratify their prices unevenly, which is to say that the difference between 87 and 91 might be 30 cents, but they price 89 as just 10 cents less than 91 octane...making a free 5 cents a gallon.

The spark plugs ignite the fuel/air mixture in the cylinders. Fouled or worn plugs will reduce performance and mpg. The other likely mpg item is the injectors getting dirty, which messes up the mixture and reduced combustion efficency.

Honestly, it's time to drag the TSX to a honest independent shop for a complete once over...shouldn't cost too much, and then they can give you a list of issues, the cost to fix, and advise you on their priority. BTW, a new battery deosn't mean it isn't dying...some come bad from the factory...and a weak alternator or charging system issues can kill a new battery quickly.

 

This was a common complaint. 4 cranks is pretty much normal (I can't recall my car ever doing it with less cranks). I think the most common explanation was that it is done on purpose to reduce our emissions upon start up. The other explanation was the small batteries our cars have (some people upgrade to bigger batteries with more Cold Cranking Amps), but I don't recall if it helped with their slow cranking).

For your readings, are you using the car's calculations or are you computing it at the pump? I find that my car is never accurate.

Also, when did you take your readings? Perhaps one average is from when you were using summer-grade fuel while the other is from using winter-grade fuel?

Also note that a few of us have experimented with octane levels and have found that unless you only drive a lot of highway miles regularly, using anything less than premium octane will cost you more. If you do a lot of stop and go traffic or short trips, premium octane is more fuel efficient. The engineers who designed your engine designed it to work on premium fuel, but they made the car smart enough to retard its timing to protect itself if you choose to use lower octane. Thus, lower octane causes your engine to restrict itself and lose power so that you'll have to stomp on the gas more to get moving (ie: from red lights, etc).

Using lower octane might save you $2.60 per tank, but you will visit the gas station more often and will suffer performance losses. Using premium lets you enjoy your car more and reduces your trips to the gas station...all for $2.60 (20 cent price difference times 13 gallons = $2.60).

The sound while turning is most likely a cv boot/joint issue.

As for the sound from your passenger seat, I haven't heard of any issues with that seat. I know the driver's seat is known for being loose, moving around, and making noise, though. Perhaps with enough use the passenger seats are affected also?