Just wondering if the people who are experiencing spark knock ("pinging." detonation) have manual or automatic transmissions...

 

There's already a thread about the pinging issue and you'd probably get better responses in that thread... plus it might help those of us subscribed to the other thread learn something new about what's causing this problem.

https://acurazine.com/forums/showthr...0&page=1&pp=25

I have a MT.

 

I'm well aware of that and I've posted to it.

Virtually no-one is discussing the pinging as it related to transmission type.

I suspect that it's more likely to occur in manual cars, since the automatics will shift down by themselves when the engine is under heavy load (e.g. light throttle and low rpm while climbing a hill).

 

In that other thread, someone mentioned that Acura said it is a problem that is more prevalent in the MT type-S. I have an MT and I have the knock/spark issue. My dealer has thus far refused to acknowledge any problem.

 

I would suspect that it's virtually unique to the MT cars, which is one reason I thought I'd ask.

MT cars can be short shifted/skip shifted (e.g. 1st to 3rd directly) /lugged, while automatics can't.

That greatly increases the likelihood of knock/detonation - particularly in the lower RPM range and when a "higher than recommended" gear is used.

Contrary to popular belief, predetonation/engine knock is more likely to occur in higher gears, under part throttle and at low rpm.

Acura probably needs to come up with a unique spark/fuel map for the MT cars. This engine is essentially a transplant from the RL and that was developed in conjunction with the automatic, which is the only available transmission in that car.

Regardless, these cars shouldn't be doing this. I regularly selected taller gears for any given speed (e.g. 40 MPH in 6th gear) in both my '06 Accord V6/6 speed and my '99 LS1 Camaro. I never heard a single instance of "pinging" during the more than 100K miles I logged (combined) in those cars.

 

My 2007 TL-S is a 5AT, and it pings almost constantly at light loads. I noticed the pinging the week we purchased it.

 

I wasn't trying to be a dick - I just thought that since so many people are already subscribed to the other thread your question would get more attention.

It may be more useful if you ask a mod to set up a vote box at the top of the page. That would give a percentage collation to what types of transmissions suffer the most.

Again, I'm not trying to thread-jack just very interested in what you come up with.

 

Strange. I mentioned to the Acura mechanic that the TL-S had the same engine as the RL and he told me the RL engine was a completely different engine. I was kind of surprised. This whole time I thought the TL-S engine was just a detuned RL engine. He was adamant that it was a different engine altogether. Now I am a little confused.

 

Aren't the engine codes the same (J35A3 or something?)...

I don't think there's any difference in tuning. Both have identical torque figures, and the peak horsepower RPM is the same. Either the power output is identical but Honda Corporate doesn't want to advertise them as such, or the minor changes to the intake and exhaust systems on the TL Type-S results in 4 less peak horsepower. If anything I'd expect the TL Type-S plumbing to produce more peak horsepower, so it's probably just some corporate glazing or rounding of the numbers.

 

That particular mechanic must be smoking crack:

http://en.wikipedia.org/wiki/Honda_J_engine

J35A3

* Acura MDX
* 2005+ Acura RL
* 2007+ Acura TL Type-S

"Detuned" is also a misnomer. The RL makes 290 HP and the TL-S makes 286 HP. That's a 4 HP delta. Minor differences in the air filter set-up and/or exhaust system alone could easily account for that difference in otherwise identical engines.

 

So I was right. That is BIZARRE that one of their own mechanics would say that. Maybe they're all smoking over there. I remember reproducing a creaking sound from the rear deck about 7 times, and their mechanic claimed he didn't hear a thing.