Hello everyone. First post here. Recently bought a 2007 TL Type-S. So far I love it. I've encountered one frustrating problem though. When it's low 80's or less than 80 the car will accelerate like crazy, if I pedal to the metal from a stop it'll go to high RPMs very quickly and wheelspin for a moment even with VSA on, with VSA off it's gonna literally burn them no problem. One hot day (low 90s) I noticed the car would crawl from a stop, I thought maybe I'm going crazy? But today the same thing happened, 90s+, pedal to the metal from a stop and the RPMs will crawl from 750>2000, then stay around 2000 for a while and start going higher, once 4500RPM+ it gets full power, it won't wheelspin even with VSA off. I have tried to google it but couldn't really find anything related to that problem. Could it be engine getting too much hot air?

I have this aftermarket air intake: AEM 21-513P, AEM Cold Air Intake System Factory Direct
The filter they used is this (by the way it's beat to the level it's not worth cleaning, I'll just replace it): AEM 21-2110DK - Universal Air Filters, AEM DryFlow Air Filter Factory Direct
Filter I'm going to buy instead of the one I have (I'm getting a little bit bigger one): AEM 21-2113DK - Universal Air Filters, AEM DryFlow Air Filter Factory Direct

Could it be the filter? Could it be a leak in the air intake system?

I changed the timing belt about 2 weeks ago, I read online it might be caused by timing belt missing a tooth... but then wouldn't the slow acceleration apply even in low temps?

I don't think my engine overheats (the temperature shows to be around the 'middle' whether I drive in cold or hot weather).

Any suggestions? I changed coolant two weeks ago for one that meets Honda requirements and the level is ok.

Please help. Thanks.
Matt

 

Look up heat soak

 

The heat soak usually comes with problems starting the car. I have experienced nothing except for significant decrease in car's acceleration.

 

Look up heat soak again.

 

Alright, but as I mentioned it's an aftermarket air intake which should let more air go through(?), yet it doesn't feel like a 10-20% power drop, it's more like a 50% drop, the tires won't make the slightest squeak off a stop... should there really be THIS much power gone when heat soak occurs?

 

Heatsoak! As you've stated, the call pulls better when the temperature is in the 80s compared to the 90s. TLs don't like this summer weather, if you wanna fix it you can always add a methanol kit. lol

 

hot air is less dense than cold air, less air in your engine means less fuel which means less power. A CAI actually makes heat soak worse as the aluminum pipe heats up to engine temp very quickly and heats the incoming air vs plastic tubing. Only way to prevent this is to look into the ultimate cooling mod.

 

Would I notice a difference if I went back to stock intake (plus lets say K&N filter)?

 

No, just wait til fall and you will be happy again...

 

you can mod the car to alleviate heat soak. but, it comes with drawbacks and only for the serious extreme modifyer.

you can cut the hood and add a vent from another car, like the BMW M3 or MB AMG series vents.

 

you can also move the IAT to a cooler location, which will help trick the ECU

 

Would a short pipe (usually ends with filter around battery) help? I currently have a long pipe that ends right behind the bumper.

 

That'd make things worse

 

You failed to tell us about your other issue with the fans not running: https://acurazine.com/forums/3g-tl-p...ll-one-947746/



well no shit, your engine is hot, our cars already have bad heat soak, Just to top it all off, you don't have proper cooling!! That just further exacerbates the problem!!


Fix that issue first.

 

the short pipe will suck up all the hot heat from the engine.... remember a gas engine is an "Internal Combustion Engine" Combustion = to burn.

 

I made this post before realizing the fan wasn't engaging, and already solved the problem by driving with A/C on all the time (both fans engaging). I also ordered all 5 relays (they were under $60 with delivery, OEM).

 

did someone already say heat soak to be the issue

 

Maybe he missed the 4 posts about it.

 

I am having a similar issue to you but I don't have a solution yet. I have owned my 07 Type S 6MT for 5 summers now. I have always noticed a drop in power on a hot day in stop and go traffic. This summer it seams worse. I am also having symptoms of a bad Accelerator Position Sensor that seems to correspond to the power loss when it gets hotter. I am getting a little shuttering and jabbing in acceleration and a slow throttle response. The power seems to be missing between idle and 2000 rpms and then as I accelerate I get these bursts of power between 2500 and 4500 rpms with no change in my foot on the accelerator pedal. A new APS sensor seems to be about $140+ these days so I am waiting until colder weather to see what problems remain and avoid replacing a sensor when it isn't the problem.

 

I'm in the same boat... I've been dealing with this problem since early May with no resolution so far. I was running a short ram and thought that might be the problem but switched back to stock airbox and if anything it maybe prolonged the slugging for another 10 mins of driving. It gets really annoying when the cars driving normal and you get in a situation where you need to take off and you floor it just to keep rolling along until you hit 4k and then you're moving

 

Sorry for undigging something very old, but the topic was orignally mine.

Now, I'm not 100% sure it's heatsoak anymore, because sometimes at 90degrees the car will go like a beast and some other days at 67degrees it will accelerate sooooo slooooow... it popped P0174 and P0171 at one point, I cleaned the codes, they came back, cleaned again and never came back for like 3 months now. I usually use Costco/Shell gas, always premium. Any ideas what could cause weak accelerating (sometimes, 50/50) except for heatsoak? Thanks.

 

APP Sensor?

Regarding your P0174 Code (https://www.yourmechanic.com/article...-blake-griffin)

Regarding your P0171 Code (https://www.yourmechanic.com/article...y-andrew-quinn)

 

LOL your car is TELLING YOU something is bad with the check engine lights. clearing them the first time, is a good way to check to see if the problem persist if the light comes back on..WHICH IT DID!! DING DING DING! you have a problem with 02 Sensors! DING DING DING DING! you shouldnt have cleared them the second time..instead, you should have replaced the 02 sensors

 

But if I keep clearing them, there is no problem!

 

The OP can read, just not when the words say "heat soak"

 

There is a TSB for 07-08 TL Type S that when P0174 and P0171 appear it is due to a misinterpretation of Data by the ECU. The fix is having the Dealer re-flash the ECU with updated firmware to correct error. It does not mean the cats are bad, That being said, bad firmware can cause a bad cat or other problem if left unresolved long enough.....Before you throw parts at it, I would have the dealer update the firmware.