I have a 2004 TL w/ 45k miles. I recently got my car back from body shop because of front end damage from accident( about 3 weeks ago). Mostly body damage and minimal mechanical damage. Car sat in bodyshop for about 1 month before completely fixed.......... Car was running like a dream before accident. I was getting at least 22 mpg overall. Now, performance is horrible. The pedal feels heavy and accelaration is sluggish and Im getting 10 mpg and 190 miles on a full tank!!!

Changed oil/ oil filter (castrol synthetic oil)
mobil 93 octane gas always (added fuel injector cleaner)
Checked tire pressure @ 34 psi
changed air filter

Took it to several mechanics and they dont know what it is. Does anyone in here know what the problem might be. Thanks in advance.

 

no CEL? running rich? how many miles have you noticed this? did you clean your air filter? something sounds wrong but give it a little time.. best check is to clear info on the HWY and then take a measurement of mpg.

Are you noticing anything else / unusual?

 

If you have a stock intake.. make sure the airbox is seated properly and is locked in place... a leak can suck in very hot engine air and cause your symptoms.

Reset your ECU: disconnect the positive terminal on the battery and let sit overnight. Reconnect (have radio code handy) and drive normally -- see if it improves anything.

Wonder if your fuel filter is an issue -- it did sit for a month perhaps with little gas in it? Though you'd probably get a CEL... worth thinking about...

oh... do the "several mechanics" feel that there is something wrong about the way the vehicle drives after they test drove it?

 

No CEL and no signs of oil or fuel running rich (no unusual smells, stains or leaks. Brand new air filter with oil change a week ago. I have driven about 400 miles since I got the car back.... Today on the highway it read 28mpg but pedal was very heavy. It was like a foot workout to keep it at 60 mph.

 

Yes it is a stock/oem filter. I will check the filter in the morning and reset the ECU when i have enough light. I was thinking about the fuel filter and I am going to replace it. I took it to three mechanics but only one drove the car. He noticed the bad mpg and said the pedal was a little stiff but only I could compare it to how the car used to drive...

I'm hoping its as simple as the fuel filter...... i did make an appt at the dealership for Monday. I just hope its not something serious.

Could it be bad o2's or spark plugs?

 

I have seen body shops do strange things to cars in my lifetime...

What you need to check out is the cold air intake snorkel that comes the airbox..... sometimes that gets crushes in the accident and they fail to replace it. This will greatly hamper your performance. Or there could be a rag stuck in it even ! I seen a RSX with stuff in the intake snorkel and when reved up you can see the rubber intake tube collapse...

 

You are right on with the "snorkel" being damaged. I noticed it a day after i picked up my car while i was doing an oil change. I ordered the part and replaced it along with the air filter. It went from 8mpg to 10-11 mpg.

 

Yeah.. agreed. When they're spraying paint around a car.. they'll stuff the snorkel to prevent the intake from snorting it up to the filter ... permanently damaging the filter or worse...

Your pedal feels more stiff?

 

bad 02s?? you'd see a CEL, not likely

bad plugs? Not with your mileage and not since the car was perfect prior to the accident..

 

The pedal feeling stiff is probably you not being used to the car any more. The pedal is not connected to the engine in anyway. It's just a sensor.

You mentioned front end damage. Have you double checked the alignment?

 

Mechanics were trying to get me to change my plugs and o2 sensors. Those couldnt possibly be bad if the CEL didnt come on like you said. I reset the ECU this morning(had to re-enter the radio code) and I checked to see if air filter was fitted properly..... Yeah it still feels stiff, slow response when accelerating. Still same symptoms.

The alignment appears to be fine....... I havent had another pro look at it though. Ill have acura look at it on Monday morning. This is depressing.... Could whats wrong possibly be covered under warranty?
Would the accident void any kind of warranty I might have?

 

Just to ease your mind .. it might be worth taking it to Acura to have them diagnose it at least... if they pull the "accident void" card... at least you may have gotten a diagnosis of the problem...

 

You could always try and push it to see if it's abnormally hard to push. This would tell if the alignment is way off or if you have a brake that's hanging up.

 

does the engine sound "labored?"

 

Is there anything stuck under the pedal? I know one member had something under his pedal. Wouldn't hurt to look.

 

What car were you driving during the repairs of your TL?

I know that whenever I drive a "faster" car while I'm without my TL... getting back into my TL is a very sad process.... i realize how slow it really is...

 

The engine sounds fine........ It feels like some sort of blockage somewhere. Maybe its not getting enough air, so its over compensating with too much fuel. Its crazy because I dont smell any extra feul burning. I'm thinking mass air flow sensor or some type of sensor now.

 

lol, I was driving an 07' g35 coupe. But i wouldnt be too upset about that. Its the fact that im getting 11 pmg overall.

 

The TL uses a speed density system so it does not use a MAF meter. It calculates airflow based off of rpm, throttle position, and manifold pressure, with intake air temp, coolant temp, and some other small inputs.

Is there any chance 87 octane was put in the tank? Did you check the mileage before and after? When mine was in the bodyshop, it came back with 37 miles on it.

 

yeah that's the kicker.. If it were you MAP you would probably get a CEL as well. Maybe open up the head cover of your Intake Manifold and do a visual inspection. How many miles do you drive before you fill-up.. 100-200?

Check for blockage on your exhaust system from your precats to your tail pipes.What I suspect though is possibly your Timing.

1. Check for blockage intake & exhaust and vacuum lines.
2. Clean fuel injectors w/ Seafoam / B-12 / Techroline
3. Check timing, compression, knock sensors, map sensor, egr valve.

Other than that I'm just a very interested observer. Keep us updated.

 

[quote=I hate cars;10463295]The TL uses a speed density system so it does not use a MAF meter. It calculates airflow based off of rpm, throttle position, and manifold pressure, with intake air temp, coolant temp, and some other small inputs.

Is there any chance 87 octane was put in the tank? Did you check the mileage before and after? When mine was in the bodyshop, it came back with 37 miles on it.[/quote


Its a possibility they had to add gas to test drive it..... but I have made the mistake of putting 87 in before and never saw a difference this drastic.

 

I am getting about 190 miles per fill up. I used to get at least 350 per tank. I am going to have the dealer inspect the things that you mentioned in your reply this Monday.

Thanks for all replys and I will definitely keep everyone updated.

 

87 may cause detonation / knock but as long as you keep the car in relatively low rpm you should be okay. But problems that can occur caused by the use of 87 can cause the same symptoms that you see.. but 400+ miles and no CEL.. that's the other thing that has me foncused. Best of luck on your visit.

 

So u have to fill your car up every 4days or so?

 

The detonation itself can cause a loss of power and mileage but when the knock sensor gets involved and the computer pulls timing, power (especially torque) and mileage suffer a lot. When mine knocked it did it at low to moderate throttle at lower rpms.

 

This knock you guys are talking about, can you hear this when your driving. Does it sound like a actually knocking sound coming from the engine? And does the engine feel very sluggish? B/c i put 89 always so idk?

 

It's tuned for 91 octane. Using less octane costs you money in the long run due to the mileage decrease. It has been proven time and time again on here. You may save $2.00 on a fillup but get 3mpg less so you fill up more often.

 

Ohh, well my car is making 215hp and 187trq, so i guess 89 isn't causing any problem? But i guess i could change to 91, thier is about 6k on the car?

 

the damage done is the damage done, no reversing it now, but running 91+ from now on will prevent problems from arising faster. What I simply don't understand is that folks afford a 30K car, yet cry over a few dollars a month, only to have to replay it back 10 fold at 65K. Also have you been running 89 since you got it or after break in? If after, check your oil levels to make sure none is being consumed.

 

also try this and see if it helps:

1. turn on car and then shut off A/C, radio, lights, etc.
2. Turn off car
3. Turn car to positon 2 (radio, navi, guages, etc come on)
4. Press the gas pedal to the floor for about 30-35 seconds
5. Turn off car
6. Turn on car and then go for a SPIRITED (that means very fast and pounding within limits) drive

See if it helps since that will reset the trans and ECU logic to a factory state.

 

I have a 07 TL-S and I get get 200 miles on a full tank consistenly. No I dont have a lead foot, I drive normally I guess. The dealer is saying we cant run a diagnositc untill you put the stock intake back in. Wat bullshit huh, 200 Miles on a full tank!!

 

did you relocate the IAT sensor to the "off road" position for more power? If so that reduces MPG by 1-2 but gives you a little more power.

 

When i get out of my wife's '08 G35x and into my '04 TL... I feel like my TL is a DOG.... the G is quick... i think we found your problem, LOL!

 

u must not own a type s

 

What caused the knock in your car? any significant damage to your piston heads?

 

No damage, I ran xylene in the tank to bump it to 97 octane to get rid of the pinging temporarily until I found the source.

If we're talking the GN, I've gone through 6 headgaskets and one forged piston due to knock while learning to tune.

 

I've driven a Type S ... i have a 2k4 with AEM v2 intake... before that i had a 2k2 Type S with Comptech all around (ran 14.4, trapped 100) but I have driven the 3.5L engine extensively (5AT) in both the '08 and '09 (new style) and was not impressed compared to the infiniti in the low->mid range department.

 

Why are you using 89 octane? did you Dyno your car? If you are concerned about the health of your engine and the power output you should use 91+.. Premium grade out here in TX is 93.

 

ouch.. well there goes that low rpm myth.. do you think it was 1 bad tank of gas? These horror stories have me worried.. my buddy just destroyed his front wheel bearings on his Tahoe @ 80k miles and he drives the thing like Ms. Daisy. He's a real gearhead so his whole weekend was ruined.. he said.. makes me want to buy a KIA.. This from a guy who worked at GM / Delco for 15+ years.

 

You're right that detonation usually occurs under high load and rpm. These cars are just odd. It happened for a year or so. I ended up getting it to stop by trying the key-pause method which was turning the key to on, pausing for a second or two and the cranking it.