im sure theres threads on this, but i cant find one that relates EXACTLY to my problem.. there are ppl experiencing similar problems tho.. but with that said, i recently bought a used 05 TL. Because of budget issues, i was forced to buy one with 90k miles!! but to me it was well worth it, it was fully loaded, white ext grey interior which i wanted but could never find, and i mean hey its a japanese car, they will get far more miles than 90k. plus the price was right. i had a full engine diagnostic from an acura dealer before purchasing the car. Now on to my problem. The car just doesnt seem to be as quite anymore. I loved how at low rpm it had that very quite rev, almost like a supercharged prius or something (haha) and when you get into high rpms you really hear the engine roar. When idling the car (as i remember) was nearly silent, but now it seems to be louder. It sounds like maybe any normal car would, but this is a luxury car, not a normal car, and i never noticed this before. I dont want to say its knocking...but it is kinda sputtering and its definatly a louder idle than it used to be. Also, when i shut off the car, after the engine powers down, there is a click. Almost like my turbo is shutting off except, as we know, i dont have turbo! Im not sure if the click is just something i never noticed because 1. im paranoid about the louder engine and 2. i ussually listen to loud music. Sorry if my post is completely confusing and worded poorly, but does anyone experience this problem, or is it not even a problem and rather something i never noticed? Do your cars have a "click" sound when you power down?

 

is your car idling at higher rpms? and hows the weather? if its cold the car will be louder at startup while it warms up. also what you mean by a click? there is a bit of a hiss sound when you turn off the car though.

 

the click is after the hiss =\

 

take off the engine covers and look at the vacum lines connecting to the motor. Have a friend rev the motor and listen for it, you might have a line with a hole or it might be loose. Also when he does this check to see if the motor shakes a lot front and back. If so you might have some broken motor mounts. also are you running premium fuel? with 90K on the car, do you know what maintaince was done to it prior to buying it? If so please tell us, if not tell us you don't and I'll give you a list of things that may need to be done.

 

I agree with the above. It may be that you're getting used to the car. If I drive my other car for a day or two and get back in the TL, I can't hear the engine at all.

Also, there should be some very light ticking at idle, this is injectors and valvetrain. I've always run a 30wt and it definately reduced valvetrain noise over the 20wt.

 

make sure the screws are tight on the air box.

 

thanks for the responses guys. You know i was thinking it was one of two things:

a. something is loose or
b. the VERY first time i filled up my car, i wasnt sure what octane to use so i used 89 octane. I didnt notice the sound during the whole tank but the problem did seem to start the next time i filled up with 91. I have filled the car up with 91 once more but the problem is still there, it may however just be the mixing of fuel or something but it will eventually stop?

as for the "click" its after the hiss and sounds like "pshhQ" not very helpful i know :P haha

Also, a lot of people say the car is louder in the morning when its cold out. My question is, what would be considered cold? Today in the morning it was about 55-60 degrees and my engine sounds CONSIDERABLY louder. It did seem to wear off after my classes when it warmed up to about 80. The sound was coming from the passanger side of the engine and almost sounded like when you hear a gardner from outside your window. A feint leafblower motor sound, almost as if it was a seperate engine. It did however go away later in the day. However along with the normal loudness i was referring to in my previous post, it also seems like my steering wheel is shaking more also, so im hoping something is just loose. I dont know much about engines but when i did pop my hood it seemed as if the fan in front of the actual engine cover was working super hard cus it seemed loud. Also i noticed sometimes when (i have a 5at) it switches gears from 3rd to 4th, it shakes a bit, almost as if its forcing into gear. I have read that this is a common problem with 07 6mt, but nothing about 5at.

I do not have complete service records for the car, but it did have a clean car fax and title, passed a full engine diagnostic, and did have an overall record saying that the oil was changed regularly, and over all the car exterior and interior was EXTREMELY well kept. I will definatly be checking the engine like you said and also im looking into buying some of that "anti knock" liquid for the fuel.

Once again, thanks for all your responses and help, and anymore insight will be appreciated

 

Speaking of servicing, how much does the 90k service cost?

 

well my engine diagnostic was 250

 

Actually your description of the hiss sounds just like a CAI. If your TL has the stock airbox, do as 240SX says and make sure the airbox screws are tight. If you have a CAI, it's normal.

 

with 90K on the car, this is what you should do to restore the car to great condition:

1. Oil change and oil filter change (do it when your MID tells you to)
2. Seafoam treatment (do it about 20 miles before you have to go for your oil change, pour it in the oil, gas and through the vac line)
3. After oil change and seafoam, change your spark plugs, NGK is the recommended brand
4. Check and change your engine air filter, they can last from 15k-30k depending on driving conditions
5. Check and change your cabin air filter, they can last from 15k-30K depending on driving conditions.

 

Only thing I don't agree with is Seafoam in the oil. It's a bit harsh. The best hands down oil treatment is Auto-Rx. There is nothing better and it cleans gently over the course of 7,000 miles.

 

thanks guys ill try it out but over all it sounds like its most likely nothing serious