Hello, it is my understanding that this is a fairly rare issue, few threads exist on this matter and I have been researching a solution for about a couple of months now but have yet to find answers. Included is a video of the noise from my car, my valves have been adjusted and my timing belt, water pump, tension and idler pulley were just done 1000 miles ago. I am completely stumped I have put about 2000 miles on the car since this started it still runs and drives perfectly. I just want to know if anyone has a definite solution to this problem. My car is a 2004 tl 5at with 198k miles any help would be greatly appreciated thank you.

 

anyone?

 

Hi. It's not that uncommon for these engines to develop a knock that can be more or less severe.

My old TL had a knock that was definitely lighter than yours. I consulted my trusted mechanic who has loads of experience on these engines and basically there's not much you can do short of a rebuild or a used engine swap. He basically told me to drive it like that and that it probably had lots more life in it even with the knock.

Your situation might be different since the knock is quite louder than mine was. Here<s a link to a youtube video I took of mine.


You'll see lots of people talking about the timing belt tensionner. Good idea to check it as it does have a tendency to create somewhat of a knocking sound. Could be the source of your noise if you're lucky (wasn't the case for me).

 

Hello,

If I understand you correctly, the problem began 1000 miles before your timing belt job. Did it also begin before your valve adjustment?

As you've probably read, those types of sounds can range from rod knock, bad pulley bearings, tensioner, etc.

One idea is to remove serpentine belt and run engine. This should be safe to do as long as you have a fully charged healthy battery and only run the engine less than a minute (you want to make sure the car can draw current from the battery as the alternator will not be working). If the noise disappears, you know it is one of the serpentine belt pulleys.

If it doesn't disappear, I'd get a mechanic's stethoscope and try and narrow the area of the noise. This method takes time because sounds bounce inside the engine, but hopefully you will narrow the area.

 

The old ears couldn't really pick up the "knock", but check crank pulley as they have a tendency to fracture and sound like a bottom end knock.

 

thank you all for the replies, I am pretty sure its not my timing tensioner because that is brand new but yes the noise started a couple days after I did my valve adjustment I don't think there's any correlation because this is a bottom end noise but ya never know haha. Running the car without the belt on is a good idea and that will be what I try next once I do I will report back with what I find could be the crank pulley as its definitely the oe from the factor and has never been changed. Again thank you all for the replies I really appreciate it.

 

after putting the car up on a lift and carefully listening I have come to the conclusion that the noise is piston slap and I am just going to keep driving it and changing the oil regularly.

 

I'm sorry man. As I said earlier though my mechanic told me these engines can last a long time while knocking like that. Ofc it depends on how severe the knock is, Hopefully you can get a bunch of miles out of it still.