bohingy

Hey guys, I recently picked up a 2001 UL with 170k on it and I've been super excited to drive it around. Since I purchased it about a month ago I've put about 1100 miles on it. A week or two ago I was leaving the drive-thru line and the sound from my car bounced off the walls and I noticed a ticking noise as I accelerated. There's a constant ticking noise and it grows faster with acceleration.

The car has had only two owners and the previous owner had it for 13 years with a pretty good maintenance history behind it. The timing belt was done at 90k and again at 150k by an independent shop. Checking the gauges it hasn't overheated and all fluids are topped off. The power steering fluid is in need of a change though.

The noise is present when the car is warm, I've noticed it more after getting off the freeway and onto the main roads where I can hear the engine a bit more with the windows down. I changed the oil to Mobil 1 Extended Performance 5W-30 but the noise is still present. I hooked up an OBD reader and there were no check engine codes or pending codes.

I'm not too familiar with larger engines since I used to work mainly on 4 cylinders. But is this noise something to be concerned about? Is this type of sound typical for a high mileage car that's 20 years old? I read on some forums that it could be the VVT solenoid, spark plugs, or a small exhaust leak but I feel like all of these would have thrown a CEL.

I've linked a video below but it doesn't pick up the sound too well. You can hear it more around the 35-second mark in the video.

I would greatly appreciate any help or input! I want to drive this thing everywhere but I've been trying to drive the car less until I figure out what may be causing this noise or if I should be concerned.

jharris400

It sounds like an exhaust leak and it's a very common thing for these cars. The stock exhaust y pipe can rust where the bands hold the heatshield on and eventually start to leak from those areas. If the ecu does complain about it it'll be a P0420 or P0421 or catalyst efficiency below threshold. Nothing to worry about just a minor noise if that bothers you, aftermarket Y pipes do exist if you want to replace it. There are cheaper versions that require you to transfer over the old catalytic converter or just replace it with a section of pipe if that's your style and you have a welder.

https://www.ebay.com/itm/11205744401...8AAOSwGtNXiQ4M

YODAONE

Well built exhaust system, but 20 years is a long time.

OEM Y-pipe is the way to go for fit, reduced NVH, heat transmission and durability.

jharris400

I agree with you, I'd love to be able to get an OEM y pipe at a decent price but new from Lexus $1600, that's a third of the value of a 01 LS430.

https://www.lexuspartsnow.com/parts/...410-50310.html

LS430inDE.

Get a stethoscope or very long screw driver or short wooden broom handle (as a makeshift stethoscope), and touch various components with your ear to the end of it.

It would be nice for you to determine if the ticking noise is from the engine bay or from underneath the vehicle (ie exhaust leak).

I don't recall a ticking noise like that when my LS developed several holes in the Y pipe. The engine simply sounded slightly louder and deeper in tone. I wasn't sure exactly WHY the engine sounded louder (almost like headers), until a winter morning I started the LS, and I saw the condensation/smoke whisping from underneath the passenger's front door! I drove the car for several months with the leak, and it never threw a code.

I ended up buying a genuine Lexus pipe from Ebay and paid I think about $1,200 and had a buddy put it on for me. He had to grind the old hardware off the old exhaust, and the new slipped on and fit perfectly. I was then in love again with how amazingly quiet these cars are. This was several years ago. I did write a post about it on here but can't remember if I added onto an existing thread or if I created a new thread about my experience.

Find the source of the ticking before you start replacing the exhaust, potentially unnecessarily.

EDIT...I have a 2005, live in the NE, and it had about 150k on the odometer.

heartygrn

I agree on checking the Y pipe for leaks. Mine leaked for a while and did not throw any codes but I didn't hear any ticking it was just louder than usual. I couldn't really hear a ticking in your video it just sounds a bit loud. I installed the Davico y pipe from Rockauto. Installed it myself several years ago with just hand tools, inexpensive, no issues, still going strong. I almost always use OEM parts but that pipe is crazy expensive.

Jabberwock

I could not hear any pronounced engine ticking sound on your video. If it runs and idles super smooth, and isn't throwing any codes, I would not worry too much about it. Make sure your PVC valve is in good shape - it's cheap and easy to change. Also maybe run a 2-3 gas tanks with Techron concentrate fuel system cleaner thru it.

Also check this thread -
https://www.clublexus.com/forums/ls-...on-damper.html

caesosa

Much like the above, I don’t think it’s anything serious like a valve ticking inside the engine (you would feel that at rough idle or a code). My first thought was an exhaust manifold leak, but as I listened to it more, it sounded like a bad pulley on the serpentine belt. As someone suggested above, get an auto stethoscope and set it on each pulley (it helped me diagnose a bad alternator on a LC) and see if anything stands out. If it doesn’t, then chase the exhaust. Even if it was a bad pulley, I don’t think it is a terminal sound yet.

ABN Mechanics Stethoscope – 2 Piece Automotive Stethoscope Kit Car Stethoscope Automotive Engine Diagnostic Tool
hope it helps and good luck with the new car.

bohingy

Thank you for all the helpful responses!

I'm going to take a look at my pulleys this weekend and do a smoke test on the exhaust. I have a feeling one of the pulleys may be on its way out. I hear a slight knock upon start usually, warm or cold. I can also hear what sounds like a bearing after revving the engine.

heartygrn

This reminds me that a friend of mine had the bearing in the large pulley in the serpentine belt area go out and it made a ticking sound that made him very worried that there was something wrong with the engine. His issue prompted me to replace that pulley when I did my timing belt as I had easy access to it. This part is called engine water pump bracket, 1663050011. Worth looking into.

FloridaML

I just came across this thread while browsing. I love this forum. What the heck did we do before the internet

bohingy

Update: I had my mechanic take a listen to the pulleys and the engine using an automotive stethoscope and he didn't find anything out of the ordinary. I'm going to go ahead and assume it's a minor exhaust leak.

It is odd though that a cold start and the first few minutes of driving won't present the noise. Thank you for everyone's input on this!

FLX430

did you ever find out what is causing noise

bohingy

No, my mechanic checked it out and said its probably nothing to worry about. I've put about 10k miles on the car since then!

It might just be loud injectors, lifters, or an exhaust leak. I'm not entirely sure lol.

BaggedLS4

I started a thread with what i think is a similar noise but got no responses as of yet mine seems to be louder on the passenger side car runs smooth with no issues no hics or idle surges idles just fine just that noise heres a Zip file (sorry only way i could add a video on here that i knew of) of the sound heres to hoping its nothing