2000 LS400 whining from crank pulley? / surrounding area

DanMystro · November 6, 2022

This whining noise has only started since I installed a new tensioner a few days ago, but after taking off the belt which puts the auxiliaries out of action the sound still persists. Listening closely to the noise it appears to come from the crank pulley? / surrounding area so hard to tell really. I had installed a new water pump, cambelt and idlers last year so it shouldn't be that although I did not replace the hydro tensioner (could it have lost a bit of tension causing the noise?), checked the valve body and filter but that was clean as can be with no crud or gunk, although the fluid was brownish/red. All fluids, PS, Coolant, engine oil, ATF etc are all topped up. Not really sure what it could be, any advice/help greatly appreciated.

ColinBarber · November 6, 2022

It could potentially be the crank pulley/harmonic balancer. The rubber in it could be cracking and any extra tension put on it whilst replacing the belt may have accelerated its demise, although it doesn't appear to be wobbling in the video.

Worth trying to take a picture of the front if it to see if the rubber looks ok.

DanMystro · November 7, 2022

19 hours ago, ColinBarber said:

It could potentially be the crank pulley/harmonic balancer. The rubber in it could be cracking and any extra tension put on it whilst replacing the belt may have accelerated its demise, although it doesn't appear to be wobbling in the video.

Worth trying to take a picture of the front if it to see if the rubber looks ok.

Thanks Colin, I'll have another look when the weather is nice, whenever that is.

Supafly · November 8, 2022

I've had my fair share of coincidences which have sent me on wild goose chases, it has taught me to cover the basics first.

The parts you changed last year, were they genuine lexus/toyota parts or aftermarket?

In your video there seems to be a 'clicking' sound too but that may just be injectors or the mic picking up noise from the head, it's hard to tell from a video. Do you notice that noise in person and was it there before?

You've eliminated the logical first suspects already by removing the belt and separating all the accessories and new tensioner.

I would eliminate one further suspect before considering checking the parts from last years work...

You may have dislodged/dropped something that has fallen behind/somehow touching the crank wheel and is now catching/making the noise.

Also, engine oil level? Does it make the same noise warm and cold?

DanMystro · November 8, 2022

22 minutes ago, Supafly said:

I've had my fair share of coincidences which have sent me on wild goose chases, it has taught me to cover the basics first.

The parts you changed last year, were they genuine lexus/toyota parts or aftermarket?

In your video there seems to be a 'clicking' sound too but that may just be injectors or the mic picking up noise from the head, it's hard to tell from a video. Do you notice that noise in person and was it there before?

You've eliminated the logical first suspects already by removing the belt and separating all the accessories and new tensioner.

I would eliminate one further suspect before considering checking the parts from last years work...

You may have dislodged/dropped something that has fallen behind/somehow touching the crank wheel and is now catching/making the noise.

Also, engine oil level? Does it make the same noise warm and cold?

Hi Supafly, thanks for the advice, that faint clicking noise has always been there, think it's just more pronounced on video since the phone was semi-in the bay, I removed the crank pulley and inspected it not only AFTER the car decided to just shut off completely after about 10 seconds of idling... Oh boy it, it doesn't get any easier, does it. Pulling four error codes related to MAF & o2 sensors but that's for another thread I'd assume. (Codes 24 27 29 31 if you're wondering which I would think shouldn't affect the engine firing)

I was going to test the car with the pulley off to see if the noise persisted or not but now I can't even start the darn thing, cranks but no start, no spark, all fuses fine, haven't checked the fuel pump yet... Ugh. Still love it though.

Supafly · November 14, 2022

Any joy yet?

DanMystro · November 15, 2022

8 hours ago, Supafly said:

Any joy yet?

Kind of. Think there's a short in the harness somewhere, managed to get spark and fuel but seems to be starved, FP fine (currently bypassing relay to make sure fuel is constant for testing) , crank and cam sensors fine, changing the fuel filter tomorrow but still need to do a pressure test, codes still there even after switching MAF sensor (24 & 31), could be injectors but not entirely sure, still troubleshooting.

My guess is the Ecu isn't getting signals from various sensors.

DanMystro · November 18, 2022

Update: Think I might have found the problem to both the no start and whining noise, took off the right hand cam cover only to find the belt was jumped up over the lip, turned the crank pulley over a few times only to find the belt timing mark(s) are out of alignment with the marks on the cam gear by about six teeth, hopes up!

Will be stripping down the front of the engine (Uhh 😪) to re-adjust the belt and pray that was it.

Malc1 · November 18, 2022

good luck with all that ...... wonder what *** did the last cambelt change then ?

Malc

DanMystro · November 18, 2022

2 hours ago, Malc1 said:

good luck with all that ...... wonder what *** did the last cambelt change then ?

Malc

To be honest it was me 😂. Although I did it two years ago following a guide to the T, pictures and all, no issues for the last two years until recently when I made this post some weeks ago. I didn't install a new hydro tensioner when I did the work so I'm guessing it just got weaker and weaker over those two years causing it to finally jump. Lesson learnt...

Almost done with the work but I'm going to buy a new tensioner and resume once that arrives.

Mikaelse · November 18, 2022

Hmm. The noise sounded like a belt or metal rubbing against a stationary object in my opinion.

I suspect it is not a problem with the tensioner. those seem pretty long lived.

The tensioner is reasonably a metallic spring with fluid damping to dampen belt vibrations.
I changed these for new when doing a LS400 cambelt because they were in the kit. The old one (20 years old probabaly) felt fully serviceable though when manipulating it.
It is perfectly possible that that type of device fails but if it happens it is reasonably that the damping is bad due to leaked fluid or a worne damper.
Experienced that on other make cars. gnereically speaking after damper deteriorates serious belt vibrations migh arise and very bad things happen.
Spring weakening you discribe in a more or less stationary metal spring is unlikely in a LEXUS design I think.

DanMystro · November 18, 2022

Update: Put the old hydro tensioner on for testing purposes after re-timing the belt, car fires right up (Great! We're getting somewhere) but dies after a second or so, there's next to no fuel in the tank due to draining it to replace the fuel filter so will pour some in tomorrow and give it another go. So far so good but not 100% yet.

DanMystro · November 18, 2022

1 hour ago, Mikaelse said:

Hmm. The noise sounded like a belt or metal rubbing against a stationary object in my opinion.

I suspect it is not a problem with the tensioner. those seem pretty long lived.

The tensioner is reasonably a metallic spring with fluid damping to dampen belt vibrations.
I changed these for new when doing a LS400 cambelt because they were in the kit. The old one (20 years old probabaly) felt fully serviceable though when manipulating it.
It is perfectly possible that that type of device fails but if it happens it is reasonably that the damping is bad due to leaked fluid or a worne damper.
Experienced that on other make cars. gnereically speaking after damper deteriorates serious belt vibrations migh arise and very bad things happen.
Spring weakening you discribe in a more or less stationary metal spring is unlikely in a LEXUS design I think.

I did notice after re-timing the cambelt then starting the car the cambelt edged forwards a bit, on the right hand cam gear the belt is literally sitting on the edge of the gear, when I fitted it I pushed it back a bit, I also noticed the belt has moved so much it has edged slighlty off the tensioner idler (If that's what you call it? The bit the tensioner pushes up on).

I'm guessing the tensioner is on its way out.

Would a weak tensioner be a prime suspect?

Thanks for the input, any advice appreciated.

Supafly · November 21, 2022

Good to hear your making positive progress with this. Wishing you all the best.

Sorry, I don't know enough about timing belts and tensioners to offer any help.

I personally would replace the belt and old tensioners that weren't replaced the last time around. Leaving the other new items and sticking to the replacement schedule based on the previous jobs time/mileage.

Supafly · November 21, 2022

On 11/18/2022 at 10:14 PM, DanMystro said:

I did notice after re-timing the cambelt then starting the car the cambelt edged forwards a bit, on the right hand cam gear the belt is literally sitting on the edge of the gear, when I fitted it I pushed it back a bit, I also noticed the belt has moved so much it has edged slighlty off the tensioner idler (If that's what you call it? The bit the tensioner pushes up on).

I'm guessing the tensioner is on its way out.

Would a weak tensioner be a prime suspect?

Thanks for the input, any advice appreciated.

Re-read your post and had a thought....

Something is definitely out of alignment to cause the belt to want to wander off. Are you able to crank by hand watching to see where it first starts to go off line? or push it back, crank on the starter, check and repeat until you find the cause?

Can you see from the side/top of the engine if anything is bent/out of alignment?

Have you checked/retorqued all the pulleys/bolts etc? One could be loose

DanMystro · November 24, 2022

On 11/21/2022 at 1:44 PM, Supafly said:

Re-read your post and had a thought....

Something is definitely out of alignment to cause the belt to want to wander off. Are you able to crank by hand watching to see where it first starts to go off line? or push it back, crank on the starter, check and repeat until you find the cause?

Can you see from the side/top of the engine if anything is bent/out of alignment?

Have you checked/retorqued all the pulleys/bolts etc? One could be loose

Sorry for the late reply and thank you. I've got a new tensioner but just waiting for a free day to install it (Friday), when I put the old one back in for testing purposes the rod that pushes up against the tensioner pulley didn't even push the pulley up at all as if it lost all strength, once I fit the new one I should be able to see if there's any difference, I did notice the belt was a bit oily as well which is a cause for slip, so will be checking seals and cam cover rubber seals. I will be re-torquing all bolts to spec again. Nothing looks out of alignment that I could noticeably see.

Supafly · November 24, 2022

Good luck for Friday 🙂

DanMystro · November 26, 2022

Update: Installed the new tensioner, the belt now sits in more (not as close to the edge). The car wouldn't stay running on it's own without my help pressing the throttle down and it would fluctuate the revs up & down, BUT after some fiddling around I finally got it to stay running on it's own, I had to adjust the TPS and play with the throttle motor.

I do believe my throttle motor/actuator is dying, normally you hear that slight buzz from the motor but it had no noise coming from it with IGN ON, I had to turn the IGN to OFF and ON a few times for it come on. I have an APEXI NEO installed which measures my throttle position among other things and noticed when the pedal was fully depressed the motor had no power and the butterfly valve only opened a tiny bit due to the wire, after I got the throttle motor to finally turn on and I pressed the pedal I noticed the throttle position had full movement, turned on the car and Boom! It's alive!

I won't say it's fixed for now until I reassemble everything and do a little more testing but for now it's looking good.

Supafly · November 28, 2022

Great news!

Really interesting to read about the throttle. It's the first time I've read about a fault with this. You're very fortunate to have the APEXI installed.

Does the APEXI allow you to change ignition timing? My LS is LPG converted and it would be great to tweak the timing for the fuel type.

- Quick search points to it only allowing fuel adjustment, which I can do via the lpg ecu.

DanMystro · November 28, 2022

9 hours ago, Supafly said:

Great news!

Really interesting to read about the throttle. It's the first time I've read about a fault with this. You're very fortunate to have the APEXI installed.

Does the APEXI allow you to change ignition timing? My LS is LPG converted and it would be great to tweak the timing for the fuel type.

- Quick search points to it only allowing fuel adjustment, which I can do via the lpg ecu.

Yes, the APEXI only allows fuel adjustment but it's such a nifty little device to have.

DanMystro · November 28, 2022

Update: Everything back together. Works a dream, even a little better than before! Had a small lumpiness at idle with tiny backfire pre-problem which has now gone away and is smooth as can be, fantastic. When I first started it up after repairs it was smoking quite a bit but I guess that was just condensation buildup and what not from sitting for weeks at an angle, coolant was bubbling out the reservoir which scared me as I thought the head gasket had blown but later realised it was just air burping out the system 😂, silly me. No more smoke and no coolant bubbling, awesome.

At this point I'm going to call it a successful job, not much to do now apart from driving it and making sure it all runs right, miss driving the ol' boat so will be a joy to get back behind the wheel. Thanks a lot to everyone for their suggestions and comments! It's been a pain and a pleasure.