Whining noise from engine.. 1MZFE

[bazza46]

Hi,

I've just gotten a nice 99 V6 Camry Touring ,manual transmission. It goes well, doesnt use oil doesn't leak (as previous owner had crank, cam seals and cam cover gaskets replaced recently. He also (about 5000km ago), had a Dayco timing belt kit fitted.

Problem is, while the engine runs superbly, idles quitly, when you rev it up it makes a soft whining sound from the centre of the engine which rises in pitch as the revs rise.

It isn't the alternator or power steering pump as I disconnected both belts and ran it, but the noise continued. It isn't a grinding or scraping noise, just a sound like gears make when they are slightly noisy.

A professional mechanic I spoke to asked me if it had had a timing belt change recently and when I said 'yes' he said that it sometimes happens when the belt is too tight.

Well, the belt on the 1MZFE has a hydraulic tensioner that can't be adjusted, correctly or incorrectly, as I see it.

Using a home made broom handle stethoscope I sort of tracked the noise to the centre of the front of the engine., but the noise also could be telegraphing to the back of the cam boxes.

Has anyone else had such a thing happen? Could it be worn sub gears on the cams?Or have the people who changed the belt stuffed it up?They did leave off the 10mm nuts that hold the wiring harness to the cober on the back cylinders. No water pump was fitted, according to the invoices,so could it be that?

As I said earlier, It goes really well and I could live with the whine if it's too difficult or expensive to fix.

If anyone can shed some light on the matter, thanks in advance.

Bazza

[trentmeyer23]

No water pump is a bad idea. It could be that, it could be the oil pump as well.

[bazza46]

I sure hope it is something other than the oil pump, as that could not be replaced with the engine in the car,and I'm not prepared to do an engine removal. Tomorrow I intend to take off the upper plastic belt cover and see if there is anything obviously 'funny' in the belt department.

[trentmeyer23]

It may not even be those things. Oil pump can be done with the engine in the car. It's not fun, but it can be done.

[bazza46]

Hi Trent.

I'm astounded that the oil pump can be done with the engine still in the car. It doesn't bother me about it 'not being fun', as most of the jobs with these cars falls into that category. That gives me hope. I'd hate to have to ditch this good looking car because of a crummy noise. I could stand the torture of working in that confined space if it will fix my engine.

Back to the advice I got from my rego inspecting mechanic- Do you think it's possible that an over tight belt could cause a whining sound?

Because I just got the bright idea to undo the two bolts that hold the hydraulic tensioner slightly, slip in a couple of 1mm thick U -shaped aluminium shims I'd make up, to pack out the lugs on the tensioner, thus releasing the tension a bit, starting up the engine and listening . I've heard that some generic timing belt parts are not always to proper specs. I found this out with a cheap water pump on my Corolla, so I'm hoping that some improperly made part might be the problem here.

Cheers, Bazza

[trentmeyer23]

Back to the advice I got from my rego inspecting mechanic- Do you think it's possible that an over tight belt could cause a whining sound?

It will depend on the sound, but I would doubt the hydraulic tensioner would over tighten the belt. It's hard to judge without inpecting it personally.

Generally the issue lies with old unchanged parts as the newer parts add more stress on them, due to not having as much slack in them.

[Jim.]

I think I would replace the water pump first. Even if the problem is not that, it is a good idea. Obviously the vehicle has done more than 100,000 klms. Good insurance, so to speak.

I had a pump collapse on me once without warning. Meanwhile, another vehicle same make and model (5SFE) did the same while passing a big truck on the highway, around the same time.

[bazza46]

Thanks for the advice, all.

I first tried putting 2mm spacers under the tensioner lugs and running it. It made absolutely no diference to the sound.

So I bit the bullet and took off all the bits to get at the cam belt. I mus say it was a lot easier than doing the Corolla due to the extra diatance between the engine and the body, with the exception of the power steering pump return hose, which I eventually disconnected and wired out of the way. Lots of fluid remained in the reservoir, however, and made a big mess.

And taking the crankshaft nut off was a snack after I spent half a day constructing a tool to hold the pulley, and a 70cm extension to my socket, from a 45 mm thick wall tube to allow me to use the breaker bar outside the edge of the fender.

Also, undoing the camshaft nuts was impossible till I made a tool to hold the sprockets securely, then they came off easily.

I decided to use the new genuine Toyota water pump I bought, as I thought that may be causing the noise.

However, when I got the covers off, I discovered two things. First, the belt had been installed the wrong way around. The arows showing the outside were facing the inside, and the three marks that align with the crankshaft ulley and the two cam pulleys would not align no matter how many times I turned the engine over. So I thought," Yes!!!, perhaps this belt needs to be on the right way around ot it'll be noisy, and aas it's done less than 4000 km it won't mind being reversed again."

But I also decided to use my new water pump, despite the old one being a genuine Toyota one, too, and appearing to be in perfect condition, running smoothly, with a little bit of tightness to indicate a good seal, and having no slack or roughness in the bearing.

ButI found it impossible to get the water pump off, firstly because of the two studs causing it to hit the side of the body rail, and because of the sheet metal rear cam cover which overlaps the pump body edge and has to be remove first, What a stupid design! If they'd made it with a tiny bit more clearance around the cutout, you could have slipped the pump off without removing it.

That's when I had to make my cam sprocket removing tool, which took another two hours to make, but held them easily. With those out of the way, it was easy to remove the tin cover.

The inside of the pump was pristine, so I knew it wasn't that, but, as I'd taken the old one off and the new one wasn't going to be any use siting on my shelf, installed it.

The belt is a Dayco,but made in Italy, and the idler and tensioner pulley are GMB bearings, which felt new and rolled smoothly and tightly. Si I'd checked everything and it looked fine and new. The belt had no nicks of damage of any kind on it, and is obviously new, as are the bearings.

The tensioner took a large pressing in my vise to return the plunger to the start point where I slipped a wire through the hole. Funny thing was, when the tensioner was all bolted up, the wire could be pulledout easily, as the two holes liked up perfecty. I thought the plunger would move out a bit and take up the tension, but there was tension there (I presume) with the plunger all the way in.

So, with much elation, I put the belt on the right way, checked the marks and saw they lined up, and carefully reassembled the cams, using my big and litle torque wrenches to get exact tensions on the big and little bolts. This had to be it!, I thought.

BUT... when I started it up without the acessory belts fitted so there'd be no mistaking the source of the noise, There was the blasted noise!!!!

Oh, man, was I disappointed, although it seemed that it was a bit quieter, maybe. I was really p****d off.

But after driving it a bit, it does seem to be a bit quieter, and my wife (who has no ear for motors) says she can't hear the sound at all, now, and my best friend, who is an optimist, says that it now sounds quiet and the slight soud of whining is perfectly normal for that car.

And after Googling 'whining sounds after belt changes, I read of many who got a similar noise, and were told that the new Kevlar belts do that, etc, so I'm holding my breath and going to monitor it and see if the sound gets quieter as the kms roll on.

I still don't think it's normal, but I'll see.

[bazza46]

P.S. I got the water pump off by jacking up the motor and jiggling it a lot. I know you're not supposed to do this, but I put a thick block of wood as big as the sump under the sump and carefully watched it for signs of any deformation as I jacked it. It wouldn't go up much, so I assumed the engine mounts are good, but enough to get the pump off.