Toyota Nation Forum banner
1 - 20 of 43 Posts

·
Registered
Joined
·
630 Posts
Discussion Starter · #1 · (Edited)
In the past couple of months, my car has started this kind of whining noise which is hard to describe. It sounds just like a belt slipping on a pulley when the belt gets wet. The noise seems to be coming from right under the black plastic timing belt cover that covers the front cam gear. I had the timing belt job done at 77K miles, and the car has 92.8K on it now. I'm wondering if this could be the idler pulley getting ready to go? I wanted to have the tensioner and this idler pulley replaced when the timing belt job was done, but my mechanic said they hardly ever fail. How hard would it be to take this black plastic timing belt cover off? How hard would it be to just replace the idler pulley if it is bad? Thanks, Endzone.

The whine seems to be coming either from the #2 idler pulley or from the front cam gear itself. When I push in on the black plastic timing belt cover (on the front) the noise seems to go away. When I pull out on the black plastic cover, the noise gets louder. Could the bearing supporting the front cam gear actually go bad? This car was a sludged engine and my mechanic said one of the cam seals had sludge in it when he replaced both of them.

 

·
Registered
Joined
·
528 Posts
Are you really sure it is from under the timing belt cover? The alternator is in this area and is prone to whine if going bad.

Did they replace the water pump when doing the timing belt job? Water pump can begin to whine if the bearing in it start to fail.

I am at a loss as to what to think about the change in the whine when you push on the cover.

As to how hard it would be to remove the cover, it's not hard at all...just time-consuming. Take a peek at this video and see if you really want to get in there.

 

·
Registered
Joined
·
1,657 Posts
I was guessing hydraulic tensioner but that would not be a continuous whine I think. So I did not say anything.
 

·
Registered
Joined
·
630 Posts
Discussion Starter · #4 ·
Are you really sure it is from under the timing belt cover? The alternator is in this area and is prone to whine if going bad.

Did they replace the water pump when doing the timing belt job? Water pump can begin to whine if the bearing in it start to fail.

I am at a loss as to what to think about the change in the whine when you push on the cover.

As to how hard it would be to remove the cover, it's not hard at all...just time-consuming. Take a peek at this video and see if you really want to get in there.

https://www.youtube.com/watch?v=_c_a-ECaWSU

Thanks for that video. He really did a good job on that! I'm certain the noise is coming right from the center of the front cam gear under the #2 timing cover. I thought I could just pop the #2 timing cover off and then listen for it, but that is a lot more work than I want to get into. I wish I had a video camera and I could post the link to how the noise comes and goes by pulling and pushing on the timing belt cover in the area that covers the front cam gear. It is really weird. Yes, the water pump was replaced when the timing belt job was done. Thanks for your replies.
 

·
Registered
Joined
·
285 Posts
Wow, I'm surprised that your mechanic said to not bother with the bearings. Considering how little they cost compared to the labour to do it again...
You can narrow down the cause of the noise, by removing the drive belt to the alternator/AC then start the motor and listen...still there? Do likewise with the PS pump belt. Once you've eliminated those possibilities, pull the upper timing belt cover and start the motor. If you have a stethoscope (they are cheap at most auto service stores) you can isolate where the problem lies easily. If not, use a long screwdriver, place it against the suspect bearing mounting bolt and put your ear against the handle. A bad bearing will be noticeably louder than a good one.
 

·
Registered
Joined
·
630 Posts
Discussion Starter · #6 · (Edited)
Wow, I'm surprised that your mechanic said to not bother with the bearings. Considering how little they cost compared to the labour to do it again...
You can narrow down the cause of the noise, by removing the drive belt to the alternator/AC then start the motor and listen...still there? Do likewise with the PS pump belt. Once you've eliminated those possibilities, pull the upper timing belt cover and start the motor. If you have a stethoscope (they are cheap at most auto service stores) you can isolate where the problem lies easily. If not, use a long screwdriver, place it against the suspect bearing mounting bolt and put your ear against the handle. A bad bearing will be noticeably louder than a good one.

Thanks professor, and I'm glad to see you are still around. How is everything in Ontario, Canada? I will try to follow your steps. What I would really like to do is remove the #2 timing cover from off the #3 timing cover. I see that there are 5 bolts securing the #2 cover to the #3 cover. Is there more involved than just removing these 5 bolts? I'm guessing there is. But, I will begin to look into it and either get a stethoscope or a long screw driver.


Wow, only 4USD at Harbor Freight:
http://www.harborfreight.com/mechanics-stethoscope-69913.html
 

·
Registered
Joined
·
285 Posts
All is well in the Great (not yet, but soon) White North. Got a newer computer that is hopefully going to be reliable... Why doesn't Toyota make computers?
There is slightly more to removing the top, No. 2 cover. Just getting the engine mount out of the way (the dog bone shaped thing and the cast aluminum part on the passenger side) so that you can access the cover. You do not have to support the engine in order to remove it. The wire harness has to be moved up out of the way too. It is all pretty obvious when you take a good look at it.
If you do have to switch out pulleys, be very careful that the cams and crank are at TDC when putting on the belt....it is so easy to be off by one tooth! The engine will start but it will be a dog. Check, double check, start the engine, shut it off and triple check before putting the cover and everything else back on.
 

·
Registered
Joined
·
630 Posts
Discussion Starter · #8 · (Edited)
Glad you found a reliable computer. I'm still using a "Systemax" 2008 Core 2 Duo machine that works just fine. I bought it new in 2008 and upgraded from Windows XP to Windows 7. I did a clean install when I upgraded. Still think Windows XP was the best operating system ever.

I did some checking on the car yesterday. Here is a strange thing about this scraping or whining noise. In the picture below, when I pull the #2 cover towards the right front tire, the noise gets much louder. Then in the 2nd picture, when I push the cover towards the engine, the noise goes away. In the last picture, this is the #2 cover seated up against the #3 cover, and this is just above the alternator. The #2 cover doesn't seem to be seated right into the #3 cover. Does this matter? Could the timing belt actually be scraping against the cover? Thanks for taking a look.







 

·
Registered
Joined
·
285 Posts
I think what is happening is the No. 3 cover (which is metal) has been bent a little such that it is touching the back of a pulley. The No. 2 cover can be rather difficult to pull out, even with all the bolts removed...it's a tight squeeze. I think it probably got bent while changing the belt. The covers should fit very snugly together to keep water out, so the fact that they don't implies something is out of whack there. I would definitely take the cover off and investigate. Check that all the bolts are tight while you have the No. 2 cover off. I happen to be in the midst of doing my timing belt at the moment so I snapped a few photos of the No. 3 cover bolts. I bet you'll find the bolts shown in the 2nd photo, seen just behind the front cam gear, are loose.
 

Attachments

·
Registered
Joined
·
630 Posts
Discussion Starter · #10 ·
I think what is happening is the No. 3 cover (which is metal) has been bent a little such that it is touching the back of a pulley. The No. 2 cover can be rather difficult to pull out, even with all the bolts removed...it's a tight squeeze. I think it probably got bent while changing the belt. The covers should fit very snugly together to keep water out, so the fact that they don't implies something is out of whack there. I would definitely take the cover off and investigate. Check that all the bolts are tight while you have the No. 2 cover off. I happen to be in the midst of doing my timing belt at the moment so I snapped a few photos of the No. 3 cover bolts. I bet you'll find the bolts shown in the 2nd photo, seen just behind the front cam gear, are loose.

Thanks for those bolt locations on the #3 metal timing cover. I'll try to check it out. I may just go see if the metal cover is loose. I also plan to get a stethoscope at Harbor Freight and listen for exactly where it's coming from.
 

·
Registered
Joined
·
630 Posts
Discussion Starter · #11 ·
The bolts on the #3 timing cover were tight. The problem is the bearing right behind the front passenger side pulley. It is making a scraping kind of noise. I can really hear it at idle, and when the engine goes to 2000RPM I can't hear it anymore. I guess it wouldn't do much good to just replace the bearing cap would it? If the camshaft has to come out, I'm going to let my mechanic do this. In the 2nd picture I just happened to take a picture of this bearing when I first got the car 18 months ago. It was really heavily sludged, and I guess it just starved this bearing of oil. The maintenance on this car was so neglected I've even thought about selling it. I have to wonder what other internal damage there is. But, thanks for all your help!





 

·
Registered
Joined
·
285 Posts
When you had the engine apart I imagine you had a good look at the cam journals. If it was really starved for oil you would likely have seen damage/ discolouration.
My brother had a rather high mileage Camry that sheared the oil pump drive gear. It ran with no oil pressure for several minutes. After another mechanic "fixed it" it ran horribly. Turns out he put the timing belt on wrong. Once I corrected that it ran great, but it knocked badly from the bottom end on start up (ok once running, but...). I pulled the pan and replaced the main and rod bearings. He put nearly 200,000 kms more on it until it got rear ended by a drunk driver.
Most likely on yours, the thrust washer/bearing that prevents lateral movement of the cam is worn, allowing the pulley to move into the cover. Changing the cam bearings should take care of it. The cam does have to come out. As you know if it is the rear cam, the intake plenum has to come off. Make sure to get him to switch the 14mm bolt at the rear brace by the firewall for a stud and nut arrangement. You/he won't believe how much easier it is to reassemble or service it in the future. Show him my |Youtube video
Skip to the 22 minute area for that. Good luck.
 

·
Registered
Joined
·
1,657 Posts
@professor sir, would you recommend replacing the knock sensor harness while replacing valve cover gaskets while the covers are removed? I was planning to do both timing belt and valve covers at the same time. I will examine sludge and bearings as well. I still have not seen what inside looks like yet.
 

·
Registered
Joined
·
285 Posts
I must admit I have never had to change these cam bearings, but usually there is a design feature, either part of one of the bearings or a separate piece that prevents the cam from moving laterally. I don't have a factory service manual, but if you look in the engine rebuild section of yours there should be a test to check it (usually you use a feeler gauge and a pry bar)...similar to how you check the crank thrust bearing freeplay.

Surgeon0, I would seriously think about doing the knock sensors and their harness since you have 75% of the work done already doing the VC gaskets. As a matter of fact, I just came in from doing exactly that on my own car (cams and crank seals too!). The Timing Belt job is a little easier while the intake plenum is off...just cover the holes in the intake with a cloth so crap doesn't get in there while your working on everything else. It really depends on your wallet since Denso sensors and harness aren't cheap (don't use other brands...I've regretted it most times). There is a coolant hose under the intake manifold that many people change at the same time. If you need spark plugs or the A/F ratio sensor they are easier too, but can be done later just as well. You will need a number of gaskets and seals...often a complete engine gasket kit is the best deal as opposed to picking and choosing...you usually forget something! and you'll have leftovers for the next time you need to do something. Stick with a good brand like FelPro. Shop around for deals on Amazon, eBay, RockAuto etc.
 

·
Registered
Joined
·
630 Posts
Discussion Starter · #16 ·
How are the cam bearings lubricated? Does anybody know? The scrapping noise is getting louder. The noise is coming from right behind the front cam pulley that drives the front exhaust cam. It isn't coming from the journal bearings though--not event he bearings closest to the pulley. Could this problem possibly be a cam seal that was put in kattywhompus?
 

·
Registered
Joined
·
285 Posts
I just purchased a FSM online... I'm still evaluating it to see if it is worth recommending to TN members.

What I can tell you is I doubt a seal is the cause of the noise. I'm afraid you're going to have to dig into the engine a bit to do some exploratory surgery. I think it will be the cam gear rubbing against the cover due to excessive lateral movement of the cam.... as we were already talking about. Removing that cam gear will allow you to see if it has/ hasn't been rubbing. If it has...not good! The "Camshaft Thrust Clearance" is supposed to be between 0.040-0.090mm (0.0016-0.0035"). The maximum allowed is 0.120mm (0.0047"). There doesn't seem to be any way of reducing the movement. The book says to replace the camshaft. If necessary, the bearings and/or cylinder head as required. Yikes! Auto wreckers???

As far as how the cam is lubricated, it is the same as the crank: oil comes up a passage and through a hole in each bearing, then it seeps out and drains back to the oil pan via a passage at the end of the head. If the Thrust Clearance is excessive, a blockage of the passage may have caused it, but it's too late...the damage is done. :frown:
 

·
Registered
Joined
·
630 Posts
Discussion Starter · #18 · (Edited)
I just purchased a FSM online... I'm still evaluating it to see if it is worth recommending to TN members.

What I can tell you is I doubt a seal is the cause of the noise. I'm afraid you're going to have to dig into the engine a bit to do some exploratory surgery. I think it will be the cam gear rubbing against the cover due to excessive lateral movement of the cam.... as we were already talking about. Removing that cam gear will allow you to see if it has/ hasn't been rubbing. If it has...not good! The "Camshaft Thrust Clearance" is supposed to be between 0.040-0.090mm (0.0016-0.0035"). The maximum allowed is 0.120mm (0.0047"). There doesn't seem to be any way of reducing the movement. The book says to replace the camshaft. If necessary, the bearings and/or cylinder head as required. Yikes! Auto wreckers???

As far as how the cam is lubricated, it is the same as the crank: oil comes up a passage and through a hole in each bearing, then it seeps out and drains back to the oil pan via a passage at the end of the head. If the Thrust Clearance is excessive, a blockage of the passage may have caused it, but it's too late...the damage is done. :frown:

Come on now professor sir, you keep telling me what I don't want to hear--haha. I bought a paper FSM for $70USD about 18 months ago. I was also reading the section about the lateral movement of the camshaft, and the FSM does say the only solution is new bearings and a new cam shaft and possibly a new head! Wow is right! But I'll tell you, when I removed the plastic #2 timing cover and started the engine, I looked at that front pulley that the timing belt goes around, and I did not see any left-right motion and I did not see any up-down play on the pulley. I wish I would have physically tried to move it with the engine off, but I didn't check that. Man, this is weird. I keep hoping that the problem will actually turnout to be the #2 idler pully for the timing belt, but I'm almost certain it is right behind the front cam pulley.
 

·
Registered
Joined
·
285 Posts
Yeah, I doubt anyone could see any movement...max is just a bit over 4/1000ths of an inch. The book says to use a dial indicator to check it. I have one I bought at Princess Auto....our version of Harbour Freight. You'd have to remove the Valve Cover to set it up and check. That might be easier than pulling off the Timing Belt and pulley...
 

·
Registered
Joined
·
630 Posts
Discussion Starter · #20 ·
Hello my friends. Well, after 2 months, the noise from the timing belt area of my 2003 Avalon is getting louder. I'm not certain where the noise is coming from, so I am thinking about changing the 2 idler pulleys. The timing belt, water pump, cam seals and crank seal have already been replaced, but the idler pulleys weren't replaced. On this top idler pulley in my picture below, I'm wondering if I can just put tie wraps around the front cam pulley and belt and then put tie wraps around the rear cam pulley and belt to hold the belt in place. Then I'd like to back out the bolt on the top idler pulley with a socket. Is this doable? Is the thread left handed or right handed? Does it require a lot of force to remove it?


What I'm trying to do is change the idler pulleys without removing the timing belt. Is this doable the way I want to do it? I really don't think there is a lot of tension on the top pulley. Then, the bottom idler associated with the tensioner. I'm guessing this will be more work and tougher to get to. Would it be possible to also change this idler pulley without removing the timing belt. I know if that belt gets off by even 1 tooth I'm messed up. Would you recommend Toyota OEM idler pulleys ore Rock Auto or even Autozone? Thanks for any suggestions!!


 
1 - 20 of 43 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top