Recently changed timing belt on my 97 4 cylinder Camry. The two idler pulleys seemed smooth and without any play. I turned the crank shaft two complete turns with the tensioner pulley unlocked. After putting it back together I notced the belt has a slapping noise at 2000 RPM.
Can I readjust the tension by only removing the upper timing belt cover?
Can I change the tensioner pulley and spring with only removing the upper cover?
Thanks in advance.
=============== I'm not sure about access through only the upper cover - you can try. The main point is that the tension at the tensioner pulley spring is insufficient to tension a new belt. Also, you should always use a new spring. You need to place a pry bar against the tensioner pulley, or use a hook tool to exert a lot of force on the belt, then release the tension with the adjustment bolt loose enough to permit movement, allowing the belt to relax back being held by the spring tension. That will work. But the spring cannot exert enough initial tesnion all by itself and you wind up with the belt too loose. I used a hook tool, and pulled smoothly but hard enough with both arms, to move the whole engine three times before releasing, and that worked just fine.
The Haynes aftermarket shop manual does not say anything about pulling the idler pully up with great force. Is this to overcome the possible friction at the tensioner pulley against its mounting? Is this the first car you have done this with?
Being the belt has some tension in it, how many revolutions of the crank shaft do you suggest after the three pulls on the tensioner pulley?
Marvin
====================== First you pry or pull with some considerable force on the tensioner pulley to tension the belt. Then you allow it to relax back held by spring tension. Whereafter you tighten the tensioner pulley adjustment bolt securely so it is held in place. Finally, you just turn over the engine a couple of times using the crankshaft pulley bolt, just to make sure everything stays lined up. The manual recommends two full revolutions at the crankshaft.
The 4-cyl will jump tooth on you unless you go very slow and smoothly with the plugs removed. The spring tension really foul things up for you.
Yes, you can adjust the tension by removing the upper timing belt cover. But is the belt in reuse condition now? It may still work fine, but I pesonally wouldn't trust it.
Make sure the belt is correctly seated in all the pulleys including crank with the cover on. Turn slowly without the belt jump tooth as it will most want to.
97 should be tensioned at 45 deg BTDC, not 0 TDC! This is very important. This is where you should tighten the idler to 33 lb/ft. And after that turn several more revolutions (the spec calls for two but I do more). And each time the cam and crank timing marks should line up.If the tensioner spring is the updated one, you should be OK. It's gotten shorter to about 1.6 from about 1.8. But at about $5 cheap enough to get a new one in any case after you spend all that time. Yes you can change the tensioner and spring with the cover on, just don't drop it or you'll have to fish it out.
You can pick up a torque wrench at your local Harbor Freight, on sale for $12.99, reg $19.99 and use it on the idler if you don't own a torque wrench already.
snipped-for-privacy@yahoo.com wrote:
John,
I'm confused, please comment. You said the tension idler pulley should tightened to 33lb-ft at 45deg BTDC and then turn the crank shaft 2 more turns. Since the tension idler pulley is now locked the tensioner spring won't add any additional tension to the belt. Did you accidently reverse the adjustment sequence?
Marv> The 4-cyl will jump tooth on you unless you go very slow and smoothly
No, I merely mentioned the steps of tightening the tensioner idler pulley, and then turning the crank several revolutions to very all the marks are still aligned.
Of course, before you tightened the tensioner pulley, you've already turn the crank two revolutions.
My advice to timing belt work is to follow the instructions to the letter. The only difference I added was to turn the crank several more turns than spec. That's all.
Now, did you turn the crank and verify the marks line up after you tightened the tensioner pulley?
snipped-for-privacy@yahoo.com wrote:
When I did the timing belt 4 weeks ago I set the timing marks, forced the idler tensioner pulley fully open to ease the installation of the belt, installed a new belt, turned the crank shaft bolt two full turms, locked the idler pulley and verified the timing marks were correct. The engine is performing normally except at 2000 RPM there is a slapping noise from the timing belt cover area. The noise ceases when the engine RPM is not at 2,000. I will be doing the readjusting on 9/1.
The clearance between the T belt covers and the fender wall requires me to remove the dog-bone engine mount, the engine mount bracket and relocte power steering fluid reservoir so I can the cover screws out.
Its a dog of a job. It took 6 hours to fully do the job. The hardest part is removing the 2 bolts holding the engine mopunt bracket to the engine block. One of them can be removed from under the car but the other requires the engine to be jacked up a few inches. I'm curious does everone with a 1997, 4 Cylinder engine have these problems? What does a dealer get to do this job?
Thanks > No, I merely mentioned the steps of tightening the tensioner idler
I did this job about 8 weeks ago; there was some vibration in the belt, but not enough to slap the cover. I think this happens because the load on the belt changes cyclically as the various cam lobes engage.
yup
the engine mount bracket and
yup
nope. I didn't have to do this on my '99 4 cylinder. I bought the smallest air-powered socket wrench I could find and it fit between the fender and the engine.
I didn't have to jack the engine up.
I'm curious
It took me about 1.5 7-hour days to do the belts and water pump. It almost makes it worth the CAN$350 (plus parts) the local mechanic wanted to do the job.
I replace my timing belt and drive belts 2 weeks ago @ the dealer for a cost under $350.00 US. It took them under three hours to do it.
After a timing belt change, following the instructions to the letter, the engine should run quieter than with an old belt. You might want to use a mechanic's stethoscope (or a long screwdriver with your ear against the handle) to identify if the belt is actually hitting the cover, be careful of moving engine parts.
Some people have run the engine without the upper cover. This is risky as things can get into the cover under the timing belt and pulley causing wear and possible damage. But I'm not sure the rubber access cover over the tensioner bolt will reveal anything.
Besides the belt have you changed out anything else?
As far as the right engine mount goes, no need to jack up the engine. yes, the dog bone and right mount always come out. Didn't have to move the PS reservoir. A long 3/8" ratchet (only come as 11" flex-heads) with better leverage than the standard worked fine because you know where the bolts are and I can reach them by feel.
Normally you should be able to get it changed in about 3 hours of time, with experience I'll say 30 minutes to swap out the belt (no pump or seals) is possible, not counting the time to lay out the tools, jack up the car, remove the wheel and apron at a leisurely pace.
Belt alone costs about $160 with coupon.
Good luck!
Typical parts replaced in a timing job:
======================== Remove the crankshaft pulley first. Makes the process_much_ easier.
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