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Category: Toyota
Satisfied Customers: 598
Experience:  ASE MASTER CERT. 15 YRS EXP.
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Toyota Camry: I have an 1998 Camry w/ 2.2. New timing belt,

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I have an 1998 Camry w/ 2.2. New timing belt, pulley and water pump installed. There was a rattle that seems to come form under timing belt cover that has not gone away with the change. Ran the engine w/out PS and AC or alternator and rattle is still there so they are out of the loop. The rattle occurs only when the engine is cold and only in the 1600-2000 rpm range. No heat shields seem to be loose. Could the noise be an oil pump? There are 160K on the engine.

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Was it there before the belt change?

Customer: replied 5 years ago.
Yes, and there was no leakage from the oil pump seal when the timing belt was removed. I have seen similar posts that reference a heat shield on the back of the engine. If that is the case I have not been able to locate the shield in question.
Does the noise get worse or louder if you power brake it in D or R? Does the noise go away completely when cold?
Customer: replied 5 years ago.
The noise seems to be consistent when idling, driving or braking in the given RPM range. When warm the noise goes away. There might still be a small rattle, but it is not obvious above the normal engine idle sound.
This engine was notorious for counter balance shaft noise especially with higher miles and it normally quiets down after warm up then there have problems with carbon knock. Did you do a decarbon soak on the top end.?
Customer: replied 5 years ago.
I have not had the top end apart other than to replace Valve cover gasket at 140K. I have never had a single noticeable knock.

Is there a way to isolate that the noise is the counter balance shaft? What is the remedy to the noise?
IF it is the counter balance shafts then the shims between the balance shaft assembly and the block have to be change to obtain the correct clearance to stop the back lash rattle. The shims are select fit. The oil pan has to come off and the back lash measured. The top end has to be soaked with decarbon to make sure it is not carbon build up. I have to step out for a few hours if you need anything else just reply and I will get back to you this evening.
Customer: replied 5 years ago.
Is there a problem with letting the counter balance shafts rattle? If you bother changing the set out, and clearing out carbon, what other items (i.e. oil pump) should be replaced?
The counterbalance shaft backlash rattle generally does not create a problem. Unfortunately noises are very difficult to diagnose in this format unless you can get some type of audio recording and post it here is difficult to say for certain what exactly is making the noise. When doing a D carbon on the top and after soaking the tops of the Pistons for an hour rotate the engine around so that the other two Pistons are the top of the cylinder to allow them to soak the carbon on the head also. Once you crank the engine over and push all of the cleaner out of the cylinder spark plug holes and get the engine running it will then become necessary to change the oil. The oil pump pumps rarely are an issue. Depending on the mileage you can also confuse carbon knock with low and Rod knock due to excessive wear and the bearings.
Customer: replied 5 years ago.
The noise is located right at the point of the shafts and is consistent under all loads so it could not be carbon. Also, the location of the noise makes rod bearings unlikely unless cylinder #1 was totally trashed and plug wear and such do not indicate an issue.
Can you get an audio file of the noise?
Customer: replied 5 years ago.
I will try to get one. There was a posting on Youtube of a Camry with the same noise, but a totally different diagnosis.
Do you have the link?
Customer: replied 5 years ago.


The rattle sounds the same, almost as if gears were out of sync. Thats why i thought it would be the oil pump. My noise seems to go away easier than the one on the video.

It got busy in the shop. I will review the video and get back to you with some thoughts.
That video was P/S pump noise. You said the noise was there prior to the belt and I assume you checked the P/S fluid. You are certain the noise is from the front of the engine ie passenger side?
Customer: replied 5 years ago.

Yes, had the noise with no belts attached. Wen running I can feel the vibration in the skirt of the block behind the oil pump. That is where the front bolt for the counter balance shafts is.

Have you run these engines without the counter balance with the oil supply for the unit plugged?

No have not tried that. Not sure where to go with this with out being there hands on.

The timing belt is too loose and smacking against the cover, remove the upper cover and run it, the noise will be gone. Tighten the t-belt more

Customer: replied 5 years ago.

It is worth another shot. Snugged the pulley up as much as possible earlier.

I will try again.


How did it turn out?


Customer: replied 5 years ago.

I picked up a new set of tensioning springs and idlers last night. I will install them later this morning. It should resolve whether the belt tension is the issue. I will respond as soon as that is completed.

On the tensioner. I take a pry bar and gently push on the metal tab that has the small hole for the spring, to tighten. If you over do it, it'll whine, if you under do it, it'll rattle.

once you are done, throw the upper cover on and run it for a minute, and make sure its quiet before you reassemble it.

Customer: replied 5 years ago.

New spring, made sure adjuster was all the way out and it is as quiet as could be.


Thanks much for saving me from my typical path of overdoing every project.


I will close the call out.

Im glad you got it, got luck to you..
Category: Toyota
Satisfied Customers: 598
Experience: ASE MASTER CERT. 15 YRS EXP.
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