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Discussion Starter · #1 ·
This is my first post here, a little intimidating, hope you all can help.

I'll get the bad part over with first:
My truck is not a 4X4, it's my daily driver. I'm not a regular here either, but I can tell there are some very knowledgeable people on this site, here goes:

1996 Tacoma 2RZ-FE, 75,000 miles.

Timing chain rattles at idle only, engine hot.

Tensioner seems to be the problem, not enough oil pressure. Oil pressure > 40 PSI, no rattle.
Problem existed before the timing chain was replaced, continues after, was better for 2 days. Also replaced guides, tensioner and both gears.

Anyone heard of this problem and know what might fix it?

Have heard heavier weight oil, Toyota oil filter and "don't worry about it.".

I really do appreciate all who read and answer, thanks again.

Chipsndukes
 

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I've got a 2002 4x4 with 67,000 miles that does the same thing..Only does it when it's hot and been sitting for for like 5 to 10 min.(Like when refueling,then go to start it back up)..I wouldn't worry about it if I were you..Just seems to be a Toyota 4cyl. thing..Now if you here it rattling above idle and higher rpms then it's time to worry about replacing the chain..

Heavier weight oil won't help either,in my opinion.

OEM oil filters are the best ones to use,i use them ,but it won't solve the rattle problem either..It will keep the engine a lot cleaner that the cheap fram filters

Did you replace the timing chain because of the rattle at idle?
 

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Discussion Starter · #3 ·
Did you replace the timing chain because of the rattle at idle?
In a word, yes.

Every day I idle in traffic for at least 15 minutes, temperatures here are >90F for at least 6 months of the year.
The noise is pervasive, I have never heard anything like it before, sounds like a little diesel, I have only had the truck for a year and a half.

Thanks,
Chipsndukes
 

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Did you use a OEM Chain or an aftermarket chain?
Reason i ask is because i replaced a timing chain in a old toyota 22re with 150,000 miles on it with an aftermarket chain and the aftermarket chain(being new)had just as much slack in it as the orginal chain with 150,000 miles on it,eventually changed it with a OEM chain.

what weight oil are you using?
i know that if the rpm's are below 650 on mine the chain will rattle(just not enough oil pressure to tighten up the tensioner).
 

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Discussion Starter · #5 ·
Did you use a OEM Chain or an aftermarket chain?
I used a chain made by OSK in Japan.

...had just as much slack in it as the orginal chain with 150,000 miles on it
I'll give you this, there wasn't much difference in slack between old and new, in both cases the tensioner was only extended about 1/2 of full travel.

what weight oil are you using?
Factory recommends 5W-30, is what I am using now. 10W-30 is allowed for climates > 0 F. Should be no problem, the coldest temperature on record here was 17 F in January 1962. :rolleyes:

OEM filter (90915-YZZD1) goes on this morning, recheck oil pressures, then change to 10W-30 and repeat.

FWIW here are the current pressures with aftermarket filter and 5W-30:
Idle COLD: 60 PSI
Idle HOT: 15 PSI
MAX (revved): 90 PSI

When the pressure > 40 PSI the rattle seems to stop.

Thanks again Tacoma2K,
Chipsndukes
 

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Discussion Starter · #7 ·
For anyone who may be interested or reading this post, I measured the extension of the tensioner v. total travel and came up with 67%.

Is this normal for a new tensioner to already be at 2/3 travel?

Tensioner min. extension: 8.7mm
Tensioner max. extension: 31.3mm
Tensioner current extension: 23.9mm

(23.9-8.7)/(31.3-8.7)=67% total travel
 

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For anyone who may be interested or reading this post, I measured the extension of the tensioner v. total travel and came up with 67%.

Is this normal for a new tensioner to already be at 2/3 travel?

Tensioner min. extension: 8.7mm
Tensioner max. extension: 31.3mm
Tensioner current extension: 23.9mm

(23.9-8.7)/(31.3-8.7)=67% total travel

That would probably be about right,because when you rev the engine up the centrifugal force of the chain will push the tensioner back in..

as for the rattling sound are you 100% sure it's the chain?not a main bearing?or valves out of adjustment?just trying to give you a few ideas,because i or anyone else i know with the 2.4 or 2.7 have never had any problems with the timing chain as such low mileage.
 

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Discussion Starter · #9 ·
Thanks for your reply, Tacoma2k.

I don't know that a main bearing would be dependent on oil pressure, cold/hot. Unplugging the spark plugs one at a time also didn't change the noise.

The valves do make a little noise, but it is the very distinct ticking sound that can be clearly heard with a stethoscope on the valve cover.

This noise is a rattling noise, coming from the lower timing chain cover, and only when the engine is hot.

I purchased a Toyota OEM tensioner, not so much to see if it would fix the problem, but so I could play with the aftermarket tensioner that I put on.

I think I can find a way to prove once and for all that the timing chain is the issue. I plan on modifying the tensioner in order to provide more force than normal, and will see if that changes the level of the noise. I think it will

Thanks again for writing back and to all who have looked at this post. I haven't give up yet, will report back, and appreciate any and all contributions.

Chipsndukes
 
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