thoughts on timing chain change

4 cylinders have timing chains. Timing chains don't last forever either. They can break and stretch.Any thoughts on changing them?

 

Once mechanic at Toyota dealer told me that I will not need to replace timing chain in my 1995 2.7 Taco before I replace the engine. When we change head gasket at 302k miles I did not see any anomalies in timing chain setting - the tensioner was still within normal limits, no cracks no signs of wear on gears or chain itself. I think I will continue to believe Toyota dealer mechanic.

 

How did you check for cracks in the chain?

 

Nothing fancy - just inspected it with good lamp. The same I did to all head moving parts while I had the head out.

I was curious what kind of wear is there. Nothing that I would concern about. I hope I did not miss anything but so far 4 years and 14k miles later (this truck is now the secondary as I drive new 4Runner as DD) there is no change in performance. Smog test (CA needs it every 2 years) at least 3 times below average on all numbers.

 

I believe the 2.7 has more than one timing chain because of the VVTi

 

At least 95 version has only one.

 

The 2TR-FE has two timing chains. One driven off the crank to one camshaft, and another between the two camshafts. I kinda wish Toyota kept the gear drive between the two cams, a much simpler connection.

I would not open up the engine just to replace the cam chains, no matter the mileage -- timing chains are designed to last the life of the engine and Toyota 4-cylinder engines typically live a very long time. Timing belts are another story entirely.

If the engine is open anyway, I would change the timing chains if it's over 150,000 miles or so...

 

Just use decent oil and it should last a long time.

 

Isn't the life expectancy of the 2tr like 400k miles or something awesome like that

 

That would be a very short life for a 2TR.

 

Mine started making noise a few days ago (replacement kit has been ordered).
My 2TR only has 140K on it...so I guess they don't last forever

 

How do you know it's the chain(s) making noise?

 

usually the chain guides(plastic) break and the chain starts flapping that's what happen to the 22r series engines, this in my 1st 2.7l not sure if its the same guides issue as the older 4 cylinders

 

Intermittent noise from front of motor at idle, with belt removed as well as noise when coasting.
Don't believe there's noise under power...probably due to tension on the chain.
Really hope she doesn't break before chain is replaced.

 

Will post failed component when chain is replaced.
Good info...Thanks for the reply.

 

It's kinda unusual for the chain to actually break. In the days of yore, they would stretch, then either wear a hole in the cover and dump the oil, or they would jump teeth (like a bike chain) and screw the timing all up.

If the guides are the failure point, see if there are upgraded guides available.

 

i had a 1995 22RE engine where the plastic OEM guides broke and stretched chain was really making noise. the mechanic I had replaced the chain with an aftermarket one it had steel chain guides and was a hard job to do. also replaced water pump while the engine was apart too

 

Drove the truck today, she definitely makes more noise when coasting (or lightly off skinny pedal)...no noise when under load.
Kinda sounds like a Honda vtec engine

 

I checked the oil level again, and found it to be low..2qtrs low.
After Adding Oil, the noise is Gone

Mea Culpa Mea Maxima Culpa

Feel like I dodged a bullet on this one...I will do a better job maintaining my tacoma, promise.