Timing Chain Rattle.

[Raeman]

Hi all,

Changed the oil & filter on the Yaris a few days ago and now she's starting to develop a ratte which seems to be coming from the timing chain.

Just got home and checked under the bonnet with engine running and it definately sounds like the chain! :(

Seems strange that it's just started to do this, car is running well otherwise but it's only on tick over that you can hear it.

The car has done 79k allways serviced and pampered and the oil was 5w30 as stated in the owners manual.

The oil was Castrol Edge, not cheap but i thought i'd treat it to good stuff, infact it's so clean you can barely see any on the yellow dipstick.

Just want to know if anyone else has had similar experience?

Should i be worried? will the rattle die off a bit after the oil gets a bit dirty?

Cheers.

[carlowlad]

Hi Raeman.

From what you are describing it does sound like the timing chain. It could be the case that the thicker oil was masking the rattle but it could also be the case that, while noisier, it's normal now that you are on new oil (possibly thinner but within spec?). Sorry i can't be of much help but if you are worried then get a mechanic to listen to it. He shouldn't charge for it.

If it's any consolation, my bro-in-law is a mechanic and was in my car on monday. I asked him about the little rattle in mine when i accelerate. He said it is very small and wouldn't worry about it too much. He said timing chains don't just break and the engine will run rough and power will be poor first before something drastic happens.

[alfiejts]

I had a timing chain rattle at idle on my old Yaris for its last few years. (probably came on at around 50,000 miles and we sold at 64000 miles...)

It's probably changing to a good fully synthetic oil that's triggered it - probably by flushing out some previous sludge which has then blocked (or inhibited) an oilway in the hydraulic chain tensioner. Maybe also triggered by changing to a slightly thinner 5w oil compared to the previous oil (which may well have been a 10w)...

My view would be to live with it for now. A relative with a garage had a listen to mine and said it was nothing to worry about and told me to use a flushing additive next time I changed it, to flush out any blocked "micro" oilways in the timing chain tensioner.

That helped a bit but it never went away completely....

[Madasafish]

Did you use a Toyota oil filter.

If not, and no non-return valve = rattle.

[Raeman]

Did you use a Toyota oil filter.

If not, and no non-return valve = rattle.

No not a genuine filter, the last one wasn't either. Got the filter from Halfords.

So what's the non-return valve do exactly? Does that mean that every person who changes the oil on their Yaris will get a rattly camchain if they don't use genuine filters?

[alfiejts]

But even with a non-return filter (and mine didn't have a Toyota filter for any service from year 3-8), that would only cause any issue for the few seconds from startup when it filled with oil.

If you get the rattle when the engine is running, then it can't be related to that surely?

And also - where does this idea of the Toyota filter being different from the non-Toyota replacements come from?

That's the first I've heard in many years..... Not saying you're not right, but can you substantiate the idea?

[Madasafish]

If it only rattles on tick over then I would ignore it.

Filter makers do their own designs, many non OE ones are good but cheap ones omit non return valves.

For the cost of a genuine one, I would buy genuine every time.

And yes, the NR valve only affects oil pressure on startup (when most wear happens if cold)

[Raeman]

Than for the replies guys. ;)

Drove the car today, and on first start up, this morning it did rattle (well more like a rustle) a little bit when ticking over, then after a few miles when fully warm, the noise was a bit less.

It should be ok, i can live with a small rattle, infact you an only hear it if you open the window and turn the radio off.

Even then, you really have to listen hard to hear it, the wife says she can't hear anything but she's not a perfectionist like me!

If it gets any worse, i'll pop it down to my mechanic.

[S.Kayani]

mine rattled to 3 years til it finally snapped lol