Bearing rattle?

[GrassrootsMS]

I just bought my Yaris about 3 months ago, with about 2600 miles on now. Right around 600, it seems that whenever I put load on the engine, there is this mysterious bearing rattling sound. I know from studying this that there is nothing mechanically wrong, nor is the engine in any danger, but it's not what I want to hear in my first new car.

Has anyone else had this problem? And is there anything I can do to stop the rattle without overspeeding the engine?

[PetersRedYaris]

Don't waste your time with it... Take it in and have the dealer correct the issue.

[GrassrootsMS]

I should say I noticed the problem start at around 600 miles, not 600 rpm. The car also has the manual transmission and has never been lugged or oversped. At the worst, I've shifted a hair too soon at times, but I've driven cars with over 150,000 miles that have been severely abused in every way, but don't rattle like this.

Would switching to synthetic oil of a different weight help at all?

[GrassrootsMS]

I found out what the problem was... The Yaris was designed for 91 octane fuel, I've been giving it 87. When a motor makes hissing sounds under load, it's called "ping".

[steved]

No you car is designed for 87 octane. Look in your manual.

Fuel type:
UNLEADED gasoline, Octane Rating 87 (Research Octane Number 91)
or higher

Use of unleaded gasoline with an octane rating or research octane number lower
than stated above will cause persistent heavy knocking. If it is severe, this will
lead to engine damage.

If your engine knocks... If you detect heavy knocking even when using the recommended fuel, or if you hear steady knocking while holding a steady speed on level roads, consult your Toyota dealer.

However, occasionally, you may notice light knocking for a short time while accelerating
or driving up hills. This is normal and there is no need for concern.

The suggestion I can give you is to change gas stations and fill up with 87 octane for a couple of tanks. If the pinging continues go to the dealer, because it is not normal.

[BailOut]

Well said, steved. Also, hissing is not pinging. A ping sounds like someone striking an anvil with a ball peen hammer. If you hear a lot of pings in a row it can sound like an unbalanced washing machine in a spin cycle.

Hissing usually indicates intake air and exhaust gas movement. I've heard the 1NZ-FE engine produce a hiss under WOT (wide open throttle) in a high load scenario, which is just air moving into and throughout the throttle body.

[GrassrootsMS]

Then that might not be the problem, because the car runs perfectly smooth (it should with only 2700 miles), and has plenty of power. It just seems whenever the engine's under any load, there is this rattle/hiss/chatter that sounds like it's coming from the bearings somewhere. I was also told that using higher (91) octane fuel would increase power a little, and take care of the the noise altogether. Will using higher than recommended octane harm the engine?

[steved]

Using higher octane will not harm the engine. It's just a waste of money.

Just bring to the dealer. It's quickest and easiest way to find out what the problem is.

[ern-diz]

Well said, steved. Also, hissing is not pinging. A ping sounds like someone striking an anvil with a ball peen hammer. If you hear a lot of pings in a row it can sound like an unbalanced washing machine in a spin cycle.

Hissing usually indicates intake air and exhaust gas movement. I've heard the 1NZ-FE engine produce a hiss under WOT (wide open throttle) in a high load scenario, which is just air moving into and throughout the throttle body.

what is your opinion on higher octane gas, Mr. FE?...i would honestly love to know...i find your opinions to be well researched so, i take them into consideration (although i do believe there is some truth to what someone once said to you in another thread, about hypermiling being a bit of a sport that produces some self satisfaction that drives a lot of people to do it, not always just the preservation/conservation factors alone--but thats a whole 'nother topic :biggrin:)...our friend here thinks its a waste of money, agree?...disagree?...

[ern-diz]

Well, it looks like the premium gas worked for a few of you but my MPG actually decreased by 9% on 93 Octane vs. 87 Octane.

Perhaps it's because my driving style is so different.

just saw ^that^ in the fe thread...lol

[SDsurfrider]

91 is less volatile than 87.

“Pinging” or engine “knocking” comes from pre ignition of the fuel (igniting before the spark) due to high pressures in the combustion chamber. This is why they recommend stepping up the octane if you experience pinging. Similar reasoning for higher performance engines; they are running higher pressures in the combustion chamber. So they have a need for higher octane requirement.

That is why 87 is more energy efficient because you get the same bang for less energy put into the system.