Engine idle chirping (cricket) noise poll.

[Kefuddle]

Originally Posted by deeranged

Just got off the phone with my service rep at Holman Toyota/Scion in New Jersey. He said that he knows about the chirping problem, and said it could be due to using incorrect octane gas. I assured him that I've run only 93 octane.

Here in Dubai (octane ratings are different to the US here I believe) the owners manual says to use 98 octane fuel, but that 95 octane is OK and won't cause any short or long term problems. I always filled up with 98 and always had the crickets. Recently, I filled up with 95 for the hell of it. The crickets almost immediately disappeared, until I filled up with 98 again.

In terms of performance, I couldn't sense any difference, and I generally accelerate flat out whenever possible

[HunterGreene]

Originally Posted by Kefuddle

Here in Dubai (octane ratings are different to the US here I believe) the owners manual says to use 98 octane fuel, but that 95 octane is OK and won't cause any short or long term problems. I always filled up with 98 and always had the crickets. Recently, I filled up with 95 for the hell of it. The crickets almost immediately disappeared, until I filled up with 98 again.

In terms of performance, I couldn't sense any difference, and I generally accelerate flat out whenever possible

Now this is facinating. First, from what I recall, 93 does equal 98, its just a different rating system. But last I heard that the US was the only country with ethanol in its gas, which a lot of us are blaming for the chirps. But, if you are running E0, and you are still getting the chirps--makes me think operating temperature may be a bigger factor than people think. What are the average ambient temperatures in Dubai this time of year?

[Kefuddle]

Hey Hunter,

Mid to high 30's right now during the day and low 30's at night. The temps will be dropping rapidly soon in a month or so, especially at night, it will be interesting to see if this makes a difference.

[sierra]

Originally Posted by HunterGreene

Now this is facinating. First, from what I recall, 93 does equal 98, its just a different rating system. But last I heard that the US was the only country with ethanol in its gas, which a lot of us are blaming for the chirps. But, if you are running E0, and you are still getting the chirps--makes me think operating temperature may be a bigger factor than people think. What are the average ambient temperatures in Dubai this time of year?

Or the 98 octane in Dubai also has ethanol.
The US isn't the only country with ethanol, Brazil uses it far more but not many have it in the premium brew like the US, where the twins are sold.

[hchi rku]

The theory that makes the most sense to me is that the combination, pressure and ethanol is what causes the chirps.

1. The chirps are caused by evaporating ethanol.

1. The higher the temperature the faster the ethanol evaporates (car needs to be warm to get the chirps, I did not notice any chirps when the temp is below 70)

3. The chirps are only present when the car is idling. (the pump still pushes as hard as it can but the gasoline has no place to go meaning the back pressure in the pump is higher, generating more heat, evaporating more ethanol and pushing it out with more pressure)

[sierra]

There was a post somewhere, quoting Toyota as tracing the end result, read noise, to aeration in the pump caused by ethanol.

[strat61caster]

Originally Posted by hchi rku

The theory that makes the most sense to me is that the combination, pressure and ethanol is what causes the chirps.

1. The chirps are caused by evaporating ethanol.

Are you implying that ethanol evaporates within the highly pressurized fuel system? I need to brush up on my chemistry but that seems unlikely to me...

[hchi rku]

Originally Posted by strat61caster

Are you implying that ethanol evaporates within the highly pressurized fuel system? I need to brush up on my chemistry but that seems unlikely to me...

In words of Herman Cain "I don't have fact to back this up"

[pszuvela]

I just had my HPFP replaced on Tuesday. The chirps have not returned so I'm a happy owner. I don't have the dealer's invoice in front of me now (at work) but I'll check the part number later.

I took it to Roy Robinson Chevrolet/Subaru Dealer in Marysville, WA and they replaced the pump with no questions asked. And even set me up with a 2014 Forester as a loaner. Great service! Thanks John Gilliland!

[DylanFRS]

Originally Posted by pszuvela

I just had my HPFP replaced on Tuesday. The chirps have not returned so I'm a happy owner. I don't have the dealer's invoice in front of me now (at work) but I'll check the part number later.

I took it to Roy Robinson Chevrolet/Subaru Dealer in Marysville, WA and they replaced the pump with no questions asked. And even set me up with a 2014 Forester as a loaner. Great service! Thanks John Gilliland!

Mileage since the pump? All pumps are quiet at the beginning... let us know how it is in 500-1000 miles.

[DylanFRS]

Originally Posted by hchi rku

The theory that makes the most sense to me is that the combination, pressure and ethanol is what causes the chirps.

1. The chirps are caused by evaporating ethanol.

1. The higher the temperature the faster the ethanol evaporates (car needs to be warm to get the chirps, I did not notice any chirps when the temp is below 70)

3. The chirps are only present when the car is idling. (the pump still pushes as hard as it can but the gasoline has no place to go meaning the back pressure in the pump is higher, generating more heat, evaporating more ethanol and pushing it out with more pressure)

Someone feel free to correct me if I am wrong, but the HFPF is driven mechanically by the engine. (mechanically linked to a cam maybe?) So at lower RPMs, the pump is not pumping the same amount of fluid as at higher RPMs. Same pressure possibly, much a much lower displacement vs time.

Also, as Strat61 said, it would take a lot of heat to evaporate the alcohol out of the solution at the pressures the HFPF runs at. Higher pressure means higher evap point.

There is a difference between air bubbles and aeration. Aeration refers to the amount of gas actually dissolved in the liquid.

Originally Posted by sierra

There was a post somewhere, quoting Toyota as tracing the end result, read noise, to aeration in the pump caused by ethanol.

That has come up a few times in this thread and I don't necessarily disbelieve it, but out of all the times it has been mentioned, someone has yet to dig up the referenced post.

[pszuvela]

Originally Posted by DylanFRS

Mileage since the pump? All pumps are quiet at the beginning... let us know how it is in 500-1000 miles.

Good call. I only have about 100 on it so I'll check back in in a couple weeks. BTW - The part number they installed was 16625JB000.

[zenzsh]

Still no chirp after dealer replaced pump over 2000km ago


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[Muskokan]

So I posted earlier that I don't have chirps because all I ever used was shell... Yea 4,400km and now I got them damn it. This debunks the ethanol theory I believe, because it's literally all I've ever used, and asked the dealer to fill It with shell too. ( forums are useful before buying a car). I'm thinking ethonal just prolongs it.