A strange oddity about the OEM Toyota YZZN1

[OilyOrangutan]

Now this is only personal observation. I am no scientist, and certainly have not the hours or posts logged on this site, as some of the much more knowledgeable here. Just wondering if others have thoughts or input.

I have had my Prius Prime for 4.5 years. It's a 2018. I let the dealership take care of the maintenance. It had very low mileage in those three years, and received three oil changes once yearly. At year three I found this place, and some youtubers. I realized I wanted and should (IMO) change the oil every 6 months. I also came to this conclusion having my 6 month oil in usage from year 3 to 3.5 tested. It has high fuel dilution from the lack of use, and the way the hybrids warm up. Also the EV range on the Prime means the engine was used even less than a normal hybrid. In all those 5 oil changes I have used either dealer installed, or installed by myself OEM Oil Filters from Toyota.

Well 6 months passed from the my year 4 dealer oil change in June, so I changed my Oil. Tried Amsoil SS 0w-20 and an Amsoil EA15K09 (and yes I know it's a Fram endurance (by Champion)and I could have had it cheaper. I bought it before the FE was for sale). I wanted to try a different variety than TGMO. If it was cheaper to get in Canada I'd have also considered HPL.

Now if you read all that, and you're wondering why this is in the Oil Filter section we're there!

I have multiple neighbours that have Toyota's as well. A 2019 RAV4, is a couple houses below me, an HRV across the street, and a 2020ish looking corolla. They all use the same OEM YZZN1 oil filter. Not 100% sure on the HRV however.

One thing WE ALL SHARE in common. They ALL have a rattle at cold startup more often than not, especially after sitting all night.

I surmise the ADBV on the YZZN1 isn't a perfect seal and allows oil to slowly drain back down through the oil filter. I came to this hypothesis after using my Prime for a month roughly since the oil change. In that time with the Amsoil (Champion) EA15k09. I have heard a total of ZERO engine rattles on startup no matter if I haven't used the engine in days. I think the after market filter is attaining a more solid ADBV seal.

Anyone else noticed anything similar on their Toyotas, or anything similar in general? Or any reasons why I must be patently wrong, and the filter has nothing to do with the equation? Input appreciated.

 

[CarDoc66]

I’m confused. The HRV is a Honda product. Did you mean the “CH-R”?

 

[OilyOrangutan]

I’m confused. The HRV is a Honda product. Did you mean the “CH-R”?

Sorry I made a mistake. I meant the Toyota C-HR. Apologies.

 

[CarDoc66]

No worries, I thought you were using a Toyota filter on the Honda.
I’ve noticed most RAV4’s and Camrys have the “phaser rattle” when started……with or without OE filters.
That said I suggest using the aftermarket filter if it’s quieting the start up rattle.

 

[ejes]

If you do some searching in the BITOG forums, the phaser rattle issue has a long history. I experienced it as well on a Rav4 V-6 over a decade ago. Generally, there is little that can be done about it or that gets rid of it short of opening the engine and the replacement of parts (VVT actuator, cam phaser, etc.). Often times the this doesn't solve the issue or it returns after some time. Generally it doesn't cause any issues. Toyotas that have it run into the hundreds of thousands of miles with it; it is just an annoying issue and noise of little consequence.

 

[OilyOrangutan]

If you do some searching in the BITOG forums, the phaser rattle issue has a long history. I experienced it as well on a Rav4 V-6 over a decade ago. Generally, there is little that can be done about it or that gets rid of it short of opening the engine and the replacement of parts (VVT actuator, cam phaser, etc.). Often times the this doesn't solve the issue or it returns after some time. Generally it doesn't cause any issues. Toyotas that have it run into the hundreds of thousands of miles with it; it is just an annoying issue and noise of little consequence.

Thanks for your insights sir. I’ve watched those videos. The vehicles I referred to are all newer and should not have any VVTI issues. My wife’s 2010 Corolla S 1.8L DOES have the VVT-I rattle. She has just about 315000KM on the engine, and besides burning some oil because the changes were neglected once or twice. Never had a serious problem. I was just thoroughly impressed that the different filter application seems to have made the engine start up silently.

 

[ZeeOSix]

I was just thoroughly impressed that the different filter application seems to have made the engine start up silently.

If it only makes noise upon a cold start-up, then it's most likely the ADBV leaking and allowing some oil in the galleries above the filter to lose oil while it sits.

 

[OilyOrangutan]

If it only makes noise upon a cold start-up, then it's most likely the ADBV leaking and allowing some oil in the galleries above the filter to lose oil while it sits.

Yes sir. I thought the same thing hence why I find it such an oddity for the YZZN1. It’s like the Toyota oem ADBV isn’t fully seating upon shutdown. And this has been with multiple different Toyota filters, and with my neighbours around me. I’ll have to try a few different brands down the line. But this champion made amsoil filter has impressed my uneducated butt!

 

[Nesterenko]

I've noticed when going from a nitrile ADBV to a silicone one is what does the trick. Went from an OEM Toyota filter to a Fram Ultra and problem solved. I did notice one other way that seems to work most times, and that is cycling the key. Turn the key to the start position but don't start it for about ten seconds then take key out of ignition. Completely cycle back to start position to a count of five, then start her up and voila no rattle! It has worked for me many times. I would use that method especially in winter where a really cold start up rattle would make me cringe before I started using the Fram Ultra, XG4386.

 

[ZeeOSix]

I did notice one other way that seems to work most times, and that is cycling the key. Turn the key to the start position but don't start it for about ten seconds then take key out of ignition. Completely cycle back to start position to a count of five, then start her up and voila no rattle! It has worked for me many times. I would use that method especially in winter where a really cold start up rattle would make me cringe before I started using the Fram Ultra, XG4386.

So what's going on in the oiling system when you do that with the key before ever starting the engine? You have an electric oil pump/system primer or something?

 

[Nesterenko]

So what's going on in the oiling system when you do that with the key before ever starting the engine? You have an electric oil pump/system primer or something?

Don't exactly know Zee but I heard about it a long time ago and it seemed to have worked. Maybe somehow it resets the VVT-i system or the oil control valve. I can see the reason for your scepticism though.