2013 Scion FR-S has a loud knock - Page 2 - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

highway7 · 02-07-2018, 12:44 PM

Sounds like rod knock... ever ran low on oil?

Unfortunately, you bought a Toyota but really you got a Subaru...

justint5387 · 02-07-2018, 01:38 PM

Gonna have to tear the motor. I think it's rod knock

Sportsguy83 · 02-07-2018, 01:49 PM

Knock, knock

Thorpedo · 02-07-2018, 03:17 PM

EX engine shop manager chiming in....

If you blip the throttle a rod bearing will make a single knock as the engine crests the peak rpm of the "curve". I usually blip it so that it will peak outside of the normal range where it knocks. Usually 3000-3500 depending on the engine.

I have a hard time explaining this, but I've yet to encounter a rod bearing that failed this test.

Lantanafrs2 · 02-07-2018, 04:52 PM

Backlash. I've experienced it with bike engines.

AlexT391 · 02-12-2018, 12:02 AM

Well folks, found the problem! After pulling the motor, I confirmed my suspicions that the flex plate was fractured! Part is on its way from Phoenix, and I'll have an update confirming the fix within the week.

[ame="https://www.youtube.com/watch?v=6T6fKpPg4iM&index=1&list=UUotxKZ3YpZlkp2e2 Lwd_gRQ"]https://www.youtube.com/watch?v=6T6fKpPg4iM&index=1&list=UUotxKZ3YpZlkp2e2 Lwd_gRQ[/ame]

I was in a bit of a rush to get to work after pulling the motor and cleaning up, but I'll get a better video when the new plate arrives.

humfrz · 02-12-2018, 02:03 AM

Quote:

Originally Posted by AlexT391

Well folks, found the problem! After pulling the motor, I confirmed my suspicions that the flex plate was fractured! Part is on its way from Phoenix, and I'll have an update confirming the fix within the week.

I was in a bit of a rush to get to work after pulling the motor and cleaning up, but I'll get a better video when the new plate arrives.

I can't see your video.

Well, at least you know what was causing the noise.

I haven't seen, on this forum, where a flex plate has gone bad.

How much power are you putting through that AT ....?? (I'm too lazy to go back)

Is the new one pre balanced or do you have to balance it for that engine ... ??

Keep us posted.......

humfrz

AlexT391 · 02-12-2018, 02:14 AM

Oops, still had it on private. It should be good now. Yeah, it's a pretty big relief

It's actually bone stock which leads me to believe it had to be a manufacture defect. It honestly isn't even driven rough by any means.

The new one is pre-balanced so optimistically I'll have it back together in a couple of days when it arrives.

In the meantime, my OCD has me itching to scrub out that bay and clean up the motor while I've got the chance lol

Zentec · 02-12-2018, 02:39 AM

Congrats I’m glad you found the problem and it wasn’t an engine enternal problem like a rod. Please keep us posted on the progress.

Check for any other dirty or bad hoses then power wash and a beer. Gorgia peach cleanes the bay and you watch with a beer.

humfrz · 02-12-2018, 12:16 PM

Quote:

Originally Posted by AlexT391

Oops, still had it on private. It should be good now. Yeah, it's a pretty big relief

It's actually bone stock which leads me to believe it had to be a manufacture defect. It honestly isn't even driven rough by any means.

The new one is pre-balanced so optimistically I'll have it back together in a couple of days when it arrives.

In the meantime, my OCD has me itching to scrub out that bay and clean up the motor while I've got the chance lol

I'm glad I'm over that .......

humfrz

AlexT391 · 02-22-2018, 09:34 PM

Update: New plate has been on for about a week now, running smoother than when we bought it! Thanks for the info guys. I'll follow up with this thread with any changes. Hope this may help somebody in the future. Cheers!

highway7 · 02-22-2018, 09:50 PM

Glad to hear you fixed it, never heard of a flex plate breaking like that... neutral drops?

Mr Nerd · 02-23-2018, 02:04 PM

Have you ever pulled the Carfax for this car?

I feel like this car may have been abused before you purchased it. It is hard for me to believe that a bone stock car could have this happen unless it was some sort of extremely rare one off defect. The fracture almost looks as if due to a poor heat expansion coefficient of the metal. Which means that somehow it was cooled down rapidly after running at operating temps and fractured due to the instant contracting of the expanded hot metal.

Sent from my Galaxy S8+ using Tapatalk

AlexT391 · 02-26-2018, 07:13 PM

I don't know what the previous owner may have put it through, but it's definitely been babied since we've owned it.

Actually the dealer pulled the Carfax when I took it to them, but that's the only productive thing they managed to accomplish. It's had a decently extensive history of visits to the dealer for factory defects which is why I was told the techs didn't want to touch it. I have no doubt that one of the dealers had pulled it for major service before (according to the report), and likely torqued the flex plate bolts incorrectly. Like you said, given the unlikely odds that it was an inherent defect in the metal or factory design on this particular vehicle, I'd assume one of the techs at the dealer it's been serviced through probably didn't know what he/she was doing.

02-07-2018, 03:17 PM	#18
Thorpedo The SquadWhisperer Join Date: Mar 2013 Drives: '13 Ultramarine FR-S (STX) Location: Nova Scotia, Canada Posts: 681 Thanks: 383 Thanked 477 Times in 207 Posts Mentioned: 16 Post(s) Tagged: 0 Thread(s)	EX engine shop manager chiming in.... If you blip the throttle a rod bearing will make a single knock as the engine crests the peak rpm of the "curve". I usually blip it so that it will peak outside of the normal range where it knocks. Usually 3000-3500 depending on the engine. I have a hard time explaining this, but I've yet to encounter a rod bearing that failed this test. __________________ 2013+14+15 Atlantic Region Motor Sports Autocross STX Champion 2013+14+15 Atlantic Region Motor Sports Overall Autocross Champion 2017 Bluenose Autosport Club Overall Rallycross Champion Powered by Great North Performance, Jani-King Canada, and OK Tire.

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02-07-2018, 12:44 PM	#15
highway7 Senior Member Join Date: Nov 2017 Drives: FRS 2013 Location: Toronto GTA Posts: 182 Thanks: 2 Thanked 98 Times in 58 Posts Mentioned: 1 Post(s) Tagged: 0 Thread(s)	Sounds like rod knock... ever ran low on oil? Unfortunately, you bought a Toyota but really you got a Subaru...

02-07-2018, 01:38 PM	#16
justint5387 Senior Member Join Date: Sep 2012 Drives: 4 wheels Location: CA Posts: 249 Thanks: 361 Thanked 198 Times in 116 Posts Mentioned: 7 Post(s) Tagged: 0 Thread(s)	Gonna have to tear the motor. I think it's rod knock

02-07-2018, 04:52 PM	#19
Lantanafrs2 Senior Member Join Date: Jan 2018 Drives: 2013 frs red Location: South Florida Posts: 3,517 Thanks: 2,520 Thanked 3,088 Times in 1,654 Posts Mentioned: 6 Post(s) Tagged: 1 Thread(s)	Backlash. I've experienced it with bike engines.

02-12-2018, 02:14 AM	#22
AlexT391 Junior Member Join Date: Jan 2018 Drives: 2013 Scion FRS Location: El Paso, Tx Posts: 9 Thanks: 0 Thanked 5 Times in 4 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	Oops, still had it on private. It should be good now. Yeah, it's a pretty big relief It's actually bone stock which leads me to believe it had to be a manufacture defect. It honestly isn't even driven rough by any means. The new one is pre-balanced so optimistically I'll have it back together in a couple of days when it arrives. In the meantime, my OCD has me itching to scrub out that bay and clean up the motor while I've got the chance lol

02-12-2018, 02:39 AM	#23
Zentec Senior Member Join Date: May 2017 Drives: 2017 Toyota 86 Location: Las Vegas Nv Posts: 214 Thanks: 194 Thanked 78 Times in 63 Posts Mentioned: 5 Post(s) Tagged: 0 Thread(s)	Congrats I’m glad you found the problem and it wasn’t an engine enternal problem like a rod. Please keep us posted on the progress. Check for any other dirty or bad hoses then power wash and a beer. Gorgia peach cleanes the bay and you watch with a beer.

02-22-2018, 09:50 PM	#26
highway7 Senior Member Join Date: Nov 2017 Drives: FRS 2013 Location: Toronto GTA Posts: 182 Thanks: 2 Thanked 98 Times in 58 Posts Mentioned: 1 Post(s) Tagged: 0 Thread(s)	Glad to hear you fixed it, never heard of a flex plate breaking like that... neutral drops?

02-23-2018, 02:04 PM	#27
Mr Nerd Senior Member Join Date: Mar 2016 Drives: 2013 Scion FR-S Location: Phoenix Posts: 143 Thanks: 22 Thanked 44 Times in 34 Posts Mentioned: 3 Post(s) Tagged: 0 Thread(s)	Have you ever pulled the Carfax for this car? I feel like this car may have been abused before you purchased it. It is hard for me to believe that a bone stock car could have this happen unless it was some sort of extremely rare one off defect. The fracture almost looks as if due to a poor heat expansion coefficient of the metal. Which means that somehow it was cooled down rapidly after running at operating temps and fractured due to the instant contracting of the expanded hot metal. Sent from my Galaxy S8+ using Tapatalk

02-26-2018, 07:13 PM	#28
AlexT391 Junior Member Join Date: Jan 2018 Drives: 2013 Scion FRS Location: El Paso, Tx Posts: 9 Thanks: 0 Thanked 5 Times in 4 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	I don't know what the previous owner may have put it through, but it's definitely been babied since we've owned it. Actually the dealer pulled the Carfax when I took it to them, but that's the only productive thing they managed to accomplish. It's had a decently extensive history of visits to the dealer for factory defects which is why I was told the techs didn't want to touch it. I have no doubt that one of the dealers had pulled it for major service before (according to the report), and likely torqued the flex plate bolts incorrectly. Like you said, given the unlikely odds that it was an inherent defect in the metal or factory design on this particular vehicle, I'd assume one of the techs at the dealer it's been serviced through probably didn't know what he/she was doing.

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