L-98 ESC (knock) sensor question
Thread Starter
Le Mans Master
Joined: Oct 2001
Posts: 5,302
Likes: 2
From: Atlanta GA
L-98 ESC (knock) sensor question
On my old engine, the knock sensor is located in a hole in the block just in front of the starter next to the 4th oil pan bolt on that side. On my new engine, there is a block plug. Can I remove that plug and put the sensor there, or is there something special inside the vette block right there that would negate this interchangablility? :cheers:
Thread Starter
Le Mans Master
Joined: Oct 2001
Posts: 5,302
Likes: 2
From: Atlanta GA
Re: L-98 ESC (knock) sensor question (dtorc4)
OK. Maybe it's not the knock sensor. I pulled it off my car and darn near got a coolant shower. If this isn't the know sensor, is it a coolant temp sensor? I thought those were on the heads (one per side). Someone explain this to me please :confused: :smash:
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: L-98 ESC (dtorc4)
There is a collant sensor in the front of the block under the intake and another between #6 & #8 plugs.
The knock sensor is just in front of the starter near the bottom of the block; it goes into the water jacket.
The '85-'89 Vette has an ESC module just above the right side panel near the blower motor. The knock sensor plugs into this unit, which processes knock information and relays it to the ECM.
[Modified by 65Z01, 10:17 PM 10/7/2002]
The knock sensor is just in front of the starter near the bottom of the block; it goes into the water jacket.
The '85-'89 Vette has an ESC module just above the right side panel near the blower motor. The knock sensor plugs into this unit, which processes knock information and relays it to the ECM.
[Modified by 65Z01, 10:17 PM 10/7/2002]
Thread Starter
Le Mans Master
Joined: Oct 2001
Posts: 5,302
Likes: 2
From: Atlanta GA
Re: L-98 ESC (65Z01)
Thank you for the answer 65, but can I transfer the knock sensor from my car to the new engine, which just has the block plug in it?
Just out of curiosity, how does the ESC module process knock info from coolant? :cheers:
Just out of curiosity, how does the ESC module process knock info from coolant? :cheers:
Melting Slicks
Joined: May 2000
Posts: 2,148
Likes: 1
From: Chandler AZ
Re: L-98 ESC (dtorc4)
Just out of curiosity, how does the ESC module process knock info from coolant?
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Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: (zelement)
The knock sensor signals the ECM when knock is detected and the ECM pulls timing to reduce knock tendency; this protects the engine from destructive knock.
However, after warmup the ECM advances timing till the knock sensor registers a ping; if this "test" fails the ECM goes into Limp Home mode with fixed timing and a rich mixture to protect the engine till the knock sensor is fixed.
So,yes the knock sensor is an important part of our EFI engines.
However, after warmup the ECM advances timing till the knock sensor registers a ping; if this "test" fails the ECM goes into Limp Home mode with fixed timing and a rich mixture to protect the engine till the knock sensor is fixed.
So,yes the knock sensor is an important part of our EFI engines.
Le Mans Master
Joined: Jul 2001
Posts: 6,252
Likes: 2
From: Silicon Valley Kalifornia
Re: L-98 ESC (knock) sensor question (dtorc4)
The GM manual specs NOT TO reinstall the knock sensor. Once torqued down, then that's it. I guess it is so sensitive that the untorquing and re-torquing will distort the sensor housing and affect its performance. Good luck!
Thread Starter
Le Mans Master
Joined: Oct 2001
Posts: 5,302
Likes: 2
From: Atlanta GA
Re: L-98 ESC (GRX)
The GM manual specs NOT TO reinstall the knock sensor. Once torqued down, then that's it. I guess it is so sensitive that the untorquing and re-torquing will distort the sensor housing and affect its performance. Good luck!
