: 5.7 Knock sensor location

Johnny Kaka
07-03-13, 10:15 AM
Hello again everybody. I posted about a bad knock sensor a few days ago. Right now, I'm replacing the plugs and cap, since there was some misfiring in the engine, and that may have caused the knock sensor to slow the car down. But Since I bought the sensor and wire anyway, I was going to replace it. My question is, WHERE IS IT? I know on a lot of cars it is under the intake manifold. But on others it's on the side. Some 350's that I have been looking at have them on the side.
I scoured the factory manual last night. I could not find ANY info on the knock sensor. There was one line in the index that said "Knock" under the "engine" category, but that led to info for a 5.0. Plus, taht page had nothing on knock sensors.
I'm really confused here. I don't want to start tearing the car up blindly. Is this an easy swap? Or does the manifold have to come off, radiator drained, and so forth? This is a 1990 Brougham with a 350.
Thanks as always guys!

07-03-13, 12:09 PM
On an LT1 knock sensors also serve as coolant drain plugs. You might want to check out the bottom of engine block as well.

07-03-13, 12:23 PM
I believe its on the side of the block near the bottom.

Johnny Kaka
07-03-13, 01:31 PM
Great, thanks a lot! After reading a bit further, I also wonder if it's the electronic spark control. Some boards have listed that as a solution to code 43. Losing the ESC can cause the same exact symptoms (power loss, check engine light).

Could that be the case?

07-03-13, 02:32 PM
Im dealing with the same problem, my onbaard diagnosticis threw the ac controlls pulled a 43 out of the -01 so that means a got to change my knock sensors, i got a 96 and heard i got 2 knock sensors? What year do you have? I think 1s by the starter

Johnny Kaka
07-03-13, 02:53 PM
I'm dealing with a 1990 Brougham - 5.7 liter chevy 350.

07-03-13, 02:55 PM
Yea i think you only got 1 and should be right y the starter on the block

Johnny Kaka
07-03-13, 03:09 PM
Can I ask how you found this out? I was in my manual for a while last night.

07-03-13, 03:14 PM
Found the knock sensor or the code?

Johnny Kaka
07-03-13, 03:38 PM
The sensor itself.

07-03-13, 03:50 PM
I remember seing them but didnt know they was the knock sensor but i googled imaged it

07-03-13, 04:35 PM
To be perfectly honest, I don't know if an L05 (TBI 350) actually HAS a knock sensor...

Johnny Kaka
07-03-13, 05:41 PM
Thank you Jay, I'm wondering this myself. I cannot find it anywhere. And if it isn't in the factory manual, then.....

However, I still have the typical power loss, along with a code 43. That could also indicate the electronic spark control module. Same symptoms, I believe. When this happened, it was very wet out, and has been humid for weeks here. to a disgusting degree. It would also explain the strange, intermittent starting problems I've been having.
Before I go any further, I just want to rule out the knock sensor for certain. How can I find out if this model had a knock sensor?

07-03-13, 08:06 PM
To be perfectly honest, I don't know if an L05 (TBI 350) actually HAS a knock sensor...

The F-bodies did, dunno about the Caddies. The sensor was on the right side cylinder head toward the front of the engine. It would be hard to see with the exhaust manifold in the way.

07-03-13, 08:44 PM
I still have my 93 RMW FSM. I'll look it up.

Johnny Kaka
07-06-13, 01:35 PM
I found it.


Unfortunately, it is rusted and stripped. I've hit it with tons of blaster, but I haven't been able to get it out yet. I also found this:


Not sure if this is a slow leak from the oil pan. It definitely smells like oil. However, I just found a possible intake gasket leak (VERY possible) And I'm not sure if the coolant is mixing with the other grime and forming at the bottom of the pan.

Not sure how to proceed. currently. my problems are:

-stripped knock sensor, can't budge the damn thing!

-Likely intake gasket leak

- oil pan leak.

I don't even know where to start. I'm also wondering if all of this work is worth it. I want to take it to a mech to have it checked out so I know exactly what I need to fix. How much would I pay for some diag tests?

I am also going to start a new post for all of this nonsense. I really appreciate you guys hanging in and trying to help me. THANKS!

07-06-13, 04:39 PM
Iv heard to help take the knock sensor loose is to start the car up so the block will heat up and that will help take off the knock sensor

07-06-13, 04:43 PM
If its gonna be a problem to remove, maybe just fix the misfire since the sensor seemed to do its job when it detected a noise from the misfire.