Not another knock sensor thread?!?

[Pick_T4R]

Just bought a 2nd Gen and it has the dreaded code 52. I have read a dozen or more threads on the issue and really don't want to do the cheap/easy lift mount relocation fix. It's obvious work has been done under the intake but I don't have a good history of what... My questions are:

- While I'm in there should I do the timing belt, tensioner & water pump?

- If I do the above, with >220k miles, are the heads and bottom end going to crap out shortly after I finish this phase of the project?

Just fearful that a $2k T4R might money pit into more than I want. This is a 'get around-town' (my other vehicle is a F-350 4 door, long bed dually) as well as a learner for my 2 15yo boys.

Just concerned this is going to spiral out of control (transmission, axles, etc.). Talk me off the ledge :fear:

 

[SomeInternetNobody]

Knock sensor can lead to more issues cropping up. After I replaced mine, I had more and more issues crop up. This was mainly due to half-assed or incorrectly done repairs. If your's is still in good shape otherwise, then go for the sensor replacement. A 4Runner is always worth the investment.

 

[kc15842]

I went through the 52 challenge and it was all wiring harness. I made a new shielded cable from the pig tail at the intake to the ECU. Its been perfect since. The connectors cook under the hood. You can still buy new replacements which if I was to do it again I would have replaced all of the connectors when the harness was out of the truck.
I wouldn't take the intake off until I replaced the knock sensor harness. You can do it for less than $20. If that doesn't work then go after the KS. The intake gasket replacement means unplugging injectors and sensors on the back of the intake. In my experience some will break. I'd clear the 52 and see how the truck runs and see if the motor is worth putting more time and money.

 

[Pick_T4R]

After digging into it further this weekend, someone has run a shielded cable from the ECM to the intake, I suspect this is for the knock sensor circuit - just haven't confirmed it yet.

I thought you had to pull the intake to get to the knock sensor to replace the knock sensor cable, is that not the case? I'm definitely on-board with trying that first but sounds like I may have more issues to sort our with the non-factory wiring that has been done

I added two pics; you can see the cable (grey arrow) was spliced into the ECM wiring harness (red arrow) and the shield was grounded. The 2nd pic shows the cable spiced under the hood right at the driver's side valve cover.

In all my research, I thought the cable that typically had problems was the coax jumper from the knock sensor to the connector where I'm seeing the splice at the valve cover. Am I misunderstanding the issue?

 

[Pick_T4R]

In all my research, I thought the cable that typically had problems was the coax jumper from the knock sensor to the connector where I'm seeing the splice at the valve cover. Am I misunderstanding the issue?

This is a pic from the knock sensor location thread. It was my understanding that the cable I added a red arrow to is the one that goes bad.