Bassinfool

I'm getting a code 52 (knock sensor) on my truck, and it's running rough & seems to be "missing" when I get on it. I just replaced the Head Gaskets & up. Would the knock sensor problem be causing either or those??

quick2300

Did you check the wires on the KS? Mine were badly frayed when I did my headgaskets.

Bassinfool

Here's the story... I redid the HGs a couple weeks ago. Had a small fuel injector leak, so I changed the o-rings. That made it worse, because, as I found out later, the o-rings I bought for the injectors were too big & got cut up in the fuel rail. Anyway, I replaced them with the right o-rings & put it back together last night, which was the first time I got the code 52. Before that, I didn't get the 52 & it wasn't running rough. I haven't had time to get back in to it, probably tonight...

oreomiddle

Hey Fool! Check this thread out.I was shocked!Easy fix for me at least. https://www.yotatech.com/forums/f2/knock-sensor-wire-3vz-e-34186/..

nunsa

Knock sensors - Back in the late '90's we used to do recalls for the HG recalls on the 3.0's, It got to the point that most of the ones that we did would be back within a month or sooner due to a Code 52 "knock sensor", after Toyota addressed the situation whenever we did a HG we also replaced the knock sensor. So listen up: Whenever you remove the heads from a 3.0 to do a HG or whatever, Always, Always replace the knock sensor!

p5150

The MKIII supras have a similar problem, and I think they employ the same knock sensor. Alot of the MKIII guys do a knock sensor rewire, it seems to solve the problem- check out supraforums.com or supramania.com

MonsterMaxx

the knocksensor is under the manifold
there's a little pigtail that routes the knocksensor out

this pigtail can become corroded and weak, repeted installs can cause it to break.

I'm betting you need to replace the little pigtail.

Bassinfool

Thanks, guys. I'm going to take my truck apart this weekend & check the sensor & wire. Hopefully it's only the wire, but I think I'll put the new sensor in while I have it apart anyway.

creaken

I put a knock sensor on the bracket above the rear cylinder that you put the chain on to pull the motor, we welded one with a mig welder to it, it works fine!

86tuning

The knock wire fails 100x more often than the sensor itself. Also, the wire retails for around $10 but you have to pull the intake manifold.

Whenever head gaskets are done on a 3VZ the knock wire should be replaced.

tyguy_4u

Thanks for the advice..I put the new wire on and now it runs better then ever! Even though the toyota service department said it would not change a thing when i went to buy it. but it did! changed a lot

wizzard0z

Hi creaken did you have any pics and is it still workon ok
thanks Steve

KensToy95

Hey all. In the interest of not tearing apart my toy, I have tried all of the suggestions in this thread to resolve error code 52.

I have a 95 Toyota Pickup 4wd 3.0L 3VZE engine

Further Observations would be appreciated.

1. First I disconnected, cleaned (CRC) the KS harness connection to the pigtail and reconnected all connections.
Reset EMI, tested - error code 52 came back.

2. Then I continuity tested KS harness back to ECM computer (connections clean, 0 ohms)
Reset EMI, tested - error code 52 came back

3. Then (see creaken suggestion) I mounted a new KS to an existing the intake manifold (I did NOT weld it to the lifting bracket, which by the way is on the other side of the block), with a new pigtail, connected to harness.
Reset EMI, tested - error code 52 came back.

What's left seems to be to physically tear down and replace. I'm suspicious though that there might be a computer problem, since my makeshift mounting (bolted to intake) should have worked according to creaken.

A new ECM computer is 299.00 on-line, vs 6+ hrs of nasty work, which may be required in the end anyway.

Any More Ideas ???