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Anyway to bypass the knock sensor

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Old Sep 5, 2006 | 12:08 PM
  #1  
colo-chinaman's Avatar
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Anyway to bypass the knock sensor

Anyone know of a way to bypass this damn thing. i have a code 52, when I disconnect the batt it runs great for about a clean 4 seconds, then bogs back down. So I was thinking if there was a way to bypass the sensor, get rid of the code then I could just run premium and not worry about it for a while
Thanks
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Old Sep 5, 2006 | 12:26 PM
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You need to figure out why it's throwing the code and fix the problem.
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Old Sep 5, 2006 | 12:29 PM
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A shop quoted 500 to fix...does that sounds pretty reasonable??? also suggested timing belt for a couple hundred extra. Anyway I don't have the money right now so i wanted to get by for a little while longer if I could, thats why I inquired about bypassing it
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Old Sep 5, 2006 | 01:00 PM
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From: Siletz,Oregon
what motor do you have
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Old Sep 5, 2006 | 01:15 PM
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Originally Posted by Elton
what motor do you have
He mentions a "code 52" so we at least know it's pre-OBD II... But yeah, knowing the motor would help with specifics.


Originally Posted by colo-chinaman
A shop quoted 500 to fix...does that sounds pretty reasonable??? also suggested timing belt for a couple hundred extra.
I'm in such the wrong business.

Umm, the knock sensor is a tricky one to bypass, I've cheated out the pair on my 3.4L by shorting them together thus giving me a spare. They're a PITA to replace.

The part itself is about $130 from the dealer, the PITA comes from getting to it to replace. On the 3.4 it's under the intake manifold, and it takes time to pull apart the top end, as well as $$$ to replace the gasket(s) that you're _supposed_ to (I use FIPK when I do it).

So... if you have tools and are comfortable with them, then $500 is A LOT to replace a knock sensor. $200 for a timing belt is actually pretty good and considering THAT fun - it could be worth it.
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Old Sep 5, 2006 | 02:44 PM
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If you have a 22re engine, it's very easy....a 3vze is not so easy.

You can get a knock sensor for hardly anything and put it in easy on a 22re.

Most likely it's the wire or connector.

No way I would pay that much for a shop to do it.

I had a code 52 forever and couldn't stand it. Finally I got a good used one...put it in and SOLDERED the wire to the thing and cut the connector off. Works good.

As far as bypassing it...I really don't think so. You don't wanna anyhow because it helps your engine.
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Old Sep 5, 2006 | 03:12 PM
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I've heard of a few guys drilling a hole in the engine lifting hook and installing a knock sensor with a new wire. A cheap and easier way to replace it but it is no longer near the pistons and may not be able to detect detonation or preignition. Just be aware of any piston rattle and of the ignition timing. If mine goes south that's what I, would do till I, have time to replace it.
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Old Sep 6, 2006 | 06:36 AM
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I got a quote of just over $1000 to replace the knock sensor in my V6. When I get the balls to remove my intake I'm going to do it myself.
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Old Sep 6, 2006 | 07:04 AM
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Originally Posted by geoduke
I got a quote of just over $1000 to replace the knock sensor in my V6.
thats because on a 3vze it sits in the valley between the cylinders on the block, under the lower plenum.

to access you have to take off upper plenum, and everything to do a timming belt because the upper idler pulley is bolted to the front of the lower plenum.

its a good solid 4+ hr wrenching ONE WAY.
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Old Feb 12, 2007 | 07:29 PM
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I have the same code and I am considering the temporary solution until I can get ready to pull all this apart for a timing belt, pcv, knock sensor project.

I just got my 3.0 10 days ago and I just cannot tear it all down right now.
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Old Feb 12, 2007 | 08:15 PM
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From: austin, tx
Originally Posted by DirtCheap
I've heard of a few guys drilling a hole in the engine lifting hook and installing a knock sensor with a new wire. A cheap and easier way to replace it but it is no longer near the pistons and may not be able to detect detonation or preignition. Just be aware of any piston rattle and of the ignition timing. If mine goes south that's what I, would do till I, have time to replace it.
You can do that. You shouldn't have to. The issue needs to be fixed.

If you go with forged slugs, you need to relocate the sensor away from the cylinder as shown in this photo:

http://lakebox.dnsalias.com/photos/1...orrelocate.jpg
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Old Feb 12, 2007 | 08:20 PM
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Originally Posted by snap-on
thats because on a 3vze it sits in the valley between the cylinders on the block, under the lower plenum.

to access you have to take off upper plenum, and everything to do a timming belt because the upper idler pulley is bolted to the front of the lower plenum.

its a good solid 4+ hr wrenching ONE WAY.
i did them the other day at work in 5.8 hours. start to finish
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Old Feb 13, 2007 | 05:43 AM
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1000 bucks to replace is too much shop around... 4-500 is more like it.
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Old Feb 13, 2007 | 08:54 AM
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Originally Posted by DirtCheap
I've heard of a few guys drilling a hole in the engine lifting hook and installing a knock sensor with a new wire. A cheap and easier way to replace it but it is no longer near the pistons and may not be able to detect detonation or preignition. Just be aware of any piston rattle and of the ignition timing. If mine goes south that's what I, would do till I, have time to replace it.

That is what I did about 3 weeks ago. Works fine. Used a used Knock sensor off ebay and new wire from dealer.

I agree that it is probably a suboptimal solution, but I will just run premium until I can find the time to do the replacement.

When I do the replacement (in factory location) I'll also know I'm dealing with a good wire and knock sensor. I've heard of a few guys who've done the replacement and ended up with the same code. Turned out the wiring farther up the harness was buggered.

Also - conventional wisdom says that it is likely not the knock sensor that is buggered - just the wire to it (which is shielded) has become brittle.
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Old Feb 13, 2007 | 01:04 PM
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From: Hudson Valley, NY
don't bypass the knock sensor...

especially if your truck is modified. even if it isn't, don't.

it's usually just the wire, which you can replace with some rg-58 sheilded coax cable, and probably never have to worry about it again.

when code 52 is registered in the ECU, the timing will be retarded, and the fuel trim will increase (rich) in an effort to prevent detonation/pre-ignition.

bypassing that feature wouldn't be smart, to say the least...

-shaeff
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Old Feb 13, 2007 | 01:14 PM
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Holy crap this sensor is expensive by itself. $215-$240 is what I am seeing from advance autoparts and napaonline so far. Add $100 on top of that for gaskets to take the plenum all the way off and I can see why the shops are charging $100 for the job you have $350 + in materials before you even get started.
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Old Feb 13, 2007 | 01:45 PM
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Originally Posted by DirtCheap
I've heard of a few guys drilling a hole in the engine lifting hook and installing a knock sensor with a new wire. A cheap and easier way to replace it but it is no longer near the pistons and may not be able to detect detonation or preignition. Just be aware of any piston rattle and of the ignition timing. If mine goes south that's what I, would do till I, have time to replace it.
Thats good, but how hard it it to get the wire from where it is to the new location in a 3.0
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Old Feb 13, 2007 | 01:55 PM
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Don't worry about buying a sensor... It's 99% going to be the wiring harnas.

That said... does anyone know how to make the engine not run at fail safe and or limit its effect. I just replace the plugs at 20k and they were all solid white, indicating the fail safe's effects of running the engine hot. Would running premium gas help?
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Old Feb 13, 2007 | 03:51 PM
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Yeah I just want to get this beast out of this limp mode until I can take care of the rest. The plugs indicated good combustion and I run 87 octane at 6000+ feet elevation. Not going to knock on its own up here.

I called the local Yota dealer parts counter. They have the sensor for $203 and they want $15 for the wire.
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Old Feb 13, 2007 | 04:41 PM
  #20  
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well Swank... get the sensor and wire (and injector gasket) test your old sensor if its good, which it will be, but it back on and take the new sensor back. I promise you that the wire is bad.
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