govt.mule

is it true that when replacing head gaskets on 3.0 you should also replace knock sencer thanks

Bumpin' Yota

you should DEFINATELY change out the knock sensor wire, but the KS itself is optional. For me, peace of mind is worth the 150 and I got a brand new KS.

shaeff

if you have an ocilloscope, test it out! they don't usually go bad. toyota also used the same KS's on many different models, so even if it is bad, you could grab one from the boneyard pretty cheap.

for me, a new KS isn't preventative maintenance.

-shaeff

keithguts

Why is it so inportnent to chang the wire?

shaeff

after time, the wire gets old and the insulation becomes brittle. when this happens, it's possible for the sheilding in the wire to come into contact with the signal wire inside, thus making a short to ground.

in this case, your truck will go into a sort of "safe mode", or limp mode. the ECU will enrichen fuel mixture and retard the timing in an effort to prevent detonation.

rg58 multi strand sheilded cable is the best to use for the re-wire, and a new connector from the dealership isn't a bad idea either. use a wire loom from autozone, radioshack, etc.. to protect the exterior insulation of the new wire. trust me, it helps.

-shaeff

Bassinfool

A new wire is only $11 from the dealer. It's DEFINITELY worth doing the wire. Stupid not to, as I learned, because you'll be taking the intake manifold, fuel rails, intake plenum and several other parts off, spending about $150 in new gaskets to get to the $11 wire you should have changed two weeks before when you were rebuilding from the headgaskets.

Sensor itself is not necessary.

shaeff

^ it's easier just to use rg58, as it's more durable, and you can make a dedicated run for it, rather than having to rip everything apart...

-shaeff

Bumpin' Yota

what is this RG58?

And did you know that the Knock sensor wire has only one wire attaching to the knock sensor itslef? Where does the other wire go?

shaeff

it's a sheilded cable with a multistrand core. (if you can find the multistrand, otherwise solid copper core will work alright, like the stuff used for cb radio antennas)

basically, you use the center wire for the signal wire to the ECU, then you twist up the outer wire (which is sheilded) and solder another wire to it. ground that wire, so that if any electrical interferance does penetrate through the shelding, it'll go straight to the chassis ground and not interrupt the signal. (which would retard the timing and add more fuel)

-shaeff

thook

Oh, I thought that nebulous second KS wire went to the 3.0 void...where other things go wrong.