[milkbelly]

I have a 2002 Xterra SE s/c with 152,000 miles on it. About a month ago it developed a very minor knock which was only noticeable at idle. The knock slowly got worse each day I drove it until one day it got really bad. It was very noticeable when driving, the truck would buck and snort, had no power and gas mileage went way down. The CEL threw 4 codes- 2 for Random/ Multiple Cylinder Misfire, and 2 for Knock Sensor.

About 2 weeks ago I replaced the knock sensor , which by the way is a real PITA, as it is hidden on top of block under the intake manifold. While I was in there, I also installed new NGK Platinum plugs and wires, new fuel filter, and cleaned the MAF sensor. The cap and rotor were replaced last winter, probably about 20,000 miles ago, and still looked fairly good. Everything else I took apart looked really good. I was impressed that the fuel injectors looked brand new. I cleaned everything up and put it all back together with new gaskets.

The truck ran extremely well. Probably as good or better than when I bought it with 3000 miles on it. It ran good up until yesterday when it started to knock exactly like it did before. In the 2 weeks since the repair work I drove about 600 miles running premium fuel through it.

Anyone have any ideas? Could the knock sensor I put in have been defective? Is there anything else I should check?

 

[dejablue]

have you checked out the distributor?

 

[milkbelly]

I took off the distributor cap and rotor and took a quick look inside. Everything looked good to me. Is there anything specific I should look for or any way to test it. I know some people on the forum said that they saw metal shavings in theirs when it went bad. I didn't see anything like that.

 

[Xterra Mike]

we just had a member that had a knock and he replaced the whole dist and the knock went away. Let me see if can find his vid.

 

[Xterra Mike]

ok so i missed his last post when he said that the knock came back in the morning but here is the video anyway:

 

[jclmaster]

Has the timing belt ever been changed? It was due at 105,000 miles.

 

[dejablue]

you have do more than pull the cap and rotor you need to pull the electronics out and look in the very bottom and see if there is any black dust or bearing fragments

 

[milkbelly]

The timing belt was changed at about 130,000 miles.

This morning the misfire was bad, and I lost all power again. It was hard just to get it to 30 mph. I kind of gave everything a quick check and noticed the cap and rotor had some light corrosion. I replaced both the cap and rotor and the truck instantly ran much better, but it is still not running like it should. I drove it about 150 miles to get home, and it ran fairly well but it still had a hiccup every now and then. The CEL did not go off though. When I got home I checked it with my OBDII scanner. I got the P0300 code for the random misfire, and P0328 for knock sensor circuit high input. I erased the codes, then started the truck and let it idle for a couple minutes. The CEL stayed off but I know that the Knock Sensor will not trip the CEL, so I checked it again. Sure enough, I got the same P0328 code.

What does it mean that the knock sensor circuit input is high, and what should I check or test?

 

[milkbelly]

Tomorrow I should have some time to check the distributor over a little better.

 

[dejablue]

http://www.clubxterra.org/forums/showthread.php?t=3139&highlight=distributor
look at post #31 is what you are looking for ,this one is really bad truck would not start. the black dust tricks the electronics and makes it send a false signal to fire a plug.

 

[mikeman1985]

what's it sound like?

I see xterra mike put linked my video up there, is it anything like that?

I still have not figured mine out yet. Mine did not have a misfire at all, only the knock. When listening with my stethoscope I narrowed it down to where the distributor shaft goes into the head. So I replaced the distributor thinking that was it, knock was back in the morning; and that's where I stand with it right now.

Have you checked your timing?

You can pull the rotor off, then pull off the cover that sits on top of the electronics in the dist. have a look under it and see if any metal shavings or anything is in there. you really can't see down in it with the cover on.

seems to be a bunch of mikes that drive x's, what's up with that?

 

[mikeman1985]

For what it's worth mine turned out to be the timing belt tensioner.

Did you ever figure yours out?

 

[Xterra Mike]

what's it sound like?

seems to be a bunch of mikes that drive x's, what's up with that?

ha ha yea i don't know