Knock Sensor Location.. front of block?!

[Metallic36]

Alright, so a few months ago I had a new head put on.. and the shop that did it found that my knock sensor wires were pretty shoddy. So they replaced it. I got it from Advance and took it to them, but the wiring harness was a lot shorter than the one that was on the car already. Sooo.. the knock sensor is on the front of the block, above the exhaust mani, to the left. I didn't think anything of it until today when I crawled under my car to hook up my wideband O2 sensor, and looked up, to see a knock sensor still screwed into the back of my block with no wires coming out of it. Just curious to see if it is actually okay for it to be in the front of the block, or if it needs to be in the back, like the OEM one was. My car is still idling high, so I don't know if that would be the cause of it, but just curious.

 

[ItsSlow]

If its above your exhaust manifold, then its not a knock sensor or else somebody really f'd something up.. Because last I checked, your exhaust manifold is bolted to your head, not the block..

Got any pics of your findings?

 

[Metallic36]

Yup, I'll go out and take a pic right now. I tried driving today and got three codes, P0300 (multiple misfire) was one of them, along with P0037 and P0480. I say "tried" because I didn't get far before my CEL started flashing. I think if they screwed this up, they probably didn't set my timing back right either. Sure doesn't feel like it.

Got any pics of your findings?

 

[Metallic36]

Block - I was referring to the entire thing.. not the particular section of the engine (bottom end, head, etc.), I was trying to describe where it was located.. anyway, the pics are above.

If its above your exhaust manifold, then its not a knock sensor or else somebody really f'd something up.. Because last I checked, your exhaust manifold is bolted to your head, not the block..

Got any pics of your findings?

 

[Jaysanooch]

The ideal spot is at the stock location...not sure if it would help your high idle though.

 

[shane02pro5]

Umm what the hell??? Who the hell would put the knock sensor there!?

There is no way in hell that's working correctly there! Your timing is throwing everything off with the knock sensor probably going crazy from the valvetrain noise! My J&S knock sensor is in the front but only about 5" up from the oil pan!

 

[Metallic36]

Exactly what I thought!! I'm getting multiple cylinder misfires like crazy, it's shaking all over, and it sounds like a lawn mower.. can barely get the car out of the driveway.. even after seafoaming it today. I'm going to try to get it back to the stock location, hopefully that will help it out.

Umm what the hell??? Who the hell would put the knock sensor there!?

There is no way in hell that's working correctly there! Your timing is throwing everything off with the knock sensor probably going crazy from the valvetrain noise! My J&S knock sensor is in the front but only about 5" up from the oil pan!

 

[shane02pro5]

Let us know how it turns out... I think your future is getting brighter!

 

[Metallic36]

I definitely will, thank you so much for your help!! That makes perfect sense though, because wouldn't the knock sensor make the ecu advance the timing depending on the knocks that it detects? And since it's way up near the valves, it would pick up tons more, rather than if it were in the lower/rear stock location it would only pick up the ones in that particular location, the ones that it's actually looking for, thus the reason the factory put it there to begin with.

Let us know how it turns out... I think your future is getting brighter!

 

[shane02pro5]

I definitely think so...and it would retard the timing!

 

[ForceFed]

I will tell you now that the Knock Sensor location is NOT the problem with your lawn mower.

It was running fine for some time now..It didn't just magically start becoming the problem because of its location.

 

[shane02pro5]

She said this was when it started? Did you see the pic...it's 1" from the valve cover.

 

[ForceFed]

From what I understood...this has just happened recently and the car was running fine?
No?

 

[Metallic36]

No, ever since I got the car back from the shop it's been bad, not even drivable and it's been sitting.. that's why the gas was supposedly old, because it's been sitting since September. It came back with a very high idle, it would idle at 2500 rpms and not budge any lower. I got it back from the shop, they were going to charge me $1900, $900 of which was for labor for them trying to figure out what was wrong with it.. I bitched because they obviously didn't fix it at all, so they dropped it down to $1400 and I took the car back to figure it out on my own. The most I've driven it since getting it back was the other day when I got the flashing CEL for multiple cylinder misfire after driving it for about 1/2 mile down the road. Uploading videos of it idling when I got it back from the shop, will post soon.

It was running fine before I took it to the shop, the water pump went out, so they replaced that and the thermostat, put on a new head, and then they decided to replace the knock sensor because the wiring was old on it and showing. So, I got one from Advance and they put it on, only they said that the wiring harness wasn't long enough to put it in the stock location so they stuck it there. I drove it home with the high-ass idle, and parked it.

I'm going to put the knock sensor back to the OEM position, what the hell can it hurt anyway if it's back in the stock position where it's supposed to be? (dunno)

From what I understood...this has just happened recently and the car was running fine?
No?

 

[ForceFed]

And you paid them for this work why?

 

[Metallic36]

Because I couldn't change out the head myself. They had a lift, so I also got them to put on the GHL exhaust, and the GT28RS, and the MAM mani. They separated that labor, and it was less than what they charged for their "time" trying to figure out what was wrong with the idle, etc. after they put the head on. I was tired of paying them for nothing, so I got it back. It's worth it to me to get the car back than have it sit there and pay someone to tell me they don't know what's wrong with it.

And you paid them for this work why?

 

[Metallic36]

Why would the location of the knock sensor not matter?

 

[Metallic36]

Here's a video, this was right after I got it home, like a couple days later.. when the idle would raise itself. You can see the knock sensor, around 23 sec. in the video.

http://www.youtube.com/watch?v=FW-Uif_-bCU

 

[MSP2003.5_Nick]

I wish i lived closer to help you figure it out. I don't trust shops to do any work to any car.

The knock sensor should be on the bottom end because it listens to spark knock in your cylinders, being in the head will mess this up quite a lot I'd imagine. It could be mistaking the valve tick for spark knock which would make it go nuts!!

Also I'd double check the timing to make sure they did that right as timing a DOHC engine can be tricky when the cams don't want to stay in the right place. Sounds like mickey mouse worked on your car, so it wouldn't hurt.

It's not too hard, just pop off your valve cover, take out the spark plug in cylinder 1 and put one of those extendable magnets or something down there. Then crank the engine by hand til you see the piston is at top dead center. Once there just look at the cams to make sure the timing marks line up.

looking from the passenger side at the engine, the cam on the left should have an E and mark next to that and the right cam should have I and a mark next to that meeting in the middle. If the marks line up you're good, but if the letters are wrong thats not good haha because there is E and I on both cams just to make it right easy (Thanks mazda!)

Thats assuming the cam gears are on right becasue they can go on the cams 2 ways too lol. Which is why I like to do things myself, lets face it most mechanics have a hard time changing tires

 

[Metallic36]

I got as far as taking out the knock sensor, then searching for the old one, and realizing that the alternator bracket and the downpipe is blocking the way for unscrewing it. So I took a chance, and started my car without the knock sensor at all. The odd thing was that my CEL's weren't there. It did the same thing for a couple minutes (shaking), but then when I revved it up to 3K rpms, it evened out, then I took my foot off the gas and it dropped to about 1k and idled fine. There is still a knock sound, but that damn shaking is not there. I put my hand on the valve cover, and the cylinder (I think it's the 1st?) closest to the timing belt had more of a knock to it that I could feel. Going to take off the valve cover in a little while and check out the timing.