dan.worts

Hey guys,
Got a nasty surprise at my mechanic's a few days ago. Went there to find out which wheel spin sensor went bad, left knowing it was the rear right and... that I have a bad knock sensor (code 325)

I know these things can get pretty expensive to replace, and after researching and finding the plethora of information on replacing a 4th gen's, I wonder if it is possible to replace my 5th gen's without removing the intake manifold?

I tried to find that out on my own, but I can't seem to spot the knock sensor in my engine! I can see the corrugated wire (under the intake manifold and on top of the block) that I think leads to it, but I can't seem to find an angle with my flashlight and eyes to see in there deep enough.

Has anyone successfully replaced their 5th gen's KS without taking out the intake manifold?

I'm trying to save a whole lot of cash here, and I am completely open to doing it myself if I must.

Thank you in advance to anyone who can help.

tookrzy4u192

iTrader: (19)

I can't remember if the 5th gen manifold is different than 5.5 gen but when I relocated my knock sensor I didn't have to remove my manifold.. My intake might have been off for easier access but that's about it, hope this helped..

essential1

iTrader: (5)

This has been explained before but its probably hiden among other random topics.

You have to take the intake manifold off to change the knock sensor on the 00-01 maximas. This is because the VQ30DE-K has an additional collant passage/water neck in place of where you would put your hand to get to the knock sensor. You wont even be able to see it with a flashlight. 4th gens and 02+ maximas dont have this.

dan.worts

Relocating is intriguing, but if the intake is going to be off why go through the extra trouble of moving it? A replacement ought to last a good 100K at least, and on a car with already 108K I question if relocation is worth it.

Rochester

iTrader: (3)

Try reading this thread. Jump down to post #24 for pics.

http://forums.maxima.org/5th-generat...ere-we-go.html

ZGadson

There's a thread with a How-To for bypassing the knock sensor all together with a resistor to make the car think the sensor is there. I did it - was $1 for the resistor from Radio Shack. Do a search for the thread if you're interested in that route.

Its very simple - you pretty much just unplug the knock sensor and bend a 100ohm resistor into the + and - side of the plug and it makes the car think the sensor is still there and working as it should. Virtually free, vs $120 from autozone.

dan.worts

What if something actually goes wrong where the knock sensor is needed? It can't be useless or it wouldn't be there to start with. And if I were able to reach and to unplug the knock sensor, I would just replace it.


And Rochester, I have no idea how he was able to reach it with the coolant line in the way! He says nothing about it in the thread, I've read it previously.

Thanks for the feedback so far guys

onebadmax666

just pay the mechanic u got somthing to fall back on if somthing goes wrong

Rochester

iTrader: (3)

I've not done it myself, but I did scope it out, and it looks very accessible with the extension and elbow ratchet. I wonder what I'm not seeing that you are? What coolant line?

luvlexus101

iTrader: (6)

I spent like 30 minutes staring at the fsm and the engine with the knock sensor in my hand trying to figure out where it was last week lol

Rods03Max619

iTrader: (5)

Looks pretty easy to swap out on a 5.5 dont know about the 5

tcaughey

iTrader: (6)

^^^

This. Totally agree. I've changed several knock sensors on the 4th gen, and when it came time to change the knock sensor on my 5th gen, there was NO way I was able to even see the knock sensor due to the coolant line on the DEK.

In reality, taking off the intake manifold isn't terribly hard anyways. All you need is some confidence to tackle the vacuum line salad, mechanical experience, and a good set of tools. Oh, and some good research skills and a know-how guide

dan.worts

Ah, I noticed your car is an 03, mine is an 01.

It appears that it is not possible to do it in the 5th gen, but it is do-able in the 5.5 gen

Rochester

iTrader: (3)

Yep. I should have noticed that before getting involved. My bad.

Good luck, champ.

dan.worts

Thanks

Dimitri459

Can someone answer my question,

I have two codes, one is for one of my rear O2 sensors, and the other one is due to a faulty knock sensor. I have a 2001 Maxima (113k) and some people have told me that a faulty knock sensor does not trigger the check engline light, is this true? What does a knock sensor do? if i do not replace my knock sensor am i damaging my engine? how about my car in general?

Thank you guys in advance!

dan.worts

knock sensor alone does not trigger SES. It detects detonation in the engine/pinging and retards engine timing to prevent pinging (in a nutshell). You won't damage your engine if you don't replace it but your engine will run in "limp mode" -- meaning you will get poor power and poor gas milage.

Dimitri459

Thank You,

Do you have any idea how much the labor will cost. I know the part itself is around $150.00. Again i will like to thank you for your quick response.

Dimitri

dan.worts

I will let you know what price I get from my mechanic once he calls me back... could be a day or two. And that $150 is for an OEM part, you COULD go nuts and get a mystery $20 knock sensor "OEM quality!" from ebay.....

Dimitri459

Oh ok, good point. Well let me know what your mechanic quotes you.

Thank You

knight_yyz

iTrader: (40)

probably 3 hours labor to remove and reinstall the Upper IM. If you're doing that you might want to do your plugs at the same time.

dan.worts

Funny you said that, I just bought new plugs last week and I am going to install them when it's off!