Advice needed

[Wingrider]

Hi everyone. I have recently bought a Maxima SE, 1998, 105000 mls. which is a bit of a rarity here in UK. After reading several posts on this forum, which can I say is one of the most helpful I have ever seen, the wealth of info is astounding, I think I need a new knock sensor. I called my local Nissan dealer who quoted 256 GB pounds (about 395 US dollars) Ouch!! The guy did actually say “You might want to sit down” I see knock sensors from the US on ebay a lot cheaper but they are all for the 3 litre engine. My question; is the 2 litre V6 engine in my Maxima the same as the 3 litre (apart from size obviously). Engine designation is VQ20DE. Thanks in advance for any help you can give, apologies if this has been asked before.
Kev.

[loystock]

The KS used in the Maxima-VQ30, P/N: 22060-30P00, is the same one used in the Maxima-VQ20DE, Left-Hand or Right-Hand Drive, per link below:

http://nissan4u.com/parts/info/2206030P00/

I bought an OEM sensor from eBay thru Deutsch Parts for $45 shipped. I installed it in my 99 I30-California Configuration last weekend and so far it's working very good. In other Maxima/I30 models, you could barely put your hand inside the slot for the KS but with the California configuration, it's impossible due to the EGR valve and connecting rods plus a bracket for vacuum tubes. Removal of the mounting bolt and KS assembly is not difficult with a universal joint, extension (10" or longer) and 12mm short socket, long pliers and a good dose of WD-40 (and of course a bright flashlight) . You also need a very strong magnetic pickup just in case you drop anything inside the engine. But installation, in my case, is difficult - aligning the mounting bolt with the threaded hole . So instead of wasting so much time trying to get it aligned, I bought a similar bolt (8mm diameter x 1.25mm pitch x 30mm deep) and modified it into a self-aligning bolt by using a bench grinder to grind @ 1/8" of the bolt tip (use masking tape to protect the remaining threads) and using an 8mm nut to make sure the threads are intact. For installation, I used a 1/4" U-joint as it is more flexible than a 3/8" drive U-joint. The modified bolt went in the the first attempt.

I don't think you will have a similar difficulty as in my case but it will help if you refer to the YouTube link below on how to remove and replace the KS, courtesy of "boredmder"

http://nissan4u.com/parts/info/2206030P00/

http://www.youtube.com/watch?v=fPIMOIwL ... re=related

[Wingrider]

Thanks for the reply loystock. Plenty of useful info much appreciated. will order my KS now and looking forward to starting working on the Max.

[NutriaforBreakfast]

You could test your existing knock sensor with a multimeter to see if it is
bad before getting a new one.

[Wingrider]

Thanks for the advice. I have read the article on here since posting my original question so that is the next step.

[loystock]

KS resistance is 500-620 K-ohms. In my case, the KS has an open circuit. When you check the resistance, make sure you do it with engine cold and hot. A KS may pass the resistance check when cold, but may show an open circuit or out of range when hot (cracked plastic housing). Only one of two pins of the KS connector is used with the ground on the metal ring as it is bolted to the engine.

[Wingrider]

Thanks for the info loystock . I checked the KS resistance and it was 580 K-ohms. Engine was not to operating temp but close. However I am now totally confused. I decided to see if there was any CEL code as described elsewhere on the forum. Removed the cover over the ECU and found the small piece of tape covering the screw hole. Removed this, no screw head. Squirmed myself right down into the footwell to get a better look, still no screw head. Used strong torch and a mirror, still no screw head. I could see printed circuitry but nothing that looked like a screw head. As this is a right hand drive car I removed the cover over the right hand side just in case they made the ECU the other way round for the RHD market (very unlikely) but nothing doing. Does anyone on here know if Nissan made a version of the Maxima ECU for the RHD market without the CEL code facility? Any help would be very much appreciated. Just for info the car drives really well but for a slight hesitation below 2500 RPM. Nothing drastic just a feeling all is not quite right and it would be nice to be able to say yes “X” is faulty, or no, its your crap driving!

[loystock]

You will have a sluggish acceleration with a defective KS since the ECU will retard ignition timing to prevent pre-ignition/knocking.

I'm not sure why you don't have the diagnostic screw on the ECU. Maybe the previous owner has damaged it. Your best bet is get an OBD II scan to find out if there is any problem with your car. A defective KS will not turn on the CEL but will store a trouble, P0325. Here in the US, we can get free scan from car parts store. I don't know in the UK.

You car may have dirty intake components and/or leaking vacuum lines. Check clean the entire air intake - check/replace air filter, clean the MAF sensor and Throttle Body with zero-residue Contact Cleaner (available from Electronics as well as some car parts store). Do not touch the MAF sensor with bare hands...just spray with contact cleaner until it's clean. If the dirt is stubborn, then use Q-tips gently since the heating element and sensor are very sensitive. For the Throttle Body, NEVER spray directly into the body and throttle plate as the cleaner may seep into the sensors and damage them (the TB is expensive). Check the vacuum lines for leaks and clean or replace the PCV (Positive Crankcase Ventilation).

[NutriaforBreakfast]

Yes get the OBII scanner. It is too hard to read the flashing lights. I like my Actron code reader
a lot and have helped other people with their cars too. I think it is a CPN8195 reader. Actron is
a name brand in the automotive industry and they have a website. It will read the code # and give
you the option to turn off the check engine light.

If its hot outside, you want to check the KS when its cold too-put it in a bag and then put it in the freezer for a while and then check it agian

http://www.nicoclub.com/FSM/maxima/1998/EC.pdf
look on page 240

[Wingrider]

.... Here in the US, we can get free scan from car parts store. I don't know in the UK.....

Unfortunately here in UK we get nothing for free! Thanks for the info guys, looks like I will be getting an OBD II scanner.

[loystock]

Scanner is one of the best investments I've ever made. Mine is a basic one for trouble codes and reset as well as SRT (System Readiness Test) status for SMOG Check. I'm planning to upgrade in the future with real-time sensor display and the likes.