I read in a few places on the forums that SU7012 can be used in lieu of the much more costly SU7015 my '99 XK8 calls for. $30 vs $105.

Rolled the dice and bought 2 of them and can confirm they seem to work properly. Torqued them down properly (can't remember the spec) and have driven the car a dozen or so times since installing and haven't seen any knock sensor codes since then. Try at your own risk, but working for me so far.

 

I swear I hear knocking from my engine every once in a while. Can the sensors malfunction without throw a code? I'm desperately trying to avoid kicking myself for not putting new ones in when I changed my valley hoses.

Make sure you post this info into the Alternative Parts Thread.

 

I don't know enough about the ECU to say if they could miss a knock. If you download the Torque Pro app and run with an OBD II Bluetooth sensor, you can add in their knock sensor module. It might just rely on the installed knock sensors though... Somebody smarter than me on this stuff should know more.

 

He should test the sensor to check if its working?

Does anyone know where you can find the SU7012 $30 sensors in canada? I have been getting quotes around $150 "each" area.
I may need to drive to Michigan.

 

Have you checked your fuel trims? I had knock when my LTFTs were in the teens. Plugging air leaks brought the trims back down to low single digit, and the knock is gone. Yes, this is without codes. Worst was low rpm going uphill (high load, low rpm). Obviously, the load has to be low enough not to kick into a lower gear and bring the rpm up.

Best of luck, keep us posted.

 

Odd that you would bring that up. I've got my LTFTs down to around 10. Not bad for a 130,000 mile engine in a 215,000 mile car. But I just discovered some micro cracks forming in the bellows of my snorkel. I'm going to wrap the entire bellows section in self sealing tape which will seal all the cracks and "should" maintain some flexibility. If the snorkel had actually been leaking, this might bring my trims down to single digits. We'll see.....

 

Around 10? Way too high.

 

Hi John. Agreed. But the right side LTFT used to max out at 19+, with the left side around 12 (and of course that would throw OBC codes). Replacing every seal and gasket in the induction system, improving the Brake Booster vacuum line connection to the elbow, and replacing a cracked EGR pipe brought the Trims way down. I haven't had a code in 18 months and my gas mileage is superb. So long as all the spark plugs look good I know the ECU is maintaining a proper mixture across all eight cylinders, and the world is good. Sealing the snorkel bellows should drop the Trims even farther. I'm really not worried about a thing, and considering how many miles are on the car, I'm ecstatic about how well she runs.

The potential knocking concern may be nothing as well. It may even just be psychosomatic because I've been kicking myself for not replacing the sensors while I had the top of the engine apart.

 

I now see why you'd want to live with it at 10ish.

 

Haha, ... yup - I have no problem at all. We both know there are pampered cars out there with a quarter of the miles I have that don't run that well. I've got to figure that sooner of later either the transmission or the differential will explode - those are "really" my most likely concerns.