Knock sensor & Magnets

VWnoob · Post by **VWnoob** » Wed Apr 06, 2005 4:21 pm

Hey guys and gal, I have a simple computer geek question, that I need your help on.

Have you seen those magnetic oil drain plugs? Well I have something better.
I took the magnets off of an old SCSI hard drive and want to stick them to the bottom of my oil pan to collect any metal particals in my engine. As you know, these are some HARD CORE magnets!

My question is this... Will this interfere with my knock sensor? and does my year cabby, 86, even have a knock sensor?

I know its a ghetto fix but who looks at the oil pan anyways....

Jim

Post by **Calimus** » Wed Apr 06, 2005 9:36 pm

as far as I know, the JH engine (standard cabby 8v) doesn't have a knock senesor. I know that 16v engines do as well as the 2L 8v's.

As far as that magnet goes, I know all too well how power full they are, but at that distance, even if you did have a knock, it shouldn't interfer with it. The field on those magnets is only good for about 3-6 inches at best.

kda339 · Post by **kda339** » Wed Apr 06, 2005 9:47 pm

I really don't think it would interfer either way. I also belive you don't have a KS ingition system on your car since it is stock, so you should have no problems.

The Knock sensor is for the the high comp engines ie. 10.1 motors and the OBD II systems which control a little bit more than the standard CIS setup. As for the 8.5:1 motors of the 80's your safe to know there is not one. There is no ECM so to speak of like on the newer cars that control all of this.

Please if I am wrong let me know.

Thx -K-

VWnoob · Post by **VWnoob** » Wed Apr 06, 2005 11:11 pm

Cool! Thanks for the info guys!
I hope these magnets pick up every little metal sliver, but then again, I hope that it doesnt, ya know what I mean?

Jim

-vertigo- · Post by **-vertigo-** » Thu Apr 07, 2005 8:04 am

you're not wrong, there is definately no knock sensor on pre-1990 cabbys as stock. even if you did have one retorfitted (look on the front on the block, passenger side) then magnets wont prevent it from working anyway, especially at that range.

bubster007 · Post by **bubster007** » Sun Apr 24, 2005 8:32 pm

I am getting off the subject but I have a 91 Cabby and she has a knock sensor. I busted my exaust on a long road trip and the exhaust was touching the front sway bar. The vibration was extreme and audiable. I drove the car about two hours like this and I really drove her hard. I always heard that the knock sensor would pickup vibration and retard the engine but as far as I could tell, it did not retard the timing or change the performance of the car at all. That car runs like a scalded dog.

Moljinar · Post by **Moljinar** » Wed May 04, 2005 12:34 pm

Knock sensors use NO magnetic field. Magnets won't affect them. They are crystals that put out an voltage when squeezed. The "knocking" of an engine causes the KS to put out voltage that is read by the ignition module. Sometimes they ae TOO sensitive and overreact causing your ignition timing to run retarded more than necessary. This can be reduced by using an aluminum (ask Dean to pronounce this for you) mounting to dampen the vibrations to the KS. Techtonics Tuning has them ...

http://techtonicstuning.com/viewpart.as ... um=133.375

Post by **Calimus** » Wed May 04, 2005 2:29 pm

Very good info. An dean must be brittish, which means that he prnounces it Alu-men-E-um. Takes some getting used to, but after a while you don't even think about it when it's said that way.