Knock sensor


I have a 1997 villager/quest 140000 mi. It stopped dead in the road while driving and won't start. The OBD 11 flashes 3 long 4 short indicating a problem with the knock sensor. I have voltage at the conector but no change in reading when engine is hit with a hammer. Is it possible for the knock sensor to disable the engine if it goes bad. I understand that it controls the timing. When cranking the engine sounds like it's trying to run for a couple turnes after letting of the starter. Should I be looking at the timing belt? The engine has spark and spraying cleaner into the intake has no effect. I'm trying to find an easy answer before I take the top off the engine to replace the sensor. Thank you in advance for your attention to my problem.

Do you
have the same problem?
Wednesday, May 9th, 2007 AT 11:57 PM

1 Reply



The knock sensor will not disable your vehicle its purpose is to retard the ignition timing when it senses a detonation/spark knock/pinging

You stated putting cleaner into the intake has no effect and also has spark. If compression and fuel were okay it should fire and start.

If its a distributor system-unclip/unscrew the D/Cap while cranking the engine is the rotor spinning? If not investigate the T belt/chain.

Rotor spinning could be a valve and ignition timing problem that's preventing it from starting up.

Check the fuel pressure and comeback.

Was this
Thursday, May 10th, 2007 AT 12:26 AM

Please login or register to post a reply.

Recommended Guides