2003 Dodge Caravan no knock sensor, my engine toast?

Tiny
DAVE101
  • MEMBER
  • 2003 DODGE CARAVAN
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 77,000 MILES
I purchased this vehicle two months ago. The engine has been making the marble knock sound when warmed up at idle. Engine sounds fine when cold at first start but as it warms up the noise becomes noticeable. I can't hear any knocking when I'm driving. Only when the engine is idle I can hear this sound and it is getting louder. No loud knocks, just sounds like more marbles. I have done research on engine knock to find out newer engines use a sensor for ignition timing. I thought mine might be bad so I wanted to check it. When I crawled under the van to remove the knock sensor, there was not one there. The hole had been plugged with a threaded plug. I then at that time came to the realization that this engine is possibly ruined. I do not know how long it has been gone. The check engine light is not on. I have noticed when I step on the gas there is no strong acceleration, it's slow to respond. Please tell me your opinion, when I put a knock sensor in will the timing be re-calibrated so this noise will be gone? Or is my engine beyond going back to normal and the damage has been done in which the sensor will have no effect?
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Sunday, March 23rd, 2008 AT 3:04 AM

3 Replies

Tiny
SERVICE WRITER
  • EXPERT
Is the wiring harness pigtail there for the sensor?

Can you talk to the previous owner?

A pinging engine can cause a variety of problems including headgasket failure.

IF the fuel isn't burnt effieceintly it may have damaged the converter.

When you first turn the key to the on position does the check engine light up for a few seconds?

Have you checked the pcm for any codes?
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Sunday, March 23rd, 2008 AT 6:54 AM
Tiny
DAVE101
  • MEMBER
Thanks for the reply Paul. I checked the codes and it read -1- -2- -3- then paused -4- -5- -ERR-. The check engine light does come on for a few seconds when I turn the ignition to start then stays off. There is a connector that is not connected from the main wiring harness that passes over the transmission on the backside. Looking at pics of the sensor for this engine, there is a wire that plugs into the sensor and the other end into what looks like the connector. I bought the van from a used auto dealer. I also have not changed the spark plugs yet but I did look at one and it is normal as far as heat wear but the electrode looked a little small and the gap looks wide. I did not check it. Is there a chance that maybe the plugs could cause this marble knocking? I am hoping for an easy fix. I know the knock sensor being gone is certainly not good. Thanks, Dave
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Monday, March 24th, 2008 AT 2:22 AM
Tiny
SERVICE WRITER
  • EXPERT
The plug gap is.048 to.053 and is a double platinum plug, so your description sounds about right. Those plugs do have a samller electrode and larger gap than a standard resistor plug.

I would definitly get the sensor installed first. The torque is important on these, it should be 7 ft lbs.
IF the torque is incorrect it can cause a misreading by the sensor.

The codes need to be pulled with a scanner. Sounds like the codes your pulling are the insrument cluster codes, which is different.
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Monday, March 24th, 2008 AT 5:25 AM

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