Knock Sensore code P0325 in K2500 7.4

[WojTec]

Hi there !

I got a code P0325 - Knock sensor Bank1.
When trying to remove connectors from the knoc sensors both plastic lips got cracked. So I shortly decided to install 2 new sensors - I got NTK

You must be registered for see images attach

Instaled them both - and started engine with scanner. Code was gone... for a moment. And now is back.

When DTS is reseted it is comming back after first higher rev. Check Engine is not turning on. In Loging I can see that KS - is activelly retarding the ignition.... -4deg -5deg when reving.

So a question now - ECU does react to KS - and does retard ignition. I cannot here any strange noise from the engine.

I got NTK- Rock Auto show it as a match - and later on saw that OEM number on it is 10456232 ...when AcDelco Gold shows OEM number 19236387

What could be the scenarios:
1. Wrong pair of sensors ? Get the ACdelco then?
2. One or both sensors are correct type but just broken?
3. Accorging to Service Manual - if sensors are ok and wires are ok - replace the VCM (ECU)? - couldi it be like that?
4. Fuel is for sure ok (Euro 95 octane), new filter, new injectors Bosch, no missfires, no other issues, New sparks, new distributor and cables - that was done recentyl and there was no P0325.

 

[WojTec]

This is Ac Delco.
But NTK adn AcDelco are recomended by Rock auto to my ride. COuld it be an error by RockAuto?

You must be registered for see images attach

 

[WojTec]

This is Ac Delco.
But NTK adn AcDelco are recomended by Rock auto to my ride. COuld it be an error by RockAuto?

You must be registered for see images attach

 

[WojTec]

So, I checked that NTK are 8kOhms each.... is that correct?
I tessted them in vise - and max I got 0,4V ...so to less.

 

[WojTec]

Hi there,

I got othe set of 2x knoc sensors this time from AC delco.
Code is still on.
Look - the previous new sensors were NTK.
Tested them now again - both no reaction.

xc_hide_links_from_guests_guests_error_hide_media

I check wires to ECU - all good.

this is how engine sounds

xc_hide_links_from_guests_guests_error_hide_media

undercarriege

xc_hide_links_from_guests_guests_error_hide_media

and with 1400rpm

xc_hide_links_from_guests_guests_error_hide_media

I hear no knocknthere like rocker or lifter ...!!!

 

[WojTec]

Dear All,
Got confused! Guys help!

I will make small summary. Iam still with P0325. No MIL/CheckEngine light - but ECU is retarding spark using KR (Knock Retard) as a parameter - (above on the graph) to prevent detonation.
What detonation?

1. I hear engine running properly - no harsh noises. Tested for yoo on movie at 630prm - warm and 1400 - 1600 steady - no noises - according to me.

2. Output on ECU to supply KS is correct 5V

3. Resistance on each KS and with wiriening to ECU is correct - 8.1kOhm and 4kOhm

4. Groung to KS is correct / instalation was with 19nm / instalation was correct

5. Got 2 pairs of new KS - from NTK and from AC Delco. But look at the movie - both sets should give easily 1V over on testing - didin't. 2 pairs faulty? That get me confused.

6. I will add today Octan booster - just to see if there could be any fuel issue - but it is fresh and it is BP PB95 and new tank and new filter.

7. To be checked - I got my 1998 new FPR - to get 4.0Bar (before it was 3.5-3.7Bar with new Ac delco FPR). For my knowlage 4.0 is a correct one for 1998. I have new injectors (Bosh_, plugs, wires, rotor, cap)
Could change form 3,5 -> 4.0bar get knock sensor on or engine to knocking ?

 

[WojTec]

Any one ?
Any tip ?
Any sugestion ?

 

[Spareparts]

If the KS are over torqued that could be your problem. Carbon fowled cylinders maybe, Bad wiring, Low quality fuel, Poor spark, timing. You need to eliminate everything as a possible cause.
You might not hear it, but if the New AcDelco sensors are torqued correctly and registering knocks and all else is correct, you have an engine problem.

 

[Schurkey]

Or a wiring problem, or a faulty computer.

"I" would like to see the knock sensor signal graphed on a scan tool.

 

[WojTec]

Or a wiring problem, or a faulty computer.

"I" would like to see the knock sensor signal graphed on a scan tool.

Iam not GMT400 expert but my scan tool - that is HPtuners Scanner - has no such an input.
I can see only KR - knock retard - as prameter to the error code P0325