typeR

ive been emailing steve about an intermitatant CEL i get after ibstalling an off brand crank pulley...the code is read knock sensor...where is the KS located and might there be any other explainantions...bad motor mount...bad CV (vibration at speed) the pulley itself vibrating or rubbing against something...i should be looking at the car wednesday and hope to have some ideas of what to look for...

vuduvida

hey Steve, the service manual shows the knock sensor mounted on the top of the engine block, in the space between the cylinder banks, closest to the side of the block where the pulleys are. It's buried deep- looks like you'd need to remove the intake manifold and the heads to get to it.

Hopefully one of the other guys can chime in about other possible explanations for the code.

allmotor_2000

It's in the middle of the block - you have to take the manifold off to get at it.

There were some cars where mice kept eating knock-sensor wiring as its a nice warm place to snuggle at night!

allmotor_2000

BTW, a vad motor-mount or CV is not going to trigger a DTC from the knock-sensor!

typeR

thanks...might cleaning the engine with...de greaser like simple green at a coin opp doit? this also was when it happened?

Ant7701

yeah I'd remove that crank pulley if I were u...We've done many knock sensor wire harnesses that have been chewed by mice and like allmotor said it's ontop of the motor. If ur just replacing the harness u can sneak it out w/o removing the lower intake manifold. If you have to replace the sensor then u must remove fuel rails and lower intake manifold. But i think the pulley is warped which is causing the CEL to come on...have u tired clearing the code and re-installing the stock pulley to see if it comes back on??

allmotor_2000

If you are getting such vibrations as to set off a knock sensor DTC... then your motor might have some significant damage - I'd try the stock pulley first!

EricL

Do you have the specific code?

typeR

the code is p 0325 if i remember correctly it reards circuit malfunction..bank 1 of 1 knock sensor...i havent tried replacing the new crank with the o.e. but it's on my list of things to try...i have cleared tohe code several times and it always seems to re activate while cruising at low RPM at low throttle input after having been driving aggressivly...and it will not trip for days if i keep the revs up...i.e. driving in 3rd ...i appreciate the help so far and ill have lots of ammo now when i look at the car tomowwrrow...if i dont see anything obvious ,ill try replacing the pulley first...

would therre be any reason why an under powered battery would be envolved? ive been driving around for 2 months also around when this started on a 240CCA battery light weight 20lbs...the car starts every time doesnt seem to be an issue but just throughing stuff out there...

the thing i want to be most clear is...though soe of these thing coincide the few minutes following the install i got a gflashing engine icon ...probablly temp mis fire,and the next night i got the CEL so i feel it's related to the pulley and or it's install ...thanks for the help guys

allmotor_2000

It could just be a bad knock sensor? Maybe mice have eaten the wires?

typeR

i suppose anythings possible...but ive never seen a mouse...but it did start imediatly after the install...and i did hit the o.e. pulley with a tourch trying to break it free...

EricL

HELMS: DTC P0325: “Malfunction in Knock Sensor Circuit”


1. Reset the PCM (see page 11-3) [You already did this]

2. Start the engine. Hold the engine at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on, then let it idle.

3. Hold the engine at 3,000 – 4,000 rpm for at least 60 seconds.

Is DTC P0325 Indicated?

YES – Go to step 4.

NO – Intermittent failure, system is OK at this time. Check for poor connections or loose wires at C103 (located at the right side of the engine compartment), the knock sensor and the PCM.

4. Turn the ignition switch OFF.



… You have clearly described an intermittent – according to the service manual -- and I haven’t shown the rest of the Helms’ diagnostic procedures/steps.


Some questions for you?

Which pulley are we talking about? UR? Not-UR, then ???

Did the problem happen right after installing the new pulley? I believe you said YES, but I want to be sure.

Can you setup the car to idle at 3000 or 4000 rpm with NO load and see if the problem shows up? IOW, can you eliminate the engine load as possible contribution to the problem? AND, IF you are actually finding the problem at lower RPMs (lower than 3-4K rpms), can you get the engine to just run at that speed (xxx-rpm) for some extended period of time to eliminate the engine load?

If the sensor was bad, you would be getting the error code all the time. (Not just intermittently).

If the wires were cut or shorted I would expect the error code to show up all the time (Not just intermittently).

If you have a resonance or jitter that is being caused by the pulley, it can cause you get “falses” for misfires. The engine management system looks to the CPK (Cylinder Position Sensor) for its timing information, and if it see fluctuations in the engine speed over a revolution, it will consider that this is caused by a misfire. (If every spark isn’t happening at the right time, and with equal strength, the pulses arrival are “skewed” and it’s like hearing wow and/or flutter in an old tape deck.)

It's very interesting (at least to me) that you got the misfire indication AND the knock indications AFTER you popped on the pulley? (Did I get that wrong?)

That jitter could also cause the knock sensor to hear resonances that could be interpreted as “too many knock events”; add in spark scatter (of a sort), and it could get messy.

You might want to try the stock pulley. Maybe some more people will chime in on this…

YMMV

typeR

ill do the above test...the pulley is not UR...last the first few seconds after the install...i took it out and got on it...the check engine icon flashed several times...was told this was "temp mis fire" but no code was set...the next night started my first CEL when it first comes on VSA lights up too...then after you restart the car just the CEL then after a few cold cycles that goes away but is still stored...also ill mention that when installing the pulley we pulled the fuses for the ignition and the fuel pump...ill check for bad connections there also...thanks...

typeR

did the above test and no DCT...next ill try driving and see what happenes...if it sets then ill put the old pulley back on...BTW i think my pulley is by OBX... i should mention that i looked for any connectors and made sure they were all connected just by pushing on them...however im not sure where C103 is?....right side from facing the engine or from inside the car?

EricL

Curious:

How hot did you get the pulley?
How hot did the surrounding area get?

Was the pulley and/or surrounding crank area "baked" or "cooked" with that torch.

typeR

the pulley is 8 lbs of cast iron...i maybe held the tourch on it for as long as 30 seconds at the most...and concentrated on the bolt that held it on...

EricL

Never mind...

The only concern is the magnetic timing sensor, and how they tend to get messed-up with a lot of heat...

typeR

i drove around for a while today ,and it didnt throw the code...but ill hold off judgement until i drive around for longer tonight...BTW where is this C103???? what am i looking for

typeR

another thing...i know the crank pulley isnt anywhere nere the KS but how close is the power steering pump? we had to loosen that and undo that near by side motor mount...could i have loosened a connection or pinch a wire there

Ant7701

Possibly...the ks harness is located right behind the power steering pump. If ur looking from the right fender into the engine that is. Check them out. How is ur idle w/ the new pulley on??

typeR

the car runs perfect...however it is much faster right after an ECU clear then when the code is tored even though i dont notice a difference...what about this C103 location?

EricL

The crank pulley may not be near the KS, but it is near the CKP sensor. The CKP sensor is sitting right behind the crankshaft pulley. Engine heat == ok. Really hot can mean possible “soft” failures.

I don't know how close the wiring is to the steering pump.


RE: C103

Boy, the picture is small. Here is the page if someone can scan you the page in the Service Manual (mine is the 2001 version). On page 22-18, they list the Engine Wire Harnesses in a table; here is one row of the table:

Engine Wire Harness (cont’d)

Connector or Terminal: C103
Ref: 50
Cavities: 1
Location: Middle of engine compartment
Connects to: Knock sensor sub-harness

And, here are two rows of the second table on the page titled:

Knock Sensor Sub-harness

Connector or Terminal: Knock Sensor
Ref: 44
Cavities: 1
Location: Middle of engine compartment
Connects to: <BLANK>

Connector or Terminal: C103
Ref: 50
Cavities: 1
Location: Right side of engine compartment
Connects to: Knock sensor sub-harness


On page 22-19 (2001 CL/CLS Service manual) they have a wiring diagram (pictorial).

Ref 50 (the C103) may be hard to see (I’m not sure from the drawing).



The schematic shows the wire connection in a way that lead me to believe that your looking for a shielded cable (coax?, etc) If that’s the case, a bad/loose connection would really cause you some grief and it would probably show up an intermittent connection/noise..