Trucho-951

The part number on my original 1986 Porsche 944 Turbo knock sensor: Bosch part number # 0261 231 001. Factory specified resistance: 270Kohm to 330 Kohm.

However, I replaced my knock sensor last June but all I could find listed at paragon is a newer model # 0261 231 006. The newer model seems to have much higher resistance is greater than 1,000 Kohm.

I am not sure if the replacement sensor uses a different technology, but my car runs normal again.

kasturbo

HOLLY COW....My car is now alive. It has never felt better. You can now feel when it hits the upper wot maps. Throttle response is awesome.

Thanks all for the help.

Kyle Donley

Good to hear Kevin, I was a little dissapointed at the last dyno run. I guess now we know why.

MM951

Bump. I am having similar problems (even bought 2 new knock sensors with the same 4.8 mega ohm problem) - does anyone know why replacement knock sensors are no good and does anyone have a spare knock snesor that reads 280-330 k ohms?

Josh B

Thought I would add to this thread as well. Apparently the newer knock sensors have a higher resistance than the older ones...

Motosport

This sounds very much like my car has a similar problem.. Its a '89 951 S and seems to run fine with smooth power build up when just cruising. But it just doesn't make enough power in the upper rpm range and gets absolutely terrible fuel economy. Even when just cruising and staying off boost it can only manage about 13 mpg. Which here in Europe with gas prices of around $8 pr gallon is not good..

So I had the car dynoed and it could only manage 191 rwhp, and topping out at only 4800 rpm. Same story with torque, only managed 315 nm - sorry, don't know what that is in non metric value - and torque topped out at a measly 3550 rpm. Both power curves looks nice on the print out though, the power just tails off to soon with the consequent low output it seems.

So could the knock sensor be the culprit here as well, or should I look for other problems.?

Thanks - Alex.

Techno Duck

Was doing some reading about knock sensors and found the data sheet that should answer the question about the resistance across the 0 261 231 006. Basically it just seems the 006 sensor superseded the 001. The resistance you should see across both pins on the newer 006 is somewhere around the 1M ohm range as noted in in the data sheet under self-impedance.

What i found interesting is i replaced the sensor on my '88 when i did my rebuild a few weeks ago. The sensor i pulled off was the newer 006 one, not the 001. I have very detailed records of this car going back almost 17 years and so no mention of it ever being replaced. I wonder if what i pulled off was original or not.

Oddjob

Probably original on an '88. My early 89 (6/88 build date) came with the late style knock sensor. My 87s had the early ones. Cant remember for certain, but think my spare 88TS motor also had the later style.

According to PET, the PN 944 606 145 00 was used for M44/51 engines and the S/S2s, and 951 606 141 00 was used for M52 engines in MY89-91, but the 951 part is now N/A and superceeds back to the 944 606 145 00 sensor - not sure how those PN's correspond to the bosch 001 & 006 parts, as PET seems to incorrectly indicate the early part is still available, and the late one is discontinued.