Porsche 944 - Crankshaft Position Sensor Testing & Replacement Tutorial

[@chabat124]

Your productions are very good. I always appreciate the quality of your content, especially how you are a documentarian as you walk us through the repairs, giving specific details. It was good you showed tach bounce as a lot of people think it is going to bounce much higher because they don't know what they are looking for. A lot of people replace parts that don't need replacing, hoping to get lucky. It's not terrible with cars this old, but teaching people to actually diagnose... You're teaching them to fish. Thanks for serving the 944 community.

[@NC944er]

That’s high praise sir, thank you! I think it serves a niche community at this point, but it also seems to provide tremendous value to those who are part of the group.

[@jeromefressancourt8121]

Greatly valuable information for 944 owner community !! Many thanks for your work on this channel !

[@estanisqss2216]

Just bought an 85 944 and discovering this channel has saved my life. Top notch content 👌 please keep it up!

[@NC944er]

Nice, congrats on the purchase! Certainly a lot to learn my friend! Glad the content is helping you get started. Cheers!

[@liamflynn6929]

One tip- stuff a rag into the flywheel inspection hole whenever you're working near them. This will prevent any bolts from falling into the bell housing

[@NC944er]

Yep, or a small piece of painters tape. 👍🏼

[@johncooper7242]

what an excellent detailed comprehensive yet easy to follow video tutorial . This is so well produced that i don't think that I shall be making any more of my own. Thank you NC944er

[@NC944er]

Thank you! I certainly wasn’t trying to discourage others from producing content, but I appreciate the compliment. There isn’t a lot of info out there on the S2 cars, so I’m sure you could still add some useful tips to the existing body of work. Cheers!

[@laglord]

Great video as always! I had such a time with this job when I first got my car. It was hard diagnose in the first place because the sensor wiring was damaged INSIDE the connector, but looked fine. When I finally got the repair done, I ordered a replacement locking bolt for the bracket from a parts outfit, and they sent an M7 instead of an M8. A minor visual difference that translated into a stripped eyelet on the car before I knew what was happening. I have to run a nut/bolt/washer combo for the lock now, making an already fiddly job even more so. I don't buy from that parts outfit anymore.

[@NC944er]

Oh man, that sounds terrible! I won’t ask who the parts outfit was, but I have a couple ideas from my own experience based upon similar part mis-picks. 😂

[@ThingsBreak]

Great overview! I recently changed mine for preventative maintenance since they are known to fail. They were quite difficult to remove even with a makeshift slide hammer on locking pliers...but I got them out!

[@NC944er]

Yeah, you can spend 45 minutes to an hour removing just one sensor if it’s really jammed up. Pretty ridiculous. 😂

[@Cad1900]

This is an outstanding video I learned some things I didn’t know thank you 🙏. Replaced mine about ten years ago and I’ve been worrying about them lately haha

[@NC944er]

Thank you! Everything on the car worries me… 🤣

[@jsm0m]

Your videos are always 🔥 always a good watch! Thank you for your continued education! Love this channel!

[@JGStone]

Very nice instructions here and fortunately apply to my 1983 S1 too. Now, I am just a little concerned. Both sensors measure 850ish ohms on the first two pins and the same on the dme connector. But the over 1 million both give back a 1 as a reading so nothing can be measured. Now am I too stupid or are they just both gone? Used the 2000k setting on the multitool. Cars symptoms so far are a hard start and turning off after few seconds again, and the crank sensors are the last thing I had yet to test.

[@NC944er]

@@JGStone The “over 1 million ohms” is synonymous with an infinite reading on the meter, and it sounds like that’s what your getting, if the other reading the within spec, they’re probably ok.

[@JGStone]

@NC944er Aight thank you m8, guess I will just take em out and continue visual inspection, kinda hoping they are busted so I have finally solved this cars mystery.😅

[@JGStone]

@NC944er After visual inspection while taking both out, they both look fairly new... and rpm gauge does work, so I think I'll switch the two sensors and see if something changes.

[@glow9999]

Great videos, as always. That speed reference cable, is this what gives you the rpm on the tach? My tach not working. Everything else seems to be running properly.

[@NC944er]

The speed sensor counts the teeth on the flywheel and sends this signal as pulses to the DME computer to determine engine speed in RPM. The DME then sends this data to the tachometer gauge on the dash. If the speed sensor tests good and the engine is running fine, you’d want to inspect the tachometer gauge and related connections and electrical components.

[@glow9999]

@@NC944erThankyou for your response. I’m getting zero readings at pins 8/27, and 25/26 at terminal under passenger dash, with battery disconnected. No problem starting, so does it appear that the probable cause of the tach not working, is a wiring issue? If so, I will need to find a way to take instrument cluster apart. Downside is that I have dual air bags, and it’s a pain getting dash out with steering wheel in the way. So frustrating, but so rewarding when it’s solved.

[@NC944er]

@@glow9999 If the engine runs, you should get a reading across those two sets of pins. Maybe the test leads couldn’t get far enough into the connector? At any rate, those are the pulses from the sensors to the DME computer, the computer then sends a separate signal to the tachometer gauge from another pin on the connector. Could either be an issue with that wire, pin, or the tach gauge itself. Most often it’s the gauge. There are a number of different components on those boards that can burn up, get oxidized, or have cracked solder joints.

[@phil6012]

BMW used the same sensors, only they had longer leads and were half the price. The Bosch sensor is the BMW sensor with the 610mm lead. OE is around 400mm. BMW part number 12-14-1-708-619-M14. Recently found your channel and am enjoying the content. Brings me back a 15 years ago when I started building my 951.

[@Oncewaslostbutnowimsaved]

What does it mean if I'm getting 0 reading from either plug from either sides of the cables? I could see 1 cable going bad or even 2 but no reading from all 4 connections from both cables both ways is mighty sus.

[@gawsies]

Going to check the sensors this weekend! Does it need to be gapped still even if I’m just changing the sensors?

[@NC944er]

Nope, as long as the bracket was correctly gapped beforehand, the sensors can simply be swapped out with the bracket in its existing position.

[@gawsies]

@@NC944er awesome thank you!

[@Oncewaslostbutnowimsaved]

You earned a like and subscribe 🎉

[@nickfarrow9032]

My car runs fine, but I have no tach activity at all. No bounce on start up and no movement at all while the car is running. Is it likely to be a speed sensor issue, or should I look elsewhere?

[@NC944er]

Hey! So while the speed sensor determines the RPM, which is sent to the DME, and then the DME sends a signal to the tachometer gauge, if the speed sensor has failed, the engine would run VERY poorly if at all, because the DME wouldn’t have a reliable signal to correctly apply fuel injector cycling. So in your case, I would look at the tachometer itself… sometimes the connections behind the gauge cluster can become corroded or the pins get pushed out of the plugs, so they have a poor connection with the gauges. The circuit boards for the tachometer also have components that can burn up or a failed circuit trace. You’d have to pull the steering wheel off and then remove the gauge cluster to get in there and inspect for those issues. If the tachometer checks out ok, there could be an issue with the wiring that leads from the DME to the gauge cluster.

[@nickfarrow9032]

@@NC944er awesome thanks chief, you're an absolute legend!

[@RichiWang-ef4mp]

Is it necessary for the bracket that holds the 2 speed sensors to be bolted to the intake manifold for the car to start? I'm having a no start situation. New Focus 9 DME relat installed toaay. New speed and ref sensors have been ordered, arriving next week.

[@NC944er]

No, the wiring connector bracket doesn’t need to be bolted up for the engine to run, just that the sensors are properly connected. If the new sensors don’t resolve the issue, I’d check for spark and fuel. Here is a helpful resource to get started - www.clarks-garage.com/shop-manual/ts-01.htm

[@RichiWang-ef4mp]

Awesome thank you, much appreciated, very helpful. Does the sensor need to be regapped if the bracket wasn't loosened? Can I only unbolt the sensor and drop in a new one?

[@NC944er]

@@RichiWang-ef4mp Yeah, in most cases you can leave the mounting bracket adjustment as it is and simply swap out the sensors, unless you have reason to believe that it’s not adjusted correctly or was taken off for other recent work like a clutch replacement, etc. If the car was previously running fine with the current bracket setting, you should be good to leave it alone.

[@zachnorman4234]

My Friend just bought a 1988 924s. We have replaced the Ignition coil, Distributer Cap and Rotor. The new coil tested positive for 12v. We also replaced the plugs and wires. Still no spark. Any suggestions for the next step/ test to run?

[@NC944er]

Have you tested the speed/reference sensors? Are you seeing tach bounce when cranking the engine? Is there a factory alarm installed on the car? If so, have you bypassed the control module to rule that out? The DME Computer is another possible suspect. Here is another resource to help start diagnosing “no start” issues: www.clarks-garage.com/shop-manual/ts-01.htm

[@zachnorman4234]

Thank you we will try those! We will keep you updated!

[@grkfrk04]

Awesome video. Abrupt ending lol

[@NC944er]

I’m trying to cut down on the fluff. 😂

[@gibso]

I dropped my bolt and I don’t know if it landed in my flywheel inspection hole I can’t find it anywhere it’s not on the floor😪

[@NC944er]

That sounds super annoying! There are quite a few little crevasses on that side of the engine where things can disappear. It may be worthwhile to poke around with a magnet to see if you can grab it. Also, you can look through the clutch inspection hole at the bottom of the bell housing and/or pull the starter off to get a view at the lowest point inside, see if maybe the bolt is hanging around down there.

[@gibso]

⁠@@NC944erpulled the starter off and got it thank you. I’m not getting any signal from the pins for the reference sensor at the DME. I’ve just replaced both sensors so I’m stumped. Hopefully not the loom itself

[@franksm2001]

Appreciated ! I know that sensor replacement and setup can be one of the more confusing aspects for 944 people

[@NC944er]

They sit in a terrible location for sure. 😂

[@franklinrondon5283]

Saludos. Si el carro tiene en sensor y los cables bien y a un no prende puede ser la computadora. Habra otro motivo para que corte sa señal positivo del Sensor.

[@NC944er]

Sí, en el caso de los sensores del cigüeñal, también es posible que el sensor en sí esté dañado o que el soporte de montaje no esté correctamente alineado.

[@franklinrondon5283]

Gracias

[@NC944er]

@@franklinrondon5283 De nada

[@pntntim]

I don't know how to measure 1 million ohms

[@NC944er]

It’s greater than 1M ohms, so essentially infinite on some ohmmeters. If you get a lower reading, you’ll know something is off.

[@THEPASSIONATEDRIVER]

hello, very informative videos. I have an 89 94s2 convertible and it stopped running some months ago but I didn't have time to work on it until now. Tried going through all the steps in this video but ran into a few issues. New DME relay, I only have one reference/speed sensor?? and my computer has three rows of pins?? (944.618.124.02)

[@NC944er]

@@THEPASSIONATEDRIVER Yeah, the general process here will be for the 8-valve engines, some of it will align for the S2, but not all. The S2 only has one reference sensor due to differences in the flywheel.

[@THEPASSIONATEDRIVER]

Ah I see. Thanks. Do you know which pins do I use to check resistance for the reference sensor on my 3 row pin connector?

[@NC944er]

@@THEPASSIONATEDRIVER Here are some shots of the S2/968 pinout diagram, check out 47 and 48... forums.pelicanparts.com/porsche-924-944-968-technical-forum/675801-944s2-dme-pin-out-diagram.html

[@THEPASSIONATEDRIVER]

Thank you