mckenziepiping

Hey all, I just got back from my regular garage for the 3rd time regarding the same problem and this time he said he simply can't figure out what's going on and doesn't want me to waste money by continuously replacing the same part without addressing the root cause. He advised me to try gaining some insight from forums and/or bring it to the dealership for a diagnostic. It seems as though something is causing my crank sensor to go bad repeatedly. Each time I replace it, the car works well for some time and then the sensor goes bad again.

About 4 months ago, the car start exhibiting 3 symptoms that will always start intermittently while driving and after about 10 min of driving, they happen consistently:

1) Inability to exceed 3000RPM. Once I hit 3000RPM, any attempt to give it more gas will just make the car stutter and I won't get any extra acceleration. If I want to speed up after hitting that RPM, I need to upshift. This also means the car can't go faster than 90km/h (55-56mph) because that's when I hit 3000RPM in 5th gear.

2) When I depress the clutch or otherwise shift into neutral, the engine stalls. Sometimes it'll even stall when I'm rolling at high speed if I depress the clutch and don't shift quickly enough. After stalling, I can start the car again easily by turning the key.

3) At all RPM's below 3000, there will be random stutters that are short-lived. Not like the ones at 3000 which will last for as long as I keep the throttle open to maintain those RPM's.

These symptoms never occur within the first 5 min of the first drive of the day (unless it's really hot outside). They only start once the engine has warmed up. I'll try to take a video and post it here soon.

When this started happening, I brought it to my mechanic and the code said crank sensor fault so he replaced that. Then the car worked fine for 2-3 days until the same problems started happening again. Same code so he replaced the crank sensor again (didn't charge me for it, since we figured the new crank sensor must be a lemon). Then the car worked perfectly well for 5000km (~3000mi) until a few days ago when the problem returned. We haven't even bothered checking the code this time because of the highly specific nature of the symptoms being exactly the same as the previous times.

Most of the explanations I can find online regarding other issues that can cause a crank sensor to fail seem inconsistent with the fact that the most recent replacement bought the car so much time & distance.

Anyone have any ideas?

claymore

Has your car ever been serviced for Valve clearance? Out of spec occurs frequently and will cause those symptoms.

mckenziepiping

The valves were done 3 years ago (at 280,000km / 174K mi) and now the car has another 100,000km / 60K mi.

Could valve clearance issues make the car throw codes for crank sensor?

mckenziepiping

The nature of the issue has changed from the details mentioned in my earlier post. It's now very random. Sudden and short-lived hiccups/shakes when driving, followed by a stall once revs are low. Seems to be independent from the clutch and totally dependent on revs. The issue is temporarily remedied by turning off the engine and starting it again several times in a row. I've been finding myself turning off the engine while driving and then just bump-starting (dumping the clutch with the key set to position II) while in 2nd or 3rd gear, testing an aggressive acceleration and if problem recurs, then I just restart the engine and eventually it'll run just fine for hours. I just did a scan with my Bluetooth OBD and saw crank sensor again. But as explained in the original post, something keeps causing that sensor to need replacing repeatedly.

ricar

Pull the sensor wire out of the harness ad physically move it away from the other wires, specifically the Coils.

mckenziepiping

This is actually what I ended up doing and it worked

Zaif

Hi, i have the same issue, please spare some minutes and tell me how you separated the sensor wires? From ECU to sensor throughly or just you separate the sensor wires from coils area?

mckenziepiping

So I literally just unplugged the position sensor, plugged it back in, and looked at any wires that connect to the area and pushed them off to a different side..... and haven't experienced the issue again ever since. I didn't separate any wires. I left them all together but just pushed them to one side. I also didn't do anything with the ECU or under the hood.

Zaif

​​​​​​From separation i mean you kept the sensor wires off from the coils wire or just leave it as it was. What do you mean by pushed them to one side?

Zaif

I need full guidance on how to move the sensor wires to other side? Just move it from the rear coils area or move it away to ECU completely. Please help as I'm going to do this but stuck here.