GolfGTIforum.co.uk
Model specific boards => Golf mk7 => Topic started by: GTIlad on 24 May 2023, 15:19
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Hey guys I'm wondering if you can help me diagnose what's going on with my new (to me) GTI MK7.
I had a CEL come on earlier this morning, took it straight to a garage to have the codes read. Car runs absolutely fine no limp mode / hesitancy or lumpy idle etc.
Garage found the following fault codes on the car:
14865 (P036500) Camshaft position sensor 'B' circuit (Bank 1) (Sporadic fault)
14873 (P036600) Camshaft position sensor 'B' circ. (Bank 1) Range / Performance (Sporadic fault)
Garage cleared the codes and I drove the 2 miles back home without the light reappearing. They advised me the car is probably OK to drive unless the light reappears - which I suspect it will.
Unfortunately the local VAG specialist is booked up for 3 weeks so I can't get a gauge of what I'm dealing with until I've had a proper diagnostics performed. Obviously that's quite far away so was hoping someone with some knowledge about these cars may know the issue or be able to recommend a fix. Not too keen on driving the car until I have a bit more insight into the error codes.
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Google it, probably a diy job.
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Cam sensor is just to the right of coil pack no 4 (no 1 is oil filler cap end), make sure it's plugged in, no obvious damage to the wiring, etc.
Unplug, undo the retaining bolt, pull out sensor, replace.
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Cheers guys.
Have had a look at the sensor and checked its resistance and did the same for sensor A - both have exactly the same resistance value. Therefore it seems unlikely it's a sensor issue although there could be more to it than that.
A good friend of mine who's a mechanic is pretty sure I may have a timing chain or adjuster issue due to the two fault codes.. Hence why I'm very cautious to drive the car.
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I would think if you had cam chain/adjuster issues you would be seeing fault codes relating to the 2 cam sensors, one on the inlet cam, and one on the exhuast, as it would be out of phase (timing) on both cams.
Have you checked the inlet cam sensor as its below the inlet manifold??
The fact you have checked the resistance i would discount as you say the fault is "sporadic" it may read ok when you test it and be breaking down when it gets hot for example.
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I have checked these two sensors on the diagram attached at bottom of post. Sensor A8 and A5.
I’m pretty sure sensor A5 is the inlet cam sensor (sensor A) ? and Sensor A8 is sensor ‘B’ - the exhaust cam.
There is some oily residue in the area of sensor A8 as it is immediately below the oil filler cap. Perhaps this could be causing some issues with the sensor.
I see what you’re saying regarding the sporadic terminology of the faults.
Also, I’m not sure if this is relevant but the CEL initially came on after I turned onto a very tight, very steep 1st gear turn at a junction. Although just to reiterate the car is running fine and isn’t making any strange rattling noises at idle or when being driven.
Cars can be such a pain :angry: Only picked this up on Saturday and it’s been an absolute riot to drive so far!
(https://i.postimg.cc/HsDq54BT/IMG-1399.jpg) (https://postimg.cc/NLDCvX3n)
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A5 and A8 are the camshaft adjustment valves, not the cam position sensor.
You need to look at the sensor just to the right of coilpack 4, held in with a small torx bolt. (Disregard the number on the picture next to the coil pack, thats for the manual description, thats coil pack 1)
Item 6 in diagram exhaust cam sensor.
Item 9 is inlet cam sensor.
Item 12 is crank sensor.
Item 2 is knock sensor.
(https://i.postimg.cc/MGSM5LMQ/Screenshot-2023-05-25-093735.png) (https://postimages.org/)
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Not sure what fault code reader you have. With vcds you can measure the cam timing phase difference - engine up to temperature and running. Would check this after testing the cam position sensors. Indicates chain stretch or faulty tensioner.
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A5 and A8 are the camshaft adjustment valves, not the cam position sensor.
You need to look at the sensor just to the right of coilpack 4, held in with a small torx bolt. (Disregard the number on the picture next to the coil pack, thats for the manual description, thats coil pack 1)
Item 6 in diagram exhaust cam sensor.
Item 9 is inlet cam sensor.
Item 12 is crank sensor.
Item 2 is knock sensor.
(https://i.postimg.cc/MGSM5LMQ/Screenshot-2023-05-25-093735.png) (https://postimages.org/)
Thanks a lot for this, very helpful. Been looking in the wrong place the entire time!
I've had the exhaust sensor (sensor B) out for an inspection and all looks OK. Was pretty stiff to remove once the plug was disconnected so the O-ring is doing its job nicely. Can't see any sign of anything wrong visually. Not really sure how to test it with a multimeter as it's 3 pin - any ideas?
I didn't bother removing the intake sensor (sensor A) as it's a lot harder to get to. Until I can find a way of testing the sensors then getting the intake sensor doesn't make much sense.
Not sure what fault code reader you have. With vcds you can measure the cam timing phase difference - engine up to temperature and running. Would check this after testing the cam position sensors. Indicates chain stretch or faulty tensioner.
This is good to know, thank you. I've just ordered a Ross-Tech VCDS HEX-V2 which should hopefully arrive tomorrow. Have you perhaps got a link or can offer any guidance on how exactly I can check this? I've never used vcds before so going in as total noob.
I'm considering driving the car around later on this evening and seeing if it throws the code again.
(https://i.postimg.cc/L5GJYckB/IMG-1403.jpg) (https://postimg.cc/QKk8vnyH)
(https://i.postimg.cc/zDQbchmb/IMG-1404.jpg) (https://postimg.cc/CdjxZzxS)
(https://i.postimg.cc/4Nh7k3Z8/IMG-1405.jpg) (https://postimg.cc/hfcPVcXx)
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Just been to dealers for a new sensor. Will install and see if CEL comes back. Either way will attempt to check the timing / cam position on vcds once my cable arrives.
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Just been to dealers for a new sensor. Will install and see if CEL comes back. Either way will attempt to check the timing / cam position on vcds once my cable arrives.
How much was the cam sensor if you dont mind me asking??
Let us know if this cures it.
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£66 with the VAT. Saw some cheaper aftermarket options but when it comes to sensors etc I always go OEM.
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£66 with the VAT. Saw some cheaper aftermarket options but when it comes to sensors etc I always go OEM.
Very sensible.
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Not sure what fault code reader you have. With vcds you can measure the cam timing phase difference - engine up to temperature and running. Would check this after testing the cam position sensors. Indicates chain stretch or faulty tensioner.
There are a number of videos on the net just search vcds engine measuring blocks. The blocks you need to check are the group 90 to 98 and I think one you want for cam phase is 93. Measure with the engine warm and at normal idle speed. The reading will not tell you the wear on the chain or tensioner only the stretch.
Found this a while ago when checking my mk6 gti EA888 from the Skoda forum so the values may not be correct for mk 7 engines:
How to diagnose a chain stretching? Connect VCDS ---> go to Block - 1 (engine) ---> measured group ---> 93 group ---> Phase Position. What is the angle of misalignment of shafts critical for us? 0 - 2 degrees - a value characteristic of the new machines, or machines with the new circuit; 2 - 4 degrees - the recommended chain replacement value at which you can hear a clear metallic ringing of the left side of the engine))) 4 - 6 degrees - Urgent replacement or dumb luck.
Hope the cam sensor sorts your problem.
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Not sure what fault code reader you have. With vcds you can measure the cam timing phase difference - engine up to temperature and running. Would check this after testing the cam position sensors. Indicates chain stretch or faulty tensioner.
There are a number of videos on the net just search vcds engine measuring blocks. The blocks you need to check are the group 90 to 98 and I think one you want for cam phase is 93. Measure with the engine warm and at normal idle speed. The reading will not tell you the wear on the chain or tensioner only the stretch.
Found this a while ago when checking my mk6 gti EA888 from the Skoda forum so the values may not be correct for mk 7 engines:
How to diagnose a chain stretching? Connect VCDS ---> go to Block - 1 (engine) ---> measured group ---> 93 group ---> Phase Position. What is the angle of misalignment of shafts critical for us? 0 - 2 degrees - a value characteristic of the new machines, or machines with the new circuit; 2 - 4 degrees - the recommended chain replacement value at which you can hear a clear metallic ringing of the left side of the engine))) 4 - 6 degrees - Urgent replacement or dumb luck.
Hope the cam sensor sorts your problem.
Thanks Joe6. Managed to find the value with your help. As it’s a EA888 Gen 3 I’m not sure how relevant the numbers are given all the guides and posts I can find on the subject are for pre MQB cars.
Here’s what I found anyway.
Camshaft intake phase position -0.3 deg
(https://i.postimg.cc/8kdPTdVJ/IMG-1444.jpg) (https://postimg.cc/QVtrbTCh)
Will report back if the fault comes back. Hoping it was just a duff sensor, will get the timing checked anyway in a couple of week for piece of mind. When buying used cars you never really know the history / reason for sale..
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Early Mk6 had chain and tensioner problems, hence the obsession with phase values. -0.3 sounds a good value.
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Any updates on this?? Did it cure your problem??
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Any updates on this?? Did it cure your problem??
The CEL has not come back since replacing the sensor and I've done a fair bit of driving since then, so I'm pretty confident it's been solved :smiley:
Would have thought if it was something else the light would have come back by now..