Autoquip

Unfortunately some folk don’t realise how difficult cars can be nowadays. I’ve been caught out in the past. I have my own garage and I try to diagnose everything without throwing parts at it. It’s not always easy and sometimes you have to admit defeat. But it’s nice to get a win now and again. This post has helped a few folk and I’m sure there are a lot more helpful posts on this forum as there are some very knowledgeable folk on here.

Hi dani19 sorry I’m not great with these forums. you can get it from the top, I had to use an inspection camera to help locate it. It’s on the passenger side of the engine and it points into the flywheel. Best way I found was to take the sensor out with the plug still attached as I couldn’t get in to unplug it, the bolt is captive in the sensor I’m sure. Then once it’s out plug the new sensor in and feed it back in and tighten the bolt. Might make life a little easier if you remove the header tank but I managed without removing it. let me know how you get on 👍

Hi Craig. Sorry I’m not great with these forums, sometimes I miss the messages 🙄 that’s great. I’m glad my post has helped 👍

You don’t have to tell me about rain. I live in Scotland 😂 let me know how it goes 👍

Used a camera 🙄

It’s on the passenger side of the engine. Points at the flywheel. It’s pretty buried. Might be easier to take the coolant bottle out. I ideas a camera to help me locate it. It’s done from the top.

Hi Craig. It’s a bit awkward but the best way to do it is to leave the plug on the sensor, loosen the bolt and take the plug off the sensor once you have it out. I bought my sensor from Audi and I’m sure the bolt is captive in the sensor. Do you know where the sensor is located?

Hi Toby, that’s great news! It’s certainly a strange one and to be perfectly honest if my car had came into my garage I wouldn’t have gotten to the bottom of it I don’t think. I would have told my customer to take it to Audi. The only reason I persevered for so long was because it’s my own. Would have been so easy to load the parts cannon and take aim but I don’t do that if I can help it. just for future reference I’d have fixed it for you for £1500 😂 Glad I could help and hopefully more people see this post and it helps them too. take care Davie 👍

Yeah unfortunately mate. Hope you get it sorted

Hi Toby. Are you just outside London? If so it’s at least a 12 hour journey to where I am. 😳

I’m in Wick in Caithness. Where are you? im sure I could fit it for you no problem. If your willing to travel 👍

Car has been fine ever since I fitted the crank sensor 👍

No problem. Wanted to be sure it was a fix before I tempted fate

Hi mate. Turned out to be the crank sensor in my case. Pig of a thing to change, my car is the 2.0tdi ultra. if your going to change it, my top tip is unbolt the sensor with the plug still on. Fit the new sensor and then plug it in. An inspection camera helps. hope this helps, certainly cured mine.

Hi toby, sorry for the late reply, turned out to be a faulty crank sensor. Unbelievable how it never once threw a fault code. I changed it at the end of last week and it’s been fine ever since. Pig of a thing to change. Well I say that could probably do one in about 20 minutes now. Easy once you’ve done it. if your going to change yours my top tip is don’t try and unplug the sensor, remove the bolt and take the sensor out with it still plugged in. Fit the new one and then plug it in. An inspection camera helps, luckily I have one.

So the update…. last night I eventually got round to replacing the crank sensor. I’d like to take this opportunity to thank the team of designers for putting the crankshaft sensor in the most awkward place. however I got it done and will just have to wait and see if it’s a fix or not. I will keep you all informed in the coming days. top tip if anyone is going to try this at home. Don’t mess around trying to unplug the sensor. Take the bolt out (it’s held in the sensor so shouldn’t fall out) then unplug the sensor when you take it out. Fit the new sensor and then plug it in. myself and one of my mechanics both had a go at unplugging it but it’s not easy to get to. Now that I’ve done one I reckon 20 minutes would change it but it’s always easier the second time round.

Hi mate, yeah you’re spot on about the glow plugs playing a bigger part in modern engines and truth be told I haven’t checked them. Might look at them if the fault is still there, cheers for the info 👍 going to post an update in another message.

Just beats me how these cars can have so much fancy electronics in them and this sensor has been playing up for months and yet it has never put on the engine management light or a fault code. I’m just thankful it’s not a customers car because this would have taken hours upon hours of diagnosis and I would have given it back and only charged a couple of hours. Difficult to charge all the hours when you don’t have a solution.

Hi Brian, my car has manual transmission so sort of takes that out of the equation for me. my car varies to be honest sometimes it’s very slight other times it’s quite a jolt. I'm going to try and get it on a ramp this morning, I’ll post later and let you know what I find. cheers

Evening folks, so might have made some progress tonight. On the drive home I was monitoring and recording live data for various sensors. My wife was in charge of pressing the “flag” button if the fault happened. This time it did happen and sure enough poised like coiled spring my wife hit the flag button. When I played the recording back, at the point that was flagged there was a dip in both the cam and the crank sensor readings! So I nudged the readings frame by frame until I got the frame before the hesitation the frame at it and the frame after. Luckily I was also monitoring crankshaft signal status as on the frame before and after the hesitation it’s reading is GAP FOUND but at the point of the hesitation it’s reading is WAITING GAP. I’m not going to get over excited for now. However, at least that gives me a starting point. I’ll remove the sensor and check the ring and flywheel condition as best as I can and then I’ll order a genuine sensor from Audi. I’ll run the car for a week or so and then I’ll come back with an update. I’d say this rules out a fuel issue, if it was lack of fuel I would still expect it to see the gap for the crank sensor. The only other possibility I can think of is that something is switching the ignition off for a split second but how unlucky would I have to be for that? (I do have a lot of bad luck to be fair). My only slight worry is that it’s visible on the graph for the cam, in my head I can make arguments as to why it would and why I don’t think it should be visible on both graphs. But let’s start with the crank sensor and take it from there. very sorry for the extremely long post, I’m not on many forums, I think they are a great source of information and I’m trying to be as informative as possible. wish me luck 🤞 Davie 👍

Nope not yet 😡. To be honest I’ve been busy with other stuff the past few days so haven’t really been in the car. I’ll get the diagnostics back on it probably over the weekend. I’ll keep in touch 👍

Hi toby, thanks for the reply, i certainly will let you know if i find anything. cheers, Davie

Spartacus I had thought about that fuel pump but couldn’t work out why it would cut the fuel for a split second. I think it would have to stop for a period of time before the engine would notice it due to the high pressure pump. However definitely worth checking out.

Hi toby, did you get a solution to your fault? Sorry to dig up an old post

Hi did you resolve your issue? I have the same kind of problem with my 2.0tdi ultra. However I’ve had no dpf light or engine management light and no fault codes either.