Audi A3 2011 2.0 TDI (8P1-CFGB) Crank no start, no DTC codes

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Re: Audi A3 2011 2.0 TDI (8P1-CFGB) Crank no start, no DTC c

Postby FioranoCars » Tue Nov 22, 2016 10:16 am

Thanks for the nudge! and continued interest, sadly it's not a commercial job for us, we have paying customers to deal with :shock:

We'll try and get a look at lunch time or late tonight, but the ability to have some thinking time is no bad thing, rather essential actually, although while there are further tests we COULD do,

Not had time to read all the replies and digest them still, as pretty busy, but had started this post a while ago, so I'll dump it here, as this job is a good fit ... bear with me ... :?

I'm not sure if this was a commercial job if we would do that many more tests, more likely we'd strip the inlet and inspect, as we'd get answers (good or bad) of a more conclusive nature faster ... and could still do a compression test with the cover off (concern over injectors might not get good resolution though).

One caveat, that if we thought we MIGHT learn something to help us in future diagnostics of other cars, then we MIGHT burn some technician time to see if there was a learning outcome to be gained (you've got to speculate ...) ... but sometimes we don't have the time or the client wants immediate answers, so speculative testing is not always possible.

We will try to fit in some tests, as I've got a few ideas based on my own thought's, STC's and the other input from here, which is both excellent and really appreciated. Thanks to all again. BUT no promises, a young man is without wheels, and the fastest repair might not align with the inquisitive side of my brain or the clear interest here at the Forum :(

Also to note, on a commercial basis, sometimes it's pragmatic (maybe this is cynical, but life's lessons teach you to protect yourself) to not spend effectively unrecoverable hours testing and diagnosing the fault completely, as once you've done the hard work, sometimes the customer will turn around and say, thanks, but actually my mate (substitute incompetent previous garage/beer buddy/google grease monkey/forum gorilla/...) says he can swap xyz for half that ... and as you've not undone much he's happy to take it on!

The xyz is often only a symptom, but the owner never heard that, well not much between his ears for it to stick in, and you get the blame for mis-diagnosing the fault ... sometime better, even if you have got a fairly good idea of the fault, with proof, to still say you need to strip the car to prove your suspicions, confirm the damage and the root cause ... being too clever often does not pay. :!:

Oh, the reason for the moral lesson (not that I'm qualified to lecture, so this is all IMHO, no offence or egg sucking intended), is that except a compression test to prove under or excess pressure, and/or an injector swap to confirm not a leaking injector causing fluid to accumulate, there is not much that can economically or usefully be done (well I'm sure a few purists would disagree, and so might I), but over testing is sometimes as bad as undertesting. I've encouraged myself to overtest many times (sometimes for learning outcomes, some never obtained)...

But yes will post back further test results and when we strip it (hopefully some pictures too), but thought it time to also ensure people don't loose sight of the real world goal (worst offender sat behind this keyboard! I'm imperfect, go figure) :oops:

Our job is not purely to diagnose, or play with scopes, there is a very real need to be commercial and pragmatic, I'm just reminding myself first and foremost, and letting others know to bear it in mind. I hope you can either have a laugh, bear it in mind, or ignore it without offence, as none is intended.

And don't let this stop further ideas coming forwards, all still welcome and will get due consideration, I'm still a curious inquisitive nerd at heart :lol:

Best
Richard
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Re: Audi A3 2011 2.0 TDI (8P1-CFGB) Crank no start, no DTC c

Postby grunf1976 » Thu Nov 24, 2016 10:29 pm

I agree with you 100%. I always like to test everything and want to be sure what the problem is and I like doing as much asI can with the scope. But as you said time is a critical factor in this line if work and I think that there is not enough time in most cases.
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Re: Audi A3 2011 2.0 TDI (8P1-CFGB) Crank no start, no DTC c

Postby FioranoCars » Fri Nov 25, 2016 12:23 am

Absolutely!
Will be on it hopefully on Saturday now, as this week has blurred past.

Worse, we've got a Peugeot arrive with various issues, but might be a timing issue, so new thread to start shortly, asking for help, long time friend of many of our team and ex owner of our core marque, but appears he's been let down and we have another charity case to decipher :shock:

Time eh, "stop the clock" ... was that Anneka? I wish :D :lol: :D (Clearly an English joke of a certain generation!)

Can't wait for the weekend

Richard
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Re: Audi A3 2011 2.0 TDI (8P1-CFGB) Crank no start, no DTC c

Postby FioranoCars » Wed Nov 30, 2016 12:02 pm

Hi
Managed to get a working compression tester on this last night and got 4 readings by hand, have ordered a PP970, and will get a reading on that to share when it arrives, just to make it a little more relevant for pre and post comparison ...

Any way, readings as follows:
Cylinder 1 = 14bar
Cylinder 2 = 16bar
Cylinder 3 = 14bar
Cylinder 4 = 14bar

Cylinder 2 leaves the engine sounding different from the other 3 when the tester is installed and reaches all levels of compression faster.

We'll strip the cam cover when time allows ...

Richard
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Re: Audi A3 2011 2.0 TDI (8P1-CFGB) Crank no start, no DTC c

Postby grunf1976 » Wed Nov 30, 2016 4:30 pm

Hi,
Those readings are way too low.
Compression pressure bar
When new 25.0 … 31.0
Wear limit 19.0
Maximum difference between cylinders 5.0

If you need any specific data from ELSA I can send them to you
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Re: Audi A3 2011 2.0 TDI (8P1-CFGB) Crank no start, no DTC c

Postby FioranoCars » Thu Dec 01, 2016 12:39 am

Thanks, will Pm you over next couple of days to get a bit more info, need to understand a bit more, and the cam strip should help with questions we need answered ... time ... that precious resource!!

Richard
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