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View Full Version : Please Help BRD cuts out following engine removal for hex shaft fix



chaz1995
12-12-2020, 08:59 PM
Hi all,
Have spent some time searching on this forum so thought i'd start my own thread. I have a BRD 2.0TDI 170 A4 avant and love it. It's on 173k but in great condition.
Recently I had the oil pressure light and decided to repair it, with guidance and support of a mechanic friend. Reason for doing this was mechanically and visibly there was nothing else wrong with the car, no other issues with the engine etc.
We had the engine out in my garage, did the hex shaft replacement from KMB. Also found a cracked exhaust mani so replaced that and a turbo from a breaker with significantly less play. At the same time also replaced service fluids, filters etc.

*edit: forgot to add - we also fitted a new timing kit + water pump. My mate realigned with previous timing marks. I dont think this is causing any issues otherwise it wouldnt start at all, but it is worth noting.*

We have the engine back in and have had trouble starting. Sometimes it will crank for ages and not ignite, occasionally it starts and runs for 2-3 seconds and cuts out. After significant cranking we get the glow plug light but this disappears after cooling. We thought there would be air in the system so tried bleeding it through with a hand pump. it turns out the replacement filter does not have a one-way valve in it, so for the time being the old filter went in. It was apparent there was a huge amount of air coming through the clear pipe in the post-filter return. It is worth noting at this point that the front of the car was raised on stands for 2-3 weeks with the engine out.... and we didn't think the bung the fuel pipes, so no doubt they all drained back. However, it had been primed with the filter full after all of this. Over the past few evenings we had cranked it so many times and gone through so many battery recharges, we actually burnt through the plastic handles on the jump cables....

Currently have the following codes:
P3102 manufacturer control
P2413 EGR system performance
P2425 EGR cooling valve control circuit open
Obviously the EML light is on and also a steering/DSC light, but i think that's cos we don't have any PS fluid in at the moment.

We are not sure how much of this problem is still with air in the system or is there something else going on, perhaps EGR/ASV valve related or some other sensor? I appreciate it's a bit of a punt asking for advice just based on what i've said, but i'd greatly appreciate some thoughts. I am c. £800 with this repair and would love to have the car running before Xmas.

I've been advised it's tricky to bleed the injectors on a BRD block as they are quite far down, is this true? is it something we should try and do? I realise we should have kept the clear pipe after the filter in to observe any bubbles, so that may go back on. Is there anything I can do as far as EGR/ASV problems? Is it possible one of them could have been mis-installed? At this point i'm totally open to ideas. We tried starting it on easystart and all this resulted in was a lot of flame. Or am I over-thinking it and there is just a huge aount of air present in the lines?

Thanks all,
Charlie

VAG-Abound
13-12-2020, 12:34 AM
This sounds very like a problem someone on here had 6-9 months ago. I'll try and find the thread, but mentioning it to encourage you to keep looking as well.

VAG-Abound
13-12-2020, 12:56 AM
This isn't what I was thinking of, but shows how odd things can be: Please Help Aaaagh, non start, no brake lights - Page 2 (http://www.vwaudiforum.co.uk/forum/showthread.php/176397-Aaaagh-non-start-no-brake-lights?p=1017932#post1017932)

Crasher
13-12-2020, 12:53 PM
Did you have the injectors out?

chaz1995
13-12-2020, 08:49 PM
Hey Crasher, thanks for getting in touch.
We hadn't at the time, no. But we tried it today. We could get no1 and no4 out, the middle 2 were quite tricky so left them in. We cranked it over very briefly and there is definitely diesel purging out of both of them, so it all went back together.
TBH i'm not sure we know any more information having done that, but at least we know fuel is getting to the last injector (so assume it is getting to the 3 before it as well!)

chaz1995
13-12-2020, 08:53 PM
VAG-Abound thanka for pointing this out. Yes, indeed, a rather frustrating and easy fix there. I am thinking there is an "easy fix" with mine - it clearly isn't something major because we don't have the same repetitive fault every time. Some times it starts etc etc.

Crasher
13-12-2020, 10:37 PM
I think you have injector seat seal face combustion gas leakage into the fuel supply system of an injector which shows as bubbles in the fuel return, a common symptom of this is pungent fumes from the tailpipe which make you back off spluttering.

chaz1995
14-12-2020, 09:30 AM
I think you have injector seat seal face combustion gas leakage into the fuel supply system.

How would that have happened? The car was fine before we took the engine out and definitely didn't have pungent fumes. I wouldn't even say they were pungent now, but obviously we can smell diesel.. I've been told that there would be significant air in the lines due to them sitting inclined on axle stands for a while without being bunged up!

Crasher
14-12-2020, 02:51 PM
It is a common issue on the PD TDI 2L 16v head and I have seen/smelt it before. The problem was VAG in their infinite wisdom decided to do away with injector fire rings and go injector steel to head ally directly.

These are VAG's own pictures of the problem

https://hosting.photobucket.com/albums/dd20/Crasher1964/.highres/16vPDTDIinjectorseatfaces.jpg

https://hosting.photobucket.com/albums/dd20/Crasher1964/.highres/16vPDTDIinjectorseatfaceinhead.jpg

chaz1995
14-12-2020, 03:40 PM
Sorry, the pictures aren't showing for some reason, not sure if it's a problem my end! Is there a way I could check to rue this problem out? Surely I would have experienced this before doing all of this work?

Crasher
14-12-2020, 07:58 PM
I posted the pictures from Photobucket at work on a PC and I can see them at home on my iPad so you should be able to see them. If you have a significant stream of air bubbles in the return there is only one place it can come from.

chaz1995
14-12-2020, 10:49 PM
If you have a significant stream of air bubbles in the return there is only one place it can come from.

Ah yes it works on my laptop now, thanks.
Hm.. the guy i've been doing this with is convinced the air would have got into all the lines as the fuel would have drained back to the tank etc. The bubbles we've seen in the return line are quite big, so obviously when they get into the engine it is taking up a large amount of "length" in the lines, if that makes sense. Surely the air in the system would have been from that & the filter change?

And when we had the rocker cover off we cranked it and no fuel seemed to be purging out from around the injectors.


I appreciate you answering my queries, i'm a little out of depth & knowledge with this!!

chaz1995
17-12-2020, 09:26 AM
So I had a mobile mechanic come out and last night and use a snap-on scanner. Turns out there are more codes than the few we found on a generic OBD reader:

P1495 - Switch - Over Valve for EGR Cooler (N345) Open or Short to Ground, Open Circuit/Short with ground
P1443 Potentiometer for EGR (G212) Signal too low Short with ground
P0341 Camshaft Position Sensor (G40) - Implausible signal, Short with power - intermittent
P3102 Motor for intake manifold flap (V157) No signal short with power - intermittent
P0321 Engine Speed Sensor (G28) Implausible Signal short with power - intermittent
P3008 Camshaft Position Sensor (G40) Signal out of Range short with power - intermittent
P0671/2/3/4 Cyl 1-4 Glow plug circuit (Q10-13) electrical fault short with power - intermittent

Now the mechanic said it is likely to have a wire pinched or nicked when refitting the engine. Plausible of course. He also mentioned the injector loom under the rocker cover can absorb oil and stop working (??).

A friend I spoke to suggested the cam sensor would set most of these codes off and that my low battery could be causing the power codes.. it is very flat and haven't had chance to charge it.

Is there anything else I could look for or try before getting someone back out to spend some serious time fault finding?? Thanks all

Crasher
17-12-2020, 12:08 PM
Did he clear the codes and then see if they came back? To me they all look like codes generated when something is unplugged and are possibly meaningless although the only code there which would make it cut out is the engine speed sensor. You really need your own copy of VCDS, solving a problem like this without your own system is nearly impossible and you could waste more money than a VCDS dongle costs... they usually pay for themselves and owning the latest HEX-NET with unlimited VIN's make you very popular with people that own VAG cars, even a used old HEX-CAN of fleaBay would be better than nothing but avoid illegal clones. If the injector seats leak the resultant air you see tends to de a foamy stream of small bubbles, due to the seal design you would see nothing inside the cam cover and if you did that would be very bad! Modern cars hate low batteries, get it fully charged. The first thing I would be looking at is the crank speed sensor signal in measuring blocks.