Hi Forum

 

Fitted new alternator to my 55 Octy 1.9tdi Estate, all good for a day or two then emissions engine light appeared and car went into limp mode.

 

The car is actually quite drivable, no engine noise, smoke or anything that would concern me.

 

So I have error codes 04737 and 16621 to play with.

 

I have changed the boost sensor but still the car limps, when erasing codes I get a clear dash but the above mentioned codes do not erase, emissions light reappears after a couple of journeys.

 

I am wondering if I have left anything off or not replaced hoses etc after doing the alternator but after checking and rechecking all looks good.

 

I did have to take off the air filter to follow alternator wiring when checking a previous fault which ended up being a fuse, I have checked again to make sure I put everything back there too.

 

The fact the car is running perfectly - apart from limp mode - makes me think it is something silly like a cable but after a dose of contact cleaner all round and a check over everything seems fine.

 

I am now at a loss and the next port of call is garage - I'm skint, or we carry on using the car and avoid overtaking as it has lost its oomf, seriously lost its oomf.

 

Any helpers with any suggestions, my dream answer would be a method for resetting it out of limp mode as the boost sensor I fitted has fixed the problem..... dream on!

 

 

 

 

 

 

http://wiki.ross-tech.com/wiki/index.php/16621/P0237/000567

 

Have a look at the link from VCDS.It suggests that it is something to do with the manifold boost pressure. When you removed the boost pipes are you sure they are all correctly clipped in ? If not you will be losing your boost - hence lack of power and CEL being on.

Hi thanks radders567 I have checked all the hoses for splits, seals and all clipped on. to change the 'alt' I did remove them top and bottom but I have gone over them closely checking they are all back in tight and clips fitting. Wondering if the sensor cable has been loosened and power to sensor is up the spout. I have checked it and visually it's OK and all tight.

Edited 9 April, 201511 yr by jmlove

Plugged the MAF back in?

Thanks mbames, I didn't take the MAF off when I pulled the air filter but I'll go and give it some contact cleaner.

Get someone to rev the engine while you feel the boost hoses. You should feel the swell slightly. If they are not swelling this could indicate a leak - you may also be able to hear it.

Quick question - should the EGR manifold flap area be whining for a few seconds after the engine has been turned off?

 

Edit

Sorry I think now this is quite normal.

Edited 13 April, 201511 yr by jmlove

UPDATE - EGR Valve off and cleaned, thick gunk.

 

Taking Turbo off today, considered cleaning kit in situ but would rather get it off and clean it on the bench.

 

I'm hoping this fixes it, if it doesn't it is still a job well done because it is seriously caked up.

Might be too late in this thread to ask another question but I'll try.

 

Do I have to replace the oil feed banjo bolt on the turbo, I can not get the original one back in, it will not pick up the thread no matter how many turns I give it? 

You should be able to get the banjo bolt back in, unless of course you have cross threaded it. Try loosening the oil feed pipe at the other end first this may give you a bit more wiggle on the pipe.

A quick update for those interested.

 

After cleaning EGR valve, turbo and all that jazz still in limp mode.

 

Took it to local independent VW specialist and he found the wire supplying power to the boost pressure sensor had worn against the engine and was shorting, common problem he tells me!!! £102 later and all fixed.

 

On the upside I now have a car with a pure clean boost and it runs better than before.

 

A week later engine light back on but no limp mode, error code 09887 which doesn't even exist..... if I didn't laugh I'd cry!

I'm guessing that you are using a generic code reader?

 

You might benefit from a scan using VCDS, this will get you a proper fault code to be cross-referenced here...

 

http://wiki.ross-tech.com/wiki/index.php?title=Category:Fault_Codes&pageuntil=16555%2FP0171%2F000369#mw-pages

 

Local users who might be able to help...

 

http://www.briskoda.net/forums/topic/224376-vcds-owners-map/