Ticking AFN engine 1.9 TDI 110Bhp

[johnbuz]

Hi

I have a weird fault that is driving me mad.

My engine is making a LOUD ticking noise, sounds like it is coming from the cam belt end of the engine.

I have replaced the following:
Cam shaft, hydraulic cam followers and injectors.

These have made absolutely no difference to the noise at all.

With the engine heald at about 1200RPM I have cracked the diesel feed to each injector in turn, this makes no difference to the noise. (This isolates the firing on each cylinder in turn)

So......doesn't seen to be cam based, doesn't seem to be piston problem.......engine drives completely normally, no performance issues.

It has started overheating recently, although i have drained the coolant out completely and I'm not convinced that I have all the air out yet.

Any ideas?

John

PS injection timing checked with VAGCOM very slightly advanced, but well within green line on TDI timing graph, cam timing checked and spot on. Timing marks on flywheel and crankshaft cam belt pulley are in alinement, so no creap on cambelt pulley in relation to the crank.

Noise

 

[90landrover]

Hi

Have you thought that the overheating and the ticking may be connected. Maybe the impellors on the water pump have started to shear off ( I believe they are plastic but that metal ones can be bought ). The pump on a 1800 V20 engine is mounted in between the cam belt pulleys so would give a sound as if coming from the cam but not sure of the mounting on a diesel. Worth having a look.

 

[johnbuz]

Hi
Good point the water pump is driven by an auxillary belt that also does the power steering. I will drop the belt off to see if the noise changes.

 

[johnbuz]

Ok

Its not the water pump, power steering pump, alternator or AC compressor.

Just had cam out again, checked each cam follower, all pumped up and hard - as they should be.

Double triple checked timing all spot on -cam and injection, tried advancing and retarding injection timing - no difference.

I have not been able to change this knocking in any way.

Must be lower down in the engine - little end??? although loosening off the injector feeds and the noise is still there, just doesn't change.

ARGHHHHHHHHHHHHHHHHHHHHHHHH.

John

 

[johnbuz]

Well pulled the head off, all OK.
Looked into the bores.............not OK
Pot1 light scoring
Pot3 rub marks

Pot 1
Pulled the piston out, and it looks like something has got caught in the side of the skirt, the piston has heavy grooves in it, piston rings all OK not broken. The bore has slight grooves (just catch with finger nail) also lumps of 'stuff' stuck about 20mm up from bottom of bore.

Pot 3
Slight galling on the piston, bore just marked but not scored.

I managed to clean up both bores, replaced piston 1 with another from the first engine (same weight and size group) and polished up piston 3 to remove the galling.

Just got the plumbing to put back on, and then fire her up to see what we have.

Engine rebuilding on a budget of zero.............

John

 

[toyink]

Rattling AFN engine

Hi John,
Did you manage to overcome your problem in the end?
I had an Audi with the exact same symptoms you describe and followed the same steps, except the piston removal bit. I wonder if the pistons could have been the problem?

Unfortunately, I got rid of the car without getting to the resolve the problem. Sold it to someone in Cambridgeshire, you're not in Cambridgeshire by any chance are you??

Anyway the initial problem was caused by a previous mechanics failure to properly tighten the pulley on the auxilliary shaft that drives the oil pump and vacuum pump.

This resulted in low oil and vacuum pressure with both lights flashing on the dash. The cambelt eventually snapped before I found out what the problem was.

Anyway, put it all back together (replaced bent valves, tappets, cam, belt, shaft, pulley etc) but was never able to eliminate that really annoying sound!! I even had the big ends off but they were undamaged, really frustrating....

 

[johnbuz]

Hi

No the engine is still exactly the same.

I have completely overhauled the head - made no difference at all. (Replaced cam and hydraulic followers, removed and checked each valve spring, lapped the valves)

Replaced the con rods on pots 1 and 2, checked 3 and 4 (very slightly play in the 1 and 2 small ends before)

Replaced pistons 1 and 3 (1 had heavy galling 3 had very light)

Replaced the injectors.

All gone back together and the noise is exactly the same!!

Driving it around at the moment waiting for something to break!

John

 

[twig]

might be worth having a look at this: http://www.seatcupra.net/forums/showthread.php?p=2675445#post2675445

Seems a few of us are having the same problem.

Hopefully nothing to worry about though, eh? Mine's been doing it for a good few months now and no problems so far.

 

[johnbuz]

Got fed up with mine and changed the engine.......nice and quiet now!

Sorted

 

[twig]

lol drastic but effective!

 

[johnbuz]

well I'd tried everything else, head rebuilt, sump off and pistons out. I wasn't able to make any change to the noise at all. the engine actually drove fine, no smoke, no knocking just an annoying ticking noise. I have it for sale on ebay at the moment, good source of parts for someone.