Rocker arm/tappet clips Broken

[Almurray42]

Hi All, First post here 👋

I've recently acquired an Audi A3 (2.0 TDI with CBAB engine) With issues, and attempting to fix.

Long story: "Brakes pedal is hard" I was told, on investigation I found there was no vacuum to the Brake Booster/brake master cylinder - traced back to Vacuum pump (Camshaft driven) - took this off and found it to be completely torn apart, looks like it seized. My guess was it had seized due to no oil reaching it - so thought it wise to check the oil pickup pipe and pump.

Pickup pipe was fine, and pump was also in very good condition. I did however identify a rounded end on the hexagonal oil pump drive shaft bar - apparently a common problem on these! New bar is on the way, but then I noticed....

In cleaning out the sump, I found a small clip which looked like a retainer for the rocker arm to tappet.. looked up the rocker arms and it matches perfectly!

So... I have now removed the rocker cover and found that 3 of the rocker arms are missing the clips - luckily I believe I've managed to collect all the broken bits, but my question is - are these necessary? It seemed to run fine without the clips and unsure what purpose the serve other than for ease of installation... I will replace if needed, but it'll mean the whole TDC cambelt off water pump job which I'm not fancying!

TLDR:

Audi A3 Rocker arm - hydraulic Tappet retainer clips: are these strictly necessary? Or are these more of an assembly aid?

Image below showing a rocker, the clip being the Mild steel on the left of the Arm. 

 

Thanks In advance for any replies!

Al

[cliffcoggin]

Alastair.

I have no certain knowledge of those clips, but I don't believe Audi would add to the cost of the car by fitting them unless they were necessary. When every penny of manufacturing cost has to be justified to the bean counters the design engineers must have had a good reason to fit them.

I also don't understand how the clips got into the sump. Clearly they were not fitted correctly to the rockers by whoever has had that engine apart in the past, but I don't recall a passage between head and sump large enough for the clips to fall through.

Of more concern to me is the fact that the engine has been run without lubrication, a potentially destructive operation. Have you driven the car yet, and if so how does it sound and what is the oil consumption?

[Almurray42]

Hi Cliff

 

Sorry I haven't replied before now! Somehow didn't get notified of a reply...  

 

As I don't have the time/patience nor money to go taking off the camshafts (Apparently need an expensive alignment tool just to get the cams back in correctly?) I took a risk and put the rocker cover back on to test, as I didn't know if there were any other issues too!

 

Seemed to run just fine without these clips - I assume that they are there to prevent the followers from slipping when the cam lobe is up? But either way these have been fine - There's some decent sized oil passageways from the Head down to the sump, but these clips were broken up into 3/4 pieces.

When I had the Cam cover off everything did look still fairly well lubricated, and turns out that the cause of the Vacuum pump failure was due to a piece of debris blocking the oil entry to the pump. I've had the Cam cover off again yesterday and all looks good under there, no excess movement on followers and nothing looks damaged. 

I have recently noticed another issue - but that's one for another post - Just wanted to provide an update on this post!

 

Al

[cliffcoggin]

Thnks for letting us know Alaster. Let's hope the engine is OK.