PD Elements: BKD Car Seats

I occasionally experience jerking and cold start problems with my A3 BKD.

According to MWB 13, the first cylinder has a value of +2.99 mg per stroke.

Today I removed the glow plugs, and the seat for the first cylinder doesn't look good.

In addition, the oil channel fitting on the roller rocker arm, on the side of cylinder 1, is no longer properly seated.

Is there a way to repair the seat, or is a head replacement the only option? Or could it be that the valve isn't opening properly due to the oil plug, although I doubt that's the case.

The right one refers to the cylinder #1, and the left one refers to cylinder #2.

And a picture of the cylinder head for cylinder number 2. I'll send you a picture of the one for cylinder number 1 later.

chli1976 wrote:

Or perhaps it's caused by the oil plug, preventing the valves from opening properly, which I doubt.

But that's the case, it's a known problem:

/viewtopic.php?t=21918&highlight=stopfen

"I'm familiar with this issue from my 2-valve engine, but in my 4-valve engine, the core hasn't popped out yet."
I will send you the pictures later tonight.

"I occasionally see error code 16685, which indicates misfires in the first cylinder."

Here's a picture of the tilting lever axle and a picture of the seat from the first cylinder.

"The new head has been installed, and the jerking/stuttering and cold start problems are gone."

Hello,

Thank you for the feedback! How many kilometers were on the engine?

Best regards, Rainer.

Approximately 150,000 km.

What is the cost of such a procedure? (new, used, or refurbished parts?) Is it reasonable to expect goodwill from the VAG group? Or is it again a case of 'the customer has to figure it out'?

In Austria, the cylinder head with valves and camshaft costs 1140 euros from the original manufacturer. It includes everything you need except the head gasket (PD O-rings, screws, etc.).

In the replica, we only had one cylinder head without camshafts, but it would have been more expensive to include the camshafts than to use the original.

Sorry for the question, but could you please mark the part that often comes loose?

Best, Chris.

I saw something like that for the first time. I took it out and glued it back in.

Quote:

The new head has been installed, and the jerking and cold start problems are gone.

Did you also replace the PDs? They should show similar patterns to the ZK.

Today, I had another Audi A4 BLB, belonging to a good acquaintance, here with the same problem.
"I already had all the valve stem seals replaced about 1.5 years ago at 170,000 km, with the note that the cylinder head and all the valve stem seals should actually be replaced. Today, I replaced the seals on cylinder 2 again (for the last time). The fit between the valve stem seal and the cylinder head seems to be only an oval clearance fit."

At that time, I already had the feeling that the injectors (mounted) were no longer perfectly vertical in the cylinder head. It appears that the injectors from cylinders 2, 3, and 4 are tilting towards the rocker arm shaft, at a right angle to the mounting holes.

The question I'm asking myself is whether and how it might be possible to carry out a repair that is fair in terms of its value.

If these vehicles were two years older than they are now, they would still be repairable with proper maintenance (e.g., cylinder head and timing belt replacement costing approximately 3450 EUR plus labor).

Economically, a complete disaster.

Given that these vehicles already suffer from significant quality issues, such as the dual-mass flywheel, the driveshaft module, potential piston failure, or the front axle, etc.
I personally find it very difficult to recommend such a repair to people.

That's why I'm looking for a "socially responsible" repair method to keep these rolling design flaws alive.

I reused the old PDs, but they weren't as well-processed as the ones in your picture.

The BLS has a PD (pressure distribution) system with screws that are attached once and have a copper disc, and it also lacks a balancing wave module.

In this game shown in the video, the fuel tank can no longer be sealed properly.

Oops, it's a BLB, not a BLS. I've corrected it.

Hi there.

Is there perhaps a difference between PPD and regular PD elements?

Maybe I should ask a laser welder if they can weld it back together 'cheaply' (in the headrest) and then do some finishing work... the shape of the headrest doesn't seem that complicated...

Quote:

Is there maybe also a difference between PPD and the regular PD elements?

Die PPDs scheinen in der Tat präziser gefertigt zu sein (s. Photo).
They also appear to have a much smoother surface overall, and the guides seem to be designed more generously. About 4 weeks ago, I replaced 2 of these on a Passat 3C BKP. (Unfortunately, they don't perform very well electrically). I was surprised that these weren't worn out.

Quote:

Maybe I'll ask a laser welder sometime if it can be welded "cheaply" (in the head) and then reworked... the shape of the seat in the head doesn't seem that complicated...

I don't think that's really feasible.

I'm looking for a cost-effective solution that is also feasible and reliable.

Roughly, what I have in mind is the following:

Re-work the borehole in the ZK (both diameters) using a reamer or similar tool to dimensions X and Y until the borehole is round again.

"Disassemble the PDs and generously remove any damaged portions of the guide (Image 1), replacing them with a custom-made ring (either pressed-in or shrink-fitted). Then, machine it down to our specified dimension X and smooth the surface. This would restore the upper guide. The aluminum guide component would need to be newly manufactured with appropriate over-dimensions X and Y. The guide surface could be further optimized without narrowing the fuel channels."
Then all you need to do is find sealing rings with an oversized diameter.

Currently, I am not yet aware of whether all of this is feasible and at what cost. I am concerned about how to restore the perfectly smooth surface of the ZK bore.
A mechanical engineer or engine mechanic would probably have something to say about that.

What do you think about it?