Cylinder Head Leaks: Causes of Water Loss and Misfires

Hello everyone,

I have a Volkswagen Golf V 2.0 TDI manufactured in 2004 with 151,000 kilometers on the odometer, equipped with the BKD engine.

"I've been experiencing a persistent coolant leak for about two months. An analysis performed after removing the intake manifold revealed that cylinder 1 has the well-known crack."
For now, I continued driving because the water consumption was within acceptable limits and the starting behavior has been/is still not problematic.

Unfortunately, I'm also experiencing significant jerking at partial load. This mainly occurs in gears 4/5/6 around 2000 RPM.
I've already ruled out the AGR valve; it was cleaned just 6 months ago, and the problem persists even with the vacuum hose disconnected.

Therefore, today I read out measurement block 13 during the journey.
When there's stuttering or lag, the following situation almost always occurs:
-1.25 -0.99 -0.78 2.99

Am I correct in understanding that the values should be significantly below 2, and that 2.99 is the maximum value?

What could be the possible causes?
Is the PD element integrated? Or is it defective?
PD cable assembly?


While I'm quite experienced in repairing older VW models like the Golf 2 and VW T3, I don't have much experience with more modern diesel engines or those with common rail (PD) technology.
Economically speaking, it probably only makes sense to do it yourself. The cost estimates I've already obtained for the main project were all at least €3500.

Thank you for your help.

Regards,
Lukas.

I would start by replacing the PD wiring harness. How can you tell if there's a crack and not a blown head gasket?

Rüdi wrote:

I would start by replacing the PD cable harness. And how can you tell if there's a crack and not a blown head gasket?

Hello Ruedi,

Thank you for the answer.

It's impossible to say with 100% certainty whether there's a crack until the head is removed and can be examined by pressing on it.
However, my car's manufacturing date, combined with the BKD engine code, 16V configuration, and the part number of the cylinder head, exactly matches the pattern where cracks are extremely common. Furthermore, the water was found in cylinder 1, just like in cases with cracks. All these points also perfectly match the information that VW has published on this topic in its Erwin (siehe Fehlerdatenbank) database.


Bzgl. Kabelbaum, ist hier abgesehen vom Kabelstrang noch weiteres zu wechseln? Seals, etc.?

Is there a way to isolate the cable run without physically disconnecting it?



Thank you.

Regards,
Lukas.

Good morning.

If there's an issue with the intake side, you will inevitably need to replace the cylinder head gasket!

"Mine had something on the exhaust side – just a minimal amount – I poured in some radiator sealant and it worked great! (Currently at 330,000 km)."

I wouldn't have considered 100,000 km to be particularly bad – maybe losing 100 ml of coolant every 6 months. However, I suspect that I also damaged an original turbocharger after about 50,000 km due to this – a stuck VTG (Variable Turbine Geometry) unit!

The turbo and EGR valve were very dirty overall!

Regarding the +2.99 mg PDE:

Probably broken.
I once replaced the PDE wiring harness at around 300,000 km as a precaution, but nothing fundamentally changed.

There's a set available online for around €1100.


Sure, here's the translation:

"SG" can have different meanings depending on the context. It could stand for "Spielgemeinschaft," which is a German term for a sports club or association that combines players from multiple teams or organizations. Alternatively, it could refer to "Säkularkantor," a type of church musician who does not hold religious beliefs. Finally, "SG" might be an abbreviation for "Sonstige," meaning "other" or "miscellaneous."

Okay, then I guess I'll have to go all-out. Here's what's on my list; have I forgotten anything?

Cylinder head including valves.
Cylinder head bolts.
Cylinder head gasket.
Valve cover gasket.
Omission poetry.
Intake manifold gasket.
Poetry plug PDE tree.
PD Seals.
NW storage trays.
Timing belt kit.
Water pump.
V-belt.
PD Cable Strand.


According to Erwin, the adjustment screw in the rocker arm, the rocker arm ball joint, and the mounting screws for the PD (presumably a component) also need to be replaced. Does anyone know where to get them?


I would have the PD elements checked by Bosch service. Has anyone received a recommendation or has any experience with them?


Which of the specialized tools are absolutely essential? Besides marking tools and a dial indicator with holder.

Can anyone else offer advice? I'm a bit unsure about the setup process right now.


Thank you.

Regards,
Lukas.

You also need a sealing pump. 8 screws for the pressure-sensitive elements. 6 screws for the rocker arm shaft. Oil seals for the camshaft.

You absolutely need the camshaft sprocket puller, holding tool, and locking tool.

Regarding the pump nozzle gasket sets, there are large and small sets. This refers to the fact that sometimes the adjustment screw is included in the set, and other times it is not.
I would only use an ultrasonic bath for cleaning PDEs. Proper inspection is absurdly expensive and time-consuming. I don't know anyone who can or wants to perform a precise inspection.

It all takes quite a bit of effort if you want to do everything properly.


Okay, something completely different. What tool is used to remove the locking nut on a 16V TDI engine when you need to replace the injector nozzles? What's the name of that socket? It looks kind of like a 24-point socket.

Hello,
As mentioned before, I would only verschandeln the injectors in an ultrasonic cleaner, focusing on just the tips. You might have access to an ultrasonic cleaner. VW sells a cleaning concentrate for this purpose, which costs around €17. After cleaning, they should be reinstalled promptly and not left out for days.

Regards,
Charmilles.

Okay, I'm ready. Please provide the German text you want me to translate into English.

Thank you for the answers.

"Definitely water is entering from the intake side; I already removed the intake manifold and water came out."

Regarding the camshafts:
That means I need to remove the camshaft sprockets, right? And replace the gasket there.

Okay, here's the translation:

"If I now remove the entire camshaft sprocket, what is the best way to optimally re-align the camshafts? Is there only one position where the sprockets can be mounted, or do I have to completely readjust them using a dial indicator? Would it make sense to mark the camshafts with something like paint in this case? I don't want to mess up my valve timing."


Regarding the deviations in the performance of the PD (pre-catalytic converter) elements: if these are caused by carbon deposits, why does this behavior only occur when the engine is warm? Does the engine management system continue to reduce fuel delivery for some time? Does anyone have any practical experience with this?
Otherwise, the problem might be with the seat in the nozzle or the upper two seals of the injection system.

I have already ordered the following items:

Cylinder head including valves.
NW Bearing Shells.
Cylinder head bolts.
Water pump + timing belt kit.
Oil filter.
Shaft seal, crankshaft.
Poetry, cylinder head cover.
Manifold.
Poetry, exhaust manifold.
Poetry, cylinder head.
Poetry, fuel pump.
PD element sealing set including adjustment screw.
PD element mounting screw.
V-belt.

Thank you very much.

Regards,
Lukas.

Herrweiss wrote:

In my case, the water is definitely coming from the intake side; I already removed the intake manifold, and the water came out at me.

In my opinion, there's also the possibility that he already started the engine with water in the cylinder (multiple times). Consequently, it's possible that he has already experienced a hydro lock, which could have bent the connecting rod and explain the uneven running.

Roger wrote:

Herrweiss wrote: In my case, the water is definitely coming from the intake side; I already removed the intake manifold, and the water came out towards me. Then, it is also possible that the engine

had already been started (multiple times) with water in the cylinder. Consequently, } it may have already suffered a hydraulic lock, resulting in a bent connecting rod, which would explain the uneven running.}

But then only within the load range of 1900 to 2400? And specifically where do the PD elements exhibit deviations from the standard?

Then the engine would always run unevenly, right?

Herrweiss wrote:

Then the engine would always run unevenly, wouldn't it?

Not necessarily. Even this engine, with its two severely bent connecting rods, still ran relatively smoothly, aside from a rough cold start and problems at low RPMs.

I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

I don't want to scare you, but highly compressed diesel engines can be damaged by relatively small amounts of water in the cylinder, and based on your description, a minor hydraulic shock is at least within the realm of possibility.

Roger wrote:

Herrweiss wrote: Then the engine would always run unevenly, wouldn't it? Not necessarily. Even this engine, with its two severely bent connecting rods, still ran relatively smoothly, aside from a rough cold start and problems at low RPMs. I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL. I don't want to scare you, but highly compressed diesel engines can be seized with relatively small amounts of water in the cylinder, and based on your description, a minor hydraulic lock is at least within the realm of possibility.

I have to agree with you on that – unfortunately.

How would you approach this? Checking the compression on a BK engine shouldn't be straightforward because of the glow plugs under the valve cover (would disconnecting everything and cranking the engine work?).

An alternative would be to pull the PD (presumably referring to a component or system), verschandeln it, and see if that helps.

If I have the engine upside down, should I be able to see a bent connecting rod by observing the position and movement of the piston?

Compression would be one way to do it, yes.

When the head is facing downwards, you can measure the height differences of the pistons.

Roger wrote:

Compression would be one way, yes. When the head is facing downwards, you can measure the height differences of the pistons.

Actually, something just occurred to me that I forgot to mention, sorry:
As long as the engine isn't warm, I don't experience any misfires, and it accelerates smoothly. This should hopefully indicate that the connecting rods are probably okay, right? It should then run better when the engine is warm.

I will definitely check it when the head is facing down. I'll then take pictures and upload them.

Thank you very much for your help.