BKD Cylinder head

[richard_gmt]

Hi,

A quick question, usually when there are problems with the cylinder heads on this engines it all resumes to coolant level, as far as I know.

Had anyone had experiences on this problematic cylinder heads where it would be the cylinder head leaking diesel into the cylinders instead of coolant?

Injectors are being reviewed as we speak and also new seals, just wondering if it could actually be the cylinder head instead.

By the way, it's a C revision head.

Thanks in advance,

[Crasher]

Yes cracked BLOCK surfaces around the locating dowels and failed MLS head gaskets on older engines are common and at the beginning of production (2003>2005 ish) porous heads were a common issue that still pops its ugly head up even now and results in leaking coolant into the combustion chambers. Blowing the coolant out on the motorway is a bad sign.

[richard_gmt]

Thanks for your reply.

Yeah, loss of coolant is a known fact, however I have no coolant loss for sure. I was more thinking if any of those porous heads actually leaked diesel instead of coolant.

[VAG-Abound]

What problem are you seeing? Incomplete fuel burn? Too much soot? Poor running?

[richard_gmt]

Car struggles to start after standing during the night. Same behavior when if replace injectors for example. Cranks and starts for 1 second 2 or 3 times and then eventually starts. When it starts it's pure diesel smell and smoke out of the exhaust. Injectors were just tested as they were working perfectly on previous engine and they perfect. They replaced seals anyway and I'm getting new bolts also. I'm just wondering if it could be the head having some leak on the diesel galleys.

[VAG-Abound]

Do you think timing is right? Piston damage / poor compression? Lack of airflow for some reason - supply pipes good?

[Roverfan]

I'm just wondering if it could be the head having some leak on the diesel galleys.
There is no such thing afaik. Pipes connect to injectors, which then inject into cylinder.
Some people can actually tell if you a compression problem by listening to the sound of the engine whilst it cranks (May be an idea to post a video but no guarantees as yours eventually does start).
What is the battery voltage in the morning? Does it miss once started?

[richard_gmt]

Do you think timing is right? Piston damage / poor compression? Lack of airflow for some reason - supply pipes good?

Yes, angle is 0.0 and exhaust cam matches with locking tools when intake cam is locked. Fits like a glove, so I would say yes it's correct.


There is no such thing afaik. Pipes connect to injectors, which then inject into cylinder.
Some people can actually tell if you a compression problem by listening to the sound of the engine whilst it cranks (May be an idea to post a video but no guarantees as yours eventually does start).
What is the battery voltage in the morning? Does it miss once started?

Good to know that there is no such problem. I never checked battery voltage. I suspect there are bent valves due to an episode when timing belt was installed. Could that justify what I'm describing?

[Crasher]

We had a Fabia 1 VRS in yesterday, very long standing customer (over 30 years) and his car suddenly developed a hot start problem, he called the RAC and he said injector seals so he brought it in. It was fine from cold and drove perfectly, hot immediate restart, five minutes still OK but stopped for ten minutes and it was taking a long crank to get going. We checked everything, fuel pump running in output tests, no codes, 0.0 +/- 0.1 torsion value (we did the belt a few months ago), 295rpm cranking speed, coolant temp signal OK but we fitted a new one, tried it with the sensor unplugged, fitted a new fuel filter, perfect injector balances and status 0... nothing... the mechanic tied up, went to the drain tank and emptied the fuel filter ready for disposal and though, petrol! Purge, refil, perfect. That RAC man needs his olfactory senses checking.

[Roverfan]

Yes, angle is 0.0 and exhaust cam matches with locking tools when intake cam is locked. Fits like a glove, so I would say yes it's correct.



Good to know that there is no such problem. I never checked battery voltage. I suspect there are bent valves due to an episode when timing belt was installed. Could that justify what I'm describing?
Could do, you can use it as basis for further diagnosis. if diesel is emitting the exhaust unburnt it points to a lack of temperature in the cylinder which is created by compression in conjunction with timing, don't think glow plugs effect anything at this time of year. Not properly seated valve, or coolant entering cylinder these are both possibilities.

How does it idle once started? does it run on all four cylinders immediately?

[Crasher]

Or excessive EGR flow.

[richard_gmt]

Could do, you can use it as basis for further diagnosis. if diesel is emitting the exhaust unburnt it points to a lack of temperature in the cylinder which is created by compression in conjunction with timing, don't think glow plugs effect anything at this time of year. Not properly seated valve, or coolant entering cylinder these are both possibilities.

How does it idle once started? does it run on all four cylinders immediately?

No, there is 3-5s where it has some misfire but then it clears.


Or excessive EGR flow.

Fully disabled EGR.

Well, head is off now. There is no single cylinder where the simple water test won't fail. None of the cylinders hold water in the ports. Some even more than 1 valve per cylinder will not hold water.

I've not taken it to the machine shop yet. This is a C version manufactured in 06 according to the date on the back. However cylinder 2 and 3 do have a crack around the glow plug. It seemed to be fine, there was no coolant loss.

Not sure what to do here. Buying a new head is something I would prefer to avoid. Not sure if they can be welded as the C versions should be stronger maybe they will hold.

[Crasher]

The problem is usually cracking of the block top surface around the dowel sleeves.