DHK Withdrawal Issues: Troubleshooting Guide

Hi! I'm having a problem with a 1Z engine. I had trouble removing the cylinder head bolts from cylinders 2-4. However, I'm having absolutely no luck with the cylinder head bolt for cylinder 1. Penetrating oil, a 15mm socket, and a hammer haven't worked either. Is there perhaps a hydraulic bolt extractor like the ones used by Mercedes-Benz? I've basically given up on the cylinder head already. Please, no unqualified answers. Regards, Rudi.

I'm sorry, I don't have enough information to answer that question. I am a large language model, trained on a massive dataset of text and code. However, I am not able to access external websites or specific files. Therefore, I cannot provide you with a definition of "DHK."

To find out what "DHK" means, you could try searching for it online using a search engine like Google or DuckDuckGo. You could also try asking someone who is familiar with the term.

Diesel injector assembly, also known as an injector nozzle.

I'm sorry, but time helps! If you don't have time, it will be difficult. I would flood the cylinder with diesel or WD40 and then try to turn it over with the wrench (size 15), pulling slightly, turning, turning... Is the spark plug already removed or installed? Mixing suggestions for both scenarios:

Here's a translation of the German text:

"An unconventional method would be to remove the glow plug and support the entire process by turning the engine to the 1-OT (one-turn) position and injecting diesel fuel into the combustion chamber. Of course, the diesel fuel must be removed before starting the engine!"

If the engine is still running and installed, clean the other injectors and slightly loosen the mounting bracket of the first cylinder. Hopefully, the vibration will help resolve the issue.

If the head is exposed, another option would be to put it into vibration. You could, for example, suspend the head with a blanket, using wood as a base and straps, and place it on a vibrating platform for about an hour, if you have access to one. Alternatively, you could take the head to someone who has a large ultrasonic cleaning bath. (From a motor repair specialist)

The important thing is just to make sure you don't damage the seat, but I'm sure you already know that.

If the camshaft is broken, you could also place the cylinder head on a hot plate to warm it up and allow it to expand slightly. Maybe not on the one in the kitchen, but perhaps you have something else old lying around.
However, I would first need to examine it more closely to ensure that nothing can break on the head and to see if it gets hot enough to affect the area where the "DHK" is located, due to expansion.

Greetings.

1. DO NOT only turn it counter-clockwise! Doing so will cause the DHK (direct heat key) to unscrew, and the internal components will be damaged. In the worst case, the nozzle and the union nut will become stuck in the ZK (cylinder head).
2. Insert key DHK and turn it back and forth while pulling it upwards. This works 99.9% of the time.
"In 0.1% of cases, if the engine is a disgusting, rusty, oily mess, and instead of glow plugs, there are only brown pine cones stuck in the cylinder head with hardened oil: Simply loosen the screw on the glow plug retaining bracket so that the glow plug has about 2mm of clearance. No more, otherwise the fuel line may break later. Then just insert it and drive around. Full throttle at 3000 rpm helps. Don't forget the wrench to tighten the retaining bracket when you drive home, you'll hear it when the glow plug is loose."

Best regards, Rainer.

Thanks for the suggestions!!! The DHK (glow plug) is out. Apparently, my 2kg impact wrench doesn't always get the job done. Although the impacts make the motor shake quite a bit (it's strapped to a wheelchair!). Today, I borrowed a >5kg impact wrench and had a corresponding adapter welded on. After just a handful of impacts, the DHK came out. Since I had the stuff on hand, I also tackled an AHU (engine). It was outrageous; even with that engine, I had trouble with the tool. So, TDI engines that are 15 or 16 years old can sometimes be quite a pain. In my opinion, using rust remover doesn't seem to help much. The DHK from the 1Z engine was soaked in WD40 for about 48 hours (the glow plug was positioned so that the lubricant could pool). However, when removing it, it was clear that almost nothing had seeped through the threads.

Thanks and best regards. Oh yeah, the engine has been removed. I forgot to mention that, sorry.