Cracked head at injector base!!??

[Black Smokin' Diesel]

This happened while removing injector #2. It was pretty tight (more than the others). I applied constant force to free it at first (didn't pull hard many times) and started to loosen it. Then BANG!!! This crack appears on the head!

"WTF OMG MY HEAD IS SCREWED!!!" I thought.


Now I know the head is screwed, the crack reaches the threads inside the head. I can feel a "step" on the threads. If I ever try to torque down a new injector the "cup" is gonna break off the head.

What I'm wondering is "how did it crack while loosening it?" It was pretty cold, maybe -5°c, did it cause the aluminum of the head to contract so much it broke with the force?

I'm not very frustrated, it's better now than AFTER P&P and all that jazz. Still... I need to find a new head, that's the worst part I think  

[malone]

You're not supposed to pull your ratchet/breaker bar/whatever towards you to loosen the injector. You're supposed to push the bar away from you so the injector will lean against the head (the opposite direction of where your crack is) while it's being loosened.

That sucks some 1.6 heads aren't expensive, fortunately.. were you planning on rebuilding a head?

[Black Smokin' Diesel]

Thanks for the tip Malone. Unfortunately, I was pushing toward the head when it happened  :?  

It makes things even more mysterious. Ohhh the drama!

[HP]

It was pretty cold, maybe -5°c, did it cause the aluminum of the head to contract so much it broke with the force?

I thought 1.6L heads were steel! Aren't they? I think I read that somewhere. At least the 1.6TD ones!
By the way, the blocks. They are made of iron, right?

[Black Smokin' Diesel]

Yes Iron block and aluminum head on all 1.6 diesel and later 1.9. Don't know about 1.5, probably aluminum too.

[malone]

Interesting.. it could be the cold temp as you stated or the previous owner overtightened the injector at some point, or likely both.

Seeing as this happened I'll lightly pre-heat my injector bases prior to removing injectors (unless the engine can run and be warmed up), if the temps are real low here.

[Black Smokin' Diesel]

Interesting.. it could be the cold temp as you stated or the previous owner overtightened the injector, or likely both.

Seeing as this happened I'll lightly pre-heat my injector bases prior to removing injectors (unless the engine can run and be warmed up), if the temps are real low here.

Thats a good idea. I never ever thought it would happen :? I'm lucky it didn't happen with the engine in the car. Now that would've sucked.

[RabbitGTDguy]

I cracked mine on the old 1.6 NA engine that was orginally in the Rabbit that I have... Mine was so bad the piece actually fell off. I took it to an experienced welder and he was able to weld it for me and it worked fine. Never had a problem with it. Injector screwed in and still sealed as well... I think you could still use it if you want. My repair cost me like $45 at the time...

Joe

[Black Smokin' Diesel]

I cracked mine on the old 1.6 NA engine that was orginally in the Rabbit that I have... Mine was so bad the piece actually fell off. I took it to an experienced welder and he was able to weld it for me and it worked fine. Never had a problem with it. Injector screwed in and still sealed as well... I think you could still use it if you want. My repair cost me like $45 at the time...

Joe

You really think it can be fixed? That would be great!

[RabbitGTDguy]

trust me...that doesn't look half as bad as the one that cracked on me...like i said, a part of the boss actually came off... in a "cone" V style piece... stunk... It was fixed and I didn't have problems with it leaking, etc. and it still maintained is mpg, etc. Might be something you want to look into... your fix is much easier...

If you do go the route of another head....don't throw that one out...

Joe

[Black Smokin' Diesel]

I'll look into that once I get the head off. Stupid stripped head bolts are driving me crazy lol

[Black Smokin' Diesel]

Since you guys say it can be fixed, I'll give it a shot a take the head to a shop.

Thanks for your input!

[fspGTD]

Black Smokin', when I have had my head aluminum welded, my engine builder had to completely strip it down so he could pre-heat it in an oven prior to welding.  But the welding repair he did was to cracks between the valve seats which had pressed in steel inserts, so maybe he felt those had to be removed to weld the nearby aluminum area and that would have necessitates basically disassembling the head entirely.  Since your crack is not very close to any of those pressed in steel parts, hopefully you will be able to successfully have it aluminum welded without it needing to be stripped down.

Let me provide what I know about aluminum welding a big chunk of alumunum, like your cylinder head.
* It is a BIG heat sink, so may be difficult for average people even those experienced with thinner-gauge TIG welding to handle.
* Usually AFAIK, people preheat such a large aluminum object in an oven prior to welding with TIG (to a temp of something like 400 deg. F).  If that much preheating may do something bad to a completely assembled head like smoke the oil, but I'm not sure.  If the head need to be stripped down before welding, there is probalby not much additional cost to have it rebuilt.
* There IS an aluminum welding process that can be used on heavy aluminum pieces such as a cylinder head without any pre-heating!  But, very few people will probably have experience with it as this need doesn't arise often.  It involves using TIG process but set up with expensive, highly pure helium shielding gas (instead of the argon gas mixture usually used for TIG welding aluminum) and a TIG welder set to DC current.  I can't remember if the electrode polarity is negative or positive, but if you find the right guy for this job, he should know.  And hopefully has practiced on a junk head if this is his first!

If you fail to find someone who can repair it by welding without complete disassembly and rebuilding of the head, consider a repair using JB Weld or Marine-Tex high strength, high temp epoxy as a less expensive alternative to rebuilding the head.  If you try this yourself, you will probably want to widen the crack out to allow you to get full contact of the exoxy on the cracked surfaces.  You will need to be able to restore the threads afterwards unless you can manage to keep the epoxy from getting in.  You might want to practice your epoxy on some other piece of cast aluminum similar to your head and see how well it holds.

Be sure to fully clean and threads in your head and on the injector, and apply an even coat on anti-seize to them.  Torque using an accurate torque wrench, towards the head as others have described, and do not exceeding the torque spec.

Good luck, will keep my fingers crossed!

[tylernt]

I routinely soak them with penetrating oil over a few days interspersed with driving the car.

Seconded. I just discovered this stuff called PB Blaster -- way better than WD-40, the stuff is amazing at what it will break loose.

[Black Smokin' Diesel]

Thanks a lot for the info fspGTD. I have to have the head striped anyway to replace the guides and P&P the ports.

There's a diesel shop in my area, I'll hook up with them. They probably know a lot about VWs, there are lots of diesels here.

I don't think I'll go the DIY way for this. It's a relief to know it can be fixed.    

Thanks again guys!