Cracked head! Any help appreciated

[hayey1992]

Today we have gone to do the head gasket on our ml when We noticed we have a crack between the valves and the glow plug is it possible to have this repaired? If it is how would we go about doing it? Or will we need to buy a new one? Or will it be ok to drive? Any help would be great

 

[Frontstep]

Not to helpful an answer unfortunately but it depends on the crack and who is repairing it.

An engine reconditioning firm a proper one that is who are equipped and competent should be able to tell you.
Put your area on and someone may be able to steer you in the right direction.
As to driving we can't tell from here.
A picture may help.

 

[hayey1992]

I'm not sure if the picture has uploaded

 

[hayey1992]

We are local to peterborough

 

[Robg45]

Cracked head

Aluminium head ?

Can be welded but all depends where it is and how accessible it is to get to , there normally drilled at each end of the crack to stop the crack in its tracks then welded up with aluminium weld ...

I've not had success in cracked heads , ( motorcycle ones ) as too complicated to carry out , but where there's a will there's a way !!

 

[television]

Cast iron heads can be fixed with metal stitching, you could check to see if possible on alli

 

[hotrodder]

Yep, while cast iron's the most common suspect for metal stitching (aka surelock, lock 'n stitch etc) other flavours of metal can be repaired including aluminium. Some examples here... http://www.locknstitch.com/Repair%20pdf%20files/Aluminum%20crack%20inspection%20and%20repair%20examples.pdf

Pic's too blurry to see what's going on properly but if the crack is between glow plug and valve seats then if you carry on using it eventually a valve seat is gonna fall out and cause loads more damage

First thing i'd do is priced a used a cylinder head from a breakers personally... i've welded plenty of cylinder heads over the years but always rare ones and/or heads that have had loads of time/money invested in modifying them

 

[brianbrian]

Cracked head

I had a cracked head repaired by the engineering company who skimmed it. Cost 500 Pounds. Hope this helps

 

[EmilysDad]

.....
First thing i'd do is priced a used a cylinder head from a breakers personally... .....

Agreed, especially where the head is cracked

 

[turbopete]

I had a cracked head repaired by the engineering company who skimmed it. Cost 500 Pounds. Hope this helps

good used head would be cheaper, id imagine

 

[Alex Crow]

So that was the cause of the crank case breathing and pressure - why not update that thread?

The crack will have been caused by something, typically overheating, so you need to ponder what went wrong first.

As has been said, it is likely repairable for significant cost, but a used one would be a better option.
Also, repaired heads cannot be as strong as original, so even the best possible repair will not withstand the same thermal shock abuse the original did.

We do not usually see any such damage to Mercedes CDI cylinder heads or blocks, so I would be worried there are other undiagnosed issues (eg water pump impeller broken/corroded away).

A better picture will get better advice.

 

[Frontstep]

I have welded an aluminium head with a mig took quite a bit of preparation and drilling out to get to bottom of crack oh and a lot of overall heating to keep things straight.
It was an old Alfa I think and I couldn't find a head.
I dressed it with a Dremel and its still running around shows and things.

Having a father who used to make plane stuff helped though.

Getting a second hand one seems a much easier way though.

 

[SL63 Mark]

I agree with Alex, it's daft contemplating welding a head until you know what caused the crack. It would be a lot easier/quicker to buy a complete used one.

The only reason I had the cast iron head on my 1924 Ruston and Hornsby 3.5 hp agricultural engine welded was because they are simply unobtainable.

The head was cracked through frost damage, by the way.

 

[hayey1992]

We have had the head pressure tested and it passed, it's been skimmed aswel, now there has another problem arisen the number one injector once the bolt is removed has filled with water! Anyone know why this would be? It's only that one injector it had a diesel leak so my partners gone to fix it and that has happened but if the bolt is in it does not leak water, sorry to be a pain but I'm new to this site and this is our first ml we have had and the first he has ever worked on, it just seems to be one thing after another with the car and is close to being scrapped!

 

[hayey1992]

So that was the cause of the crank case breathing and pressure - why not update that thread?

The crack will have been caused by something, typically overheating, so you need to ponder what went wrong first.

As has been said, it is likely repairable for significant cost, but a used one would be a better option.
Also, repaired heads cannot be as strong as original, so even the best possible repair will not withstand the same thermal shock abuse the original did.

We do not usually see any such damage to Mercedes CDI cylinder heads or blocks, so I would be worried there are other undiagnosed issues (eg water pump impeller broken/corroded away).



A better picture will get better advice.

The engine that had the pressure build up has been changed

 

[Xtractorfan]

Water way below the injector bolt has been holed, I would suggest getting another head as now you have a head with two problems.

 

[television]

I agree with Alex, it's daft contemplating welding a head until you know what caused the crack. It would be a lot easier/quicker to buy a complete used one.

The only reason I had the cast iron head on my 1924 Ruston and Hornsby 3.5 hp agricultural engine welded was because they are simply unobtainable.

The head was cracked through frost damage, by the way.

I had the head of my 1928 RR20hp stitched by Metallock, it was fine for the 10 years I ran the car.

 

[oigle]

Did you change the full engine or only a short engine?
If you did the full engine, have you looked at the condition of the head on the old one? Might be better than the "new" one.

 

[Alex Crow]

The bolts will break out into the water jacket at the bottom, with very little excuse. This will happen if ANY debris remains at the bottom of the hole, and a bolt is screwed in.

We always clean out the bolt holes meticulously, to avoid this common issue.

The other possible cause is another crack, that was missed...

 

[Frontstep]

You could always take a bit off the bottom of the bolt and plug it with a soft washer the car seems to be building up problems.