Bollocks!

Hello,

Well most of you know I've just completed my 200TDi conversion and I'm really impressed. It's always made a bit of a hissing noise under load though, so I swapped the copper washers on all four injectors today and it was still there. Turns out the head gasket is blowing right at the back! Bugger! Well I'm whipping the head off tomorrow and a company is collecting it, skimming it and brining it back later that day, or early morning the following day for £27. I've already got my elring (OEM) head gasket and manifold gasket at the ready. Just my luck! Got to drive from Leeds to Ipswich on Friday too. At least I can see whether my bores have still got the cross hatching marks and I suppose I know its good for another hundred thousand if not more .

Do I really need to skim the head just out of interest, or will a bit of emory cloth in the effected area do the job?

Good old land rovers!
-Pos

was head distortion the problem or did the head gasket fail

I dunno yet, I haven't taken the head off. I'm guessing it's just the gasket thats gone. It's the small length / strip of gasket between number four clylinder and the very edge at the back of the engine. It's only a narrow area. I hope the head isn't distorted - is that the reason for skimming?

-Pos

Err, no emery cloth will not do the same job as a preciscion milling machine!

AFAIK the leak will be lower than the rest of the head, so there's a lot of material to remove by hand to bring the rest of the head down to the same level...

yeah normally you only skim if you want to increase the compression ratio or have distortion in the head face, have you ever checked a head face before? are the company capable of crack testing the head? if you are sending it off it would be worth getting it checked

lerk said:

Err, no emery cloth will not do the same job as a preciscion milling machine!

AFAIK the leak will be lower than the rest of the head, so there's a lot of material to remove by hand to bring the rest of the head down to the same level...

Click to expand...

Alright, well off to be skimmed it is then - it's only £27. That shouldn't cause any issues with the valves or piston crown clearances should it? And what does AFAIK mean!!!???

-Pos

G-man said:

yeah normally you only skim if you want to increase the compression ratio or have distortion in the head face, have you ever checked a head face before? are the company capable of crack testing the head? if you are sending it off it would be worth getting it checked

Click to expand...

I've never checked a head before no because I don't have the tools or the equipment to do so accurately. I'm not too sure whether or not they're capable of crack testing either. I'd rather not go into that because if they find a crack I won't be happy and I can't afford to have it repaired How many thou / hundreds of a millimeter do they remove when skimming?

-Pos

AFAIK - As Far As I Know...

Once skimmed you'll need the right thickness Gasket to compensate for the missing metal, they are usually identified by notches on the edge. You'll need to know how much they skim off first though.

pos said:

How many thou / hundreds of a millimeter do they remove when skimming?

-Pos

Click to expand...

As much as they need to!

skim it and when fixed let it tick over for the afternoon to run in before your long run...

Ahh right. I don't lie the sound of this whole skimming business. I'll have a look at it tomorrow when it's taken off. So the main principle then, is that carbon will have built up where the gasket has been blowing, and that's what needs to be removed? So skimming is only technically really needed to ensure that the rest of the surface of the head is totally flat?

-Pos

Beast o Bodmin said:

skim it and when fixed let it tick over for the afternoon to run in before your long run...

Click to expand...

Ta.. will do. Bloody hell, I never had all this messing about with the head on the N/A when I did the head gasket. I just whipped it off, cleaned the gunk off with a chisel (not gouging it!) and then emory clothed the surface down. Whipped it all back together and whollah - no leaks! Then again i suppose that was cast iron, not a much softer aluminium. Still though - it seems like a lot of fannying around!

-Pos

it'd be cheaper if they find a crack now rather than wasting a headgasket set and having problems, to check a head face for distortion you need a flat bench and a strait edge, you put the head fac up on the bench and put the strait edge on the head face while looking across the face with your eyes level with it, you should see no light under the head face repeat across the whole face until you are sure it is either distorted or not,


oh and don't forget to clean the face first with medium to fine grit emery on a flat block using wd40 or duck oil as a cutting fluid

yep its easy to see when ther wrong.a good eye is all it takes.

G-man said:

it'd be cheaper if they find a crack now rather than wasting a headgasket set and having problems, to check a head face for distortion you need a flat bench and a strait edge, you put the head fac up on the bench and put the strait edge on the head face while looking across the face with your eyes level with it, you should see no light under the head face repeat across the whole face until you are sure it is either distorted or not,


oh and don't forget to clean the face first with medium to fine grit emery on a flat block using wd40 or duck oil as a cutting fluid

Click to expand...

That's the way forward, I'm liking the sound of that . So if I inspect the head, and it looks totally true. should I just clean it up with said emory cloth and some oil and it should be good for another gasket without the need for a skim jobby?

-Pos

pretty much, make sure both the head face and the block face are clean, also make sure you keep the bores clean and free of **** cause what is left after you have cleaned ( the oily mess) is like grinding paste and will ruin yer engine!

i used to use a steel rule ( a pukka one not a pound shop one) as a strait edge as strait edges are serious money, and i had a steel block(with a machined face) i used to use as a sanding block to avoid sanding low spots on ally heads

G-man said:

pretty much, make sure both the head face and the block face are clean, also make sure you keep the bores clean and free of **** cause what is left after you have cleaned ( the oily mess) is like grinding paste and will ruin yer engine!

i used to use a steel rule ( a pukka one not a pound shop one) as a strait edge as strait edges are serious money, and i had a steel block(with a machined face) i used to use as a sanding block to avoid sanding low spots on ally heads

Click to expand...

Right, thats brilliant. Well, I'm doing it all down at my local specialists, so I do have access to a whole world of tools, gadgets, gizmos, jigs and the like . I'll ask hem to double check with me that it's a perfectly flat surface. If it isn't, I'll get it skimmed - simple as. Should I get away with the standard gasket after skimming, or will I have to buy a thicker one as suggested earlier?

-Pos

ERM???? £27 are you sure?

pos said:

Right, thats brilliant. Well, I'm doing it all down at my local specialists, so I do have access to a whole world of tools, gadgets, gizmos, jigs and the like . I'll ask hem to double check with me that it's a perfectly flat surface. If it isn't, I'll get it skimmed - simple as. Should I get away with the standard gasket after skimming, or will I have to buy a thicker one as suggested earlier?

-Pos

Click to expand...

depends how much is skimmed off if they only take a gnats cock off it'll be al-reet, but if they take a ****load off you may need a thicker gasket, some engines you can get away with standard gaskets even with massive skims

pos said:

Hello,
Do I really need to skim the head just out of interest, or will a bit of emory cloth in the effected area do the job?

-Pos

Click to expand...

FFS pos you're always on here dishing out wisdom about engines and stuff then you come out with that! Can you see now why I had no interest in helping you fit that tdi you were going to buy off me? How long has you'r "quick" conversion been going on now?