Second head gasket in weeks 300tdi

[rijidij]

I recently replaced the head gasket on my 300tdi, including new bolts, but the new gasket has blown only a few weeks after fitting it.
I had the head machined, thoroughly cleaned the top of the block and torqued the head bolts as per the manual.

What would be the most likely cause, should I have used something like Hylomar on top of the block.

Any suggestions welcome.

Cheers, Murray

[dullbird]

did you check the block edge for straightness to?

I'm sure there has been someone on here that had endless head issues and the only thing overlooked was the face on the block had actually warped or something like that, once that was found it was sorted.

[steveG]

Did you lube under the heads of the bolts?
What type of head gasket?

How clean was the block - scotchbrite and acetone/thinners clean?

Steve

[Ancient Mariner]

Head gone soft:o

[THE BOOGER]

did you check the block edge for straightness to?

I'm sure there has been someone on here that had endless head issues and the only thing overlooked was the face on the block had actually warped or something like that, once that was found it was sorted.

Yep 3 head gaskets replaced new head ordered 3rd mech looked put straight edge on the block and that was the problem:(

[dullbird]

I was going to also say much like ancient M had could the head be soft?

Did you get a hardness test done on it after skimming.


Geoff I couldn't remember whether it was you it not with the block. There was another guy in here too that had endless head issues

[isuzurover]

Which head gasket did you use? What torquing procedure? Did you lube the bolt threads.

[rijidij]

did you check the block edge for straightness to?

I'm sure there has been someone on here that had endless head issues and the only thing overlooked was the face on the block had actually warped or something like that, once that was found it was sorted.

No, I didn't check the block surface, but certainly will when the head comes off again.


Did you lube under the heads of the bolts?
What type of head gasket?

How clean was the block - scotchbrite and acetone/thinners clean?

Steve

Yep, lubed the threads and under heads, and block was cleaned with scotchbrite and acetone.


Head gone soft:o

I had the head hardness tested. He said it was at the softer end of the acceptable hardness, but quite ok to re-use.


Which head gasket did you use? What torquing procedure? ..........

Replaced with the same 'three hole' gasket and followed the torquing procedure as per the workshop manual (rave disk).


Sounds like the main thing that needs checking is the top of the block for straightness.

Thanks for the great replies.

Cheers, Murray

[isuzurover]

Sounds like the main thing that needs checking is the top of the block for straightness.



Yes, but also use either an Elring gasket - or the Victor Reinz [sp?] one that Tank has mentioned. Also look at using a larger number of smaller angle increments (check Bush65's posts on this).

[dullbird]

I thought when you had it skimmed you had to change gasket size...or is the 3 hole already the thickest??

[bee utey]

You know there's a brand new head for sale on the forum:

http://www.aulro.com/afvb/verandah/205988-2-5-300-tdi-cylinder-head-brand-new.html

[isuzurover]

I thought when you had it skimmed you had to change gasket size...or is the 3 hole already the thickest??

The head gasket thickness is related to piston protrusion from the block. You only need to change it if you have the block machined.

[Jode]

The head gasket thickness is related to piston protrusion from the block. You only need to change it if you have the block machined.
But, yes, the three-hole gasket is the thickest standard gasket available.

[justinc]

But, yes, the three-hole gasket is the thickest standard gasket available.

The 'no hole' gasket (1.6mm) is actually the thickest one now, 3 hole (1.52mm IIRC) was up until a few years back.

JC