head gasket problems

packers · September 17, 2010, 04:28:28 PM

Help second blown head gasket in 3 months despite using new bolts +gen VW gasket.
only thing that i am not sure about is the guy who skimmed the head was concerned
that the valve faces are almost flush with the head itself will this cause very high compression ratio leading to the failure or am i looking in the wrong area.any advice appreciated

hayesey · September 17, 2010, 05:04:25 PM

it's a flat head anyway so that's not going to be a problem. Are you using the correct g40 gasket (or the 6n metal one) and are you doing the bolts up to the correct torque? Is the torque wrench you are using knackered?

packers · September 18, 2010, 12:51:48 AM

py engine gasket as vw spec torqued to 30 stage 1+-44lbs stage 2+ 90 degrees times 2
torque wrench is fine dam thing could not be tighter but fails every time.?

hayesey · September 18, 2010, 08:48:50 AM

Maybe the block is warped

packers · September 18, 2010, 10:39:56 PM

I was hopeing that was unlikely but if the problem isnt the head or gasket then it
does seem the only option left. cheers Hayesey

packers · November 19, 2010, 04:59:24 PM

Fitted a block i got off pete g40 worked fine for 3 weeks now back to water leaking into no 1 pot. am running out off options

hayesey · November 19, 2010, 05:27:50 PM

perhaps get a 2nd opinion on the condition of the head?

also, are you sure the torque wrench you are using to do up the head bolts is OK? This could be caused by over or under tightened bolts.

samg40 · November 19, 2010, 08:37:07 PM

If you want a second opinion on the head I use Rotherham Engine Supplies in Wincobank. I've had two heads done there and they've both been spot on.

The torque wrench could be an issue though like Hayesey says maybe?

Turbodaily · November 19, 2010, 10:58:18 PM

Yeah, i would be looking at getting the torque wrench calibrated/checked

Tommo · November 20, 2010, 09:38:14 AM

Im guessing they arent going due to detonation?

packers · November 22, 2010, 08:59:15 PM

Dont think detonation is the cause .Engine runs fine and problem only ever occures in no 1 cylinder causing coolent to leak in .

brownysblower · November 22, 2010, 09:24:42 PM

did you clean the threads in the block. and allways start engine without water in for 2 mins to bond lacquer to head and block then put G12 anti freeze in

Yoof · November 23, 2010, 06:45:14 AM

Quote from: brownysblower on November 22, 2010, 09:24:42 PM
did you clean the threads in the block. and allways start engine without water in for 2 mins to bond lacquer to head and block then put G12 anti freeze in

That will happen anyway, even with coolant in- you're better to run coolant from the outset as your water pump won't run dry then.

hardchargin40 · November 23, 2010, 08:05:15 AM

So there's definately no micro cracks in the head around No1 then? Or has the head guy gone over it with a fine tooth comb?

packers · January 09, 2011, 07:14:49 PM

Got hold of replacement head from local scrap yard had it skimmed and cleaned been fitted 5 weeks now and no probs so whatever the fault was it was in the old head although visual inspection seems fine . thanks for your input.