Skim Head?

[Furryballer]

Hi All,

Looks like I have a head gasket issue between cylinders and wnated to know if I should get the head skimmed as a standard practice whilst its off.

The engine was supplied as new/reconditioned in 2005 and I've not done that amny miles since.

Any advice would be appreciated.

[bmcecosse]

Not unless you see any obvious damage. Hopefully you didn't drive the car any distance with the gasket blown...... Who supplied the engine - and was the head re-torqued after the first heat cycle? That's MOST important!! When fitting the new gasket - make sure both faces are spotlessly clean, make sure the studs are all firmly set in the block, spread a v thin smear of clean grease on both faces and fit the head, torquing to 44 ft lbf in easy stages. Set the valve gaps to 12 thou inlets and 15 thou exhausts. Run the engine up to full temperature, allow to cool - then retorque, and re-set the valve gaps. Job done !
It would be worthwhile grinding in the valves if you have the time - before refitting the head.

[Furryballer]

Thanks for the advice. Didn't think I had to, but always worth asking.

Just wait for the bits to arrive before diving in!

[bmcecosse]

Bits to arrive ? You get a head gasket from your local Autoparts place for ~ £4.......

[dellerie]

out of interest here, i recently fitted a head gasket. after 100 miles, i've gone to re-torque it, but it didn't need doing... or rather the torque clickedat what i'd set it at first of all. 44LB.

is that normal?

[phurn]

Yeah mine was the same.

[chrisryder]

when you re-torque aren't you meant to loosen each nut off and re-torque one at a time?

[Neil MG]

If they don't move it is good engineering practice to back off a few degrees before applying the torque. That removes the "stiction" - sticking due to friction that might give a false indication of clamping force.

I drove round in mine for a couple of weeks before doing a re-torque and each nut turned about 40 to 60 degrees. Maybe I was lucky not to blow the gasket, but expect it's pretty tight now!

[bmcecosse]

I suggest retorque after the first heat cycle - the threads are still nice and oily then! I would NOT go back to it after that. And certainly don't do any 'backing off'!

[dellerie]

I suggest retorque after the first heat cycle - the threads are still nice and oily then! I would NOT go back to it after that. And certainly don't do any 'backing off'!

whilst its hot or cold? i did try when it was cold.

[bmcecosse]

Pretty much as it is cooling down - but I would certainly do it before it was started again.

[chrisryder]

I suggest retorque after the first heat cycle - the threads are still nice and oily then! I would NOT go back to it after that. And certainly don't do any 'backing off'!

define 'retorque' then if you don't back it off, as has already been mentioned you will find the nuts as tight, or tighter than they were torqued to firstly. do you torque it first to a lower value, and after the first heat cylcle go up to full torque?

[Edit = spelling]

[Neil MG]

I suggest retorque after the first heat cycle - the threads are still nice and oily then! I would NOT go back to it after that. And certainly don't do any 'backing off'!

define 'retorque' then if you don't back it off, as has already been mentioned you will find the nuts as tight, or tighter than they were torqued to firstly. do you torque it first to a lower value, and after the first heat cylcle go up to full torque?

[Edit = spelling]

Definitely not drive the car without full torque on the head nuts! If the nuts move on re-torque then no need to back off, but if any do not move it is good engineering practice to do so. Backing off only needs to be a few degrees (just a movement) and so will not have any significant effect on clamping force. That said it is unlikely there will be much "stiction" but I am very surprised that two contributors have said that after driving the nuts achieved re-torque without turning. I have never experienced that, certainly not on all nine!

[chrisryder]

I have never experienced that, certainly not on all nine!

me neither, that's why i back off. i only back off one, then re-torque that one so it's held pretty firmly by the other 8 nuts! and go around all 9 in the circle pattern.

[bmcecosse]

I've always found they pull round about 1/4 turn on the retorque - I certainly don't do any slackening off! Same torque setting used - 44 ft lbf on 'dimple' studs and non flange nuts - and with a washer under each nut, 50 ft lbf on 'Y' studs with flanged nuts. Always oiled threads. Each to their own - I merely offer what has worked well for me over the years........

[phurn]

Mine didn't budge at all... I even tried it a few days later incase is gone wrong, but it clicks straight out. Mine is Abit tighter than 44lb/ ft though..... I went with the recommend tightness written on the gasket instructions of 56lb/ft, 3000 miles later I've got no problems.

[dellerie]

i've done 150 mile since i changed it now. no problems at all. pulls like a train. i think i'll leave it for now

[bmcecosse]

I've NEVER seen 56 ft lbf recommended - certainly not by MG/Rover. If you really have done it to that torque you have been very lucky not to snap a stud/rip the stud out of the block. That is FAR too high a torque figure for an A series engine.

[phurn]

Yeah I guessed I was lucky a few days later when someone on here snapped a stud at a much lower torque setting!