K series head damage

chris75 · 22nd June 2009, 21:35

Photos of a k series head I took off today due to a severe HGF .With cyl no.1 on the left , there is pitting corrosion right next to the fire ring on no2 at 6 o'clock , no 3 at 1 o'clock and no4 at 6 o'clock ; hope the photo is good enough ? The head had been skimmed before so I'm guessing this is the end of the road for this head . Any thoughts , folks ?
The block and liners are good , but there had also been a leak on the manifold gasket at no4 inlet .

kaiser · 23rd June 2009, 02:59

You can't tell from the photo. It does not look like aluminium corrosion, so it could be the ring in the gasket, that has corroded? If the head is scrap?
There is only one way to tell, and that is to measure.!

And, if this corrosion has taken place, it looks as if the antifreeze has been neglected.

I would not assume the liners are good. Firstly I would measure the protrusion of each, because these leaks have a reason.

Secondly I strongly suspect a leak behind the liner(s), and most likely corrosion.

It would be tempting faith not to remove each liner and seal it again, properly.

chris75 · 23rd June 2009, 10:28

THanks Kaiser .
The head is not warped at all , but the corrosion is into the aluminium alloy face of the head and it is this which is concerning me. THis is actually a 416 engine of 1998 vintage, and has always had the green eth. glyc. antifreeze as recommended by the handbook. If I resurrect it , will use the red OAT from now on as the green didn't seem to work very well !
Liners are sitting between flush and 2 thou proud of the block . Is this within limits ?
Will look for a second hand head as the car is not worth much.............
Incidentally, I did try K-Seal on this engine and whilst it appeared to work at first , it didn't last ; think I was asking too much of it .

kaiser · 23rd June 2009, 16:12

I think that zero protrusion is allowable, but you must check. If the head is not flat, where it is corroded, then obviously the clearance will be greater.
I would consider a light skim.
I think you are right, it is perhaps asking too much of K-seal in that area, as this is a high pressure area, where the gas/exhaust gas will move back and forth.
Which reminds me, I have to do an update on my 1.8T, which is still fine.
As for the green antifreeze, it normally works beautifully, but it only lasts for about two years. Also, if you have had water loss associated with your HGF, then you would most likely have diluted the concentration of antifreeze.

I use the green stuff, simply because it costs much less, and I am sure that somehow I will never get to run the car for more than two years, before something goes wrong, and I will have to drain the cooling system anyhow!!

Fraser Mitchell · 23rd June 2009, 19:27

Apart from heat warping, AFIK the head becomes scrap if the fire rings wear grooves in the head, as these heads should not be skimmed, (apart from a light clean-up job). The grooves prevent the fire rings on the new gasket from sealing properly leading to continual HGFs. Corrosion where the rings contact the head is also a failure situation.

The new MLS gasket, with its shim between head and gasket may, of course,allow heavier skims as the fire rings are no longer in contact with the aluminium of the head, but the grooves must not be present whatever the gasket

23rd June 2009, 10:28	#3
chris75 same car since 2005 2001 Rover 75 2.0 v6 Connoisseur Saloon Join Date: Nov 2006 Location: Ellesmere Port , Cheshire Posts: 3,811 Thanks: 379 Thanked 549 Times in 466 Posts	THanks Kaiser . The head is not warped at all , but the corrosion is into the aluminium alloy face of the head and it is this which is concerning me. THis is actually a 416 engine of 1998 vintage, and has always had the green eth. glyc. antifreeze as recommended by the handbook. If I resurrect it , will use the red OAT from now on as the green didn't seem to work very well ! Liners are sitting between flush and 2 thou proud of the block . Is this within limits ? Will look for a second hand head as the car is not worth much............. Incidentally, I did try K-Seal on this engine and whilst it appeared to work at first , it didn't last ; think I was asking too much of it . __________________ Who said it was simples ?

23rd June 2009, 02:59	#2
kaiser This is my second home 75 Tourer 2.5 Auto, 1.8T, 75V8ZT Join Date: Jun 2007 Location: Johannesburg ZA Posts: 6,200 Thanks: 1 Thanked 859 Times in 613 Posts	You can't tell from the photo. It does not look like aluminium corrosion, so it could be the ring in the gasket, that has corroded? If the head is scrap? There is only one way to tell, and that is to measure.! And, if this corrosion has taken place, it looks as if the antifreeze has been neglected. I would not assume the liners are good. Firstly I would measure the protrusion of each, because these leaks have a reason. Secondly I strongly suspect a leak behind the liner(s), and most likely corrosion. It would be tempting faith not to remove each liner and seal it again, properly.

23rd June 2009, 16:12	#4
kaiser This is my second home 75 Tourer 2.5 Auto, 1.8T, 75V8ZT Join Date: Jun 2007 Location: Johannesburg ZA Posts: 6,200 Thanks: 1 Thanked 859 Times in 613 Posts	I think that zero protrusion is allowable, but you must check. If the head is not flat, where it is corroded, then obviously the clearance will be greater. I would consider a light skim. I think you are right, it is perhaps asking too much of K-seal in that area, as this is a high pressure area, where the gas/exhaust gas will move back and forth. Which reminds me, I have to do an update on my 1.8T, which is still fine. As for the green antifreeze, it normally works beautifully, but it only lasts for about two years. Also, if you have had water loss associated with your HGF, then you would most likely have diluted the concentration of antifreeze. I use the green stuff, simply because it costs much less, and I am sure that somehow I will never get to run the car for more than two years, before something goes wrong, and I will have to drain the cooling system anyhow!!

23rd June 2009, 19:27	#5
Fraser Mitchell Gets stuck in Rover 75 2.5 V6 Club Auto Join Date: Feb 2007 Location: Crewe Posts: 898 Thanks: 0 Thanked 0 Times in 0 Posts	Apart from heat warping, AFIK the head becomes scrap if the fire rings wear grooves in the head, as these heads should not be skimmed, (apart from a light clean-up job). The grooves prevent the fire rings on the new gasket from sealing properly leading to continual HGFs. Corrosion where the rings contact the head is also a failure situation. The new MLS gasket, with its shim between head and gasket may, of course,allow heavier skims as the fire rings are no longer in contact with the aluminium of the head, but the grooves must not be present whatever the gasket