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Rover 25 head gasket
Jasper - 22/2/12 at 02:59 PM

A mates got a Rover 25 1.1 with a knackered head gasket - no suprise there. It's never overheated badly so I should think the head is ok, it's got mayonnaise in the expansion tank, but the oil in the engine is clean.

So I'm gonna give him a hand next week to fix it. Am I right in saying while we're there we should do the water pump, new oil and filter and cam belt? Anything else we should be swapping over, and anything I need to know? I was just going to following a Haynes manual to do it. I was going to get the parts from my local friendly car parts emporium.

[Edited on 22/2/12 by Jasper]


roadrunner - 22/2/12 at 03:06 PM

I would if I were you. I f a jobs worth doing, its worth doing it wright.


steve m - 22/2/12 at 04:25 PM

Jasper ,

Is it a twin cam k series? as if it is, it makes life so much easier if you lock the cam pulleys together, while the head is off

If u u2u me your address, i will pop in the post my old one, (i wont be buying a nother Rover!)

I dont know the 25, but my olf 45 and 75 k series , were pretty easy to fix
just make sure the inlet mainfold gasket is new

steve


britishtrident - 22/2/12 at 04:30 PM

before you start make 100% sure that the water loss isn't from a leaking inlet manifold gasket or leaking rad ----- the spec of the manifold gasket was changed becuause they leak at the corners and Rover radiators get leaky but the 25 1.1/1.4 rads are very cheap to replace.


Best to treat the head gasket and cam belt as separate jobs, do the gasket get it running then if its due do the belt and tensioner.
ISTR all 1.1 twincams were on the 48,0 00 mile change interval. later K engines used a wider belt and a different tensioner. so measure the belt width and be 100% sure you have the right parts before you start.

Before starting the job read the manual and stick to the procedure too the letter.
These engines are timed at half stroke the engine must be set to half stroke before lifting the head. No special tools are required but Laser do a cam locking tool that makes things a lot easier and can be found for buttons on the internet see

Laser K16 tool 2626

The only must have tools for head gasket are a decent 3/8" drive lowish range torque wrench and the correct Torx socket. The alternator belt tensioner is released by turning back with a 13 mm ring spanner and is then pinned by insert a pin into a hole in the tensioner body.


Best/easiest to split both the manifolds from the head, the inlet manifold should always be replaced, improved modified part is colour coded bright green.
Do not disturb or remove the cam carrier or cams from the head, if you do you will add a couple of hours to the job and need the correct sealant.

For replacement gaskets there is a choice the original Paynes gasket should only be used if the engine is suffering from dropped liners. Normally the later dual layer gasket is the first choice. The modified block ladder sold with some kits is not required.

The head bolts can be re-used unless the they have been reused 5+ times already, but the threads must be cleaned but not oiled.
When replacing the head bolts getting the first stage of the head bolt tightening right is critical get it wrong and all subsequent angular tightening stages will be worthless.


[Edited on 22/2/12 by britishtrident]


britishtrident - 22/2/12 at 05:17 PM

Part 2 the cam belt

When removing the lower engine mounting take care to note where each bolt as different bolts lengths and threads are used.

The crank pulley bolt will be very tight and difficult to undo but a long bar jammed against ground and a kick or several with the starter motor works.

Before completely removing the pulley bolt set the engine to half stroke line up the marks and lock the top end with the Laser locking tool.
New belt goes on top first then bottom, NB:
both toothed sprocket and outer pulley are drive by a "D" flat on the crank make 100% sure the outer pulley is correctly located on the D flat and use a suitable grade of Loctite on the bolt, the torque figure quoted for the crank pulley bolt varies depend on the manual you read but 175 to 200 nm should fine in other words bloody tight.

[Edited on 22/2/12 by britishtrident]


britishtrident - 24/2/12 at 08:18 AM

More info

Forgot to say use Loctite on pulley bolts and don't rotate the crankshaft with head off unless the liners are restrained with a special tool.

Head gasket info below

k series head gasket info
k series head gasket info


Jasper - 24/2/12 at 12:02 PM

Right all seems a bit more complicated than I envisaged! Last time I did a head gasket was on a Mini.

Really appreciate all the info. How do we tell if the leak is at the inlet manifold rather than the head? And do we really need a new inlet manifold as my mate is skint and we're doing it on the cheap, can't we just do the gasket?

And do I need a special tool just to do the head gasket to lock the cams.?



[Edited on 24/2/12 by Jasper]


britishtrident - 24/2/12 at 02:08 PM

The tool is less than a fiver and cuts the time to do the job by an hour because it saves an awful lot of fiddling faffing and double checking.

Just a new manifold gasket must be the green plastic rubbery thing. usually loads on ebay where you will also cheap head gaskets.
Head gasket is actually simpler to do than the the BL Mini loads more room to work on the 25, only really fiddly bits are pinning back the alternator belt adjuster and replacing the M8 nuts on the inlet manifold to cylinder head joint. a deep 3/8" drive 13mm socket is the best tool for this ---- the studs are hard to get into and it is easy to drop the nuts when you try to put them on so I always have a few spare nylocs and washers handy.

The main thing is set the engine to half stroke by lining up the marks before you start, undo the head bolts in the roughly reverse order of the tightening sequence.

With the new type mulit-layer gasket the carbon build up on the top of the liners has to scrupulously cleaned off as the new gasket has wider fire rings round the top the bores than the old style same goes for where it meets the head.


And....... don't disturb the camshafts you don't need to head comes off as a unit with the cam carriers and cams.


[Edited on 24/2/12 by britishtrident]

[Edited on 24/2/12 by britishtrident]


Jasper - 24/2/12 at 02:31 PM

Ahh - that's clear now - and I really appreciate the details instructions, thanks

And Steve is sending me the tool - thanks mate