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[EXD]

Hi

I have changed the Headgasket's in my -95 MV6.
When the Cylinderhead's was of, I thought the easiest way to clean the surface was to mill of 0,1mm. 
So I did and put everything back: gasket, cylinderhead 
Now, when I'm about to put the new Timingbelt on, I cant rotate the crankshaft to Top Dead Center. It strikes something a few degrees before TDC. 
I thought it was a Valve the Piston struck...however i removed all the Camshaft's to be absolute sure nothing pressing down the valves. But nothing changed, it still strikes something! 
Tomorrow I will remove the Cylinderhead's to see what has happened. Before i put the cylinderheads back in the engine I could turn the Crankshaft around.  :-?
Does anyone have an Idea what's wrong??
Maybe some "thing" have fallen down in to the cylinder...but the Crankshaft stike's something even if I rotate the crankshaft counterclockwise, when the next cylinder is at top?!? Did some "thing" fell down in to two cylinders...I dont think so!

Another thing, a repairman told me:
The Cylinderhead's on the V6 engine to Opel (Vauxhall) must not be resurfaced! 
I was told that after I've resurfaced mine.
Have anybody done that, resurfaced the Cylinderhead's and got the engine to start??
The example he refered to was a MV6 that went hot and one of the Cylinderhead's became crooked. Then they resurfaced that Cylinderhead. After that the engine wouldn't start!?!?!
Someone been there?
Best regards Erik

[Abiton]

I wouldn't have thought 0.1mm was enough to cause a problem...unless someone has previously skimmed the heads???  :-/

[2woody]

1mm is a HUGE skim !

[Andy B]

1mm is a HUGE skim !

It is. But 0.1 is 90% less than that!       

[alank46]

Hi
Like you, I had one head skimmed before I found out that it is not advisable.  It was a lot more than 0.1mm as well, but I cannot remember how much now.  Actually I seem to remember that there is a figure in the WSM for the minimum depth to the head? and my machined head was less than that!
Anyway, my engine runs fine after the skim!
Alan

Hi

I have changed the Headgasket's in my -95 MV6.
When the Cylinderhead's was of, I thought the easiest way to clean the surface was to mill of 0,1mm. 
So I did and put everything back: gasket, cylinderhead 
Now, when I'm about to put the new Timingbelt on, I cant rotate the crankshaft to Top Dead Center. It strikes something a few degrees before TDC. 
I thought it was a Valve the Piston struck...however i removed all the Camshaft's to be absolute sure nothing pressing down the valves. But nothing changed, it still strucks something! 
Tomorrow I will remove the Cylinderhead's to see what has happened. Before i put the cylinderheads back in the engine I could turn the Crankshaft around.  :-?
Does anyone have an Idea what's wrong??
Maybe some "thing" have fallen down in to the cylinder...but the Crankshaft stike's something even if I rotate the crankshaft counterclockwise, when the next cylinder is at top?!? Did some "thing" fell down in to two cylinders...I dont think so!

Another thing, a repairman told me:
The Cylinderhead's on the V6 engine to Opel (Vauxhall) must not be resurfaced! 
I was told that after I've resurfaced mine.
Have anybody done that, resurfaced the Cylinderhead's and got the engine to start??
The example he refered to was a MV6 that went hot and one of the Cylinderhead's became crooked. Then they resurfaced that Cylinderhead. After that the engine wouldn't start!?!?!
Someone been there?
Best regards Erik

[Marks DTM Calib]

when assembling, the crank needs to be either 60 deg before or after TDC to ensue the pistons are at a safe point.

I do this from the word go but it must be done before cam fitting

[EXD]

The crankshaft was 60° before TDC when I installed the Cylinderhead.

Thanks Alan, that sounds reassuring.
I'm guessing two new Cylinderhead's wont come cheap...

[Andy B]

.....
I'm guessing two new Cylinderhead's wont come cheap...

No. But two 'new-to-you' heads shouldn't be too expensive. Do you have any local scrap yards/breakers? ( I assume you're on the European mainland somewhere )

[tidla]

keep your eye on the bay.

you can get lucky sometimes..

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=110581762569&ssPageName=STRK:MEWAX:IT

[M Kerr]

Valve to piston clearance  is very small.  The piston tops are grooved to facilitate the open valve when the piston is at TDC.  0.1mm does sound very small though.  Taking the cambelt off might not return all the valves to the closed position.  rather than go so far as to take the heads off just to check, why not just take the cams out then try to rotate the engine, if the engine then rotates the problem is valves but may not be the clearance.  as mentioned previously, setup engine to 60 deg BTDC and put the cams in accordingly etc.  (if the cambelts are fitted before atleast rough timing the cams it is quite possible that the pistons would hit valves although if you are only turning the engine by hand, you shouldn't have done any real harm and shouldn't need to take the heads off again)

Hope this is he;pful'

MK

[Marks DTM Calib]

Remember that you can view 12 of the valves fairly well with the inlets removed

[EXD]

Valve to piston clearance  is very small.  The piston tops are grooved to facilitate the open valve when the piston is at TDC.  0.1mm does sound very small though.  Taking the cambelt off might not return all the valves to the closed position.  rather than go so far as to take the heads off just to check, why not just take the cams out then try to rotate the engine, if the engine then rotates the problem is valves but may not be the clearance.  as mentioned previously, setup engine to 60 deg BTDC and put the cams in accordingly etc.  (if the cambelts are fitted before atleast rough timing the cams it is quite possible that the pistons would hit valves although if you are only turning the engine by hand, you shouldn't have done any real harm and shouldn't need to take the heads off again)

Hope this is he;pful'

MK

I have taken all the Camshaft's off, so the valve's are under no circumstancious affected...
Didn't help. I dont have any other idea what to do then to lift the heads...

[vexorg]

Sounds like a heads back off situation and see what's up.

Measure the thickness of the head when it's off to see it it has been over skimmed.

[Martin_1962]

Are plugs out?

[EXD]

I think I've found the problem!!

The Cylinderhead Gasket seems to be for a 2.5L engine!
So, the piston hit the gasket before the Cylinderhead...
I thought that the piston turned around before it reached the plane where the gasket was, but it just goes over.
I must say, It's really, really tight between the piston and the valve / cylinderhead.