Burnt out valve

2

2453kevinowen

Member
I been trying to set up the carbs on my 73 2000tc but with no success.
I took it to a garage and they could not get the carbs sorted, so they did a compression check which revealed number 3 has a burnt valve :( .
Why has the valve burnt out, I put castrol valve master plus in with the petrol
I am going to try and do the work myself, should I change all the valves while the head is off?
Where should I get the parts from.
Any advice will be welcome in getting the parts and in carrying out the work.
Regards Kevin.
 
Valves just burn out sometimes .Maybe no/not enough clearance , maybe running too hot / too weak
While you've got it stripped out replace any valves that are beyond being recut
 
The four pot head is easy to work on, as Dave said, they do just burn out. The P6 four pot seems to like doing it. Just changed the values that have gone. Make sure you inspect them all, when I did mine a few years ago only one cylinder was reading a low level but I found two of the others were cracked and looking to go.

Also try to source some spare shims. Might be worth whilst the head is off to check the side plates.

Don't forget to put the oil seal at the back of the head when you put it back on.

Follow the manuals head bolt undo sequence, some have seen cams snap when loosened off in the wrong sequence.
 
Never take a garage's word for things, Kevin. There's just an off chance you might have caught it with a tight valve clearance before it's completely shot....

Chris
 
Thank you all for your advice,I will checked the valve clearance asap, as always work comes first :(
I will let you know what my next step will be.
Regards Kevin.
 
I'd say that was the remains of coolant that's got in there and been festering away while the car has been lying unused. I'd inspect the head and the gasket for any signs of how it might have got in there.
 
2453kevinowen said:
Thanks Harvey for the quick reply I will have a look in the morning in the daylight
Click to expand...

Had a look at the head and gasket and they are OK
I did not tighten the spark plug up after the compression test so somehow or other the water had gone down the plughole because fatty deposits are all the way up the thread :oops:
 
Your cylinder head looks like it's stained with rusty deposits betwen the inlet valve and the water way so it could have been leaking coolant into the cylinder bore there.
 
testrider said:
Your cylinder head looks like it's stained with rusty deposits betwen the inlet valve and the water way so it could have been leaking coolant into the cylinder bore there.
Click to expand...

They do that when the inlet manifold gasket fails, or the manifold itself is so corroded that the gasket cannot help.
 
Demetris said:
testrider said:
Your cylinder head looks like it's stained with rusty deposits betwen the inlet valve and the water way so it could have been leaking coolant into the cylinder bore there.
Click to expand...

They do that when the inlet manifold gasket fails, or the manifold itself is so corroded that the gasket cannot help.
Click to expand...

here is the photo of the failed valve it looks like it been chipped not burnt could it be it was to tight ? http://i947.photobucket.com/albums/ad31 ... ves001.jpg
all the other valves look ok no scoring or pitting
 
Looks like you have done a nice job cleaning the head up.

When I did some work on my head, I set the valve clearances when I put the head back on. Ran the car for a while and rechecked. I found the clearances had closed up again slighty below spec. on some of the exhaust and inlet valves. So, I took the camshaft off again and set up the clearances for a second time. It was real pain but they have been OK for a few thousand miles now and the engine runs a lot sweeter.
 
Valves do occasionally chip like that, I had an 820 valve do that on me a few years back, just lapped in a spare valve I had and it was fine, never had another do it.
 
You must log in or register to reply here.
Back
Top