Another burnt valve. Only 5 months since last one.

[flanagaj]

Beginning of May I stripped down my Daughter's 3 cylinder BMD engine and had new valve seats and the head skimmed as a result of poor compression. This solved the problem and the car ran fine. Cut a long story short the engine management light came on yesterday and it went into limp mode. Got the vehicle home and the fault code reader reported the dreaded miss fire on cylinder one. SO tonight I performed a compression test on all 3 cylinders and 2 / 3 are 180 and 1 is ? 80. I put some oil in one, but reading stayed the same.

Not only am I hacked off, but also miffed as to how a valve could have gone in just 5 months. I cannot remember if it was on 1 before, but is this more likely to be a cam problem causing the valve to go.

I appreciate that until I have the head off I won't be able to tell what has actually gone wrong. Any words of wisdom would be most appreciated.

[Ev996sps]

Beginning of May I stripped down my Daughter's 3 cylinder BMD engine and had new valve seats and the head skimmed as a result of poor compression. This solved the problem and the car ran fine. Cut a long story short the engine management light came on yesterday and it went into limp mode. Got the vehicle home and the fault code reader reported the dreaded miss fire on cylinder one. SO tonight I performed a compression test on all 3 cylinders and 2 / 3 are 180 and 1 is ? 80. I put some oil in one, but reading stayed the same.

Not only am I hacked off, but also miffed as to how a valve could have gone in just 5 months. I cannot remember if it was on 1 before, but is this more likely to be a cam problem causing the valve to go.

I appreciate that until I have the head off I won't be able to tell what has actually gone wrong. Any words of wisdom would be most appreciated.

Done a few,they say don't use cheap supermarket fuel,head off again,horrid job,,

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[flanagaj]

SO having removed the head I turned it upside down and filled each of the cylinder tops with water. Low and behold water quickly started draining from number 1 and out of the exhaust port. In fact I put my bright led light into the exhaust port hole and you could clearly see the ring of light around the valve.

Now the question I have is could a cheap lambda sensor have been the cause of this happening so quickly? The reason I ask is that the Lambda sensor that I fitted 5 months ago is very sooted up and I wonder if the valve didn't burn but has become slightly stuck open because of the excess carbon deposits.

I also would appreciate any pointers on the best way forward to fix this. The head that I put on had been skimmed and according to VW the BMD head cannot be worked and so now I am thinking that it will need to be a new head which from them is £1500. I would rather pay a bit more to get this done properly as the thought of doing this again in 5 months is soul destroying.

I will also going forward use high octane fuel too?

[Ev996sps]

SO having removed the head I turned it upside down and filled each of the cylinder tops with water. Low and behold water quickly started draining from number 1 and out of the exhaust port. In fact I put my bright led light into the exhaust port hole and you could clearly see the ring of light around the valve.

Now the question I have is could a cheap lambda sensor have been the cause of this happening so quickly? The reason I ask is that the Lambda sensor that I fitted 5 months ago is very sooted up and I wonder if the valve didn't burn but has become slightly stuck open because of the excess carbon deposits.

I also would appreciate any pointers on the best way forward to fix this. The head that I put on had been skimmed and according to VW the BMD head cannot be worked and so now I am thinking that it will need to be a new head which from them is £1500. I would rather pay a bit more to get this done properly as the thought of doing this again in 5 months is soul destroying.

I will also going forward use high octane fuel too?

Get your head to an engineering shop,have a valve seat insert fitted, new valve, off you go, another horrid job but easier after a few times,you could go mad and do all the exh valve seats to be sure if you needed to,

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[flanagaj]

I have found a company in Cornwall who do a whole exchange head for £225 + vat. Given the trouble I have had with the head on this one I think I am just going to go down that route.

[Ev996sps]

I have found a company in Cornwall who do a whole exchange head for £225 + vat. Given the trouble I have had with the head on this one I think I am just going to go down that route.

I agree,best of luck

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[flanagaj]

Thanks