I have a citroen van with the 1749cc? diesel engine the problem being that when under acceleration the engine started to produce a loud metalic ticking noise accompanied by a lack of power. First thoughts were that a foriegn object had entered an inlet valve. Second was that the timing belt had slipped. The engine though noisey restarted with no problem and no smoke, black or white came from the exhaust.
It started from cold no probs and ran smoothly though noisely but with still a lack of power. Having taken the head off it seems the pistons have been making contact with the inlet valves. All the timing holes were checked twice before taking of the head and proved to be in the correct position. No damage has occured to the head and there is only the faint imprint of the valves on the pistons.
The head was recently skimmed and according to the mechanic who done it the correct thickness of gasket used. This problem has us all scratching our heads with every scenario being discussed any one out there have any ideas?
Diesel Enging running rough without power
Moderator: RichardW
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Jon
Briefly.
Well if the valves have hit the pistons, then chances are that they are bent. Thats why it won't run right. I don't know what caused this. You say that the timing was spot on. I can only think that either too much was taken off the head by machining, or that the replacement head gasket was not thick enough.
Assume that, then the only way forward is to have the head checked, replace bent valves and lap the new ones in, set valve clerances, and refit head having checked that the head gasket being used is thick enough so that there is no possibility of valves touching pistons again.
Jon Wood
forum@andyspares.com
Well if the valves have hit the pistons, then chances are that they are bent. Thats why it won't run right. I don't know what caused this. You say that the timing was spot on. I can only think that either too much was taken off the head by machining, or that the replacement head gasket was not thick enough.
Assume that, then the only way forward is to have the head checked, replace bent valves and lap the new ones in, set valve clerances, and refit head having checked that the head gasket being used is thick enough so that there is no possibility of valves touching pistons again.
Jon Wood
forum@andyspares.com
I agree with Jon. It depends how much you have had skimmed off, you may as Jon says, have a gasket that is not thick enough, also the valves may be straight and lapped in when the head was off.
The danger is although your head has been skimmed, did your mechanic have the valve seats recut to keep the valve protrusion correct, otherwise you are in worse situation now than you were before the head was skimmed, hitting the pistons.
One final suggestion, although you say the timing holes line up etc. has anyone checked the woodruft key in the Camshaft timing sprocket. If that has sheared or nearly, your timing maybe correct with the holes etc., but a mile out mechanically.
Worth a check before she Blows.
Sooty
Edited by - sooty on 20 Dec 2002 19:31:38
The danger is although your head has been skimmed, did your mechanic have the valve seats recut to keep the valve protrusion correct, otherwise you are in worse situation now than you were before the head was skimmed, hitting the pistons.
One final suggestion, although you say the timing holes line up etc. has anyone checked the woodruft key in the Camshaft timing sprocket. If that has sheared or nearly, your timing maybe correct with the holes etc., but a mile out mechanically.
Worth a check before she Blows.
Sooty
Edited by - sooty on 20 Dec 2002 19:31:38
10 penneth worth coming on in!
Someone said previously about whether or no the valves had been , sorry, valve seats, had been recut to account for the headskim/protrusion. I reckon there-in lies the problem. I think if you were talking anything else likes the woodruff etc, you would have had more major problems by now. ( mind you - seen some veryyyy strange things !)
Too... I think checking, properley, whether or nay, the new head gasket really is the "proper" one would be worth some time.
I would say before you do much else - to ascertain several aspects ie, valve benditure ( thats a new word!! ) -- etc, have or do, a compression test - and check that the results are in line with spec.
Thats all I can think of for now....... keep us in touch as to how it goes..
mike
Someone said previously about whether or no the valves had been , sorry, valve seats, had been recut to account for the headskim/protrusion. I reckon there-in lies the problem. I think if you were talking anything else likes the woodruff etc, you would have had more major problems by now. ( mind you - seen some veryyyy strange things !)
Too... I think checking, properley, whether or nay, the new head gasket really is the "proper" one would be worth some time.
I would say before you do much else - to ascertain several aspects ie, valve benditure ( thats a new word!! ) -- etc, have or do, a compression test - and check that the results are in line with spec.
Thats all I can think of for now....... keep us in touch as to how it goes..
mike