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Discussion Starter #1 (Edited)
my car is throwing oil from the valve cover cap, if I remove it blows air, I guess the compression is escaping, it runs rough when in idle and loss of power when I drive it, I found some oil in the turbo too. Could anyone advise what test should I start with to find the problem?? I don't want to remove the head just to find out that was not the problem, even though I assume by the behavior of the engine that I have a serious problem with the head, valves or piston rings.
Thanks.
 

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my car is throwing oil from the valve cover cap, if I remove it blows air, I guess the compression is escaping, it runs rough when in idle and loss of power when I drive it, I found some oil in the turbo too. Could anyone advise what test should I start with to find the problem?? I don't want to remove the head just to find out that was not the problem, even though I assume by the behavior of the engine that I have a serious problem with the head, valves or piston rings.
Thanks.
The breather assembly in the valve cover might be clogged up, so pull that and see if it's functioning correctly. Diesels tend to develop a fair amount of crankcase pressure.

The loss of power might be delivery valve seals or another fuel-related issue. Try swapping in new fuel filters and ensuring that the tank screen is free and clear. A compression test will help determine whether you have combustion chamber issues associated with your blow-by or running condition problems.
 

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Discussion Starter #3
I did a compression test and found 240 in cylinder 1 and no compression on cylinder 2, at this point I have a serious problem, what could be the cause of no compression?? I'm thinking a bad valve (I really hope not a damaged piston).
 

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Yikes! You'll need to pull the head at the very least. With no compression at all, it should be making all kinds of racket and run extremely rough.
 
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