I have now a case that 2011 2,3 JTD 150 has 2 tooth jump (counted in Cam Sprocket).
What is strange that the direction is that way that the Cams are now 2 tooth / 14 degrees forward (I would have expected that Cams would be delayed).
The reason for jumping is clear, water dropping between windscreen and plastic cover into timing belt box and freezing there.
The issue is not coming in Firing phase (as both valves are nicely closed in good time), it is coming in exchange phase when after firing exhaust valves open and are starting closing before piston is up. No real issues with exhaust valves as they are now running away/closing sooner than normally.
The problem is now the inhoust valve as they now start opening earlier than normally making it possible that they hit the piston that is coming up.
2,3 JTD seems have some clearance still, and what is strange to 16v engine is that valves are straight against pistons.... might help a bit.
One issue is that I have not been able to find any valve timing info for the engine. Nor have measured that myself.
There have been also discussions that JTD engine has rockers as 'releasevalve' so that they will bend/let go before valve/piston fails.
Back to the question : how many jumped tooth you have been survived without major engine break?
My next step tomorrow is try to have 5,5 mm endoscope/camera thru injection nozzle hole to see if any marks in piston.
BTW anyone having info about the hole size in head?
BTW2 The engine is most difficult designed I have seen, the designers should be convicted to maintain/service the engines they design for next 3 years. It would help a lot getting easier designs
BTW3 it even looks that it is intentionally build complex to ensure big aftermarket business as too difficult to do service in home garage, or at least enough invoiced hours in official service....
What is strange that the direction is that way that the Cams are now 2 tooth / 14 degrees forward (I would have expected that Cams would be delayed).
The reason for jumping is clear, water dropping between windscreen and plastic cover into timing belt box and freezing there.
The issue is not coming in Firing phase (as both valves are nicely closed in good time), it is coming in exchange phase when after firing exhaust valves open and are starting closing before piston is up. No real issues with exhaust valves as they are now running away/closing sooner than normally.
The problem is now the inhoust valve as they now start opening earlier than normally making it possible that they hit the piston that is coming up.
2,3 JTD seems have some clearance still, and what is strange to 16v engine is that valves are straight against pistons.... might help a bit.
One issue is that I have not been able to find any valve timing info for the engine. Nor have measured that myself.
There have been also discussions that JTD engine has rockers as 'releasevalve' so that they will bend/let go before valve/piston fails.
Back to the question : how many jumped tooth you have been survived without major engine break?
My next step tomorrow is try to have 5,5 mm endoscope/camera thru injection nozzle hole to see if any marks in piston.
BTW anyone having info about the hole size in head?
BTW2 The engine is most difficult designed I have seen, the designers should be convicted to maintain/service the engines they design for next 3 years. It would help a lot getting easier designs
BTW3 it even looks that it is intentionally build complex to ensure big aftermarket business as too difficult to do service in home garage, or at least enough invoiced hours in official service....
