Well after thinking I'd cured the vibration/shudder in my 2001 TD5 auto discovery it's back again with vengeance. A local specialist diagnosed a badly worn and noisy transfer box so was trusted to do the job as I don't have the facilities to drop the gearbox or transfer box. Things were a little better for a short time but still not cured. As usual after any remedial work to sort the issue it seems just that little bit better but the shudder and vibration returned.
I'm erring on the side of it being injectors. Something I've considered before but sheer cost has pointed me away from. I today tried the test that I spotted in the rave manual where exhaust manifold temperature is taken as the engine warms up. Initially the manifold at cylinder 2 is slow heat with the temp being a long way behind other areas next to other exhaust ports. As I Rev the engine to 2100 revs where the lumpiness begins number two port reaches the same temp as 1,2 and 3 but one port temp drops from about 100c to as low as 25c (using a infrared temp gauge). Could this be because that cylinder stops firing at those revs. There seems to be no power loss from the engine just a horrible lumpy vibration that reduces at about 2400 revs. I know it's a well known problem with the autos but as yet after reading many many many forums and long threads no one has yet solved the issue.
I have before installed a set of used injectors but the results were just the same, vibration still there at those revs. I today measured the resistance on those injectors and they vary from 1.1 ohms to 1.9 ohms with the others being around the 1.3ohm average, were they dodgy?
By the way I think I have tried everything else from engine mounts to a refurbished head and everything in between, at quite a cost. Any ideas would be welcome. Other than change the D2 for another car that is (though that is being considered). Love the D2 but hate the vibration.
I'm erring on the side of it being injectors. Something I've considered before but sheer cost has pointed me away from. I today tried the test that I spotted in the rave manual where exhaust manifold temperature is taken as the engine warms up. Initially the manifold at cylinder 2 is slow heat with the temp being a long way behind other areas next to other exhaust ports. As I Rev the engine to 2100 revs where the lumpiness begins number two port reaches the same temp as 1,2 and 3 but one port temp drops from about 100c to as low as 25c (using a infrared temp gauge). Could this be because that cylinder stops firing at those revs. There seems to be no power loss from the engine just a horrible lumpy vibration that reduces at about 2400 revs. I know it's a well known problem with the autos but as yet after reading many many many forums and long threads no one has yet solved the issue.
I have before installed a set of used injectors but the results were just the same, vibration still there at those revs. I today measured the resistance on those injectors and they vary from 1.1 ohms to 1.9 ohms with the others being around the 1.3ohm average, were they dodgy?
By the way I think I have tried everything else from engine mounts to a refurbished head and everything in between, at quite a cost. Any ideas would be welcome. Other than change the D2 for another car that is (though that is being considered). Love the D2 but hate the vibration.
