Looking for any information from others on here who may know more about this issue...I'm aware there are a good number of members who have a weath of experience under their belts on these cars, and the engines are common across the VW group model range, which surely means I'm not alone...
Whilst I was working on the engine top end, replacing the hydraulic lifters and generally cleaning out the gunge that had collected in oil ways feeding them, I noted that there was what I would categorise as excessive play in the camshaft bearings. I identified this fairly crudely, by manipulating the camshafts from the Pulley ends and found that I had fair amount of movement radially on the bearings. This was more evident on the front and rear bearings but I'm certain there will be similar play in the central bearing.
Both inlet and exhaust exhibited this play and I understand this is very likely to result in, at best variable behaviour of the valve opening/closing times and must result in varying quantities of fuel/air being sucked into the cylinders, as well as affecting the exhaust output from the cylinders.
Given the play seems to be greater on the end bearings of each shaft, I would suggest that the effects would be greater on Cylinders 1 & 4. This would be likely dependant to some degree on the tension in the cambelt which exerts a sideways (downwards in this case) force which will depend on how tight the belt is tensioned and will also tend to vary as the engine heats up and everything expands. These effects may be trivial when everything is new and running within tolerances, however as the engine wears with miles and, in my engines case, also with neglected oil changes, then even more play sets in, resulting in accelerated bearing wear, and a vicious circle is set up.
Now, having set a scene, I accept that things do not always play out the way logic may dictate (always assuming that the logic has been correctly applied in the first place
. Having reassembled the top end and fired up the engine, the good news was that the initial clacking of lifters taking their time to fill correctly and the gaps to settle down, eventually disappeared and things ran well for a time, then a misfire set in and although the running was much improved, it wasn't terribly convincing. I had ran out of time by then and the car was parked up and has remained idle for the past 6 weeks whilst I have tackled the very different, but equally frustrating and complicated task of investigating the extent of wet rot in the bathroom at my son's house. Fortunately, that process has now concluded and the restoration of affected flooring, timber joists and wall frames and plasterboard is done. New wet wall panelling installed and the new bathroom suite is in the process of being installed this week with some assistance from the boy. This means, I will shortly be returning to the A2 with the focus of solving the remaining running problems and getting the car back in use!
If anyone reading this can throw any further light on this subject, I would be grateful for the input. I have had a cursory look on t'interweb for replacement camshaft housings, but this has not turned anything sensible up so far. I would be very surprised to learn that this amount of wear is "normal" and doesn't result in any detrimental running effects, however, I'm not an expert in VW group engines, although that's rapidly becoming a steep learning curve!
Best regards to all and Thanks in Advance for any help.
Gordon.
Whilst I was working on the engine top end, replacing the hydraulic lifters and generally cleaning out the gunge that had collected in oil ways feeding them, I noted that there was what I would categorise as excessive play in the camshaft bearings. I identified this fairly crudely, by manipulating the camshafts from the Pulley ends and found that I had fair amount of movement radially on the bearings. This was more evident on the front and rear bearings but I'm certain there will be similar play in the central bearing.
Both inlet and exhaust exhibited this play and I understand this is very likely to result in, at best variable behaviour of the valve opening/closing times and must result in varying quantities of fuel/air being sucked into the cylinders, as well as affecting the exhaust output from the cylinders.
Given the play seems to be greater on the end bearings of each shaft, I would suggest that the effects would be greater on Cylinders 1 & 4. This would be likely dependant to some degree on the tension in the cambelt which exerts a sideways (downwards in this case) force which will depend on how tight the belt is tensioned and will also tend to vary as the engine heats up and everything expands. These effects may be trivial when everything is new and running within tolerances, however as the engine wears with miles and, in my engines case, also with neglected oil changes, then even more play sets in, resulting in accelerated bearing wear, and a vicious circle is set up.
Now, having set a scene, I accept that things do not always play out the way logic may dictate (always assuming that the logic has been correctly applied in the first place
. Having reassembled the top end and fired up the engine, the good news was that the initial clacking of lifters taking their time to fill correctly and the gaps to settle down, eventually disappeared and things ran well for a time, then a misfire set in and although the running was much improved, it wasn't terribly convincing. I had ran out of time by then and the car was parked up and has remained idle for the past 6 weeks whilst I have tackled the very different, but equally frustrating and complicated task of investigating the extent of wet rot in the bathroom at my son's house. Fortunately, that process has now concluded and the restoration of affected flooring, timber joists and wall frames and plasterboard is done. New wet wall panelling installed and the new bathroom suite is in the process of being installed this week with some assistance from the boy. This means, I will shortly be returning to the A2 with the focus of solving the remaining running problems and getting the car back in use!If anyone reading this can throw any further light on this subject, I would be grateful for the input. I have had a cursory look on t'interweb for replacement camshaft housings, but this has not turned anything sensible up so far. I would be very surprised to learn that this amount of wear is "normal" and doesn't result in any detrimental running effects, however, I'm not an expert in VW group engines, although that's rapidly becoming a steep learning curve!
Best regards to all and Thanks in Advance for any help.
Gordon.