Hi Guys,
Replacing cam belt without changing the water pump is false economy!
The attached pic shows the catastrophic failure that can happen with the water pump if it is not replaced at similar intervals to the cam belt. The vehicle is a Golf 1.9 TDI. The old pump (on the left in the pic) is next to the shiny new one (in case you couldn't tell). The failed pump is the original VAG water pump and failed at 196,000 Kms. The cam belt had been changed at 120,000 Kms, but not the water pump. I have no idea if it was a plastic impeller, because the impeller has disintegrated and vanished. There is no bearing left at all - I found some of the rollers in the lower cam cover. From the angle of the sprocket, you can guess what it did to the cam belt. Even the center metal cam cover has been re-sculptured because of contact with the free floating sprocket, and the engine mount has some interesting grooves cut into it. Fortunately for me, no engine damage, but I am still worried about the bits of metal from the pump that must be somewhere in the cooling system.
The first warning of failure was when the low coolant light came on and instructed me to stop. From inside the car there was no indication of anything wrong. Even the water temperature was just fine. From under the hood, there was a grumbling sound and steam coming from the cam cover.
If any of you are contemplating a cam belt change without changing the tensioner, consider my experience!
Cheers, Martyn
Replacing cam belt without changing the water pump is false economy!
The attached pic shows the catastrophic failure that can happen with the water pump if it is not replaced at similar intervals to the cam belt. The vehicle is a Golf 1.9 TDI. The old pump (on the left in the pic) is next to the shiny new one (in case you couldn't tell). The failed pump is the original VAG water pump and failed at 196,000 Kms. The cam belt had been changed at 120,000 Kms, but not the water pump. I have no idea if it was a plastic impeller, because the impeller has disintegrated and vanished. There is no bearing left at all - I found some of the rollers in the lower cam cover. From the angle of the sprocket, you can guess what it did to the cam belt. Even the center metal cam cover has been re-sculptured because of contact with the free floating sprocket, and the engine mount has some interesting grooves cut into it. Fortunately for me, no engine damage, but I am still worried about the bits of metal from the pump that must be somewhere in the cooling system.
The first warning of failure was when the low coolant light came on and instructed me to stop. From inside the car there was no indication of anything wrong. Even the water temperature was just fine. From under the hood, there was a grumbling sound and steam coming from the cam cover.
If any of you are contemplating a cam belt change without changing the tensioner, consider my experience!
Cheers, Martyn
