When the Vauxhall 2L 16v ‘XE and LET’ engines was produced it was built with two different manufactured cylinder heads. The original was built and designed by Cosworth and the latter was manufactured by GM. The two different heads can be identified by external casting marks found on the outside of the head. These can be seen below.

GM Cylinder Head	COSCAST Cylinder Head

The problem associated with the GM heads is the fact that the oil channel design within the head is not as good as the Cosworth units. This eventually leads to an oil water mix found in the coolant system that looks a bit like a salad cream substance. The reason you get oil in the water, and not the other way round is due to the higher pressure running through the oil ways as opposed to the coolant system.
It is wise not to run the car too long with the oil/water substance in the coolant system as it will rapidly deteriorate the rubber hoses so leading to them having to be replaced. Having the system flushed out regularly whilst waiting for the fix to take place is advised.

This problem however can be fixed by V-TUNING and involves strengthening the effected oil ways. Once this fix has been carried out it is permanent and will not need to be re-done at a later date.

All work can be carried out at V-TUNING including removal and refit of the head or if required the customer can send there problem cylinder head via the post and have the work carried out. If the head is required to be removed and then refitted to the car, an additional charge will be made to the price below.

To rectify problem cylinder head = £130

Note : Please be aware that in some cases cylinder head gasket failure may also be the cause for oil to be present in the water system.