Vauxhall Cavalier/Opel
 
2.0i 4x4 Turbo 16v (Petrol) K Plate
 
March '93 & 84500 miles.
 
Oil in the Water
Faulty Cambelt Idler pulleys
Contaminated Header Tank (Usually the first sign)
Contaminated Water Hoses with the 'Mayonnaise' stuck to the walls
     
 
 
 
Contaminated Water Pump & the Housing
 

 

Oil in the water becomes apparent with a 'Mayonnaise' like substance in the header tank , which is the highest part of the water system. It can only be described as a horrible filthy mess!

It is caused by the Cylinder Head allowing oil, under normal operating pressure, to seep from the main oil gallery to the water jacket, but not the reverse. This is because the oil pressure is higher than the water pressure.

Once the fault has shown itself, the only solution is to re-engineer the Cylinder Head and replace all the water hoses and the water pump. It is worth noting the water system in its entirety will have been contaminated and attention should be given to the radiator and heater matrix, to at least ensure there is a good flow when returning the engine back to service. One small item, often overlooked, is a small grubscrew in the water pump housing. Because the engine has probably been overheating the sealant on the screw will have been breaking down and will eventually weep if not resealed at repair time.Make no mistake it is essential that all rubber water hoses are replaced once contaminated. Oil will have attacked the rubber making it go soft. If one of the main hoses behind the water pump splits, while travelling at speed, it will take approximately two seconds to empty the engine of all its water and you know the rest. It will make this repair 'sink into insignificance'.

There are a number of engineering companies who undertake the head work, the conclusion is, it must be quite a common occurrence. One of the most popular is 'Headway' in Flintshire.

Headway Unit 16
Garden City Industrial Estate
Sealand Avenue
Deeside
Flintshire CH5 2HW
Telephone: 01244 821921

I understand this is a problem known to many, including Vauxhall. I have written to GM and so far the problem has not been acknowledged .

I also understand that at the inception of the two litre 16v engine, the first units were engineered and supplied by 'Cosworth'. The main oil gallery in the head was sleeved with a brass tube (Ah Hah!). When the engine went into mass production, with Vauxhall, the tube was left out. I assume it was designed in by 'Cosworth' as the gallery runs to within 6mm of the water jacket, hence the problem.


Cambelt Idler pulleys, centre (plus the tensioner + water pump)

Cambelt idler pulley break up - I understand that around '93 GM changed the supplier of the 'plastic' cambelt idler pulleys, of which there are two. These are in the same train are the two camshaft pulleys, the water pump and the belt tensioner. Apparently the idlers have been known to break up, the result being much the same as breaking a cambelt.

Whilst repairing the head, as above, it makes good sense to change the Cambelt and under the circumstances, the idler pulleys.

contact the author - if you have any information on either subject.

January 15, 2004

 

 

 

 

 



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