What engines are affected with porous heads?

It is claimed Vauxhall doesn't actual know the true figure of faulty heads there are out on the market. But the two main engines affected are the 2L 16v Double Over Head Cam (DOHC) 'red-top' engines, C20XE (2L 16v DOHC) and C20LET (2L 16v DOHC Turbo). These are found in the Astra GTE, Astra GSi, Cavalier 2L 16v, Cavalier Turbo, Calibra 2L 16v and Calibra Turbo. No other engines or cars were affected. So any 8v, SOHC, V6 or Ecotec engines are NOT affected by the problem.

The table below shows the years effected and the types of engines. The main culprit was the manufacture, there were two. Heads were either made by Cosworth (Coscast) or Kolben Schmidt (KS).


Supplier Year Vehicle Engine Type
Tensile strength Problem
(Coscast) Cosworth 1987-1989 KADETT-E C20XE 350N/mm˛ No Problem!
(KS)
Kolben Schmidt 1989-1991 KADETT-E C20XE 380N/mm˛ Water damage possible
(KS)
Kolben Schmidt 1989-1993 ASTRA-F
VECTRA-A
CALIBRA
C20XE
C20LET
380N/mm˛ Water damage possible
(Coscast) Cosworth 1993-199x ASTRA-F
VECTRA-A
CALIBRA
C20XE
C20LET
350N/mm˛ No Problem!
(KS)
Kolben Schmidt 1993-199x ASTRA-F
VECTRA-A
CALIBRA C20XE
C20LET
220N/mm˛ Material too soft!
Head screws come loose!

sory but all turbos dident have coscast heads as standerd as i no several people with lets and only 1 has a coscast haed and he changed that as it was the gm 1 before he snaped a cam belt

I didn't think so.....but maybe....

Some of the early Calibras had coscast heads it think.

All the turbo's have coscast heads as standard. IIRC only the astra gte's have them n/a

the cavs do come with coscast heads as ive got 1 on my let dont think it made a diferance its just some have the coscast and some dont

The engines are identical, although your not going to get a coscast head on a cavy. The exhaust manifolds are different i think, although finding a new one isn't hard (i have a astra gte 16v manifold in my garden! LOL) The looms are the same except for the length, due to different engine bay sizes and ecu positions.

No idea about the drive shafts, I wouldn't be suprised if they were the same though! You need EPC!

Are there any disadvantages for using a cav gsi as a donor rather than the astra.
I'm thinking with regards differences in exhaust manifolds, looms, driveshafts?

Beardy you posted how to modify std astra driveshafts can the same be said for cav driveshafts do you know?

Any help you can give me would be appreciated!

Ains :wave: