Cam belt/water pump

[JW01]

I have a 1990 2.0i Cavalier which has been idle in my garage for several months (I had cancer and was unable to keep it in running order so it was absolutely dead).
I got a new battery but it made some unpleasant noises when I reversed out of my garage.
I took it to the local service garage and I was told it needed a new cam belt and water pump.
I found one on eBay and checked that it would fit my registration number. They said it would and I ordered it.
I took it to the garage and they said it would not fit.
I went back to the seller and they said it matched the registration number and the engine number. I sent them photos of the existing parts and they said it was "another one" which they do not stock so I am returning it.
Can anybody please explain how there can be two versions of the same item, one of which fits the engine number and the other doesn't? And can anybody advise on how to get the "other one"?
Many thanks.

[Mk3alan]

A few years ago I changed my pump/belt, it fitted ok but just didn't sound right. Took belt cover off and found rubber dust from the belt!
The water pump I fitted had 'square' drive segments - the original was half round in section. My new belt was correct in having the correct profile but was now obviously suspect as it had been running on an incorrect pulley!
Took a while but my supplier eventually got the correct pump and new belt.
Mine is also a 2.0 1990 and I guess it was a year of change?

Alan

[Robsey]

There are various 2 litre engines,

8 valve -
20SEH
20NE
C20NE

And there are 16 valve
In 1990 it would have been
20XE or
C20XE.
X20XEV is a much later engine.

As Alan points out, there were a few changes made at chassis numbers ending with MV999999, or M1999999 or M5999999... so at the end of model year 1991.

Later rounded pulleys and belts are used from model year 1992.

So for Clarification.

C20NE / 20NE / 20SEH upto 1991 =
Timing Belt = 90 409 900 or 90 410 014
From 1992 =
Timing Belt = 9 128 725

16 Valve engines.
20XE / C20XE
Upto Engine No 14142838.
90 280 404 or 90 410 225
From Engine No 14142839.
90 411 775 or 90 530 598

Different numbers for X20XEV.

[Robsey]

For water pumps...
20NE / C20NE / 20SEH

Upto Engine No. 14608700
Part number = 90 272 361

From Engine No 14608701.
Part number 90 444 123

For 20XE / C20XE
Upto Engine No 14142838.
Part number 90 442 207

From Engine No 14142839.
Part number 9 192 370 or 24 409 355

To locate, just google Vauxhall and the part number you want (missing out the spaces in the part numbers).

[Robsey]

For 8 valve engines.

Timing Belt.
https://www.autovaux.co.uk/90410014-bel ... gp90410014

Water Pump
https://www.ebay.co.uk/itm/WATER-PUMP-O ... 4635755497
-----------------------------------------
For 16 valve.

Timing Belt
https://www.ebay.co.uk/itm/Vauxhall-Ope ... 3539957302

Water Pump
https://www.ebay.co.uk/p/13017234470?iid=283709228641

[Mk3alan]

Potentially a lot of combinations there!
I believe all modern vehicles use a square (ISH) type tooth arrangement.
Any idea why the rounded type belt went out of favour!

Alan

[Robsey]

Any idea why the rounded type belt went out of favour!

Alan

Less chance of a square tooth slipping compared to a semi-circle / rounded tooth.

So less chance of the timing drifting from intended factory settings.

More important on the 16 valve engines, where a significant slip could result in piston / valve collision.

The old 8 valve engines were 'safe' non-interference units, so piston / valve collisions were not a concern.

[JW01]

Many thanks for all your helpful replies.
I now have a better idea of what to ask for.