Technical Water pump differences CF2 and CF3

[puntodeltathema]

Hi folks

Does anyone know the difference between water pumps for Euro 2 (CF2) and Euro 3 (CF3) 1.8 engines? I see different pumps are specified.

I have a later CF3 engine (actually in a Punto HGT) and am attempting a cambelt change. The new belt feels too tight to me (I have to move the tensioner right round, off its baseplate peg to get it on), even though it is the same spec as the one that came off (166 teeth which should be correct according to the VIN). I have changed the water pump too but (stupidly) have just used a part that came with the car and I wonder if I have put one on with an incorrect pulley size.... Because it's now on it is difficult to measure!

A related question is why the CF2 cars had 168-tooth cambelts - is it because of a pulley issue like this? Or a change to the cylinder head or something?

Thanks!

Nick

 

[puntodeltathema]

So I think I have answered my own question but for the record in case useful for others at any point:

The water pump I fitted was actually for a CF2 car (confirmed by the part number on the box - 60586222). The pulley is 71mm diameter instead of 68mm for the CF3 pump (60608998). That means the circumference of the pulley is some 9.4mm bigger - and as the belt is in contact with half of it, needs to be 4.7mm longer (other things equal).

Looking at all the other pulleys on ePER, this is the only thing that is different between the CF2 and CF3 engines (unless the block-to-head relationship is also different). I note the CF2 cam belt is two teeth or about 14mm longer, but I'm hoping if I fit one (on order...) it will tension OK. Otherwise I'll have to buy and fit a CF3 pump... Which as I've refilled the coolant will be a bit of a pain .

Moral of the story I think is don't trust parts that just happen to be supplied with the car....which I'm old enough to know already of course [facepalm emoji!]

Nick

 

[s130]

Have a 2005 CF3 and did the cam belt, tensioner, pump etc with:

New Cambelt - Gates 5469XS, Tensioner T43033, Pulley T42060, Waterpump WP0028

This works for our CF3.

I did have issues similar to yours:

From my Notes:

Service

Gates

5429XS

TOO LONG

1

Barchetta

Cambelt

Power Grip Belt 5429XS Cambelt - 168 teeth by 24mm

This belt although listed was too long.

Replace with:

Old Service Part

Gates

5469XS

0

Barchetta

Cambelt

Power Grip Belt 5469XS Cambelt - 166 teeth by 24mm

Just the two teeth difference was enough to screw things.

 

[puntodeltathema]

Thanks s130.

To complete the tale, one can't just get the longer (168 tooth) belt and fit with the larger-pulley (71mm) water pump as the belt remains (obviously) too long. So there was clearly some other change between CF2 and CF3 versions of the engine. Compression ratios appear to be the same though, at least from the brochures....

Anyway, correct 68mm pump now ordered to use with 166-tooth belt (as listed for CF3), and lesson learned!

Nick

 

[HgtBill]

I know this thread is a month old but the difference in belt lenght is due to the different headgaskets (CF2 is an older style composite gasket, the CF3 runs a thinner MLS gasket).

I didn't know the water pump pulleys were different

 

[puntodeltathema]

Ah interesting - didn't realise a head gasket could make that much difference.

I guess they used the water pump pulley diameter to take up the difference to a given number of teeth on the cambelt.

Thanks