What is actually changed when the cambelt is done?

[Deleted member 74601]

Other than the belt itself, what is done when this is done?

The manual mentions something about changing the cambelt tensioner roller at 240,000 miles, so I'm assuming this isn't changed every cambelt change?

I was also wondering about the cam follower, is that changed every cambelt change?

Thanks.

 

[DOLBY]

Water pump too


Sent from my iPhone when I should be working....

 

[will.i.am]

my cars at 130,000 and when the garage ordered my cambelt kit the tensioner roller came with it, and as above dont forget the water pump best to change it all imo

 

[Muttley]

xreyuk, your profile says you have a Mk.2 Leon 1.6 TDI Ecomotive, which is going to be different from the 1.9 TDI's and other Mk.1 Leon/Toledos that most of us have.

I suspect that you won't have the water pump issue that the earlier engines have (plastic impellers breaking) so there's no need to change it.

I would suggest that it's worth changing the tensioner at the same time as the cambelt, as the tensioner is cheap but the labour to get the cambelt off is expensive.

I don't know what you mean by the cam follower - this term usually refers to a lever acted on by the cam which in turn acts on the valve. These are not service items on any car I know of.

 

[Deleted member 74601]

xreyuk, your profile says you have a Mk.2 Leon 1.6 TDI Ecomotive, which is going to be different from the 1.9 TDI's and other Mk.1 Leon/Toledos that most of us have.

I suspect that you won't have the water pump issue that the earlier engines have (plastic impellers breaking) so there's no need to change it.

I would suggest that it's worth changing the tensioner at the same time as the cambelt, as the tensioner is cheap but the labour to get the cambelt off is expensive.

I don't know what you mean by the cam follower - this term usually refers to a lever acted on by the cam which in turn acts on the valve. These are not service items on any car I know of.

Thanks mate.

Does the tensioner come as part of a cambelt kit? Or is the cambelt kit purely just the cambelt?

What's different about my water pump that means it won't need changing?

 

[Muttley]

When I had mine done the tensioner was extra - or rather there were two kits, one with and one without.

As far as the water pump is concerned, I expect that VAG went to a new design of pump with the new engines, one that eliminated the problems with the older plastic impellers. I don't know of any pump problems with them, but the new engines are outside my area of interest, and don't come up on the Mk.1 Leon/Mk.2 Toledo forums.

 

[Deleted member 74601]

When I had mine done the tensioner was extra - or rather there were two kits, one with and one without.

As far as the water pump is concerned, I expect that VAG went to a new design of pump with the new engines, one that eliminated the problems with the older plastic impellers. I don't know of any pump problems with them, but the new engines are outside my area of interest, and don't come up on the Mk.1 Leon/Mk.2 Toledo forums.

Cheers mate. Thanks for the info.

The reason I asked about the cam follower was because someone asked about changing it at the same time as the cambelt in the mk2 forums. From the way people were talking, it sounded as though it was quite normal to request this to be changed.

How much (if you can remember) is the tensioner roller (when you say tensioner, I assume you mean roller? I don't know very much about engines )

It says in the handbook to get the tensioner rollers changed every other cambelt service (assuming the mileage gets that high).

 

[big rich]

Generally Dealers will do belt and tensioner (regardless what it says about mileage) and waterpump only if leaking or specified by customer, when im doing private work i do the lot including rollers and fresh G12.

 

[Muttley]

For my car as it was then (TDI 110, ASV) there are, in addition to the tensioner, two idler rollers, to make the belt wrap round the injection pump and water pump pulleys. They are sometimes changed along with the tensioner, but it's very rarely necessary. I'm afraid I don't have a breakdown that shows the price of the tensioner on its own, I got a kit that included the tensioner - which in any case will be different from the one your engine needs.

The tensioner is an assembly including a roller and a tensioning spring. It puts tension in to the belt and ensures it engages properly with the toothed pulleys. If it fails, the belt can jump a tooth or two on the (usually) cam pulley, mucking up the cam timing and in extreme cases trashing the engine.

Cam follower. Well, well, well. It seems that 2.0 TFSI petrol engines have a cam driven mechanical fuel pump, something I've not seen since working on very old fashioned Mini engines. The only references to cam followers in the Mk.2 threads that I can find is for a cam follower between this fuel pump and its driving cam. Why you'd ever want to change it is beyond me.

I don't know for sure, but I'd be extremely surprised if your common-rail diesel had such a pump. Mind you, I don't know what it's doing on the TFSI engine either.

 

[Deleted member 74601]

Cheers mate.

So when it says tensioner rollers in the manual, do you think it just means the roller and spring that makes up the tensioner? Or do you think it includes the other rollers too?

And judging by that, you don't think the cam follower is necessary, even if it does drive the fuel pump?

 

[big rich]

tensioning roller is the tensioner, the others are idler rollers

 

[Deleted member 74601]

tensioning roller is the tensioner, the others are idler rollers

Cheers mate, just getting slightly confused with all the terms.

Plus, I have no idea about mechanics

 

[Muttley]

xreyuk wrote

And judging by that, you don't think the cam follower is necessary, even if it does drive the fuel pump?​

I've not worked on a CR diesel and I don't have any service information for one so I can't really offer an opinion. I'm guessing that, on the petrol engine, this pump is driven off the camshaft or a timed cam and supplies precisely timed pulses in pressure to the fuel line, to improve the injection timing or fuel delivery rate. I don't think that such a system would be used on the much higher pressure fuel rail in a CR diesel, but I don't know. Sorry I can't be more help.

 

[Sinbad]

xreyuk wrote

And judging by that, you don't think the cam follower is necessary, even if it does drive the fuel pump?​

I've not worked on a CR diesel and I don't have any service information for one so I can't really offer an opinion. I'm guessing that, on the petrol engine, this pump is driven off the camshaft or a timed cam and supplies precisely timed pulses in pressure to the fuel line, to improve the injection timing or fuel delivery rate. I don't think that such a system would be used on the much higher pressure fuel rail in a CR diesel, but I don't know. Sorry I can't be more help.

The cam follower on the TFSI does indeed drive the high pressure fuel pump. It's not for accurate timing, but for generation of high rail pressures (120bar). No idea if the CR TDI has a similar setup - I'd hope not, considering it seems to be a common failure point. It's a very cheap part to replace, but does very expensive damage if it breaks. For that reason I have mine changed at every service.

 

[Deleted member 74601]

xreyuk wrote

And judging by that, you don't think the cam follower is necessary, even if it does drive the fuel pump?​

I've not worked on a CR diesel and I don't have any service information for one so I can't really offer an opinion. I'm guessing that, on the petrol engine, this pump is driven off the camshaft or a timed cam and supplies precisely timed pulses in pressure to the fuel line, to improve the injection timing or fuel delivery rate. I don't think that such a system would be used on the much higher pressure fuel rail in a CR diesel, but I don't know. Sorry I can't be more help.

No worries, you've given me more than enough info.

Thanks

 

[big rich]

Cheers mate, just getting slightly confused with all the terms.

Plus, I have no idea about mechanics

No worries mate, and the fuel pump is belt driven on the cr's, its only a few of the petrols that use the cam follower type

 

[Muttley]

Sinbad wrote

The cam follower on the TFSI does indeed drive the high pressure fuel pump. It's not for accurate timing, but for generation of high rail pressures (120bar). No idea if the CR TDI has a similar setup - I'd hope not, considering it seems to be a common failure point. It's a very cheap part to replace, but does very expensive damage if it breaks. ​

Good Lord, so the main fuel pump for the TFSI is a cam driven plunger pump? That seems awfully primitive. And you'd think they'd have learned from the PD engine which has roller followers for the PD pumps.

xreyuk, as big rich says above, the CR diesels have a belt driven main pump so there should be no cam follower to need changing.

 

[Sinbad]

[

Good Lord, so the main fuel pump for the TFSI is a cam driven plunger pump? That seems awfully primitive. And you'd think they'd have learned from the PD engine which has roller followers for the PD pumps.

Yes, it is.
The new generation TSI engines (EA888) use a roller on the cam for the high pressure pump though.