Timing chain replacement

[mauro12]

Hi guys , in a few weeks I’m going to have my car in a workshop for some things to adjust . The injection pump overhaul and probably it’s good time to work on the cylinder head with new guides and possibly the timing chain too .
My question is : is it only the chain itself that needs to be replaced or also the tensioner? In other words, which part I have to buy to have it everything ready ?
Thank you

[WRe]

Hi,
usually it is sufficient to change the chain, possibly also the chain guide, in any case the sealing ring of the tensioner and don't forget to bleed the tendioner
...WRe

[Cees Klumper]

If the tensioner is in good shape it won't need replacing. Suggest your mechanic checks it when he replaces the timing chain. On the other hand, since it seems to be around EUR 200 for a new tensioner, perhaps you just want peace of mind and replace it when the mechanic is into the head anyway.

[stickandrudderman]

I always fit a new tensioner with a new chain.
Pay close attention to the condition of the gears/sprockets. If the teeth are sharp then the gear is worn and it's best to replace all of them, including the one on the crankshaft.

[mauro12]

Our car has 3 tensioners right ? 2 short and one long ?
I realized also that is available for sale a version made by plastic ( very cheap ) and a version made by metal ( really expensive ). What is your choice ?

[mauro12]

Sorry guys but I mis understood the chain tensioner with the chain guide . What is the most common part that needs to be replaced ? Both of them ?

[Figoulu]

If i make the parallel with a motorcycle, once the chain is about to be changed, all the linked components are changed in the same round: chain, guides, and gears.
The one on the wheel and the one from the gear box… if you dont do so, then the wear on one gear will use quickly the chain for example. At least this what i always been taught…

But i recognize that the crankshaft gear need to fully open the engine and that’s not the same job…

[stickandrudderman]

Our car has 3 tensioners right ? 2 short and one long ?
I realized also that is available for sale a version made by plastic ( very cheap ) and a version made by metal ( really expensive ). What is your choice ?

You are confusing "tensioner" with "guide".
Only one tensioner. Guides are pretty relaible and can be re-used if not damaged or brittle (as is common in later engines).

[MikeSimon]

Stick:

When you say "later" , do you mean later (newer) production or older?

[stickandrudderman]

Stick:

When you say "later" , do you mean later (newer) production or older?

I mean later engines like M116/117, M103/104 etc. as fiited to 123, 116 and 126 chassis
The guides in these engine become brittle in a way that those on M130 engines don't.

[mauro12]

Usually do you replace all 3 guide rails or only the tensioner ?