How do I know when it is time to replace the timing chains

[bcolins]

I've got about 120,000 miles on my 2003 MV now. Wondering if there is a known way of determining when timing chains and tensioner rails need replacing. The van is running great. I do need to clean or replace my cam postion sensor(s) and a valve cover gasket, which will require doing some of the same steps needed for the timing chains. Also have coolant cross pipe, thermostat housings, water pump that I need to preventatively replace.

Thoughts?
Brian in Austin

[EuroTec]

So much depends on maintenance history. Well taken care of they can go 200K. I did mine at 192K when I had the trans out for a swap.

No noise, running fine, I'd let it go at 120K.

When you're in there, check your rear timing cover for oil leaks. They can appear to be from the valve cover and fool you.
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If it ain't broke, don't fix it!

[elise111]

In case you don’t already know, the cam position sensor and valve cover don’t really help so much when replacing the timing chains. You have to remove then trans to get to the chains. It helps a little- you have to removing the intake manifold for both jobs I guess.

I was surprised (shocked) at the condition of my 2001 intermediate gear at around 110k miles- there was no real noise (my 2000 had real chain noise) but it was missing several teeth already. That’s not to say that it would go another 80k miles like that without the chain jumping a tooth, your results may vary.

I talked to the local EV mechanic at the time and he said the VR6’s usually give lots of noise as they go, so if you are attentive, you should be able to catch it before it gets serious.