Hi,

Being new to modernish diesel cars I am unfamiliar with thier little noises and quirks. My mk3 mondeo 2.0l car has what sounds like a minor rattle/knock on tickover. A local diy mechanic says it's an injector.

If this is the case how long will it run on this faulty part and what will eventually happen?

The car seems to be running fine and I'm getting 50mpg around town, just this rattle/knocking sound on tickover. Anything over 1000rpm and it's gone.

Tony

Hi, that's quite a common noise on a mk3! Usually the source of the noise is the serpentine belt, it's idlers or tensioner... as you stand in front of the car looking at the engine, it's on the left hand end, there IS another smaller belt for the ps and coolant pumps which is more central to the engine bay.  Both belts shld be changed at 100k miles.  If you have any Q?s ask on here and/or on the www.talkford.com        forum as the mk3 is a mature product and there's plenty of know-how here and there. If the soot level figure as measured at the mot is within the vin plate figure, then leave the injectors be!   Just do regular oil and filter changes and air filter too.  

Thanks Nick.

Iv'e had the car now for 8 months and had it serviced twice (I don't like the idea of black oil). The service mechanic hasn't mentioned the serpentine belt but did suggest that injectors are a common failure on this engine. I'm currently in Spain locked down so getting it looked at by a qualified engineer is difficult hence the question of what happens if it is an injector and it fails. Is it like a dodgy spark plug where I end up with a rough running engine (but still running) or will it stop the car?

Changing/condemming injectors is a nice easy money spinner. I'm amazed at the skill of mechanics who can tell at a glance that injectors need changing. In addition to the advice I gave above, also  change the fuel filter every 36k miles. If you're not sure when it was last changed, add it to your to-do list.                               No, injectors don't fail like spark plugs do, you're likely to see the dashboard glowplug symbol start flashing and the car go into limp mode, or you'll get white smoke from tbe exhaust, caused by overfuelling of an injector... the white smoke being unburnt diesel. If you do get the flashing glowplug light, you'll need to get the error codes read (and cleared) by an inexpensive reader., and it's an idea to buy yourself one to use with a Windows laptop or an Android phone. You can get a reliable one from Tunnelrat electronics. Take a look at their website and email 'em for advice if you're not sure of the best one for you. 

Thanks again Nick. As soon as this lockdown is over I will go to another mechanic and list what you have told me and if neede I will get the belt/idler and filter changed.

Tony

The mk3 duratorq is a lovely motor, so enjoy!