94,000 miles 2001 4.0 S-type began to run very poorly about 1 month ago. Coils intake gaskets, etc checked and now will hardly run at all but no codes shown. I hear a chattering from front of motor when it does manage to idle. Is this the dreaded timing chain tensioner problem. As I have tried to run the car for a month is it likely to have damaged the motor? If so I will sell for parts as I can see this being a money pit. Sage advice appreciated

 

I think the only way to know is to find someone who will know what the noise means or else take enough off to see inside.

Caught early there's a chance it's OK but otherwise you're talking costs that effectively make it a new engine / write off.

 

Thanks for insight. I'm scared of bent valves etc etc. Just thought there might be more tell tale signs when these so and so things break and what puzzles me (albeit a non-mechanic) is why it turns over freely without that hesitation you might expect when timing is off

 

Sounds to me like you might have skipped a tooth on the timing. Get it checked asap and don't run the engine. Curently you are unlikely to have done more damage but if it slips further it might well. Here in the UK 4.0 S types are worth the same as a chains/tensioner swap. Upgrading to a 4.2 car complete and selling the spares on the old might be cheaper.

 

Another vote for DON'T RUN THE ENGINE!!!

If it's not junk now it will be if you keep trying to play around with it.

Either tear it down and fix it or haul it to the junk yard.
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+2 Don't run engine any further. Pull cam covers off and see if cams are still in alignment. (More than likely you will find the flats are out of alignment)