NP993

Your fear is correct....hate to say it, but a liter of oil per 700 miles means your guides are very worn.

Mike J

Clacking is not good and it may not be lifters but I have had a car come in with a failed lifter and it was really loud, not just clicking, but it sounded like someone hammering on steel with a steel hammer (if that is what clacking). New lifters quieted the car right up.

Benjr, you talked about it being under full load when it made noises? While it can be internal issues (like worn wrist pins,etc), in my experience cars with 60,000 miles often have marginal lifters, so my opinion is to replace your lifters and do an inspection of the cams while the covers are off. Then run the car and see what happens. Be aware when you replace the lifters that it can take some time (I have seen up to 15+ minutes) for the lifters to become really quiet as they pressurize, even if pre-soaked.

You can do the exhaust lifters first since they seem to fail first, or just go for it and replace them all.

Worse case, if it's internal, you would have wanted to replace the lifters when its all taken apart anyways, so no loss there.

Cheers,

Mike

rdewert