Loud tapping noise from engine

[DHall1]

Double check your invoices for what oil is being used.

Check that pn to be sure it's the 505.01 Castrol diesel spec oil.

These cars are old....very few techs left from the day these were introduced. Most could care less what oil they dump in.

i second the lifter prognosis. Warm it up again and raise the revs

Sorry to see you're having problems. I switched to BND oils years ago

The dealer has been doing the oil changes and always recommend RS6 oil has been used. The last oil change was when the 70K service was completed a while back (included fixing valve cover leak), and the car driven since. I'll check the oil level on the car.
Due to travel plans, the car was sitting for about 3 weeks, and I just started it up. I think I may have let it idle for about 5 mins before I shot the video, and just got a bit worried.
Thanks for the feedback and will go through the list of options provided, and see if the sound goes away.

[NSU RS6]

Back in the olden days as they say......

My five cylinder Audis had a built in reminder for oil change time. Lifter tap. Despite the best oils being used, it would come in at about 3000 miles. Synthetics were good for way more than that, even back then.

The only cure that worked for this, and it wasn't more cowbell, was Rislone. While not exactly an oil substitute, it is a ginormous detergent supplement, and it would loosen sticky lifters for another 2K miles.

To this day, I run a half to full quart of Rislone in the engine the day before an oil change.

Probably going to be seeing flames shortly, as our Cosworth motors deserve only the best wine, but this has worked for me for 30 years

BTW - the wine I run is Redline 5W-40, per Mr. Hahn's recommendation.

Good luck, and I hope it is not a tensioner.....

[GreggPDX]

Back in the olden days as they say......

My five cylinder Audis had a built in reminder for oil change time. Lifter tap. Despite the best oils being used, it would come in at about 3000 miles. Synthetics were good for way more than that, even back then.

The only cure that worked for this, and it wasn't more cowbell, was Rislone. While not exactly an oil substitute, it is a ginormous detergent supplement, and it would loosen sticky lifters for another 2K miles.

To this day, I run a half to full quart of Rislone in the engine the day before an oil change.

Probably going to be seeing flames shortly, as our Cosworth motors deserve only the best wine, but this has worked for me for 30 years

BTW - the wine I run is Redline 5W-40, per Mr. Hahn's recommendation.

Good luck, and I hope it is not a tensioner.....

I'll probably join you in getting flamed, but I actually do something similar with Marvel Mystery Oil, top off the oil with it a few days before the change. Despite the name, it's actually got a decent reputation for helping break down deposits and reduce sludge. My grandfather swore by it, but I thought it was snake oil until I tried it on one of my higher mileage cars. It definitely fixed noisy lifters in that one. I then did research on it, and the consensus was it may or may not help, but it's probably not doing harm in any case.

First and foremost is regular oil changes with good oil, but I honestly believe a little extra cleaning on higher mileage engines makes a difference.

[DHall1]

...........

"calls for 5w40. I got that right here at my pumping station"

Double check your invoices for what oil is being used.

Check that pn to be sure it's the 505.01 Castrol diesel spec oil.

These cars are old....very few techs left from the day these were introduced. Most could care less what oil they dump in.

i second the lifter prognosis. Warm it up again and raise the revs

Sorry to see you're having problems. I switched to BND oils years ago