how do i check the valve lifters in a 1988 cougar v6
3 Answers
They are probably hydraulic lifters and over a period of time sludge blocks the orifices. To clean them you need to remove the rocker arm and .... if you are lucky they will come up and out with a magnet ... however since your car has seen a few years and perhaps mileage ,,,you may need to borrow a tool to get them out because in addition to sludge some lifters "mushroom" at the top and are very difficult to pull through the opening
firebird338 answered 9 years ago
If you are about do for a oil change leave out one quart of oil and add Lucas Engine Oil Stabilizer or if just did a oil change remove one quart of oil from engine then add Lucas the tap will go away.
If lifters are tapping I would check the oil pressure with a mechanical gauge first. It would be unusual for them all to start making noise at once due to sludge.