1998 mustang v6 originally and auto that I’ve swapped to a t5.The Car has 209 thousand miles on it. At idle the oil pressure drops and what sounds like a lifter starts ticking, but with little rpm the pressure comes up and the tick disappears. Any suggestions?
Pressure drop on the Stock OE Gauge- not a Mechanical Gauge- correct? How low does the Oil Pressure “drop” at Idle on the OEM Gauge? How many RPM’s before pressure rises back up? It’s possible you may have a lower idle speed occurring as a result of an IAC, Fuel, intermittent Spark in a Cyl, etc..Check your idle speed on the Tach, if it seems any lower than what it typically has been (700-800 rpm’s is a rough guess) that may be what’s causing you’re issue. Start troubleshooting why from there- if Not- did this just start to occur one Day, or over a period of time, like a few Weeks to a Month or more?
If you haven’t already- Take the low Tech. approach.. A simple Oil/Filter Change with quality Materials, see where you are then. Can add other products to the Oil later- if needed..
I have been using both of these in My higher mileage Ponies from that Genre’ over the years- works great!.
Mobil 1 Super High Mileage Conventional Oil, or Synthetic- Mobil 1 High Mileage Synthetic, both @ 10-30 Viscosity. Complement with a good (Motorcraft, Mobil1, K&N) Filter... Good luck!
The Mustang stock oil pressure sender is a simple on/off switch that works at 6 PSI (yes that is correct!). So assuming the sender is working as designed, if the oil pressure dash warning light comes on it means oil pressure is below 6 PSI.
First, the oil pressure sender can and does go bad. They are cheap and easy to change. However in this case it seems unlikely to me that this is s a false low oil pressure because the lifters start making noise.
If this were my car I would get an oil filter cutter and cut the oil filter open looking for debris.
Not a bad idea to actually measure the oil pressure with a real external gauge.
Given the high mileage on your motor I'm afraid the final answer will come down to excessive main bearing wear. But it's always best to check the "basics" before moving onto the big $$ items.