I did an oil change and and replaced the filter and that did not help. The oil leak that I have is at the oil pan. the truck has 170k miles on it. I have always changed the oil ever 3000 miles. Truck still runs great no difference but I have noticed that the oil presser is a bit less when I get on the gas than it use to be. So it appears that the more I drive it, it is loosing pressure very slowly.
I drove a Ford truck nearly 400,000 using Havoline 10W-40 oil with no engine problems and sold it running like new. And over the years hundreds of fleet vehicles have been serviced at my shop with Havoline, Valvoline, Shell and Chevron oil to suit the fleet managers with no oil related engine problems and many engines exceeded 300,000 miles.
Nothing lasts forever, especially car engines…In the summer, try some 15W-40 fleet oil…There is no “build-up” with synthetic oil every 3000 miles…The engine is just showing its age. You might drop the oil pan and check the oil-pump pick-up screen to see if all that stop-leak has plugged it up…And fix the oil leak while you are at it…
The paradox here is that oil leaks are harmless to engines unless the level is allowed to get below the pump’s pickup tube and pressure is lost, but large volumes of stop-leak can cause harm to engines by plugging up orifices and channels through which the pressurized oil is pumped and bearings rely on to get lubrication, plugging up the oil pump pickup screen, and plugging up the filter (fortunately, most filters have bypass tubes). In short, the leak won’t hurt the engine but the “fix” just might.
Mountainbike’s right, many of the additives can cause more harm than good.
I once had a leaky steering rack. The guy at the parts house claimed that this additive would rejuvinate the seals by making the rubber seal soften and turn back into a pliable material again.
Maybe in most cases, but in mine it changed a little leak into a gusher.
People can also cause problems by using too much of a good thing.
I once rebuilt an engine for a kid that does stockcar racing on a little local oval track. The oilpump was backordered and he was in such a rush it get the engine back and start installing all the manifolds and such. He said I should leave the oilpan off and he’d put in the pump himself.
One race and the engine was toast. He thought that I had done something wrong and took it to another mechanic for the rebuild. That guy called me and told me that there was so much “Form a gasket” dripping down the inside of the oilpan that the pickup was plugged.
Change your oil and see what the pressure is, that stop leak doesn’t have much viscosity. Oops, sorry, I wrote this before I saw your last post.
It is possible that the o-ring for the oil pump pickup is bad. Have replaced a few on these engines for this problem. You can check for this by stopping on a steep hill facing downward. If your oil pressure goes to normal at idle, then you have found your culprit. It is also possible the pickup is covered in sludge and the “stop leak” may have just plugged it a bit more.
Drop the oil pan…all will become clear.