99 Lexus ES300. When I drive the car its fine for like the first ten minutes but after that when I stop at lights and for traffic the oil pressure will drops when the RPMs go below 500 or so. I took it in and they told me to keep thicker oil and Lucas Stop Leak in it. They also told me the bearings on the Camshaft are loose and thats why I'm losing pressure. Anyone know how much this is to fix? Is it possible to fix on my own? I'm a novice at best with cars. Also why would the oil pressure drop since the bearings are going bad? Just trying to understand the problem a bit better. Thx
Oil temp effects oil pressure, too. Some internals in the engine that effect oil pressure are: Rod bearing and main bearing oil clearance on the crank, side x side clearance of rods, lifter bore clearance, cam bearing journal to cam bearing clearance, etc. These are some of the delineates. Any sludge if present comes from cold engine operation and never getting the oil hot enough for a sustained period to boil off condensation. 200 degrees is a GOOD thing. Try Amsoil 'Signature Series' oil.
It's normal for oil pressure to drop when the oil gets hot and the revs go down so unless the oil light comes on and the oil pressure is dropping that far and your warning light comes on or stays on, it's not cam bearings, it's a sludge problem. Google toyota sludge. You may need to remove the oil pan to clean off the oil pick-up.
it has cam bearings but they would not have anything to do with the oil pressure ! you get the oil pressure from the oil pump and the rod and main bearings, not the cam bearings ! do you hear any knocking ? if the cam bearings were loose you would hear a noise !
Well to start, your engine has no camshaft bearings. It utilizes dual overhead camshafts, that ride in specially machined surfaces in the cylinder head and are held down with caps that have the same machined surfaces. If excessive wear is present in these places, the cylinder heads are irreparably damaged and must be replaced. The reason for the loss of oil pressure is due to the increased clearances between the components. This is symptom is usually more a product of worn crankshaft and or connecting rod bearings. The increased space between the components provides a less resistant path for the oil to be forced through, and therefore resulting pressure is reduced.
