This discussion was created from comments split from: RX300 Excessive Oil consumption.
Hey all, I recently bought a 99 Lexus RX300 with 160K on it. Soon after, engine started to feel like it wasn’t running on all 6 cylinders, idling low, losing power while driving. According to my mechanic, the engine light code was P1354 for variable valve timing fault and he is saying the fix is a rear valve cover gasket replacement. He can replace with the old rear valve cover OR the re-engineered one for a few hundred more. I’m not sure the re-engineered one is entirely necessary based on these comments. Does the re-engineered one really reduce oil usage by a noticeable amount? Does this even sound like an oil leakage problem? I ended up refilling the oil to see if this temporarily fixed the issue and, unless it leaked out and evaporated at the speed of light (and I didn’t notice any in the driveway), it didn’t. Do you think I’m being duped?
If the valve cover gasket is leaking then yes the gasket needs to be replaced. The car has made it 160k miles on the original valve cover so why change now.
Based on the mileage, performance problems, and the variable valve timing fault (which could have been caused by low oil pressure or sludge) what I feel should be done is to run a compression test; both dry and wet.
Seeing as how the car is a recent purchase and has age along with miles it needs to be determined with some reasonable certainty whether or not there is a piston ring issue.
Ring issues are very serious and can influence financial decisions made about the car.
The problem has nothing to do with a leaking valve cover gasket. Your mechanic’s proposed fix makes no sense.
Concur w/ @texases above, the proposed solution doesn’t seem like it would address the problem. Not if topping the oil off the oil level didn’t help, and the oil remained topped off (near the full mark, but not over) for at least the duration of the trial period.
Unless there is some add’l info which the mechanic informed the OP’er and is not included in the OP above.
fyi OP, VVT is a technique car manufactures use in newer cars to get improved mpg and power. It’s usually done w/an electro-mechanical gadget in the upper part of the engine which requires both (1) a functioning electro-magnetic solenoid and (2) enough oil pressure to operate correctly. Maybe ask your mechanic which of these 2 problems he thinks it is, and how does replacing the valve cover fix it? Then report back here.
OK, the OP has a VVT problem possibly due to low or dirty oil. If there is a leaking valve cover any mechanic should suggest replacing it to stop the oil leak, not to fix the VVT. Only after fixing the valve cover gasket, or redesigned valve cover and gasket (her choice) and driving the car for a while will it be apparent if the fresh full oil has taken care of the VVT problem.