"high-mileage" Engine Oil Vs. Regular Oil.

[lsrxlex]

Hi all,

I have a 1990 LS400 with 306k miles. I recently noticed that my engine noise is getting louder and louder. Last month, I just got the timing belt, pulleys, seals, and water pump .... replaced at San Jose Lexus, and the Tech told me that "nothing unusual with the noise, except that noise at 1 or 2 exhaust valves on passenger side". And he did not recommend a valve adjustment, since the car "is too old".

But I got a feeling that the noise getting louder since I started using "high-mileage" oil 5w-30 about 2 years ago ( at ~230k miles). One time, after 6 oil changes, I tried to go back to the regular oil 5w-30 again, but the noise seemed louder, so I switched back to "hi-mileage" 5w-30.

Now, at the last oil change (at 305k), I started using High-mileage 10w-30, and the noise seems to reduce a little bit. (I change oil myself at ~5k miles).

My question is: is High-mileage oil good for my engine? What kind of oil is most suitable for my engine now, to reduce the noise?

I appreciate any input.

[curiousB]

Hi all,

I have a 1990 LS400 with 306k miles. I recently noticed that my engine noise is getting louder and louder. Last month, I just got the timing belt, pulleys, seals, and water pump .... replaced at San Jose Lexus, and the Tech told me that "nothing unusual with the noise, except that noise at 1 or 2 exhaust valves on passenger side". And he did not recommend a valve adjustment, since the car "is too old".

But I got a feeling that the noise getting louder since I started using "high-mileage" oil 5w-30 about 2 years ago ( at ~230k miles). One time, after 6 oil changes, I tried to go back to the regular oil 5w-30 again, but the noise seemed louder, so I switched back to "hi-mileage" 5w-30.

Now, at the last oil change (at 305k), I started using High-mileage 10w-30, and the noise seems to reduce a little bit. (I change oil myself at ~5k miles).

My question is: is High-mileage oil good for my engine? What kind of oil is most suitable for my engine now, to reduce the noise?

I appreciate any input.

Not sure oil with solve your noise problem. Oil is for lubrication and protection/delay of metal to metal wear. Your noise sounds like valve clearance. Its a very high mileage engine but maybe you have a mechanic put new valve shims in to take out the slop that is creating the noise. The gap is simply getting too wide which makes more noise.

[JimsGX]

Since you mention its become louder on the passenger side, you may want to check the EGR pipe. It may be developing a leak.

[eatingupblacktop]

Now, at the last oil change (at 305k), I started using High-mileage 10w-30, and the noise seems to reduce a little bit. (I change oil myself at ~5k miles).

My question is: is High-mileage oil good for my engine? What kind of oil is most suitable for my engine now, to reduce the noise?

High mileage oil will make your valves a bit quieter by swelling the valve seals. Problem is it will also eventually damage them. I would use something like LC20 to condition them instead. Noise could be valves needing an adjustment or egr as have been mentioned, could also be a manifold gasket. Mileage shouldn't be the detemining factor in what you do here. Overall condition of the vehicle and service history are much more important.