Pre lube service

[ovul82jazz]

Hi there, my '01 with 39K km on has been making a bit of what sounds like hydraulic lifter noise. The local mechanic thinks that it needs a "pre-lube service" and I can't find any information on what that actually is. I have the Bentley service book - can't find it there. Do any of you have any idea what he's talking about? thanks muchly, Roger

[Lucky]

If the noise is for a few seconds at start up, that's normal. I'd suggest running a 5w40 oil (versus the widely used Mobil 1 0w40)... it will result in less rattling at start up.

The term "pre-lube" usually refers to a system that builds oil pressure before you turn the ignition key to start the engine. This is common practice on race cars since their engines are often built to very tight tolerances and are usually filled with a thick oil which offers maximum protection at high loads, so significant wear would occur at start up before oil would circulate and build pressure.

However, I don't think your mechanic has the above in mind. More likely he is suggesting that an aggressive cleaner be put in the oil and the engine run for a few minutes before draining and refilling with fresh oil. There are many such "engine cleaners" on the market.

By the way, I can think of a really good way to clarify what your mechanic is suggesting: ASK HIM! I'm sure he'd be happy to explain what he has in mind.

[ovul82jazz]

Well, the short version is that I did exactly that... a Prestone engine clean just before the oil change and I put in 5W40 ... Issue went away! No lifter noise, no rattles, no clanking. The car is running as smooth as silk.

Thanks very much for your insights.

[Lil bastard]

Originally Posted by Lucky

...The term "pre-lube" usually refers to a system that builds oil pressure before you turn the ignition key to start the engine. This is common practice on race cars since their engines are often built to very tight tolerances and are usually filled with a thick oil which offers maximum protection at high loads, so significant wear would occur at start up before oil would circulate and build pressure...

Actually, that's not entirely true. Race engines are built to varying tolerances, some of which are actually quite loose. This reduces friction and drag and allows for higher revving and cooler running. They are however built to exact tolerances, but not necessarily tight ones.

Valvetrains are typically built to pretty close tolerances while bearings, piston rings and wrist pins have fairly loose tolerances.

The loose tolerances are only part of the reason heavier oils are used, but also heavier oil is more massive/unit volume and so can carry away more heat. Heavier oils are also more stable at higher race temperatures.