Rattle On Start-up

A common complaint of the BMW M62 powerplant is the Rattle on Start-up, also referenced as Clatter or Valve noise. The noise emanates from the VANOS valve gear fitted to the M62TUB44

This is accepted as “Normal” by both BMW and Land Rover. There is no evidence to suggest that the rattle is harmful to the engine, as worrying as it sounds the first time you hear it.

Cause/ Cures

The rattle/clatter is caused by a lack of lubrication at the top of the engine and is typically linked to the amount of time the engine the engine has been off. When sat for long periods of time, or even just overnight the oil drains back down into the sump.

The immediate thing to check is your oil level, anything other than filled to the max mark and the noise can become instantly more noticeable.

It has been suggested that low oil pressure at start-up can make this much more noticeable. The causes of low oil pressure can be:

Restricted flow due to clogged oil filter

Caused by Increased Distance/Time between oil changes. Good quality filters should always be used. Some of the cheaper types can break up in the filter housing, causing a loss of filtration. Look for branded types either by Land Rover, BMW, Mann or K&N.

Incorrect grade of oil (too thick)

The M62 engine is built to tight tolerances, at low mileage deviating from the recommended oil spec should be avoided. Some garages just use a generic oil for all cars, worst still, some garages use recycled/ re-refined oil - where they filter the oil drained from other customers cars and put it back in yours.

Incorrect grade of oil for temperature

Colder climates should often change their oil grade to a thinner one. There is a graph in the owners handbook that shows which grade of oil to use in a given temperature range. There is a lot of overlap so you cant usually get this wrong.

End of life oil lacking lubrication properties

Oil does not last forever and by 15,000 miles/ 18 months the oil really is spent. It’s thermal transportation properties reduce significantly over time. Yearly if not sooner oil changes are a must, ideally change the oil before winter so you get the best of protection over the colder months.

Other Tips

6 monthly oil changes can yield great results as the detergents in the oil really get a chance to break down any built up sludge. The oil filter also is still operating at near peak efficiency, letting the oil flow more freely. The other benefit with changing the oil twice a year is that you can swap grades, a summer grade slightly thicker oil and a winter grade thin oil.

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