- 07/18/2014
- 1 Min Read
- By: Tony Robinett
BMW E36 3-Series M3 Oil Consumption Issues & Repair
If you own an E36 M3 the chances are great that your car is consuming a little (or A LOT!) of oil. The range of consumption will vary between people and cars, but for the most part .5-2.5 quarts every 2000 miles is considered "normal," which seems crazy. Where most people get stuck is that their car doesn't seem to smoke out the tailpipe, it doesn't appear to be leaking oil, and they swear they put enough oil in on the last change. (A substantial 7 quarts!)
So...Where does all the oil go?
Oil consumption can be the result of a few different issues. Some being more to worry about than others. And some very simple replacements that are not very expensive. However, if your car is smoking out the tail pipe and burning a substantial amount of oil; its time to take it to a shop that works on BMW's. Some open engine work is needed, this is something to the effect of a blown head gasket or worn piston rings allowing blow by.
Failed CVV
The CVV (crankcase vent valve) collects oil/air vapor from the PCV hose connected to the valve cover. There, it filters the oil/air vapor, allowing the air to go back into the intake manifold to be a part of the combustion chain, and the liquid oil is sent back to the oil dipstick tube. The element that separates the oil/air vapor can become clogged and will allow oil to be sucked into the intake manifold. This can result in minor oil consumption and potentially a small amount of bluish/grey smoke out of the tailpipe. When my car's CVV was failing I didn't notice any smoke out my tailpipe, but after I replaced the CVV my oil consumption went down by 90%.
Failed CVV
Oil Weight
Another thing that can lead to oil consumption is use of the wrong oil type. The E36 M3 is very particular to oil weight. Too thin an oil and you get VANOS tick and risk more oil consumption, too thick and you risk not getting enough oil flow at start up. Oil weight can play a big part of the amount of oil you may be consuming. BMW has a list of approved oils that meet their standards for use in their vehicles. It can be difficult to choose and find the particular oil you want to use. But, some of the best oils are surprisingly within short reach. Liqui-Moly 5W-40 and Pentosin 5W-30 are available at FCP Euro, as well as NAPA if you can't wait to receive your oil. Mobil 1 0W-40 European Formula is also carried at Wal-Mart. What all these oils have in common is that they are all a European formula. European formula oils have a thicker CpS rating than standard US spec oils. Switching to a thicker oil can reduce your oil consumption and reduce valvetrain noise at start up. If you have a higher mileage motor switching to a thicker oil weight is recommended, as it helps protect bearings and journals that exhibit wear from high mileage.
If you have an E36 M3 and have oil consumption that is within the realm of "normal," I recommend a replacement of the CCV and a change of oil brand and weight to the oils above. Doing this can decrease your oil consumption substantially.
If you've experienced oil consumption problems and have found an oil that works well for you, let us know in the comments below!
About the Author: Tony Robinett
Tony lives in Spokane, Washington and is a 3-D Design Engineer, machinist, and welder. When he's not at work he is designing and fabricating parts for his M3, and other BMWs alike.
