Page 20 - KCRPCA Nov Dec 2019

20 NOV / DEC 2019 Here you can see the waterpump location on an M96/M97 engine with the front access cover removed. This pump’s bearing had starting play, allowing the impeller to make contact with the pump housing and shatter. The factory pumps come with a plastic impeller which can explode apart once the bearing starts to get play in it, and it can send those little plastic bits through your cooling system, into the cylinder heads, and cause major issues in terms of a cracked head. Not good and not cheap to x! While the failure above is extreme, it could have been prevented by replacing the original pump, and most importantly, when the car starts making a weird noise, stop driving it and get it checked out! There is no doubt this motor will have pieces of that waterpump stuck in the cylinder heads which can eventually cause cracking of the heads, and will require cylinder head removal to repair. This is what a healthy waterpump looks like! (Top right) Much better than the pictures from the previous pages. While bleeding the system can be a chore in the M96/M97 engines, replacement of the pump is very straight forward with nothing more than some bolts, hose clamps, and a drive belt. No timing belts to worry about, and nothing overly complex either. So what is the recommended interval for waterpumps in these cars? Ideally, every 4 years or 60k miles they should be replaced. This also allows you to ush the cooling system, which while having a “lifetime” coolant, doesn’t exactly mean