Date: 26 Sept 2019
Distance: 260348kms
Time for some more remedial maintenance. Just over 60 days to e30 Mega Meet.
1. Cooling System Refresh
Replaced thermostat housing, bolts, and bleed screw. Drained cooling system, replaced all hoses & clips (except the top and bottom main hoses. Flushed, filled with two bottles of fresh BMW Coolant & De-ionised water. All clips genuine, almost all hoses genuine BMW, with the exception of 2 or 3 by Vaico. I figured it was worthwhile to just go through and eliminate all of the 30-year old cooling hoses; why gamble my engine on a hose that could leave me stranded?
For those of you wondering, the M40 has a shitload of hoses. And now all of mine - every single hose, clip, and O-ring - has been replaced, along with the thermostat and rad. Only the heater matrix remains. Fingers x'd.
What a hoser. Yesterday.
2. Rocker Cover Gasket
Replaced rocker cover gasket (Topran), including helicoil of one bolt hole in the head. Jon had found this stripped a year ago, marked it, and we added to the 'list of things to do'. New gasket will keep the engine cleaner.
3. Clutch Slave Cylinder
Replaced clutch slave cylinder (Febi). Seemed like a good idea, I figured it was probably an original. Flushed and cleaned, refilled and bled. Jon said it was full of black sludge, needed plenty of flushing. Clutch action is now much smoother and lighter. Result!
4. Throttle Body
While he had that out (access to cooling system), Jon cleaned throttle body, drilled a drain hole in throttle position sensor, reassembled. It was very gunky. Smoother idle.
Can't wait for a trip in it! My thanks again to Jon & Keren at Auto38!
M40 Cooling hoses, yesterday image borrowed from RealOEM