I couldn't find much about these on the forum so here goes.

I changed the coolant on our 380 today and unlike with the 6g74 (Ralliart) where I can undo both block drain plugs on car stands, I could only get the plug for the front bank out. The one on the rear is really hard to get to. I couldn't for the life of me work out how to get access to it. It also seems to be an Allen key and the front bank is a standard socket fit. The workshop manual mentions the "left" and "right" drain plugs but only mentions removing one drain plug (the front). I was able to drain a total of about 7l so there was probably another 1.5l in the rear bank. I gave it a good flush with tap water and used a 40:60 mix of Nulon long life coolant with distilled water.

Anybody been able to get to the rear plug?

Steve

Steve,

I've had the same problem, couldn't even find the rear bank drain plug despite the details in the workshop manual, and couldn't get any leverage to undo the front plug. Well not up on ordinary axle stands anyway, just not enough room to move, on a proper hoist it should be easier.

I've read that one solution is to remove the thermostat, seeing as it stays shut and blocks off the coolant in the block until the coolant gets to approx. 88 degrees C, then drain/flush the system. It's pretty easy to remove, I replaced mine about a year ago when it carked it.

Never tried it myself but will give it a go soon as I'm coming due to replace the coolant.

Thanks,

I got the front plug out by using a 10 cm extension bar with a uni joint and accessing it from the top of the engine bay around the dip stick and heat shield. This wasn't too hard this way. The rear one looked pretty close to impossible to remove without a hoist. The third gen plugs are much easier to get out. I might use the thermostat housing technique next time.

And for everyone's information, the Nulon coolant is often on special at Repco, Supercheap, Autobarn etc for about $30 for 5 litres. Makes a coolant change pretty cheap even when you factor in a bottle of distilled water .

Steve

Anyone managed the rear plug here?