521 Over heating problems

[Matt H]

ok scrap that. The car is now running fine! It really has a mind of its own sometimes...

Honestly I feel like it was just a failed top radiator hose. What i've noticed when draining and replacing the coolant is the car doesn't like to be on a incline when you refill it. I just drove it around the block a few times and it's now settled in. I think it just needed to be driving to get the coolant moving and the thermostat kicking in.

Thanks everyone. I'm sure there will be more - but for now i'm back on the road : )



 

[datzenmike]

Your new thermostat should have a 'jiggle' valve in it. This is for L16s that don't have a thermostat by pass line. If you don't have the jiggle valve drill a 1/8" hole like Hainz sez.

 

Obviously on an L series you can't place the valve at the top but it will still vent air behind the closed thermostat. It's main use here is to vent the trapped, still cold coolant that's around the thermostat coil. That coolant stays cold while the engine gets hot. By having a small bleed, warmed water flows past the thermostat and it reacts faster.

 

[Matt H]

Thanks @datzenmike This was the type I replaced a couple of years back with the 'jiggle' valve. It seems to be running ok now

[banzai510(hainz)]

yeah the top hose is just a return line so I cant see how that would affect it. as most time the stat is closed so not alot of water goes thru there

[Stoffregen Motorsports]

One trick to burping a cooling system is to squeeze the rad hoses with your hand. It acts like a pump and can work an air bubble out.