the thermostat removal and refit

[adam01]

Hi

Have you the diagram for the thermostat removal and refit

Adam

And Many Thanks

My Bmw is 1975 2002 model

[MatthewCervi]

If you look at this diagram http://www.realoem.com/bmw/showparts.do?model=2583&mospid=47141&btnr=11_2386&hg=17&fg=05 you can see the layout.

Start by turning the heater to hot, then disconnect the lower radiator hose from the bottom of the thermostat and let it drain. Have as wide a catch pan as possible, because draining coolant on these cars is pretty messy. Next loosen the hose clamps on the other two hoses going to the thermostat and wiggle the thermostat out. More coolant will drain out.

Optional: if your coolant is more than two years old, I'd recommend draining the block also while you're doing this work. Slide the drain pan down some and find the drain bolt on the block. It is on the exhaust side mid-way down between #3 and #4 cylinders. Remove it, let it drain and reinstall the bolt.

Reinstallation is the opposite of removal (wiggle thermostat back into the two hoses near the engine and tighten clamps, install lower radiator hose and tighten clamp), however...

These cars don't self-beed very well so it helps to get the front of the car up high. Raise the front of the car and put it on jackstands, then SLOWLY add coolant until it gets near the top of the radiator neck. Put the radiator cap back on, but leave only turn it to the first indent (i.e. not fully tightened) and put your drain pan under the radiator drain hose. Start the engine and let it warm up. Periodically check the lower hose to make sure coolant starts flowing eventually (WATCH OUT FOR THE FAN BLADES!!) and check the temperature gauge so you don't overheat if there is a bubble preventing good flow. Heat coming from the heater vents is a good sign.

Once it is mostly bled and the coolant seems to be flowing, lower the car and top off the radiator if necessary. Then I'd just check the level for a few days after driving to see if it needs any more topping up as it isn't uncommon for a few more bubbles to work their way out.

Good luck. It isn't hard, just a little messy and sometimes time consuming to bleed the bubbles out of the system.