How long does it take your m20 to heat up?

[steinbachphoto]

I don't know if there's either something wrong with my gauge or with my thermostat and/or temp sensor.

How long does it take your needle to get out of the blue. I live in a small town so most of my drives are maybe 10-15 min but unless I get stuck in a traffic jam and am sitting there idling for an extra 10 min my needle never gets to the halfway mark.

Is that normal or is there something wrong with my temp sensors?

[Sagaris]

It is common in any car for the thermostat to stick closed or partially closed. Replace it. I would expect your car to be up to operating temperature within 2-3 miles on a cold day.

[steinbachphoto]

To replace thermostat do you just drain coolant, disconnect hoses from housing, unbolt housing, replace?

[cheapshot]

Mine is usually out of the blue within five minutes in the morning. I always go out before work and start her and let her idle while I go back in and fix a cup of coffee. I drive about 5 miles to work and it is usually at the quarter mark when I get there. If i am traveling longer distances it gets up to the mid point and holds pretty steady.

[Sagaris]

There is a coolant drain plug on the passenger side of the engine block if you want to drain the coolant out that way, otherwise removing the hoses and letting it spill out is another method. There should also be a drain plug on your radiator if you want to really keep the mess under control. You will want some thermostat housing RTV (usually gray and ethylyne glycol resistant) and a new o-ring. Make note the orientation and order of the thermostat and o-ring within the housing. If you dont you may waste a couple minutes wondering why things aren't fitting nice. There is no gasket for the thermostat housing, just use a conservative amount of RTV on the cleaned up degreased surfaces and make sure none squishes into the coolant flow path when it sandwiches together. You will want to fill the radiator and engine with coolant via a funnel and one of the loose radiator hose ends before you put the hoses back together, just to aid the air-bleeding process. Set the heater on HOT (fan does not need to be on, just the heater valve set to HOT) top off the coolant and bleed the system using the bleeder screw. I have never had an issue bleeding a cooling system on an E30 by filling the engine and radiator as good as I can before connecting the hoses.

[steinbachphoto]

Sounds easy enough, I've drained and replaced the coolant quite a few times lately. Just replaced the head.

[Sagaris]

I hate how messy coolant is

[steinbachphoto]

I have a wide oil pan I put under and try to position so the wild spray from the drain plug on the block goes all into the pan.