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Changing engine coolant including fluid in heater matrix


Big Mark

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My heater matrix appears to be in need of a flush as it's not blowing that hot so figured I'd follow the link below and flush it but I also need to get the engine coolant changed.

 

http://www.mkivsupra.net/vbb/showthread.php?299982-Does-this-mean-heater-matrix-has-had-it&highlight=Heater+matrix

 

I can do the matrix flush myself but plan on getting the coolant changed down the road at a friends tyre garage as it will save me the hassle of getting the car up in the air.

 

My question is: is it ok to disconnect the pipes from the engine to the heater matrix and join them together so that no coolant is flowing around the heater matrix at all? Then I can get the garage to change the coolant from the engine and radiator. I can then come home and flush the matrix, top it up with fresh coolant and then reconnect the pipes to the engine.

 

Otherwise I'd end up with new and old coolant being mixed together as the garage won't be flushing my matrix?

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But if I flush the matrix i know I'll get all the crap out of it but it'll end up with the old coolant from the engine in it won't it?

 

That should be drained out when the coolant change is done, easy enough to do, i used a

vacuum bleeder to suck out any coolant left in there.

 

 

Do the matrix flush first, link the hoses together so the matrix is bypassed then go to your

garage where they can drain the system, re connect the matrix and then re fill the coolant

Edited by Dnk (see edit history)
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That should be drained out when the coolant change is done, easy enough to do, i used a

vacuum bleeder to suck out any coolant left in there.

 

 

Do the matrix flush first, link the hoses together so the matrix is bypassed then go to your

garage where they can drain the system, re connect the matrix and then re fill the coolant

 

Thanks, sounds like a plan.

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You wont get all the water out the matrix but it wont make much difference, there is also a drain

plug/bolt on the exhaust side of the block to help drain the engine.

 

There's a diagram showing the drain plug in the coolant system wsm page CO-2

CO.pdf

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Guest Roger NE

Can't see why you would go to a garage to get them to fill the car with antifreeze

 

It really isn't that complicated to "bleed" the heater matrix . . . I've had cars like this for the last 30 years

 

1. Fill the system up with the desired mix of antifreeze

 

2. Leave the Rad Cap off, gradually warm the engine up with the heater on max temperature, and make sure the system is full to the brim

 

3. Once it is at normal temperature, keep squeezing the hose going into the heater matrix in a pumping action while pulling the throttle pulley to increase the engine revs to around 2500rpm

 

4.You should see bubbles coming out of the top of the radiator. After a few minutes the bubbles will stop - that means you've got all the air out of the Heater Matrix.

 

Sure . . it helps a bit if you can raise the front of the car a little (park on a slope?) . . . but it's not essential

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I defo recommend some sort of drain cleaner through the matrix in the flushing process , just done mine without it and although it does now blow warmer its not "HOT" ....will be doing it again soon.

 

I've got the drainer cleaner sat on the shelf ready.

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Can't see why you would go to a garage to get them to fill the car with antifreeze

 

I assumed to drain the engine coolant I'd need to get to things from below (guessing I'd need to remove lower rad hose to drain the enging and radiator), so it would therefore be easier and quicker to just get my friendly local garage to get the car in the air on their ramp. But if it can all be done from above then I'll do it myself.

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Guest Roger NE

You need to jack up the front of the car a bit to get to the radiator drain plug - surely you have a jack?

 

Personally, for quick jobs like this I park the car with one pair of wheels on the kerb, then jack up the other side, so you can get underneath.

Edited by Roger NE (see edit history)
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