Newbie needs help with Coolant Change

[Cbreeze]

Folks,

Newbie hear, 1st post actually. Well back in the day I did a million coolant changes and now for the life of me can't find a petcock on my '01 530. Dealer wanted some ridiculous amount for it and I would pay for somethings just not that.

So can anybody lend me a hand?

Thanks!

[XOC]

Hey Long Valley huh? That's where I lived before I moved here. But um, unless your 5-series is different that my 3s, the valve is at the bottom corner of the radiator and is opened with a flathead screwdriver. No valve on the radiator?

[uncle]

Open, the reservoir cap. Loosen the clamp on the lower radiator hose at the radiator. Put a container under that area. Pull the hose off, The old coolant will rush out. Don't fool with the pedcock. The flow is so much greater this way, it will do a better job of evacuating anyhting that may be in the coolant.

[thejlevie]

You'll need to drain the system via the radiator drain and the block drain. The block drain is a pain to get to as it is on the side of the engine under the exhaust headers. When draining a cooling system, leave the expansion tank cap on until you have the drain open. Only a small amount of fluid will come out until you loosen the cap. That will allow you to not be near the drain when it floods out and you won't get splashed with coolant.

I drain the radiator first. Then I snug up the radiator drain and tighthen the cap before opening the block drain. When you open the cap the block drain will splash coolant all over the place and doing it this way you'll stay dry. You'll need a new aluminum crush washer for the block drain.

When filling the system dilute the antifreeze (BMW brand is best for these cars) only with distilled water. And be sure to fully bleed the system, procedure follows:

1) Using ramps or a jack get the front of the car 1' or more higher than
the rear. That will make the radiator and bleed screw the highest point
on the engine and facilitate removal of air.

2) With the bleed screw open, add coolant until no more air comes out of
the bleed.

3) Leave the filler cap off, or at least loose, and set the heat for max
temp and fan speed. Leaving the cap loose will prevent air that's still
in the system from causing a "coolant fountain" once the engine heats
up. Start the engine and allow it to warm up to operating temp. As it
warms up occasionally crack the bleed screw to release any air and top
up the coolant as necessary.

4) Once the engine is at temp bring it up to 2000-2500 for a few seconds
several times. Then crack the bleed until no more air is released. At
this point the heater should be throwing lots of hot air, which
indicates that the heater core is filled with coolant. You may have to
repeat this a few times to get all the air out.

5) Drive the car a bit, allow it to cool back down, and recheck the
bleed for air. Over the next few days you may get very small amounts (a
few bubbles) of air out of the bleed screw.

[bimmerZ5]

you'll also want to drain the engine block's coolant. there is a plug on the exhaust side under the exhaust manifold. you'll need a new AL crush washer for that plug. turn your heater temp to full hot so the coolant in there gets out too.

make sure you bleed all the air out of the system; this seems to be the more tedious step. if your heater is cold or you start overheating, there's more air in your cooling system.

[Cbreeze]

Guys,

Thanks very much and excellent directions. One more question. Where is the bleeder valve?

XOC--- big change from Long Valley to San Diego ehhh! If Global warming or whatever is going on it won't be that different though. We just don't get a winter hear anymore.

[XOC]

Different trees, for sure.

[thejlevie]

Bleeder valve is on the top of the radiator.

[BeSeen]

Bleeder valve is on the top of the radiator.

Next to the coolant cap. It can be opened with a Flat head Screw Driver.