328 Coolant system

Well, there's no two ways around it, its a messy job!

There is a drain at the radiator (bottom right hand side) & there is a drain point on the engine block (drivers side underneath no 4 exhaust port I think).

If you want to get more out then disconnect one or more of the long pipes that run the length of the car - there is an access panel towards the front that you can drop away.

Use a 50:50 mix of good quality coolant & distilled water.

I.

 

To make life easier for the next coolant change, get a Prestone flush kit. They come with 3 sizes of fittings that go in a water line & have a capped hose fitting.

Remove the rectangular panel between the front wheels, remove the smaller (~1" OD) line that connects to the larger All water line. Be prepared to catch about 4 or 5 gallons of coolant. Once the coolant is drained, cut the line about 4" from the end. Insert the drain fitting that fits (think it's the 5/8" one, but it's been a while.) Next time, you just need to remove the cap to drain the coolant.

Not much that can easily be done about the fitting on the block, it's just going to spew coolant over everything down there & make a mess under that general area when it's opened(sigh).

Guess a ball valve with a metal drain tube could be retrofitted. Metal tube because it's between the header & the block & it gets warm enough to melt most plastics in there.

 

Just a quick note on coolant to use IMHO 1) don't use the orange extended life stuff here some interesting bad things about it. 2) use BMW or Merc. coolant 50/50 with distilled water and I always through in a bottle of waterwetter for good measure. Regards, Vern

 

When I change my coolant, I drain the system as others have described then fill the system with 100% distilled water and drive the car for a 100 or so miles then drain and add 50/50 distilled water and BMW coolant. You should bleed the radiator and the thermostat housing after the coolant is drained and refilled each time. If you don't let the car get too hot you could probably omit the bleeding of the radiator when adding the 100% distilled water.
Be careful with the bleed screw and washer on the thermostat housing--it is easy to drop in the vicinity of the timing belts and it is brass so it won't be attracted to a magnet.
When I bleed the system, I put a brake bleeder screw with a clear vinyl hose in the holes--this allows you to do a thorough bleed job. You can bleeeda gallon or so of coolant into an empty coolant jug. On my car the radiator bleed screw was modified and I have to use a home-made 6mm bleed screw, but I think the unmolested ones may be 8mm like the thermostat housing.

Mark

 

Mark, You would not have to remove the bleed screws to let out the trapped air just losen them a few turns that is enough to allow what air is in the system to escape thru the threads of the screw. You can do what you are doing but you are spending too much time. I fill the system with as much fluid as I can before I start the engine with the bleed screws open and heater valve open and let the system fill. I am usually only off about a quart or two so doing it this way. Then I start the engine, close the bleed screws first, and let it warm for a few minutes then open screws a few turns and poor the remain fluid in gravity works fairly well. Regards, Vern.

 

Vern:

I know this method is overkilling it, but I don't like the "bleeding" water dripping on the timing belt area either. Also, when you bleed it with the tube you get quite a bit of air out -- the air is mixed with coolant and it keeps coming.
I would like to get a bleeder set-up like what is used on the brakes where you can leave the bleeder in and just attach a tube loosen the bleeder...

Mark

 

Nothin' wrong with overkill! I do alot of things that could be considered that. On my 355 I put a rag around the bleed screw to catch any extra. Regards, Vern

 

greetings verell, hope all is well.
I have just fitted a stainless steel home made drain kit as you describe so well above.
I also drilled out an old exp tank cap, and fitted a threaded hose connector.
Draining is easy now via the drain cock, and flushing is a doddle, as i simply connect a hose to the exp tank cap.
apologies for pic quality.
cheers, d.

ps ... i like the idea of the brake type bleed valve for the stat housing.
Image Unavailable, Please Login
Image Unavailable, Please Login

 

I always have ther adiator in my Ferrari power flushed every three years or so at a local Goodyear service center. They hook a machine to the system that first pumps the old fluid out, then pumps a cleaning fluid through the system under pressure, the pumps a 50-50 mix of coolant in...I use BMW coolant. You will nor believe the crap a power flush will pump out... Well worth the $69.00 cost...

 

I buy BMW coolant from my BMW dealer...I've been using it for decades...I do not know if BMW makes it or another German company just puts a BMW label on it...regardless, it is specifically designed for aluminum engines and I have been well pleased...

 

I'm not real versed with the specific terms used, but the big think with the BMW or MBZ coolant is that it uses something like Propylene Glycol and it does not contain ethylene glycol a chemical that becomes acidic (corrosive) after a year or two. The container says what it does not contain--I think it is ethylene glycol which developes silicates. The silicates, or whatever they are called, precipitate out of solution and become kind of a gritty sediment in the cooling system.
I also recommend using distilled water.

Mark