328 Coolant

My coolant is currently a little on the weak side. Prior to storing for the year I was just going to drain a couple of gallons from the radiator and replace it with pure antifreeze until I conduct a complete flush next spring. Two questions: First, what type of antifreeze do people use and recommend? Second, I was looking for the radiator drain plug on a 1986 328 GTS and can not locate it. In looking at the manual it appears to be located on the bottom of the radiator on the drivers side. I can't find it. Do you need to remove the protection (cover) on the bottom of the car?

Thanks. SDF

 

I would power flush it now! If the fluid is crap now, it will be worse by spring and could clog and/or corode the system further. I recommend BMW coolant at a 25% coolant 75% distilled water mixture. Preventative maintenance is much cheaper that replacing the radiator and more later.

 

It appears the easiest way to drain the 328 coolant is to remove the heater hose where it joins the big (front to back) coolant pipe and remove the block drain plug. (these points are easy to see in the parts book) You may have to jack the car up in the back.
My recommendation would be to drain what you can and put a 50/50 mix with distilled water; then in the Spring flush all that stuff out & put some good anitfreeze/distilled water in.

Mark

 

Hi gang,
Stay away from "Dexcool" or "Dex Cool" - whatever - it's not COOL. I've seen first hand, what this sh-- will do!
Here in Calif., I'm using Prestone at a 50/50 mix rate with distilled water.
Hope this helps.
Cheers, Hank

 

I have been using the dexcool for 8 years now and have had no problems of any kind. I have heard many things bad about it and wanted to switch but I read that once you start using it it coats the insides of the cooling system with a coating that will flake off if switched back to regular AF. I have had my car apart numerous times including this summer and the aluminum pipes have nothing but the slightest hint of a white coating in them. I do change the stuff every year sometimes twice a year (alternator) and use 50/50 with distilled water. The reason I first started using it was no silicates (sand) or phosphates, which sounded good at the time for me. I have a freind who works for FOA and said he has seen water pump castings eaten through over the years for coolant. There is a new prestone product out which says it mixes with and complies with both dex-cool and regular PG. I was thinking of switching to evans but never could get the guts...... So i am the official dex-cool lab rat!

Rob

 

BMW's coolant is designed to work with all aluminum engines such as used in most Ferraris. It cost a little more than the stuff you get at a parts store, but well worth it IMHO. And, unless you live in the artic, a 50/50 mix is too much coolant. I have used a 25% coolant, 75% distilled water mix for decades in the Atlanta area with no problems...and yes the temp. does drop below freezing here in the winter! Remember, water cools better than coolant so you want to use as much water in the mixture as you can depending on your climate and still get enough of the corosion prevention additives from the coolant.

 

There seems to be a few coolants. Could you share which one do you recommend. Thank you for the knowledge!

 

Matias- May be a new record. You just revived an 18 year old thread. Note that BMWs do not have wet cylinder liners like Ferraris, so do a bit more research and there have been significant improvements in coolants in the last 20 years.

 

We’ll if the cars are 35 years old the thread’s age are irrelevant!

Thanks for the reply, I’ll keep digging.

 

If she were mine, I would put Zerex G-05 in her and change it every 2 years. Otherwise, put in a good ELC designed for wet liners like Ferraris and big diesels have.

 

This sounds like a plan! I build custom adventure motorcycles, so I am always the one drilling customers about the importance of replacing fluids, even if the mileage that year was low. I've never used coolant on old boxers, so I'm not knowledgeable about that. Really appreciates the help!

Here are the bikes I build: https://mythmotor.com/

 

Agreed - the heavy duty coolants for wet liner engines and diesels are designed to reduce cavitation - Rifledriver has posted pictures of Ferrari 308/328 cylinder liners where coolant cavitation has resulted in holes right through the liner! He recommended the same as tazandjan - Zerex G-05, change every two years (even if you don't drive it at all).

Gordon

 

I have reasearched past threads and other sources, and can confirm Zerex G05 is the correct fill for these era. It was the same blend as Mercedes of the time. It is getting a bit harder to source.

 

I would see what is specified in the owner's manual and use the equivalent available at this time. Best to flush out old coolant before you change to the new and use either prediluted or 50:50 mix of concentrate and distilled water.