I've gone and done it, coolant ratioin a 1982 300D - PeachParts Mercedes-Benz Forum

300DPETE · #1 10-23-2005, 01:25 PM

Okay, it's not so bad, just a PITA.

I mangaed to screw up the ratio of mercedes coolant to distilled water when filling my 1982 300D. I know I'm at no more than 66 percent coolant, but I'm guessing I'm at somewhere between 60 and 65 percent. The container says, don't exceed 55%.

Do I need to drain and start all over again? What negative consequences can 60-65 percent mercedes coolant have on the engine instead of the recommended 55% max?

Thanks,

Pete.

boneheaddoctor · #2 10-23-2005, 01:28 PM

Ever try hygrometer...used to measure antifreeze by specific gravity...

You will have to drain a little...with what Antifreeze costs its not wize to do...

I assume you screwed up the ratio on fresh antifreeze.

300DPETE · #3 10-23-2005, 01:31 PM

Good point. I'll get one of those measuring devices.

Yes, fresh antifreeze after doing (a couple) of flushes. Still need to get the citric acid and try that as well.

In the meantime, is it okay to drive for a few days on the higher ratio?

t walgamuth · #4 10-23-2005, 02:06 PM

a short while wont be a problem.

tom w

dieseldiehard · #5 10-23-2005, 02:06 PM

if the engine is running normal temps, that is as long as the radiator isn't clogged or something is causing it to run hot its probably ok for the iron head engine to run 65% coolant. The problem would be if you had a cooling system problem, that percentage a/f is going to raise the head temp further because of poorer thermal transfer properties as antifreeze has much less thermal trasnfer properties and is very viscous compared to water.
If BTW you were planning on driving North of the Arctic circle then that mixture might be just about right!

There was a story about a MB dealer that replaced a head on a car that failed in warranty. The same fellow brought the car back sometime later and it had another warped head. After some questioning they determined he was running on 100% antifreeze. He said he thought if 50% was good then 100% would be better. Wrong!
Still, an iron head engine probably would have survived that. I believe he had an aluminum head on a gasser, they need the proper ratio even more so than diesels which run cooler.

300DPETE · #6 10-23-2005, 02:34 PM

After some questioning they determined he was running on 100% antifreeze.

Holly crap!

I went up to the store after reading the thread from BHD and got a hydrometer. The only thing, is that none of them, except for the litmus strips you can get, read in percentages...they read in temperature ratings. The strip reads in 10% increments, meaning that I need to match a color on the strip between 50 and 60. Guess I can live with that.

Thanks, guys.

Pete.

Austin85 · #7 10-23-2005, 05:37 PM

Anyone ever use Prestone Radiator flush?
Is that stuff OK for our cars?????

300DPETE · #8 10-23-2005, 06:21 PM

Quote:

Originally Posted by Austin85

Anyone ever use Prestone Radiator flush?
Is that stuff OK for our cars?????

I tried the Prestone Radiator "Super flush" on Friday, and it didn't do much of anything. I then used "Zerex Super Cleaner" or something close to that name, and it cleaned out a lot more (dark liquid came out after doing this).

I'm still going to do the citric acid flush, though.

...the only thing is that I don't know if the heater is working since the blower's not putting anything out. I had the heater on, and drove for about 3 or 4 hours, but not sure if it was actually working under the hood for a proper flush.