Have just over 25k on my 3.4L engine and have noticed that the car "consumed" about about 1.2 L of coolant since new. I replaced it with a 50-50 mixture of distilled water and Pentosin Pentofrost antifreeze coolant. Topped it off a few months ago and no fluid loss since.

Spoke with a Tech yesterday while he swapped my summer wheels and tires for the winter wheels and tires and he said that it's normal for Porsche engines to "consume" coolant. That it's not a problem.

Anybody know anything about this? All of my other cars (including a vintage MGB) don't "consume" coolant.

 

My wifes new Mercedes Benz's consume coolant too.

Evaporation, air pockets?

 

Minor consumption is reasonable. Its more likely if running at high rpm as 911 often does. You can get an oil analysis if you are concerned. That helped me diagnosis a coolant issue on an LS2 engine. Blackstone labs is great to deal with.

 

The 991 runs hotter. Perhaps that has something to do w it

 

The 991 runs hotter. Perhaps that has something to do w it.

 

I don't think it is normal to consume coolant! The engine may not have been burbed completely when originally filled, seems unlikely. Check for leaks. The lines of course run all the way to the front. A very small leak would not leave any drips.

 

^ True. 1.2 L is not minor but it was over 25K.
Just wonder how acurately that was measured from original level.

 

I'm shocked that's too much of a coolant use!

 

What made you check? Was your temp running high?

 

Same question?

 

No. I checked it after driving it for a year and added the coolant. After reading your comments, I suppose there may have been air in the system. that theory fits as there has been no loss since it was topped off and the oil drained was not milky showing any signs of contamination.

 

Normal.
It's likely there are some air pockets trapped in a new engine - once they are expelled your level will drop. Expect anything up to a liter. The 911 has a large coolant capacity due to the radiators being in front and long pipes.

After that you will likely need to replenish once in a while depending on how hard you work your engine. There is some evaporation after you shut a very hot engine down (some boiling may occur inside the engine). Should only need to top up with destilled water - the antifreeze itself does not evaporate - only the water.

The correct way to handle periods of hard engine work is to run it relaxed for a few minutes before shutting down. This helps to keep the coolant flowing while the engine can get rid of excess heat. If you do this your coolant use should be minimal.

Rainier

 

Mine was down a liter after 18 months and 9000 miles. I added 50/50 Porsche antifreeze / water per Porsche tech recommendation. That's also when my oil level stopped indicating. I've driven it probably 10 miles so far but I didn't realize it took 20. Will be doing that this morning.

ChuckJ