COOLANT LEVEL

Distilled would be better. Fill the tank about half full, it will spit out what it doesn't want/need. Bleed and bleed again. It will help if you park it on a hill/raise the rear of the car.

 

FYI: the reason not to use tap water is that there are minerals--especially calcium--in tap water that can deposit in your engine. This inhibits heat transfer, narrows the "arteries" slightly, and can also inhibit coolant flow if any of the calcium flakes off and lodges somewhere.

Distilled water is perfect, and rain water is okay, too.

 

Glad to hear the car made it safely to the 'Peg. Welcome to the joys of 308 coolant change (always messy)!

Regarding the expansion tank, it is true; the car will barf out what it does not need through the overflow hose. Note though, that the tank is naturally only about half full when cool. If you look in the Owner's Manual, it says the spec level is 6 cm below the rim of expansion tank filler cap. That looks almost empty when cool. Make a dipstick with the -6 cm level marked.

I find that too much is made about bleeding and rebleeding. Maybe the carb cars are different than the QVs or something. Now, I just bleed the front and bleed the thermostat and be done with it (okay, I bleed the rad once in a while; there is always air there but it never seems to get worse).

FWIW, BMW coolant is well regarded for its aluminum-friendly formulation; some BMWs have nasty-small coolant channels that sulfides can plug so they make good stuff. Always use distilled water.

David Helms makes a petcock pup hose for the front heater hose if you get tired of spraying half a gallon of coolant on the floor every time you drain the coolant system.

You done your fuel hoses yet???

 

One last one, once you have filled it & started it then open the heater valves & make sure you have heat coming out the vents - its very easy to get an air lock in the heaters.

If you do, sometimes it will shift itself (in which case you will need to top up the system) but otherwise you may find it easier to find a hose joint somewhere near the heater matrices that you can use to let some air out.

 

It takes a lot of bleeding to get it all out.
Drive it some.
Bleed it.
Drive it some more.
Bleed it.

The movement of the car and coolant with help get the pockets of air out of 'trapped corners'.
Every time you drive, you should bleed it.
You will find a little bit of air will come out.
And, when it stops coming out, you're done.

 

Hi Barry,
I don't see in your write-up above where you bled the thermostat? There are two bleed points, the radiator and the bleed screw on the thermostat. Both usually need to be bled to get the air out of the high points in the system.

 

I wrote the attached procedure after researching on this site. I am inclined to suggest bleeding at the thermostat is necessary. I agree it's a pain. With my car it means removing the bonnet and removing the air box in order to be able to reach the thermostat bleed screw.
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"I ran the car for about 30 minutes. The engine after 25 minutes started sputtering and felt like it lost power,"

That shouldn't happen and has nothing to do with the cooling system…

Re bleeding. Maybe 308s are different but I have changed the coolant several times on our 328 and all it requires is filling the system, bleeding from the rad, then bleeding from the T-stat - as per the Ferrari instructions in the owners manual. It never requires additional bleeding and, IMO, if recurrent bleeding is needed, it is because there is a leak(s) in the cooling system. The expansion tank is just that - for expansion. As long as there is a bit of coolant in it when cold, that's sufficient. Having more than that does nothing for the cooling system since the cooling system is already full. OTOH, overfilling is not a problem - the car will just spit it out until it finds the correct level.

 

Wow, I lived 9 years in Winnipeg as a kid and loved it. Great town. I don't think I could move back there [in the winter at least] now that I have let my blood thin in the deep south for so long, but I still remember the great night skies and northern lights in the winter.

On my 84QV the thermostat bleed is definitely necessary. I found Verell's bleed screw for the thermostat casing to be very handy. Just crack it open a bit after the thermostat opens and off you go.

Also on my car at least, I find it took a few extra bleed sessions over the next couple of weeks from a fluid change to get all the air out. After that I just drive the car and other than ridiculously hot days in the summer down here have no probs.

Ciao,
Paul

 

Bleeding the thermostat gives you the opportunity to spew coolant all over your timing belts.
Yippy skippy.

 

I never bled the thermostat and the car ran perfectly cool through a hot Florida summer.

 

Do you guys bleed the system with the reservoir cap on, off, or just loose?

 

Cap off, but I may have a screwed up procedure.

My air bubble loves to live up front. 10,000 miles post engine rebuild and I have never had to add coolant, so I don't think it is a problem, but just the way the car is.

When I take off the cap after driving a couple of weeks or so the fluid level in the rear tank is at the top.

Then I open the bleeder on the radiator. Air hisses for 10-15 seconds, then burble of coolant. Close the bleeder.

I go back to the tank and it is at the prescribed 6 cm. I put the cap back on.

Someone suggested the air bubble moves in 10 seconds after I start, but just by keeping my eye on it it seems to take more like 2 weeks.

Like I said, I don't loose fluid, so I don't really worry about it much, just it is something to do for the preflight

 

Re periodic bleeding…

Does anybody believe that people needed to take their new 3x8s to the dealer periodically when they were new and in-warranty for "burping" service?

Fix the leaks!

Sorry, this is one of my rants…like the Doc's R12 rant.

 

If there were a leak, I can imagine how, as the coolant system pressure rises, coolant could be forced out, but I don't understand how air could be forced in. My understanding is that the coolant system pressure never drops below atmospheric pressure.

 

My 328 does exactly the same - always has.

 

Assuming the system has no leaks and is properly filled, air cannot enter or be "generated" in the system.

So if air does periodically appear in the cooling system, some possibilities are:
1. Head gasket leak - don't just think of a BLOWN head gasket, think of a slight seep…
2. expansion tank empty, allowing air back into the system when engine cools
3. pinhole leak in hose/sealing surface that is normally OK but opens under vacuum
4. slight actual coolant leak you are not seeing because it occurs only when driving at full operating temp/pressure; coolant "disappears" in the wind stream/engine heat. Engine cools - air enters via leak.

There is NO WAY for air to just "show up" in a properly functioning engine/cooling system. Something is wrong or the system was improperly bled when coolant/components were changed. Once bled, it will remain bled until the next time you need to change something…or until there is a leak.

Re the head gasket: a head gasket can seep at high load and be OK normally and show perfectly good compression.