308 QV Coolant Leak

Air in the system....

 

You could also have a faulty radiator cap.

 

Make sure it's not actually a pin hole in the reservoir. Try a new cap and see.

 

Wow, same thing happened to me this weekend, as I was driving home about 3 blocks away, car starts to leak like crazy (see pic) ..... I'm wondering if there is air in system, I did have my rad welded last year and did not drive it much.
What's the best way to diagnose if there is air in system, faulty thermostat or water pump.
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Don't pee on road......

Sorry can't help it

That's a really bad leak!

 

Only way to tell for sure is bleed it

 

This is my favorite...foolproof
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You need a new radiator cap.

If you want stock, go 1.1 bar. A Stant is better and you can get that at Auto Zone for under 10 bucks.

 

Did you over fill the reservoir? It will purge fluid if it is over filled... It isn't to be filled to the top. You can make a wooden dowel with an appropriate mark so you get the level correct.

My car did that the first few times I drove it. The level was too high. I removed a bit of fluid and it hasn't purged a drop since.

Franny

 

Just bleed out the air. Open the overflow tank, then open up the bleeder screw on the radiator. Don't unscrew it all the way, just enough to let the air out. just an FYI, hold a rag under the bleeder screw, as you want it to spill out onto the rag for like 10 seconds or so. Do this before you head out for a drive. Takes a couple of days to get all the air out. If the problem still persists after several days of bleeding from the radiator, result to doing a bleed from from the bleeder screw on the water pump. Warm up your car a little to build up some pressure, and proceed to unscrew the screw a little never all the way, as hot fluid will flow out, along with the air and you might drop the screw, keep it threaded and socket on to tighten back up. After you done the above several times and it is still pissing, then buy a new 1.1 Bar cap. And tighten all your coolant lines, as air is getting in somewhere. It took me two weeks to work all the air out of my system and my 308 hasn't pissed in the last 1 1/2 years. Good luck...

 

you probably overfilled. The tank should onlyu be about half full when cold. As a rule of thump. Stick in your indexfinger. Only your nail should be wet a little.

 

A step that many miss when bleeding is set the the heater control to hot.

 

Exactly right. When I change the coolant in my 328, I don't worry about the level in the tank too much. If, after being filled/bled there is still SOME coolant in the tank when cold, there's enough. The point of the reservoir is to keep the system full of coolant. As long as there is some fluid in the reservoir, the system is full. If I accidentally over-fill it it and it dumps some, I just ignore it and let it do that until it decides the level is correct. The car knows if there is too much coolant and it will sort that out for you.

This presumes, of course, that there is not some other issue, like a blown head gasket causing the problem!

 

I remember reading that the fluid level should be 45.0mm to 55.0mm when cold, measured from the top Flange to the fluid. Otherwise you are open to the "length of fore finger" debate!

 

It has been almost 6 months since my last post here about the Expansion / Overflow Tank. We were discussing fluid levels. Before that I had the pinhole leak in the Expansion / Overflow Tank that was fixed and then pressure tested. No leak was found after the repair, so we went ahead and Powder Coated it Black - looked great! A few weeks later, I noticed a "Bubble" under the Powder Coating, and it turned out to be another leak, so this time, the Tank was stripped, all the possible areas re-brazed, inside was epoxy coated and the outside powder coated again. It has been fine until this week when I noticed another pin-hole leak. So I guess it's time to consider a replacement tank. The new ones are very expensive, so I was wondering if anyone had a used one for sale here on the forum. PM me with details if you do. Thanks!

 

don`t buy a used one ... chances are, that very soon you will have the same problems again !

when my expansion tank started to leak, shortly after it was spraying like a watering can ...
so I bought a new steel one from superformance

do yourself a favour and treat yourself to a nice christmas present
you won`t regret it !

 

Yeah, I will never repair another one of these tanks. I did on my GT4 and learned the first pinhole is just that - the first. Many more to come and if you are paying for the repair you will have spent more than a new tank quickly. I got an aluminum tank from Superformance for both my old GT4 and my current QV and am satisfied. I did have to weld on a bung for a sensor for the QV and it is slightly different shaped (more puffy looking) but 99% of people couldn't tell the difference if I painted it black.