2003 S60 Fluctuating coolant level. (New coolant reservoir cap) Topic is solved

Cookie-the-Swede · Post by **Cookie-the-Swede** » 08 Jan 2018, 18:26

So my coolant level starts off between MAX and MIN when the car is cold. After driving around for a few miles and the engine warms up the coolant level rises... completely filling the entire reservoir... and bubbling.
Then when the car cools back off, the level drops way back down to the MIN line. I notice that some coolant drips out (by the front passenger tire) until the engine cools back down, were it doesn't leak anymore.

Does anyone know what's going on here?

Thanks in advance.

Post by **velorider** » 08 Jan 2018, 23:55

I hope I'm wrong but this sounds like a leaking head gaskets. The air bubbles are exhaust gasses mixing with the coolant. There are machines that can test for exhaust gasses in the coolant, I would suggest getting the test done.

Post by **RickHaleParker** » 09 Jan 2018, 02:19

Bubbling and excessive expansion indicates you have a defective head gasket allowing gases to be pushed into the cooling system. There are chemical test that will check for gases in the cooling system. They go by the name "Combustion Gas Leak Tester Detector" or "Block Tester". The kits cost between $35 - $70 depending on now good of a shopper one is. A whole lot more for the type that pays too much for a Whistle.

Autozone has Block testers in their tool loan program. Your need to pay for the test fluid about $9.00 + tax. The test can be done in their parking lot so you may not need to place a deposit on the tool.

Pull the Oil cap off and look inside, pull the Oil dipstick. is the oil milky white?
Watch the exhaust when the engine is warm and running, does it have excessive steam, looks like white smoke.

Post by **jonesg** » 09 Jan 2018, 06:52

Napa block tester fluid ,$7.
See youtube videos
..
but the head gasket is leaking.

veenee · Post by **veenee** » 09 Jan 2018, 07:21

I had exactly the same problem with Suzuki Jimny (yeah I know, different pair of shoes), and the garage guys were seriously puzzled as head gasket was fine.

I finally found on the internet that it might have been faulty radiator cap, I have replaced it and - bingo! - all was good!
The faulty one must have not keep the correct pressure any more...

Worth trying.

Post by **oragex** » 09 Jan 2018, 09:26

Please, before going into the head gasket territiry, replace the green cap with a new 'original' Volvo part. I believe Gates makes them for Volvo, check Ipd or Fcp sites. And wish people won't talk so quickly into head gaskets when it can simply be a faulty $10 part.

The cap must keep the pressure up to a certain ponit. When the gasket wears, it won't keep the pressure and the level will rinse inside the reservoir and will eventually leak outside it.

Post by **RickHaleParker** » 09 Jan 2018, 09:41

The cap must keep the pressure up to a certain ponit.

The boiling point of a liquid is the temperature at which its vapor pressure is equal to the pressure of the gas above it. The reason cooling systems run ~15 psi over atmosphere is to keep the gas pressure higher then the vapor pressure so the liquid does not boil.

Your correct, checking the cap would be good first step. I was trying to gather more information, first. That is why I suggested checking the color of the oil and the exhaust, the two don't cost anything.

93SCMax · Post by **93SCMax** » 09 Jan 2018, 14:03

RickHaleParker wrote: ↑09 Jan 2018, 09:41 Your correct, checking the cap would be good first step. I was trying to gather more information, first. That is why I suggested checking the color of the oil and the exhaust, the two don't cost anything.

+1

I like that you are recommending a proactive approach that is simple and cheap to do.

Post by **jonesg** » 09 Jan 2018, 17:39

oragex wrote: ↑09 Jan 2018, 09:26 Please, before going into the head gasket territiry, replace the green cap with a new 'original' Volvo part. I believe Gates makes them for Volvo, check Ipd or Fcp sites. And wish people won't talk so quickly into head gaskets when it can simply be a faulty $10 part.

The cap must keep the pressure up to a certain ponit. When the gasket wears, it won't keep the pressure and the level will rinse inside the reservoir and will eventually leak outside it.

Here's a simple test if you buy a new cap.
Get the block tester fluid from napa.
Pour a cup of fluid into a clear soda bottle.
Drill a hole in the old cap, run hose from cap to a bottle with block tester fluid. Submerge hose in fluid in the bottle.

As the air in the exp tank heats up the fluid in the bottle will begin to bubble, watch for the color change. That's a definitive test

Cookie-the-Swede · Post by **Cookie-the-Swede** » 14 Jan 2018, 10:15

There's no milky or discolored oil OR coolant. There's no white smoke coming from the tail pipe. It's not overheating.
I replaced the coolant reservoir cap and it isn't "boiling off" anymore. I still plan on replacing the radiator since it seems to have a small leak in the front right corner of the car.