coolant overflow after each shut off. - PeachParts Mercedes-Benz Forum

Assault · #1 12-17-2014, 08:00 PM

Hello,

Merry Christmas to everyone on PeachParts, hope all is well.

This problem disappeared for a weekish and is now back; around the time I removed the upper radiator hose from the radiator and poured coolant down into the thermostat region, until coolant was at the top of the hose. Now every time I shut the car off and let it sit for a few hours, there is guaranteed to be a puddle of coolant directly below of the coolant overflow pipe (on the ground).

The only way I have found to prevent this from happening is to release all the pressure, from the coolant expansion tank.

Is there air in the system? The temp. sensor holds at 80, unless I'm traveling on the highway @60mph 90c, @70mpg 100-95c. However it drops below drops below 100c once it reaches that point and hovers around 95c - 100c

Thank you,
Alexander

Diesel911 · #2 12-17-2014, 08:10 PM

When the Cap is off of the Coolant Tank and the Engine is Hot and running does it bubble? If so there could be a Head Gasket Leak.
If you sniff over the Coolant Tank opening does it smell like Combustion Gasses or just Coolant.

I have never seen this in fact but in the Auto Manual it used to say it was possible for the Water Pump to suck Air in at the Hose Conections on the suction side of the Pump.

On My year and Model there is a little about 1/4" thick OD Tubing Banjos on the end. I am not sure what the Tube does or what would happen if that tube got plugged.

Assault · #3 12-17-2014, 08:25 PM

I have only smelled coolant, I will check tomorrow. The head gasket was replaced about a year ago.

leathermang · #4 12-17-2014, 09:54 PM

Have you tried a new radiator cap ?

Diesel911 · #5 12-18-2014, 02:49 AM

I have been assuming the Coolant Overflow Tank was not overfilled.

Remember I do not know what you did when the Head Gasket was replaced.

The surface of the Block and the Head being flat are are other factors needed to be sure the New Head Gasket is going to work; a long with a clean surfaces.

A crack in the Head could also cause the same symptoms.

Diesel911 · #6 12-18-2014, 03:01 AM

I don't know enough about the Monovalve to know if when you shut the Ignition off it is supposed to cut off the Coolant that is inside of the Heater Core.

In general for pressure to build up inside of the Coolant System like that there has to be gasses pressurized or trapped Air geting into it or the Coolant or the Coolant itself has to be getting hot enough to turn into steam.

What are the symptoms of a Blown Head Gasket? - BlueDevil Products

Blown Head Gasket Symptoms:
•Coolant leaking externally from bellow the exhaust manifold
•White smoke from the exhaust pipe
•Overheating engine
•Bubbles in the radiator or coolant overflow tank
•White milky oil
•Significant loss of coolant with no visible leaks

Blown Head Gasket? What Is It?
What is a Symptom of a Blown Head Gasket?

Some might think the most common symptom of a blown head gasket is thick white smoke bellowing out the exhaust tail pipe, but it's not! The most common symptoms of a blown head gasket are:
•Engine overheating or exhaust gases in the radiator. If you think you may have exhaust gases in the radiator, the gases would be accommodated by constant bubbling in the radiator.
•Engine running poorly (skipping, hesitating, or lack of power).
•Coolant in the oil which would cause your engine oil to become milky, and would have a very similar look to it like chocolate milk.
•Excessive pressure in the crank case causing extreme blow by out the oil cap or engine oil seals.

Diesel911 · #7 12-18-2014, 03:03 AM

I don't know enough about the Monovalve to know if when you shut the Ignition off it is supposed to cut off the Coolant that is inside of the Heater Core.

In general for pressure to build up inside of the Coolant System like that there has to be gasses pressurized or trapped Air geting into it or the Coolant or the Coolant itself has to be getting hot enough to turn into steam.

What are the symptoms of a Blown Head Gasket? - BlueDevil Products

Blown Head Gasket Symptoms:
•Coolant leaking externally from bellow the exhaust manifold
•White smoke from the exhaust pipe
•Overheating engine
•Bubbles in the radiator or coolant overflow tank
•White milky oil
•Significant loss of coolant with no visible leaks

Blown Head Gasket? What Is It?
What is a Symptom of a Blown Head Gasket?

Some might think the most common symptom of a blown head gasket is thick white smoke bellowing out the exhaust tail pipe, but it's not! The most common symptoms of a blown head gasket are:
•Engine overheating or exhaust gases in the radiator. If you think you may have exhaust gases in the radiator, the gases would be accommodated by constant bubbling in the radiator.
•Engine running poorly (skipping, hesitating, or lack of power).
•Coolant in the oil which would cause your engine oil to become milky, and would have a very similar look to it like chocolate milk.
•Excessive pressure in the crank case causing extreme blow by out the oil cap or engine oil seals.

Diesel911 · #8 12-18-2014, 03:12 AM

Plymouth Breeze Questions - Coolant resevior gurgling. Blown head gasket? - CarGurus

"It's a 4 cyl , I do not lose Coolant an it doesn't overheat . But the overflow gurgles when I shut it off, I have no idea at all I'm taking back to th Tuesday , this gurgle is not normal obviously , idk but they will That's for sure ! Do all garages have this test you are talking about , they did a pressure test they say it was totally fine and normal , is this the test you are talking about getting ?"

eatont9999 · #9 12-19-2014, 12:56 AM

A leaky or poorly sealing reservoir cap can cause this issue. However, only if it is actually leaking from the reservoir overflow and nowhere else. It probably leaks any time the car is up to temp but you only notice it when it has sat parked for a while. If your cap is not a new OEM cap, replace it and make sure the mating surface on the tank is clean and free of corrosion, etc.

Replacing and not properly orienting the monovalve internals properly can cause leaks from the monovalve area; which show up very close to where the puke tube exits. Check behind the front wheel by the brake support and fender. If the coolant is exiting there, it may not be coming from the reservoir.

leathermang · #10 12-19-2014, 11:39 AM

Quote:

Originally Posted by eatont9999

..... It probably leaks any time the car is up to temp but you only notice it when it has sat parked for a while.......

Or... ' at temp' it might not leak.... but when you turn off the engine you may be experiencing enough ' heat soak' to get over the level the radiator cap is sealing to...
Some engines have water pumps to continue the circulation of the coolant after shut down to prevent this... some had this for the supercharger oil to keep it from turning to coke...

redoubthill · #11 12-19-2014, 03:07 PM

NAPA PART NUMBER........BK 7001006

Mxfrank · #12 12-19-2014, 08:53 PM

I think you're really overheating. 100 is too high for normal operation...you should be seeing 80-85 under most operating conditions. My stab at this is that you have some local boiling due to heat soak when the coolant stops moving. You may have a plugged radiator or bad thermostat.

Also, how high are you filling the tank? It shouldn't be filled to the brim, as you need the air pocket for expansion. Anything extra will puke out, and the system should arrive at equilibrium at some level below the top.

Also, there's no need to pour water into the upper hose, as the Mercedes systems are designed to self bleed...if that isn't happening, it's a sure sign of a clogged system.

Assault · #13 12-29-2014, 12:05 AM

As it turns out hose clamps can and do fail. Avoid those cheap Chinese ones if you can.

Also decreased the temperature, found out the auxiliary pump was inoperable, reducing the flow of coolant, for now I removed it competently, and fed the hose that connects to the bottom of the auxiliary pump directly to the servo.

ah-kay · #14 12-29-2014, 12:54 AM

I think the engine is overheating. Do a test when engine is cold. Remove radiator cap and fill coolant to about 1/2" below the top. Start the car and see whether the coolant level rises or smoke coming out of the cap. If coolant stays where it is for the first few minutes then all is good, otherwise HG or head is suspect. Exhaust gas may be getting into coolant.

vstech · #15 12-29-2014, 09:46 AM

Quote:

Originally Posted by Mxfrank

I think you're really overheating. 100 is too high for normal operation...you should be seeing 80-85 under most operating conditions. My stab at this is that you have some local boiling due to heat soak when the coolant stops moving. You may have a plugged radiator or bad thermostat.

Also, how high are you filling the tank? It shouldn't be filled to the brim, as you need the air pocket for expansion. Anything extra will puke out, and the system should arrive at equilibrium at some level below the top.

Also, there's no need to pour water into the upper hose, as the Mercedes systems are designed to self bleed...if that isn't happening, it's a sure sign of a clogged system.

This is untrue. The NA diesels even have a built in bleed screw to let air out while filling.
The turbos use the same cooling system, just a better radiator.