[nictobin]

Recently I’ve noticed all my coolant draining out of seemingly nowhere. I feel as though it’s not properly pumping fluid through the system. When I open the reservoir I do see a small stream of coolant being sprayed back into the top, yet I still have issues with running warm. Could this be my thermostat? And how do I properly diagnose my cooling issues?

Thanks in advance
Nic

[Scubudo]

Yes it could, but it could also be other things too.

IDK what you mean by "all my coolant draining out of seemingly nowhere."
Is it leaking under the car but you can't figure out where, or is the coolant not leaking anywhere that you can see, but you keep needing to add coolant?
If it is just disappearing but without any signs of leaking, check you oil to make sure it hasn't gone there. It could also be going out of the exhaust.

Why do you think "it’s not properly pumping fluid through the system"?
Thermostat and water pump both affect flow.

Overheating could also be from a clogged radiator (especially if the wrong antifreeze, leak stop, or just filling with tap water.
Overheating while going slow could be from the fans not blowing.

If you don't properly bleed the system of air, it can get airlocks that block flow.

If you don't understand what I have said, then perhaps you should have a professional look at it.

[nictobin]

Originally Posted by Scubudo

Yes it could, but it could also be other things too.

IDK what you mean by "all my coolant draining out of seemingly nowhere."
Is it leaking under the car but you can't figure out where, or is the coolant not leaking anywhere that you can see, but you keep needing to add coolant?
If it is just disappearing but without any signs of leaking, check you oil to make sure it hasn't gone there. It could also be going out of the exhaust.

Why do you think "it’s not properly pumping fluid through the system"?
Thermostat and water pump both affect flow.

Overheating could also be from a clogged radiator (especially if the wrong antifreeze, leak stop, or just filling with tap water.
Overheating while going slow could be from the fans not blowing.

If you don't properly bleed the system of air, it can get airlocks that block flow.

If you don't understand what I have said, then perhaps you should have a professional look at it.

My fans are blowing. I have properly bled the system of air. I am using the correct coolant. I do not see any leaking of coolant.

[vester86]

it has to go somewhere.... so investigate further

[Tomnavigator]

Nictobin,
Your terminology is confusing. Is your issue that the coolant disappears repeatedly after you refill the coolant reservoir or is the issue a coolant circulation issue or is the vehicle overheating or not getting up to operating temperature?




First, Make sure the coolant level is correct. If the coolant needs to be filled, fill it to upper level.
Run the car a few minutes and check the coolant level again. Refill again if needed. Run engine again and check and repeat until coolant level is correct when you check it.
Second, Start engine with cap off coolant reservoir. While engine is running look in coolant reservoir and see if you can see the coolant circulating.

If you can see the coolant circulating, then the water pump is not an issue. If the coolant is circulating then the thermostat is opening and probably not an issue.

Drive the vehicle for a few days and check the coolant level every day. The level should remain the same.

[nictobin]

Originally Posted by Tomnavigator

Nictobin,
Your terminology is confusing. Is your issue that the coolant disappears repeatedly after you refill the coolant reservoir or is the issue a coolant circulation issue or is the vehicle overheating or not getting up to operating temperature?




First, Make sure the coolant level is correct. If the coolant needs to be filled, fill it to upper level.
Run the car a few minutes and check the coolant level again. Refill again if needed. Run engine again and check and repeat until coolant level is correct when you check it.
Second, Start engine with cap off coolant reservoir. While engine is running look in coolant reservoir and see if you can see the coolant circulating.

If you can see the coolant circulating, then the water pump is not an issue. If the coolant is circulating then the thermostat is opening and probably not an issue.

Drive the vehicle for a few days and check the coolant level every day. The level should remain the same.

I apologize for the confusion. The vehicle overheats despite the coolant circulating and the fans kicking on.

[Tomnavigator]

Nic
How are you determining the vehicle is overheating? Are you sure it is actually overheating? An overheating car should give you a service engine warning and/or high temperature light.

Overheating is caused only two issues. Lack of air or lack of coolant flow.
You state the fans are running so lets rule out lack of air.
Lack of coolant is left.

1) First make sure the coolant level is correct. Fill coolant to upper level.
2) Check for coolant circulation. See my previous post.

If you never see circulation of coolant or see weak flow, the thermostat could be broken in the closed position. Usually thermostats break in the open position but they can break in the closed position.
Another issue could be a bad hose. The hoses to and from the radiator are multiple layered. They have an outside rubber layer, a middle reinforcement cord, and an inner rubber layer. It is rare but the inner layer can delaminate and create a flap that plugs the line and restricts the coolant flow. I have only seen this happen once in my life. Rare but can happen. Keep this in mind but don't look for it unless everything else fails. At least 90% of the time the issue is the thermostat. The rest of the time the issue is the water pump.
I would recommend you replace the thermostat and water pump if they have not been replaced already. They are fairly easy to replace and are not that expensive. It is common for thermostats and water pumps to fail around 100k miles. Although most last longer than 100k miles. The only reason I recommend replacing both instead of just the thermostat is that the water pump is not expensive and adds about 10 minutes to the job. The thermostat mounts on top of the water pump.

[nictobin]

Originally Posted by Tomnavigator

Nic
How are you determining the vehicle is overheating? Are you sure it is actually overheating? An overheating car should give you a service engine warning and/or high temperature light.

Overheating is caused only two issues. Lack of air or lack of coolant flow.
You state the fans are running so lets rule out lack of air.
Lack of coolant is left.

1) First make sure the coolant level is correct. Fill coolant to upper level.
2) Check for coolant circulation. See my previous post.

If you never see circulation of coolant or see weak flow, the thermostat could be broken in the closed position. Usually thermostats break in the open position but they can break in the closed position.
Another issue could be a bad hose. The hoses to and from the radiator are multiple layered. They have an outside rubber layer, a middle reinforcement cord, and an inner rubber layer. It is rare but the inner layer can delaminate and create a flap that plugs the line and restricts the coolant flow. I have only seen this happen once in my life. Rare but can happen. Keep this in mind but don't look for it unless everything else fails. At least 90% of the time the issue is the thermostat. The rest of the time the issue is the water pump.
I would recommend you replace the thermostat and water pump if they have not been replaced already. They are fairly easy to replace and are not that expensive. It is common for thermostats and water pumps to fail around 100k miles. Although most last longer than 100k miles. The only reason I recommend replacing both instead of just the [...]

I assumed my vehicle was overheating because the fans remain on for approximately 5-10 minutes after turning off the vehicle and the AC blows warmer and warmer the longer I drive

[335dlci]

Originally Posted by nictobin

I assumed my vehicle was overheating because the fans remain on for approximately 5-10 minutes after turning off the vehicle and the AC blows warmer and warmer the longer I drive

Lol

[nictobin]

Originally Posted by 335dlci

Lol

Is that an incorrect assessment?

[Tomnavigator]

You do not have a problem with your car. Stop looking for a problem where none exists.

Your car regenerates the Diesel Particulate Filter (DPF) when it accumulates soot. This is done on a regular basis and is triggered by the pressure drop across the filter. The regeneration is accomplished by burning off the soot buildup. The car has a nozzle that sprays diesel fuel on the inlet side of the DPF. The fuel ignites and burns off the soot. This takes several minutes. If you turn off your vehicle when the car is in the process of regenerating the DPF, the car will run the radiator fans to cool down the engine compartment for approximately 5 minutes or so to prevent damage in the engine compartment. This is a normal operation of the vehicle.

[lnxguy]

Your car will definitely tell you when it overheats, the fans being on is not an indication of this.

[POBEP]

Originally Posted by Tomnavigator

The car has a nozzle that sprays diesel fuel on the inlet side of the DPF.

Can you please show this part on the realoem diagram?

[Scubudo]

Per my understanding there is not a separate nozzle, but rather the injectors dump extra fuel during regen cycles. This makes the system run hotter and heats up the DPF to the point that it can burn off the soot (which is mostly partially burn fuel).
So, it is sort of counter intuitive because it actually is dumping more soot into the DPF to get rid of the soot that is clogging it.

The DPF is mounted to the exhaust manifold and not further downstream, because it needs to get up to temp before it can get cleaned. The further you move it down the exhaust pipe, the harder it is to get it to operating temp, the more fuel would need to be dumped for it to reach such temps, and the hotter the exhaust manifold would be for all of that to happen.

As for why the fan continues to run:
Per my understanding, the DPF and manifold get so hot that when the vehicle is in the middle of a Regen cycle and the engine is turned off, the fans will continue to run to assure things around the DPF and manifold are not damaged by that heat.

[lnxguy]

Originally Posted by Tomnavigator

The car has a nozzle that sprays diesel fuel on the inlet side of the DPF. .

Not on the M57 there isn't...

[Tomnavigator]

Sorry my error on the nozzle. I wasn't thinking. I knew our cars did not have a separate nozzle. The important thing is that the car will run the fans to cool down for about 5 minutes if you shut down the car during a DPF regeneration.