mf375 over heating

[joseph baxter]

I hve a mf375 I have replaced the waterpump and thermostat it seems like the water pump is not flowing the water threw the radiator has anyone ran into this same problem the engine runs like a champ and Ihave also had the radiator repaired

 

[Anonymous-0]

Hi,
As the engine warms up you should have a cooler area towards the bottom of the radiator. Take the block tap or plug out and make sure that the water jacket is not full of sludge. Flush it out with a hose for a couple of hours if it is.
You say you have had the radiator repaired. Is this a puncture repair or a new comb fitted. It is possible that the rad is blocked.

 

[Jerry/MT]

Make sure the lower radiator hose is not collapsed ( It maybe OK at idle but can collapse at higher rpms if the stiffening spring was taken out or is corroded) and the water pump drive belt is tight. Make sure the air side of the radiator is not clogged with debris.

 

[joseph baxter]

thank you for your reply the radiator has flow threw it to me it seems like the water pump is not flowing the water. With the thermostat removed it seems to flow but runs at a low temp and I am not sure if it will cool the engine as needed I have inspected the block with the front water jacket off and didn't see anything that would indicate slug or any other type of blockage. Might you have any other idea's thank you for you time

 

[joseph baxter]

thank you for your reply. The reason for getting the radiator repaired was to mainly get it cleaned and flushed. there is no spring in the bottom hose but I can't see the hose collaosing I belive that the pump is not flowing water threw the radiator with the thermostat in place. I have replaced the 180 degree thermostat with a 160 degree thermostat. Might you know of any other reason for the water not to flow. Thank you for your time.

 

[Anonymous-0]

Hello Hoseph,
It is quite possible to have what appears to be a good flow of water through the radiator even if the centre area is blocked. Looking at the top of the comb through the filler might show something.
Have you tested the operation of the thermostat in a saucepan of boiling water? Make sure that it opens fully. The purpose of the thermostat is to allow the engine to warm up to its best operating temperature from cold as quickly as possible. When hot the thermostat will be fully open. They can be dodgy items so even if it is new do not assume that it will work.
DavidP, South Wales

 

[Anonymous-0]

Sorry, hit the H instead f the J.
D

 

[joseph baxter]

I have tested the thermostat and it seems to work in full range this water pump has what I call a thermo bypass where the water will move threw the water pump and block until the water temp reaches a curtain temp where the thermostat starts to open and let water start to move threw the radiator it seems to me like for some reason the engine is reaching overheating stage before the water will move threw the radiator which with the thermostat removed is not a problem but I would rather have the thermostat in the engine that way it will warm to operating temp I haven't found any blockage in the block or the radiator that is what has me so confused any pointers also the engine runs very good which leads me away from a blown head gasket or any other engine problems but could be wrong (It happens)I have kind of hit a wall with this thing once again thanks for your time and info

 

[Jerry/MT]

Have you got the thermostat in correctly? The sensing element needs to be on the cylinder head side of of the thermostat housing.

 

[joseph baxter]

yes sir i do

 

[Jerry/MT]

Joe, since you took the thermostat out and the flow increased, it sounds like there is excessive restriction in the thermostat. Are you sure it is the correct thermostat? I believe you said you tested it and it opened, Did you use a themometer to verify that it opened at the correct temperature? Is the thermostat correct for your application? the rated temperature is usually stamped on the themostat somewhere.

I"m not trying to be critical, I"m just baffled by your problem.

 

[joseph baxter]

yes I have verified the opening temp and have also checked that I have the correct thermostat I am also baffled

 

[DODGE BOY]

ONE THING TO CHECK TO SEE IF MAYBE YOU HAVE A HEAD GASKET LEAK RUN YOUR ENGINE WITH THE RAD CAP OFF AND LOOK FOR A LOT OF FOAMING OR LITTLE BUBBLES IF YOU HAVE A LEAK SOMETIMES THE COMPRESSION LEAKS INTO WATER JACKET AND IT GETS AIR BOUND AND BECAUSE THE AIR RISES TO TOP OF THE ENGINE IT DOESNT ALLOW WATER TO GET TO THE SENSING BULB OF THE THERMOSTAT AND IT WONT OPEN CHECK TO SEE IF YOUR THERMOSTAT HAS AN AIR HOLE IN IT AND IF IT DOESNT TAKE A 1/8 INCH DRILL BIT AND PUT A HOLE IN IT AND SEE IF THIS HELPS AT ALL