Still hot and not just the weather!!!

[sally.hobson]

I'm after more advice and ideas!

C220 diesel, P reg.

Overheated.
Thermostat changed - no improvement.
Block test done - diagnosed head gasket - fixed.
Car still running hotter than before problem according to temperature guage in car.
No longer overheating but temperature greater and fluctuates when driving. Especially hotter when motorway driving.
Viscous fan failed carrot test - replaced.
No improvement.

Any ideas?

Do I just put it down to the major work of the head gasket and forget about it?
Do I change the radiator and water pump as they are the only bits of the cooling system not changed?
Any other suggestions?!!!

Any help gratefully recieved!

Sally

 

[television]

I'm after more advice and ideas!

C220 diesel, P reg.

Overheated.
Thermostat changed - no improvement.
Block test done - diagnosed head gasket - fixed.
Car still running hotter than before problem according to temperature guage in car.
No longer overheating but temperature greater and fluctuates when driving. Especially hotter when motorway driving.
Viscous fan failed carrot test - replaced.
No improvement.

Any ideas?

Do I just put it down to the major work of the head gasket and forget about it?
Do I change the radiator and water pump as they are the only bits of the cooling system not changed?
Any other suggestions?!!!

Any help gratefully recieved!

Sally

How hot is hot, possibly the temp sender is inaccurate,its fine for it to be over the 80c normal running. Water pumps do fail but more often they go noisy first.

How hot is it

 

[sally.hobson]

Temperature

It is running on average at about 90 but fluctuating to a bit above and below this.
It used to sit rick solid just above the 80 mark.
I find it really difficult to persuade myself that the temperature guage has broken at exactly the same time as everything else!!!

 

[television]

It is running on average at about 90 but fluctuating to a bit above and below this.
It used to sit rick solid just above the 80 mark.
I find it really difficult to persuade myself that the temperature guage has broken at exactly the same time as everything else!!!

If you have air con, then the electric fan will take over at 100c, you may have some small air lock,turn the heater up to max for a few mins.

By the temp gauge I meant that If the car got very hot, it could have damaged the sensor for the gauge on top of the engine,

You have no worries though at 90 ish this warm weather.

 

[Uncle Benz]

Excellent ideas from Malcolm. Only thing I can add, if the thermostat was changed with no improvement, its possible the new one was damaged by the overheating. For the price of them, I would fit another.

Its always possible that the head gasket failure was a symptom, rather than the cause of the overheating... Check for any cold spots in the radiator.

 

[sally.hobson]

If you have air con, then the electric fan will take over at 100c, you may have some small air lock,turn the heater up to max for a few mins.

By the temp gauge I meant that If the car got very hot, it could have damaged the sensor for the gauge on top of the engine,

You have no worries though at 90 ish this warm weather.

No air con but will try changing the temp guage and to stop worrying!!!

Thanks!!!

 

[television]

No air con but will try changing the temp guage and to stop worrying!!!

Thanks!!!

Not the gauge the sender on top of engine.

Also read Uncle benz advice too

 

[sally.hobson]

Excellent ideas from Malcolm. Only thing I can add, if the thermostat was changed with no improvement, its possible the new one was damaged by the overheating. For the price of them, I would fit another.

Its always possible that the head gasket failure was a symptom, rather than the cause of the overheating... Check for any cold spots in the radiator.

Can't find any obvious cold spots. All fins look in good condition.no obvious problem with radiator.

Will try replacing thermostat and sensor/sender for temp guage.

Really dissapointed with car - not a patch on husbands W124 which is nearly twice as old and done twice the mileage!!!

 

[Hibbo]

Is the rad bottom hose hot? Does the heater blow HOT?

 

[Glenn Smith]

Just athought but are you sure it used to run at 80? if it's had a new thermostat the old may have beeen allowing it to run a bit cooler, my c230k runs at between 80-90 depending upon temperature, heater on or off A/C on or off standing in traffic or driving so i wouldn't worry too much, let it idle on a hot day and see if it gets any hotter if it does you may have a problem if not i wouldn't worry.

 

[fouskos]

Check if the the new coolant is the same...

 

[wireman]

Water pumps usualy fail their bearings and sealing glands leak but they still move the water about even if very sick, thus I would not be thinking about it being the problem.
It seems odd but there is only the rad left, it may be partly blocked or the system has an air lock that wont budge. The stat may have been damaged as mentioned, I do not have a reason for different coolant causing any overheating trouble other than the possibility not being compatible with the materials used in the cooling system, most decent modern antifreeze/corrosion inhibitors are suitable for almost all engines.
Does the engine temp take less time to rise from cold than it did before the troubles began?