Overheating 1.9 Tdi Ahu

[rmas]

Hi... i have a problem with my car related to overheating and this is what happens:

 

bought the car a year ago, had a blown HG, replaced it (head had water passages blocked with rust), cleaned all and reassembled everything, when i bought the car it did not have a thermostat and was running only with water.

 

Once i placed the thermostat i have the problem that the temp gauge starts to climb almost immediately after i start driving and it start to climb until it reaches the mark above the middle one (this in less then 15 minutes of driving), is i stop the car and check the water pipes, the top is hot, lower is cold and radiadtor is cold.

 

I already replaced the water pump, placed a new thermostat (opens at 84ª), replaced the thermal switch on the radiator (starts the fans at a lower temp also), replaced the radiator, replaced the fan, replaced the expansion tank and cap and it remains the same, already its the 3rd temp sensor beeing that the last one was a original VW sensor (35£)

 

the temperature only rises that much if i start to press the pedal, at slow cruise it passes a little of the middle,but when i press it it can go almost at the last mark before the red, If i slow down, the temperature decreases and if i stop the car and check the hoses, both are hot, no pressure in the circuit and the fan is working also.

 

i am baffled at this... already changed everything i can think and problem still persists :( please help me

[BrianH]

The thermostat you've installed - where is it? Some models have the thermostat in the pipe and an empty housing on the end of the block. The alternative location is halfway along the hose that feeds the housing. Possible this one is stuck if you have it?

[rmas]

The thermostat you've installed - where is it? Some models have the thermostat in the pipe and an empty housing on the end of the block. The alternative location is halfway along the hose that feeds the housing. Possible this one is stuck if you have it?

 its in the water pump... Same was happening with previous thermostat, when i changed to this one no diference in temperature,

[BrianH]

have a look at this link - item number 40 in particular - does this look anything like your hose setup and does that look like where your thermostat is installed.

 

http://eucatparts.com/?action=cat_ford_part&s_id_part=24438&s_id_model=98&s_code_image=G001578905

 

I'm wondering if your issue is still the thermostat and the one you've replaced is not the correct one/in the correct place.

Where do the hoses change temperature (if the radiator is cold then the issue isn't the fans being switched on or not by the sensor - its that your not getting hot water flowing to the radiator. Given you've replaced the water pump it shouldn't be the cause, but if the pump is working correctly you should be able to see water returned to the expansion tank via the small hose when the engine is running.

 

If the top hose is hot then follow it along and see if you can find any change the closer you get to the radiator, this should give you an idea of the area with the issue.

[rmas]

have a look at this link - item number 40 in particular - does this look anything like your hose setup and does that look like where your thermostat is installed.

 

http://eucatparts.com/?action=cat_ford_part&s_id_part=24438&s_id_model=98&s_code_image=G001578905

 

I'm wondering if your issue is still the thermostat and the one you've replaced is not the correct one/in the correct place.

Where do the hoses change temperature (if the radiator is cold then the issue isn't the fans being switched on or not by the sensor - its that your not getting hot water flowing to the radiator. Given you've replaced the water pump it shouldn't be the cause, but if the pump is working correctly you should be able to see water returned to the expansion tank via the small hose when the engine is running.

 

If the top hose is hot then follow it along and see if you can find any change the closer you get to the radiator, this should give you an idea of the area with the issue.

 

 

Hi,

 

that hose (number 40) only has a sensor there (brown one). I can see water coming from the small hose when the engine is running and if i acellerate i can see the water flowing faster, so water pump working fine. 

 

the hose itself is hot and the small hose at the same temperature, the radiator not so hot, that is the only diference i can see there, it only gets hotter when the thermostat opens and water starts to flow from the bottom hose.

 

 

that location for the radiator seems to be more practical, can it be installed in a car that has the thermostat on the water pump? at least to change it it would be more easy :)

Edited August 13, 2015 by rmas

[BrianH]

its a later design revision, but i've not personally seen it (there are some different radiators though where hoses are at either end of the radiator rather than both at the same end, so it may not fit correctly).

 

Its different for a reason (improvement), but offhand not sure why.

 

Does the heater work (both of them if you have the rear one)? just wondering if you have a blockage in those thats preventing the hot water circulating correctly.

[rmas]

its a later design revision, but i've not personally seen it (there are some different radiators though where hoses are at either end of the radiator rather than both at the same end, so it may not fit correctly).

 

Its different for a reason (improvement), but offhand not sure why.

 

Does the heater work (both of them if you have the rear one)? just wondering if you have a blockage in those thats preventing the hot water circulating correctly.

 

The front one is working, the rear one i will try tomorrow...Already had that in mind to try the one in the rear, since the front one gives lots of heat. Anyway thanks for all the help, please if you remember anything else let me know, i am always thinking on how to solve this in my head :(

[BrianH]

Actually thinking about it try the run on pump if yours has one. Info in faq section. Good chance it wants attention if its there. If rear heater not hot good chance it's that.

[rmas]

Actually thinking about it try the run on pump if yours has one. Info in faq section. Good chance it wants attention if its there. If rear heater not hot good chance it's that.

 mine does not have the run on pump... This weekend will give some update then :)

Edited August 14, 2015 by rmas

[Russats]

Are you sure, it's tucked away behind the battery area. Ridiculous to get to.

[rmas]

Are you sure, it's tucked away behind the battery area. Ridiculous to get to.

hmm, can you show me the location where it should be please?

 

update - already checked the rear heater matrix and both pipes get hot just near it so no blockage on the pipes... 

[BrianH]

http://www.fordgalaxy.org.uk/ford/index.php?/topic/7510-diesel-run-on-water-pump/&do=findComment&comment=54739

[rmas]

http://www.fordgalaxy.org.uk/ford/index.php?/topic/7510-diesel-run-on-water-pump/&do=findComment&comment=54739

never saw that kind of pump on mine... And already took almost everything out when doing head gasket change, maybe this model / engine does not use this here.

[BrianH]

I don't know then, only thing i can think is you've still got some restriction in the cylinder head cooling. Mostly because you've ruled everything else out, Do you lose any coolant?

[rmas]

I don't know then, only thing i can think is you've still got some restriction in the cylinder head cooling. Mostly because you've ruled everything else out, Do you lose any coolant?

 no coolant loss, will put the radiator cleaning fluid this week from wurth to see if i notice any diference.

 

update - changed the original temp sensor from VW to a aftermarket one, temp gauge does not climb as much as before and temp rises slower... 

[xavier]

Have you checked your oil level?

[rmas]

hi, oil level the same.