Rangie.lad
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- 64
- Location
- York
As much as i love this site, I thought I had finally fixed my problem so I didnt have to come on here everyday searching for answers..:doh:
Anyway, 2.5 DSE, auto.
Had problems with it overheating under load about a month ago.
Found the viscous coupling to be knackered, so decided to overhaul cooling system.
Replaced the thermostat, waterpump, header tank cap, viscous unit, and fan.
Before and after replacing all these parts the temp needle sits about a MM to the right of the 12 o'clock white line. (is this normal?)
Drove it today for 3 hours, stopping twice for about 15 minutes each time.
Did 60-70 steadily on the motorway on the way there, some gentle town driving at 30-40 and then 70 again for about 40 mins on the way home (temp needle never moved), as I came off the slip road and around the round-about the temp gauge started moving up towards the red, as soon as it touched the first red line I turned it off and coasted it into a layby.
Now this is where I am confused, on the first ever previous overheat I had steam pouring out of the header tank and breather tank, and had to top it up with cool water
This time although the gauge had gone into the red, there was no steam, and no bubbling, I sat for about 5 minutes let it cool, went back to normal temp, set off again, needle moved up again to the red within 20 seconds, as soon as It moved I pulled over, sat for another 5 mins until needle moving back to centre, slowly unscrewed the header cap, let the pressure out without letting any coolant out, the coolant level returned to normal.
Quick note, before letting the pressure out, the coolant level was higher than the cold level indicator (should it be lower than the mark, then rise when cold, or be higher when hot, then level lower when cool?)
Stuck my finger in to see how warm (yes not the brightest move, could have been burned) but as suspected, although it was warm as say a hot tap on, it wasnt boiling, just warm like a nice bath. So screwed cap back on, setoff, temp normal, drove remaining 35 minutes home with no trouble.
Again, no oil in water, no water in oil, no leaks what so ever, and no coolant loss at all, the level is still the same as when I topped it up this morning a few hours before I set off.
The A/C fans are currently not connected, and do not function at all, but I dont use the air con, so I didnt think this mattered.
Seems like a pressure problem, shouldnt the pressure slowly release when parked up over a night, as yesterday I took it out for an hour test run without problem after completing the parts change, parked it, checked the level this morning, and the system was still pressurised, is this normal? shouldnt it release pressure once turned off? Or am I wrong?
Finally, yes it sounds like a head gasket, or head problem, or cracked block, BUT, I dont have any coolant loss, If it was a crack or gasket, surely the coolant level would have dropped and coolant been lost?
And I have bled the system once the parts where fitted, topped up with cap off, revving at 2000 rpm for a few second, topping up until all air gone and complete. So Im sure its not an air lock either as it didnt happen until about 2-3 hours driving
Stumped, thought I'd fixed the problem, and really dont want to throw more money at it.
Any opinions welcome, dont just read it all and not comment
Anyway, 2.5 DSE, auto.
Had problems with it overheating under load about a month ago.
Found the viscous coupling to be knackered, so decided to overhaul cooling system.
Replaced the thermostat, waterpump, header tank cap, viscous unit, and fan.
Before and after replacing all these parts the temp needle sits about a MM to the right of the 12 o'clock white line. (is this normal?)
Drove it today for 3 hours, stopping twice for about 15 minutes each time.
Did 60-70 steadily on the motorway on the way there, some gentle town driving at 30-40 and then 70 again for about 40 mins on the way home (temp needle never moved), as I came off the slip road and around the round-about the temp gauge started moving up towards the red, as soon as it touched the first red line I turned it off and coasted it into a layby.
Now this is where I am confused, on the first ever previous overheat I had steam pouring out of the header tank and breather tank, and had to top it up with cool water
This time although the gauge had gone into the red, there was no steam, and no bubbling, I sat for about 5 minutes let it cool, went back to normal temp, set off again, needle moved up again to the red within 20 seconds, as soon as It moved I pulled over, sat for another 5 mins until needle moving back to centre, slowly unscrewed the header cap, let the pressure out without letting any coolant out, the coolant level returned to normal.
Quick note, before letting the pressure out, the coolant level was higher than the cold level indicator (should it be lower than the mark, then rise when cold, or be higher when hot, then level lower when cool?)
Stuck my finger in to see how warm (yes not the brightest move, could have been burned) but as suspected, although it was warm as say a hot tap on, it wasnt boiling, just warm like a nice bath. So screwed cap back on, setoff, temp normal, drove remaining 35 minutes home with no trouble.
Again, no oil in water, no water in oil, no leaks what so ever, and no coolant loss at all, the level is still the same as when I topped it up this morning a few hours before I set off.
The A/C fans are currently not connected, and do not function at all, but I dont use the air con, so I didnt think this mattered.
Seems like a pressure problem, shouldnt the pressure slowly release when parked up over a night, as yesterday I took it out for an hour test run without problem after completing the parts change, parked it, checked the level this morning, and the system was still pressurised, is this normal? shouldnt it release pressure once turned off? Or am I wrong?
Finally, yes it sounds like a head gasket, or head problem, or cracked block, BUT, I dont have any coolant loss, If it was a crack or gasket, surely the coolant level would have dropped and coolant been lost?
And I have bled the system once the parts where fitted, topped up with cap off, revving at 2000 rpm for a few second, topping up until all air gone and complete. So Im sure its not an air lock either as it didnt happen until about 2-3 hours driving
Stumped, thought I'd fixed the problem, and really dont want to throw more money at it.
Any opinions welcome, dont just read it all and not comment
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