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Old 29th April 2015, 15:24   #21
tony2
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Had the same issue a few years back with a Jaguar XJ.
Towing to Spain all ok till I got to a long steep climb with high air temps and aircon on. Temp gauge went into the red. Never happened before.
Stopped at a service station and washed out the rad core with a hosepipe, Choked with dead insects reducing airflow, fine after.
Worth a try.....
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Old 3rd May 2015, 22:34   #22
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I recently had the overheating problem on the motorway.
temp gauge started rising.
Turned out to be my water packed up and i had a hole in the radiator that popped as the back pressure increased.
Took it to horners in salford and they replaced the water pump, thermostat housing (not needed but may as well do at same time ), radiator, alternator and power steering belts.
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Old 11th July 2015, 22:02   #23
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Default 2 Speed Fan Poser will my woes end!

When towing up very long climbs in hot climes the coolant overheats and engine goes into safe mode. I thought I had solved the problem when I found that the 1st speed of fan was not working so fitted a gold resistor and checked that both speeds definately work ok.
Does anyone know whether it is possible that the 2nd speed works when called for by the aircon but doesn't when a high coolant temp demands it? I tackled a 6 mile constant 5% gradient in ambient high 30's and had to stop to give the engine a breather several times as I ground to a halt.

I was running with the OBD temp display and watched the temp climb fairly quickly up to 120 deg each time. it was a bit hairy with only half a hard shoulder and wagons roaring past but I am pretty sure that the fan was only running on 1st speed! I did also notice along the journey, no gradients, that I heard the 2nd speed come on (aircon call) and the coolant temp dropped from mid 90's to high 80's. On other climbs at lower ambient I watch the temp climb and have just managed to clear the tops with 115c showing. I have not lost a drop of coolant. I can find the fan trigger settings for 3 speed fan but not 2 speed so I am not sure at what temperature I should expect the engine to operate. At tickover with aircon on in traffic and 1st fan speed temp sits at 84deg.
As background to this:-
On a 3500 mile return trip to Portugal I have had the following:-
Burst radiator (suspect my fault abt 2yrs ago spanner slipped nicked fin)
Aircon leak (spanish mechanic damaged o ring on refitting)
Fan 1st speed not working (was ok in spanish garage was roaring away)
Heater hose holed (by bleed valve? disturbed when rad fitted?)
Aircon started whistling (when o ring changed noted condensor fins failing)
Crank pulley failed (little warning centre boss broke clean away)
Belching black smoke when under load or hard acceleration ( last 2 days)

All fixed except overheating and smoking, sorry for long epistle but any help would be welcome, apart from all this the car is brilliant!
Thanks Tony
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Old 11th July 2015, 22:28   #24
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Tony,

Have you got the original MGR thermostat in your diesel or have you fitted one of the in-line extra thermostats?

Simon
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Old 12th July 2015, 06:19   #25
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Hi Simon,
No it's the original stat. Without the van I have never had a problem, albeit have never used the OBD to check actual temp.
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Old 12th July 2015, 08:37   #26
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Quote:
Originally Posted by rovertone View Post
... it's the original stat.
OK; you say that the engine reaches an operating temperature in the high eighties/low nineties. When this happens, can you reach the long coolant pipe leading from the bottom of the radiator to the thermostat housing to feel its temperature (I'm not familiar with the diesel engine, so I'm going by the MGR diagram)? It should feel hot; almost as hot as the top radiator hose.

Towing the caravan is putting a lot more load on your engine so I would expect any latent fault to show itself.

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Old 12th July 2015, 10:21   #27
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Thanks Simon,
I haven't tried that but I will. The temp I quoted was towing. Car solo, even out in the heat of Portugal,the temp driving normally ranged 79 - 84 deg.
I was surprised just how much the temperature fluctuated. In 36deg heat towing it ranged from 92 - 114 dependent on workload but then exceeded this on exceptional climbs. In France where the ambient dropped 10deg the coolant temp dropped by a similar value. The engine cooling would seem to be working ok, as soon as the engine workload drops so does the temperature. This is why I have this hunch about the 2nd speed fan not tripping in at the top end, in hindsight when I was at 120deg I wish I had shorted out the trinary switch to force the second speed to see what happened to temperature. I don't know how I can get the engine hot enough, without pulling uphill to test the theory.
I had a 160 remap by Phil T4 in March and he reported all was ok, maybe another T4 health check might be able to test fan/coolant link. Tony
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Old 12th July 2015, 10:33   #28
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Many years ago, I used to tow with a Rover 3500 auto and had similar problems. There was an extra oil cooler available for the auto gearbox which, after fitting, cured my problems. I also found that by using the gearbox "manually" ( selecting a low gear for the climb), it seemed to allow the gearbox to run cooler, which in turn, put less strain on the engine. I also used to run the heater on hot (with all the windows open) when on long climbs in the alps. Not very comfortable for the passengers but it kept the engine temps down!
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Old 12th July 2015, 10:56   #29
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Quote:
Originally Posted by rovertone View Post
I can find the fan trigger settings for 3 speed fan but not 2 speed so I am not sure at what temperature I should expect the engine to operate.
Jules said:
For 2 speed diesel motors IIRC the ECU energises SLOW speed for a larger temp span.
From 100°C to 111°C = Slow Speed
From 112°C to 119°C = High Speed

I'd say your engine is simply responding to the high work load in a hot environment.

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Old 12th July 2015, 11:00   #30
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Quote:
Originally Posted by rovertone View Post
The engine cooling would seem to be working ok, as soon as the engine workload drops so does the temperature.
I would say that your cooling system isn't working properly Tony. The 114° coolant temperature is proof of that.

I suggest that you perform the trinary switch test to establish whether or not your fan is working on high speed.

A possible explanation is that your ATF is getting too hot. This should trigger the fan too when it exceeds 110°.

Quote:
I had a 160 remap ...
I don't know whether it's appropriate, but have a look at this from someone who worked at Longbridge.

Simon
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