MG ZT-T+ 120 (F/Lift - Manual) Coolant Temp. reaching 105°C

[SD1too]

Originally Posted by Time Searcher

6. Fan Slow Speed checked using the suggested method.

Martin,

Does this mean that you have selected 'windscreen demist' with a cold engine and the radiator fan starting running immediately and continuously (i.e. no cycling on and off)?

Originally Posted by Time Searcher

Meanwhile, they have given me a bottle of Wurth - Radiator Cleaner - 250ml - Radiator Flush to put in when the rad. cools down.

Please give that back to them unopened. I do not recommend that you use any additives or "sealants" in the cooling system, particularly on the 1.8 engine. You, or the garage, must find the problem and repair it.

Originally Posted by Time Searcher

I was not able to get the temperature up to 105°C this morning, (max. 102° when parked up before going out)

Well that's a good sign. But please check your radiator fan operation and report back.

Simon

[DMGRS]

Just a quick one, PRT thermostats can be mightily expensive when sourced on the aftermarket - I have them for under £20 which may help bring the bill down a little.
PRT Thermostat - K Series

[Time Searcher]

Originally Posted by DMGRS

Just a quick one, PRT thermostats can be mightily expensive when sourced on the aftermarket - I have them for under £20 which may help bring the bill down a little.
PRT Thermostat - K Series

Just got back from an extended 'Search' on the Forum about this problem, and realised that I had forgotten to mention that it was a PRT that is fitted.
As I live in Portugal, the expense goes up due to carriage costs from the U.K., however I'll see what the price is locally and then contact you if it's exorbitant from my local Rover/MG garage (yes one still exists !!!).
Thanks for the offer...
Martin

[Time Searcher]

Quote:
Originally Posted by Time Searcher
Meanwhile, they have given me a bottle of Wurth - Radiator Cleaner - 250ml - Radiator Flush to put in when the rad. cools down.

Please give that back to them unopened. I do not recommend that you use any additives or "sealants" in the cooling system, particularly on the 1.8 engine. You, or the garage, must find the problem and repair it.
Too late I'm afraid... I added it soon after getting back from the garage...

Quote:
Originally Posted by Time Searcher
6. Fan Slow Speed checked using the suggested method.

Martin,

Does this mean that you have selected 'windscreen demist' with a cold engine and the radiator fan starting running immediately and continuously (i.e. no cycling on and off)?
Engine coolant cool = 35°C
Air Con. - Switched off
Outside air temp. = 15.5°C
-------------------
Engine - ON - Car left stationary but revs held at 2500.
Air Con. 'windscreen demist' only switched ON - the Low Speed fan started immediately, Coolant temp rose to 94°C - demist-fan did NOT stop.
-------------------
Took car for a 5 mile spin on motorway - speed up to and held at 120kmph - temp never rose above 95°C, up hill and down although on a slight downhill it dropped to 92°C but returned to previous. (during the run, I switched demist fan On/Off, but no temp. change)

Quote: Originally Posted by Time Searcher
I was not able to get the temperature up to 105°C this morning, (max. 102° when parked up before going out)

Well that's a good sign. But please check your radiator fan operation and report back.
Simon

Not able to get the Coolant temp up to 102°C at the moment...

Many thanks,
Martin

[SD1too]

Originally Posted by Time Searcher

Air Con. 'windscreen demist' only switched ON - the Low Speed fan started immediately ... demist-fan did NOT stop.

Martin, what do you mean by "demist fan"?
Just to be clear, I am asking only about the fan attached to the radiator in the engine compartment. Please confirm that with a cold engine and the windscreen demist button pressed on the air con. control panel, the radiator fan runs continuously without stopping.

Many thanks.

Simon

[Time Searcher]

Originally Posted by SD1too

Martin, what do you mean by "demist fan"?
Just to be clear, I am asking only about the fan attached to the radiator in the engine compartment. Please confirm that with a cold engine and the windscreen demist button pressed on the air con. control panel, the radiator fan runs continuously without stopping.

Many thanks.

Simon

Yes - precisely that...the fan in front of the radiator that I see through the front grille, with the gold resistor on it...

[SD1too]

OK Martin, that's good. I can't see that there's much wrong with your engine, certainly nothing serious enough to warrant any repairs.

Simon

[Time Searcher]

Since I last posted I have ordered an 82° PRT from our friends at DMGRS. This has now been fitted and a first longish run undertaken, keeping a close eye (well Mrs. Time Searcher's eye anyway) on the indicated Coolant temp. on the Hans Gauge.
The Temperature rose reasonably quickly from the ambient and reached c84° after about 4 miles on the motorway.
Interestingly - The Temp. never reached more than 87° under any conditions but steadied at c85° for the majority of the 40 mile trip.
Bear in mind that this is a 1.8 n/a engine and had been fitted with a PRT during manufacture; this had previously cooled the engine at the high 90's (see my posts at the top of this thread).
Is 1.8 petrol engine O.K. to run at the new temperature?

[SD1too]

Originally Posted by Time Searcher

The Temp. never reached more than 87° under any conditions but steadied at c85° for the majority of the 40 mile trip ...
Is 1.8 petrol engine O.K. to run at the new temperature?

I'd say that's too cool Martin. The conventional thermostat is rated at 88° so the engine should be running at, or just above that temperature. In your shoes I'd be fitting a hotter PRT. T-Cut has posted frequently about the various types.

Simon

[DMGRS]

Personally, I'd say that's a good temperature - I've got a lot of customers using this PRT, and they've not reported any fuel consumption or other issues.
For an engine that has a history of overheating problems, I'd feel far happier about it being somewhere in the 80s!