MG ZT-T td 130 - Cooling system - Guy Relph

I have a 2005 MG ZT-T td 130 from new with 69,000 miles and until the last 3,000 or so the temperature guage has always read on the middle bar on the guage for all types of driving - Howver, once warm it tends to remain on the middle bar for normal driving but at motorway cruiing speed it dips to 1 bar below and remains consistant, moving back to the middle bar and never higher when back to slow speeds. Fuel consumption remains mid to high 40's and coolant level is correct with no leaks. This would appear to be logical but why the fluctuation after this time and should I be concerned ?!

MG ZT-T td 130 - Cooling system - madf

Winter

MG ZT-T td 130 - Cooling system - Peter.N.

Could be that the thermostat is leaking slightly and the high through put of of air at motorway speeds is causing the temperature to drop - or it might be something completely different. If it goes allright I wouldn't worry.

MG ZT-T td 130 - Cooling system - gordonbennet

I wouldn't be overly worried either.

I understand that there can be problems with the cooling fans on these (switching?) and parts can be a problem sourcing, which model this applies to i don't know, the situation on your car being connected to a fan fault i would strongly doubt, but thought i'd mention in case its summat you might need to know about.

MG ZT-T td 130 - Cooling system - Railroad.
This is most likely normal operation of the thermostat and an indication that the radiator is dissipating heat properly and efficiently. The cooling fans should never be required when you're moving because heat from the radiator is carried away by the airflow. However, if you have air conditioning then the fans should operate all the time it's switched on.
MG ZT-T td 130 - Cooling system - Collos25

I had a MG ZTT diesel it did this at around 100k it was not long before the the head gasget went once replaced the gauge returned to normal.

MG ZT-T td 130 - Cooling system - Cyd

Has the coolant ever been replaced or the system flushed at all? If not, then it is well overdue. I would give it a thorough flush and clean out with a proprietory cleaner product (GSF have an ebay shop and sell the Wynns Pro range). Now the threat of freezing has passed you could flush with a hose and fill with water and cleaner for a weeks use, then flush again and refill with fresh coolant. See if behaviour returns to normal. I'd replace the stat too.

MG ZT-T td 130 - Cooling system - pd

There is a test mode you can put the dash in to read off the exact temperature as the gauge will sit level at anything above about 70c.

Thermostat failure is common on them with the engine not getting hot enough - you can replace the thermostat but it is a pig of a job. Most people bung another in the top hose as a mod - there are plenty of details out there how to do it.

MG ZT-T td 130 - Cooling system - Cyd

There is a test mode you can put the dash in to read off the exact temperature

or, you could invest about £3 in Torque Pro app on your smartphone and about £20 in an OBDII bluetooth adapter and then you can read all the live data you like as well as read fault codes and much much more.

 

Ask Honest John

Value my car