Have been servicing my Mother-in-law's h-reg Micra today in order to gain brownie points so i can spend more dosh on the scoob. Decided to change the coolant but only managed to drain off about a litre from the bottom of the radiator. When i came to refill i could only get in about the same. I ran the engine to get it up to temperature and it was very slow to do so and i noticed the heater didn't work either. What does this mean? Would a seized water-pump stop the heater working and block off part of the system? I would of thought being low on coolant would cause it to run hot not cold. Checked all relevant fuses.
Hoping SN will come to the rescue again.

PeteS

PS Is a non-functioning heater and a very reluctant temp gauge a problem MOT-wise?

 

Anyone?

PeteS

 

I realise Micra's are boring but i assume all/most cooling systems work in the same way and someone must have an idea out there?

PeteS

 

Well I don't know about Micras.

It could be a knackered thermostat or a major airlock. Have you checked to see if you could get more water into the system with the engine running? Also, did you find all of the air-bleed points... Assuming it has them?

If it is roadworthy, I'd take it for a short spin up a nearby hill. (Take coolant with you just in case). Just running the engine on idle in the driveway will take ages to get up to temperature.

Try squeezing the top coolant hose and see if bubbles apear.

J.

 

try taking it for a short run, then check to see if top and bottom hoses on the rad are hot. if not then u might have a blockage/airlock. im assuming the water pump is driven from a belt someware on the engine, check if the belts tight. if the pump has ceized then im sure ud know, screeching etc unless the belt is slack.test the thermostat, plonk it in a pot of boiling water to see if it opens and closes. when u drained the rad did u have the lid off the expansion tank/Rad?

Rich