More Coolant loss
 

Hi ,I have a petrol 190 V6 which has recently started to push water out of the header Cap when it feels like it.
I can run it for an hour ticking over and my temp gets upto 81 degrees without pushing anything out, Take it for a run 5 miles check again and coolant on header tank ?

The Jobs ive done in the past are new water pump when belts changed 1 year ago, New Kaiser metal stat and pipes and O rings, Recently new radiator as looked suspect in places, 2 new header caps. It has had new temp sensor and digital display fitted so its accurate and i have confirmed with instrument cluster test too.

No signs of water in the oil or mayo in the oil cap, No leaks in the V of the engine or anywhere else i can see.

Tested all 3 fan speeds are working using Toaf.

Heater gets nice and hot in the car , Bled it several times with tank in the air and bleed screw open im getting stuck for ideas now ??

It seems to be more of a pressure issue than a water leak ??

Any suggestions appreciated cheers

Had the same difficulty on my latest V6, bought as spares or repair as the garage changed everything eventually saying the headgaskets needed doing and the owner gave up. https://www.the75andztclub.co.uk/for...=311885&page=3 post 26

Try a series of short trips and on return with the engine running open the bleed screw until only coolant is expelled.

Regards

Hello Julian,

My first thought is an air lock. Was the MG Rover refilling/bleeding procedure followed exactly the last time work was carried out on the cooling system? If you are in any doubt drain it completely, including the cylinder block plug, and start from scratch. Don't take any short cuts and note that the bleeding screw is only removed during the initial filling. It must be refitted before starting the engine.
In the summer I visited a member's KV6 with exactly your symptoms and this was all that was required. No parts were purchased. :D

Idling the engine for an hour is a waste of time. The car must be driven to put the engine under load so that it reaches proper running temperature. According to the IPK diagnostics, is it staying within the range 92 to 100˚ (when the low speed fan should start and lower it)?

Is the expansion tank filled no higher than the internal 'MAX' marker? A common mistake is that owners fill to the top of the fins.

Simon

Hi Simon Im going to drain everything completely and refill again using the procedure, When i fitted the Kaiser stat setup i didnt realise the stat that was in it is only 80 / 82 degrees so it has never got up as high as 92 to 100 , I have made sure tank is just filled to internal max limit but will try a complete system refill and let you know, One thing i have noticed is i havent seen water entering through the small pipe back into the header tank when engine running ?

That small hose is described in RAVE as an air bleed so ..... :D

Simon

Hi Simon ive just drained the block and removed bottom hose and drained completely filled back up as per procedure, I ran the engine upto 95 but the fan had not kicked in so turned it off waited 25 mins removed cap and topped up to correct level.

My car never gets nearly that high normally wonder if its because the aircon is running the fan all the time ? as i had made sure econ was off when running the car upto temperature and waiting for slow speed fan to kick in.

Any ideas

Hi Julian,

I know that the procedure says to wait for the fan to start running but in most weather conditions the engine won't reach the required 100˚ at a continuous idle so I do more or less what you've done! ;)

With the air conditioning running it's true that the radiator receives increased airflow but it will often be at a higher temperature than ambient due to the heat loss from the condenser. Engines with the standard 88˚ plastic thermostat assembly will run at a minimum of the low nineties even with the air conditioning working.

Let us know if there's any improvement in the coolant loss Julian which was the problem you presented.

Cheers,

Simon

Cheers Simon i will do that makes sense fingers crossed.

Just wanted to update and thanks to Simon for helping me resolve my issue , Ive been running it all week now and it hasn't lost anymore water, Im yet to go on a long distance drive but it seems to behaving it must of been an Airlock somewhere in the engine.

Cheers for the help appreciated.