Rover Sports Register Forum

Hi everyone,

I am a new owner of a 1947 Rover 12. Picked it up today and drove it home (about 20 miles). The car is low mileage (49k) but not really been used for about 9 years. The car starts easily and seems to run well. Within a few miles it was blowing water and steam from the radiator cap. The previous owner had thoughtfully left a gallon of water in a container in the boot!. Managed to limp home with a couple of water top ups. On investigation the radiator cap does not seal at all well so I made up a better gasket. I also checked the thermostat, that appears to be missing assuming it would normally sit in the little aluminium housing under the top hose. Took the car for another run and it still started to blow through the cap after a few miles. Temperature rises to about 90 on the gauge. I will try the cheap option of some sort of cooling system flush stuff but not having high expectations of that working. Water seems to drain out the bottom of the rad fine and didn't seem that mucky. Assuming the flushing does not work I suppose the next step is to get the radiator re-cored? Any hints, tips or thoughts gratefully received. My first car was one of these back in the early 60's and that never overheated.

Geoff

The radiator cap seal is only to prevent splashing as it is an unpressurised system. It is not a good idea to run without a stat either as full circulation is bypassed.

However there is clearly a silting up issue in both block and rad - so it needs flushing and descaling. The rad may be past it however so a re-core may be needed

Another possible issue may be a blown head gasket. See here https://wp.me/pXLKy-2Qk

Hello, I have a 12 Tourer and had an overheating problem. One trick that may help is to remove the drivers side front panel and hold the bonnet on that side down with a bungee. Not an ideal solution but it lets out a lot of heat and got me home...

I flushed the rad water and air side, checked the timing and tuned the carb, topped up the antifreeze, checked the water pump. All helped but they do run hotter with modern fuel.

Enjoy Tim

Thanks for your advice guys. I will repost on this topic when I get the rad back and re-install. I think the head gasket is OK. There does not seem to be signs of water contamination in the oil.

Geoff

Good luck - I have invariably found with cooling issues on every type of car for the past 50 years it's the rad in the end even though it may not look like it initially but one still tries to live in the hope it is not!

Mmm I think a 94 Toyota is rather different kettle of fish from what is essentially a pre war car. But to close this one off. I have now fitted the radiator with its new core and it runs nice and cool. In fact if I have a worry it is a bit too cool. But a thermostat is also now fitted, so I guess it is OK

I too have had cooling problems with my 46 14 SS. it wasnt too bad on a run but couldnt stand traffic at all. Eventually i decided to have a good look at the radiator that had been "professionally rebuilt" by the previous owner and it was so badly done I considered it scrap. However the car came with another rad which appeared to be completely blocked with silt. It was. I took it to a specalist who held on to it for over three months and did nothing. I collected it and thought, how difficult can this be so I unsoldered the bottom tank and gave it a through clean. The silt was so bad that i had to make a spade drill using a welding rod and drilled each tube out. Then i used a strip of brass to rod out each tube, the amount of filth was amazing. I soldered the bottom tank back on using a thin brass strip bent into a U shape to replace the turned over flange that was originally part of the bottom tank but which broke off during the unsoldering.
I machined the water pump thermostat seat and loctited in a stainless steel ring as a new sealing face and removed all of the gaskets in the water system and replaced them with Loctite flange sealant. I refilled the system using OAT coolant after doing some tests to see if there was an adverse effect on the metals of the cooling system and didnt find anything. Now the car runs cool according to the gauge and the system is fine on the OAT cooland after four years. In fact when i remove the coolant it is the same colour as when it went in so it must be protecting the cooling system fairly well.