Do I have a dodgy radiator?

[steveyd]

Hi All,

I've finally fitted a load of new hoses and my new s/h front heater matrix, filled with coolant and bled according to instructions on the factsheet (original ones). I'm pretty sure I've bled it ok as all heaters get hot, bottom hose hot and not loosing any coolant. I have a Mason alarm fitted.

Problem is at motorway speeds >65 mph the temperature gauge creeps upto the top end of the scale - 2 o'clock plus and the alarm starts to chirp (set to just over 5). BUT, slow down a bit temperature drops to 1 o'clock. Radiator fans kick in as well when hot. Sitting in traffic doesnt get the temperature up anywhere near the alarm.

Now, I've read all the recent posts on others overheating issues and mason settings - but as my temperature goes down when I slow down and I'm not losing coolant - I'm guessing the radiator isnt doing as good a job as it should do- it is pretty old by the look of it.

Am I right to suspect the radiator? I will also put in a new MAzda thermostat. Bleeding the system seemed pretty painless so I'm not too daunted by dropping the coolant again soon!

cheers,

Steve

[Northern Bongolow]

when you change the stat CHECK THE PORT IN THE TOP OF THE STAT HOUSING,sorry to shout but it is vital,shine a torch up the stat housing from underneath,you should see a bright ring/port.if it is dirty the stat will not seal this off properly when the top temps are reached.
please fit gen mazda stat,imo they work better.its a cheaper fix than a rad,it may need a rad,but try this first.

[rita]

Hi steveyd,

You are probably correct about the rad if its looking tired,after a good run you could check the rad for cold/cool spots.

Was the heater matrix leaking or choked.??

[steveyd]

Hi,

Cheers - will check the radiator for cool spots. My new heater matrix was from a Bongo breaker on ebay - no leaks and it did flow ok as I put the hose pipe through it for 5 minutes and got a good flow. I might have a hot engine but at least the inside doesnt smell of wet dogs anymore!

I guess the first thing I will do is do a good system flush then make sure the radiator and air con radiator in front are clear of crud. It did do this before I put the new matrix and pipes on but I was hoping a good bleed and new coolant would sort it.

cheers,

Steve

[David Edwards]

If you look back on some of the posts I put up about my problem steve you will see it is almost word for word with yours,lol, got a new rad and it is fine now, old one was bocked up with gunk, changed the stat as well just in case and seems to have done the trick, good luck. Just for info I got my new rad from these people, next day delivery, brand new aluminium cored rad, two year warranty as well, cost £111.00 to my door. They are Champion car radiators 01709 580456 or 07800 981750 web site www.championcarradiators.co.uk.

[321Away]

generally if you drive faster, a with car with proper guages etc (high performance types)you tend to find water temp drops and oil temp increases, if your temp is going up and down that rapidly you may have an airlock, if its the original rad bin it, they're the cause of most of the O/heating probs.
Julian

[steveyd]

Hi there,

Many thanks for the links - I'll give that radiator place a call tommorow - Mazda thermostat on order (though club shop o.o.s until early July!). Hopefully I'll fit it all this Saturday AM..

cheers,

Steve

[steveyd]

New radiator & Mazda thermostat in - so far so good but no warm days to test it yet! Took longer to warm up when bleeding than it did last time, I'm putting this down to the new radiator being more efficient than the last one.. a good sign I hope!

Steve

[mikeonb4c]

New radiator & Mazda thermostat in - so far so good but no warm days to test it yet! Took longer to warm up when bleeding than it did last time, I'm putting this down to the new radiator being more efficient than the last one.. a good sign I hope!

Steve

Sounds good so far - fingers crossed for ya

[mikexgough]

New radiator & Mazda thermostat in - so far so good but no warm days to test it yet! Took longer to warm up when bleeding than it did last time, I'm putting this down to the new radiator being more efficient than the last one.. a good sign I hope!

Steve

Sounds about spot to me....

[vanvliet]

Hope you used distilled water - it really does make a difference