Running temps, Australian 409

[MYTA21]

At a time when those with Bristol cars in Australia are reading reports about the snow in the UK, but facing temperatures approaching 40C in South Australia, perhaps I can ask what engine running temperatures are the norm for 409's in high ambient temps?
In the cooler months, the car has run about the 80-85 C mark, but in today's
35C ambient, it was running about 10c degrees higher. Fans were on very quickly and the switching on of the heater took the temperature down a noticable amount,as is usual. ( Good way of losing weight!)
I am tempted to have the radiator checked over, before we take a long trip to Victoria. I have done the usual flushing and cleaning. Any specific advice from Australian owners ref possible recoring? I have heard of some rads being worse after such work.
Thanks
Mike O

[Kevin H]

Mike, is that temp while driving along?

Is it able to hold the temp at 90-95 deg C when the car is stationary? (without the heater on!)

What pressure filler cap are you running ?

If it definitely doesn't keep getting hotter you are probably okay, although whether you are comfortable with that is a different matter. Personally I hate driving a car when I have to constantly look at the temp gauge.

A couple of things you could try - is there room to mount another electric fan on the back of the radiator? (to pull air through)

And/or you could fit a separate oil cooler.

Just my personal view, but if you decide to go down the re-core route I wouldn't bother with a straight re-core, I would replace the rad with something thicker with greater cooling capacity. I need to do that with my 411.

Regards,
Kevin

PS. They're forecasting 43 deg C for Melbourne tomorrow!

[Nick Challacombe]

The running temp for the 409 should be between 90 and 100c.
The pressure cap 15lbs
The antifreeze 25% at a minimum.

Nick

[412usa]

Please check the radiator cap, as well as the pressure cap on the expansion
tank. This proved to be the weak link when my 412 was overheating. If the
radiator cap cannot make a perfect seal then you will never achieve the 15
psi the system runs at.
Peter

[MYTA21]

Thanks for all the help on the cooling matter. In 42C yesterday, with a
brisk drive that included uphill, the gauge just got to under the 100
marker, but no sign or sounds of the of gurgling you can get and at
tickover, no noticable rise over that. Few people were out in modern cars
here yesterday!
I will look at the webosite for the other items.
Has anyone used the new Liquid intelligence coolant? I know it has a boiling
point of 190C and just allowing the engine to get hotter than it's intended
range is not a good thing. No price given on any of their data.
Thanks
Mike O

[GREG]

Change the thermostat and flush the system using rad flush, Put a hosepipe on both sides of the heater matrix and flush through. If that fails recore the original rad. Just done all the above last summer for my 408 and it doesn't move above 85 now even when stationary in a long taffic jam. And don't forget good quality anti freeze. I think that a lack of antifreeze had caused the gumming up of my rad -- previous owner. Good luck. Greg

p.s. I have spare original fans in the shroud if you need one, but I heard that the pair from a peogeot 407 diesel work great

[MYTA21]

Thanks Greg,
I'm on to that shortly.
BR
Mike

[MYTA21]

I havenow completed my cooling system work on the 409. Radiator was removed and dismantled, with some blocking noted, but repairer said core was of top quality and servicable.
New thermostat fitted.
Present Kenlowe fans changed to locally available here in Australia, David Craig ones. I had put a new motor ( MGB) on one fan, but the shrouds were rickety and the new fans fit closer to the radiator. Fan switch was questionable, so ordered one from BCL at 49 GBP + VAT if applicable.
Item is actually SU part number C 18559 for reference.
All refilled again, then flushed after trip and refilled with coolant.
I did notice that when the fans are on, there is a passage of air out of the gap between top of the radiator and front cover plate, so I am putting in a plastic piece across, so as to maximise air flow through radiator.
Then, hopefully, it's Victoria's RACV "Fly The Flag Rally" here we come.
Mike O

[Kevin H]

Mike, have you done away with the fan shroud and mounted the new fans directly against the radiator? (any pictures?)

I have added an extra fan to the back of my rad to pull air through - there are two pushing from the front.

Initially I thought it had done the job, because I sat watching the temp gauge and the fans kicked in at 75 degrees C and brought the temp down and the fans turned off again. Previously the temp would just keep going.

However, after the car had been sitting running for half an hour and I switched on the air con them temp kept rising to over 90. I turned off at that point because being a new engine I don't want to cook it.

It's still not registered (still have oil leaks which would fail the roadworthy) but I might get another unreg vehicle permit today and take it for a decent run over the weekend and see what happens. I'm fairly sure it won't overheat when it's moving, but it's when it gets stuck in traffic that worries me.

Kevin

[MYTA21]

Hello Kevin,

The two new fans from Davis Craig are mounted close up to the radiator on
the front face.
None of the Bristol/Kenlowe shroud is fitted. The arrangement gives lot more
space and visibility/
I might be able to get some photos shortly. They were mounted on with with
alloy brackets made up locally. Standard option is to use the long thin
bolts that pass through the fins, but the gap on the Bristol rad is pretty
small.
The chap who offered to do my air con says he would be fitting them on the
engine side of the rad, but it would be no great job to get this changed if
I go to air con.
Before the rad clean out, the fan switch came in around the 85C mark, but
tended to cut in and out a lot. After the rad clean out, the fan switch
appeared to operate from cold! Therefore, I bought a new one from BCL. I
would say it comes in at 85-90. Car will rise to 90 if left to idle for
length of time, but not go above that.

BR
Mike