Which radiator, and which thermostat?

[xp_wannabe]

Im replacing the radiator on my AU2 XR6 and the radiator guy said I should replace my thermostat too, and that back in the day there used to be a service bulletin going around for the AU's, which required drilling a hole in the thermostat, or using a special one, to prevent haemorrhaging in the cooling system...

Anyone heard of this?

Also I can get an ADR brand radiator (aluminium) with 24 months warranty for $222. Is this a good price and is this a good radiator?

Thanks, Mark

[FGII-XR6]

there was no such bulletin. just use a thermostat specified for the AU. sounds like a twist on the old one of pulling the guts out of the thermostat when the car overheats. the thermostat is there foe a reason and should not be tampered with . if he's feeding you lines like this I would question his suitability to work on your car if the car has been overheating replacing the thermostat is not a bad idea

Originally Posted by xp_wannabe

Im replacing the radiator on my AU2 XR6 and the radiator guy said I should replace my thermostat too, and that back in the day there used to be a service bulletin going around for the AU's, which required drilling a hole in the thermostat, or using a special one, to prevent haemorrhaging in the cooling system...

Anyone heard of this?

Also I can get an ADR brand radiator (aluminium) with 24 months warranty for $222. Is this a good price and is this a good radiator?

Thanks, Mark

[xp_wannabe]

thanks mate.

hes not working on my car, im replacing the radiator myself, hes just supplying parts.

I dont think I will bother replacing the thermostat. The car has never overheated, the guage never moves off the N on the temp guage.

The radiator has developed a pin hole and leaks under pressure, which is why im replacing the radiator.

[FTe342]

There was a bulletin for the V8's but don't know if it included the 6's. I know of mine and others which had the pin hole drilled on a service visit
Some of the cheap radiator suppliers only have the auto ones and supply the same for auto/manual so if yours is a manual and don't want the cooling line fittings sitting there doing nothing you have to get it from Ford and it costs

[xp_wannabe]

Originally Posted by FTe342

Some of the cheap radiator suppliers only have the auto ones and supply the same for auto/manual so if yours is a manual and don't want the cooling line fittings sitting there doing nothing you have to get it from Ford and it costs

just picked up the radiator and it is exactly that, a universal one for autos and manuals...

will leaving the cooling line fittings open do any damage, or is it just a looks thing?

should i block them off somehow?

[WannabeXP]

I replaced mine late last year and it came with a little hole already in it, It was Tridon brand.
I think thats what your talking about, just a little leak through the thermostat to equalize the pressures. so that when the thermostat opens it is not suddenly putting pressure on the radiator, which is possibly how your radiator developed its hole.
When i got my new radiator i opted for copper so that its easier to repair.
but yeah take a look at the tridon one at your local auto shop and it should have the little bleeder hole.
Cheers Jason
Sweet name BTW

[aussiblue]

Most (99.99%) of modern thermostats have a bleed hole; indeed unless it for a special purpose or there has been a manufacturing fault they all have bled holes. The best ones have a jiggle pin in it to keep it clear of scale and this makes the hole more obvious. Others just frequently just have a half circle or notch cut out of the edge of the closing plate of the valve. Hold one up to the light and you will see it. eg:






On the Windsor V8's with the thermostat mounted vertically the bleed hole need to be placed at the 12 O'clock position so the air bleed through it.

Like this:

[mik]

i used to drill a couple of 1/8 holes in my thermostats just to help air bleed through , and used to change thermostats according to the summer winter season, i`d put the hottest mongrel i could find for winter months (get that heater nice and warm ), and put a lower temp one in for summer, last summer i put a 170 farenheit in the au, it seemed to make no difference( it never overheated or got hot anyway, but i tow abit and thought it may help), i think the fans will just come on at the appropriate time and control the engine temp anyway , a 1/8 hole drilled in the thermostat will make bugger all difference to the engine temp if you wish to do it.

[aussiblue]

There may also have been a bulletin about using a bypass type thermostat. At one time Ford tried to rationalise stock and only supply nonbypass thermostat but these did not work on all the sixes designed for bypass thermostats and they had to go back to supplying both types.

I see Tridon recommend a TT28-195 bypass thermostat for your AU2 XR6. http://www.tridon.com.au/partfinder/default.aspx

I use bypass types in all my two Fairlanes and the EF and EL that live hear but it does seem to depend on individual cars - my car work best with the recommended bypass thermostats that block off the bypass when they open but some individual cars just don't seems to be able to run cool with a bypass thermostat. LPG cars also generally have to use a non bypass thermostat.

See http://www.tridon.com.au/partfinder/default.aspx

for how they work and differ.

A bypass thermostat has the plate on the bottom that closes of the bypass when the thermostat opens:

[aussiblue]

The only reason to drill a hole in the thermostat is where you have bought one with no bleed hole (and I don't think they've had them on a shop shelf since the early 70's) or to overcome some other inefficiency in the cooling system (whether by poor design or due to need to service).

All the CPC, Tridon, Ford and Stant thermostats have either a bleed hole or bleed notch. Drilling holes is equivalent to having a thermostat that doesn't fully close or opens at a cooler temperature and will slightly slow down warm up time making your engine run richer for longer and thus marginally increasing engine wear.

You will find this debate all over the 'net and some argue certain engines need the extra holes. You will also find a debate about if you should also add a hole to the poppet valve that closes off the bypass system in bypass thermostats. I can't see why as that bypass is only fully closed when the thermostat is fully open.

I do accept that if you might still have some casting sand in your radiator or cooling system, there is scale that might block the small notch type bleed hole or you have air in your cooling system, the beginnings of a leaking head gasket or some similar overheating issue adding an extra hole or two may will assist in cooling and offer a temporary solution to overheating. The marginal increase in engine wear from adding a 2mm holes will also depend on the prevailing climate and I accept that in most cases probably would not be significant. At the end of the day I would buy a good quality thermostat with the bypass poppet valve fitted and the jiggle pin as the jiggle pin means that bleeder holes won't clog with scale as easily as the notch or half moon type. If need be or you are concerned about risks of overhearting go for a hi-flow rather than normal thermostat.

[aussiblue]

leaving the cooling line fittings open do any damage, or is it just a looks thing?

Just looks but you can plug them if you wish.

Or find another use for them; I've seen UK magazine articles where people have run their windscreen washer fluid through them so they get to wash their windscreen with warm water; it would certainly cleans the window once you pumped enough to get to warm water but you need heat resistant washer lines and the corrosive impact of many bleach based washer fluids on the radiator would deter me from this approach. Probably a gimmick for colder climes but I wonder why the hot water on a cold windscreen doesn't risk cracking it.