So... figures that no sooner do I post in a thread about how cool Fiona runs in the heat than I almost melt her.

I notived the other day that my electric auxillary fan hasn't been coming on - I figured I needed to check the electricals and maybe the thermostat. No biggie.

Problem is, I haven't been checking the COOLENT level as well, despite the fact that I've been hearing the radiator hissing a bit after drives in the daytime heat.

Bottom line - on the way home tonight, the temp redlined and would NOT come down. I nursed the car home the last 2 miles or so and IMMEDIATELY shut her down. Now I'm waiting for it to cool off before I unscrew the radiator cap. Damn it... hope I didn't damage anything.

QUESTION: My Haynes book recommends a mix of antifreeze and water - what do people like to use here in the States? I've also heard good thing about Water Wetter - can that be obtained from a local auto parts store, and if so does it go with a specific brand or type of antifreeze?

if it ain't one thing it's another I guess... I'm just glad this happened now - the other day I drove all over Columbus on errands - at least two 25+ mile trips each way in 90-degree heat. I'm assuming that's what killed what was left in the radiator...

 

Yikes.

Yeah, "real" British radiators and cooling systems pretty much bite, IMHO... that was the bane of my existence, back in the days of the TR7... never could get it to hold pressure for long... though it sure ran cooler after I had the radiator rodded out and rebuilt...

Hope Fiona isn't worse for the wear.

 

Mine completely overheated once with smoke and everything coming out of her and i almost cried when my dad told me what could happen. Anyway, the cause of my problem was a loose bypass hose from the water pump and that fixed it and it keeps the temperature at normal. I use 50/50 water and anitfreeze and it works fine.

 

digging on the web I found a number of places recommending no more than 25% a/f to water for hot wx. Note that many race folks run no a/f at all.

I've been running 25% ever since I got OC, that's a 1275 with mods...standard rad, therm and fan...in Florida.

http://members.tripod.com/austin_america/id77.html

Last time out I mixed 20% a/f, 5% water wetter, 75% water with no noticed difference. If you use water wetter - available at most any autoparts store - be careful of your % as the bottle size is intended for a larger system. Remember we're only talking a gallon total in a stock system.

And I check the coolant level at least monthly....a small drop is a big difference in a small system....

 

I'm with bj on 75% h20/25%A/F Dash of watter wetter can't hurt.

You may be lucky if you didn't blow the head gasket, warp the head, etc. Next time, if it hisses....you got problems, pull over.

The Mini cooling system is barely adequate to begin with and poorly designed. Make sure everything is in order before driving it again. Fill it with coolant. Check for leaks. Check your hoses (esp the bypass). Check your belt. Check your pressure cap on the radiator as they do go bad. Get a new one to be safe.

 

I've always run 50/50 in my old English iron things. I usually use Prestone. IMO water wetter is snake oil for your rad, but I can't see how it could hurt so why not?

I doubt that you did any harm. It's hard to warp that iron head.

If this happens in the future, turn on your heater. That will help bring the temp down. Stop open the boot & get your gallon of pre-mixed coolant out. Leave the engine running then put a rag over the cap & your heavy leather gloves on & carefully turn the cap to it's fist stop. Wait until the steam dissipates & add the coolant you need. What you really need is a rad cap with a pressure release lever.

If you haven't done so, flush out your cooling system install a new thermostat & a pressure release rad cap. Sounds like your rad needs to be recored & when doing that you car do the rest at that time. I'd change hoses too.

FYI Capt, racers don't use antifreeze because if it is dropped on track a lot of hilarity ensues for those folioing behind. Some sanctioning bodies forbid its use.

 

I did in fact run the heater - it seemed to help a teensy amount. It's been hissing at me for about a week now, but as the level was remaining at exactly the mid-point (as usual) I didn't check it. Stupid... stupid...

I looked in the radiator this morning and saw moisture in the cap but no actual liquid. I don't see liquid anywhere on the floor on in the bay, but it was so hot it may have evaporated.

FILLING QUESTION: The Haynes Book o' Lies says that there's a wire level indicator inside the filler neck, but I don't see it - just a plate with holes in it. Do I fill to just above that plate perhaps?

Chuck - any suggestions on "re-coring" the radiator? I know i can get the thermostat and hoses from GBCarparts or Minimania. I'm also going to just hook the electrical fan to a switch - that way whatever caused the fan/thermo connection to fail will never be an issue.

Thanks, guys!!!

 

QUESTION - I read this form the above link:

"Back flush the radiator and heater core with some high pressure water, from your garden hose. Flush both until the water comes out clear."

I'm looking for a How-to that shows what needs to be removed/loosened to perform this operation but I'm not finding anyhting. And the Haynes book is, of course, not helping. Can anyone shed some light on this for me? I might as well flush if I'm refilling anyway, right?

 

"FYI Capt, racers don't use antifreeze because if it is dropped on track a lot of hilarity ensues for those folioing behind. Some sanctioning bodies forbid its use."

I know - my point is you are not contributing to the cooling ability with 'more' a/f ... the hardest run Minis are running 100% H2O!

 

"It's been hissing at me for about a week now, but as the level was remaining at exactly the mid-point (as usual) I didn't check it. Stupid... stupid... "

Not to rub it in, but that was your mistake... anything at all, check it out... better safe than sorry.

BTW, got the grill screen... this one fits much better and looks good.

Anybody ever tried polishing them? Stainless steel, right? Might look pretty sharp with a good mirror finish???

 

Imago - my Mini does not like the summers here. I run 100% distilled water after a very thorough flush and use a whole bottle of water wetter. With water alone I still code though I don't overheat. Snake oil or not, I don't code and run about 10 degrees cooler with the wetter.

 

Re: the flush: is it as simple as opening the lowest drain plug and running in hose water until it flows clear, or is there some more sophisticated technique?

Purchased a gallon of "All Type" NAPA-brand antifreeze and 2 gal, of distilled - nobody had Water Wetter between work and NAPA, but I'll try it this way. Assuming that the car will run at the mid-point with a freshly-topped radiator, I'll order up a new 180-degree thermostat form GBCarparts and see if that fixes my fan issue - I'm reading that it's usually the point of failure and not the electricals.

Actually, you know... I THINK I have a replacement thermostat and gasket in with my stuff that the origonal owner gave me... I'll check with I get home.

Is that perhaps why I'm hissing? I thought that the thermostat only served to switch on the AUX fan, which is itself *technically* "optional" isn't it? I don't remember hearing any hissing last year, even on very hot days.

Thanks guys!

PS - Goodwood - glad it fit better - if you polish it up send me a pic! I think it would look good, but I think they bead-blasted that stainless or something to get that satin finish, so you might be in for a long job. It's VERY hard stuff...

 

No, the thermostat does not control the electric fan....your coolant sensor does! usually this sensor in mounted in the head below the thermostat, in the thermostat housing itself, and I know there is one mounted in the bottom of the radiator on MPI, SPI's. To check it, you just have to disconnect it and cross the wires and see if the fan kicks on.

The hissing you are hearing is probaly a coolant leak somewhere....could be a small hole in your radiator, a cracked cooling hose, or a blow seal(thermostat gasket, head gasket, etc) One way to check this is to either borrow or buy a radiator pressure system tester, as you can manually put pressure on the whole system without the engine running and can easily see if there is any problems. Good luck!

 

"PS - Goodwood - glad it fit better - if you polish it up send me a pic! I think it would look good, but I think they bead-blasted that stainless or something to get that satin finish, so you might be in for a long job. It's VERY hard stuff..."


I think I'll just be content with what I've got, but... if you ever want to try it, sounds like a good project.

 

SOmeone posted a suggestion on flushing the radiator on MiniMania's forums... I'll either do the tried-and-true "Fill -> Run -> Drain -> Re-Fill -> Re-Run -> Drain Again -> Repeat" tihng, or if I cna get an assistant, I'll run a constant stream of clear water into the radiator while the car is running and the rear drain plug is open - reports indicate that the system can be flushed VERY rapidly with no damage to the water pump this way. As I'm alone though, with no assistant, I might need to go the "slow and steady" route.

thanks guys!

 

FYI: You can buy a Chevy 350V8 thermostat....it's the same thing.....

Pressure test your cooling system for leaks. Pressure test/replace your rad cap. Make sure you get the right pressure cap (check owners/shop manual)

Fill the rad to above the cooling fins, but not completely into the neck. It will only be tossed out when hot. Idle with cap off to make sure all air is purged out. Then top off, put on new cap.

Contrary to another opinion, BMC heads DO warp especially between cylinders, and they are also prone to crack. Make sure you don't have a blown head gasket. Besides overheating, signs include off-color oil (milky), a substantial accumulation of milky goo on your oil fill cap and in the rocker cover, and white smoke from the exhuast (steam from h20-A/F)

There's a few classic owners around Dublin. Check out zip-tph on minimania if you need local help.

 

Prestone still sells a kit for under $10 that includes a fitting that you splice into a heater hose that allows you to connect your garden hose there....and a gizmo you stick in the radiator cap opening that diverts overflow. To that I attach some 1 inch hose I have to a drainway. Then you turn on the hose and backflush the rad - it fills from the bottom and flows out the top, at what ever pressure your hose can provide - until the water runs clear...usually about 10 to 15 minutes. Prestone even has some other bottles of 'stuff' you can add to the process. Once it runs clear, remove the toys and use the provided cap to seal the new 'tap'; open the rad' drain and get that water out, then refill normally with your mix dejure.

For less than $10 it does appear to me a better flush than just stuffing the hose in the top of the rad, and doesn't involve pulling rad hoses. I actually pull the fitting back off and have a small piece of copper tube that I stick the heater hose back together with (and clamps) - avoiding car show questions of "what is this..." I'd used it on other cars b4 and knew it basically worked. The first time I used it on OC it very sucessfully pushed a LOT or crud out of the system. So much so that a new rad is on my do list cuz I KNOW some tubes must be thinned significantly. 'til then I rely on AAA

Once installed, annual flushes are a piece of cake....a thing I find a good idea for a car that isn't driven much.

 

Matt, fill to just above the fins. Like some already said if you fill to the bottom of the neck it will burp it out once it is up to temp. Getting a flushing T is a good idea. It makes the job so much easier.

I'll ask Eric who he recommends for the job. You may need your rad recored, but if you are lucky it may just be a leak that can be fixed. You'll be luckier still if it's just a bum hose.

Your car shouldn't be hissing. That indicates a leak somewhere in the cooling system.

Capt, using antifreeze at 50/50 not only raises the boiling point of the coolant, but it keeps the water pump lubricated & keeps corrosion in the cooling system at bay. Both of those things are pretty important. Racers have their cars apart all of the time. What works on a race car isn't necessarily the best thing for a street car.

 

Please explain "keeps the water pump lubricated"? I often hear this expression. Water & ball bearing do not mix well.

The water pump contains a sealed bearing. This shaft bearing does not come into contact with the coolant. If it does, the water pump seal is bad. It'll start leaking out the "weep hole" at the bottom of the casting or out the front of the shaft.

I again agree with bj on the Prestone self-flush kit (for the car, that is) It works well and pushes tons of scale out.

 

Well, I filled the radiator with clear water, just to check it, and it sat at the mid-point on the temp gauge, even in stop and go traffic. Oh, and I checked the connections to the electric fan and reassembled, and now it works. Grrrrrr....

So now I have to drain the plain water in there, but I can't reach the lower radiator hose clamp until I get a long flat screwdriver (it';s very deep and the Haynes book says you need a "very long screwdriver" - they're right). But it will do for a day or two until I can go to the store anyway.

Can someone link me to that T-flush kit? I just called NAPA and they had no idea what I was talking about.

EDIT: Went on an errand - about 20 miles and the car's great. It's not hissing now but I can hear the coolant bubbling in the radiator when I shut down - making up a 50/50 solution should help with that. I am seeing a little bit of leakage up around the fittings of the expansion tank inn the LH wing - might be a loose fitting or something. ALl I can assume is that I do have a small leak near the bleed-off tank, and over time I lost enough coolant to not only overheat me, but also to disable the temp sensors that control the electric fan - now that I know there's coolant in the radiator the fan's working fine.

 

http://www.acehardware.com/product/i...ductId=1289874

this is the only link I can find for it ... but I bought my last one at AutoZone. It was hanging near the flush mixes...

Prestone Universal Flush N' Fill Kit (Afk1t)

$6.49

AND
I am not advocating 100% H2O for a street car, what I'm suggesting is that there are those that think if 50% AF is good 75% must be better and that just ain't so. People with more experience than I have gone so far as to suggest that while Haynes and the original owners manual say 30 to 50%, one must remember that ANTIFREEZE is a cold weather treatment..prevent freezing. True, adding alcohol and glycol does also change the boiling point and in modern closed high pressure systems the recommended mixture may well exceed that of an older system; changing the system pressure also changes the boil point doesn't it?. Digging thru MANY sites on this topic - not JUST MiniMania - I find significant endorsement for 25%...in a warm clime' mix; and IME this has served well. BUT I also realize that one living in the frozen north may want to run different mix{es in the summer vs the winter}. But those same site advise that increased concentrations of AF will NOT improve heat disipation and will actually reduce it. (to wit, why doesn't ANY system recommend 100% AF) {Why make water "wetter" vs remove the water?} I agree that AF adds other value - corrosion control for sure...the lubrication issues I'm giving a maybe about. Yep, they claim that but it is a sealed bearing so......

My experiences, and what I may have found via research are being shared...I ain't WRONG .... it is an OPINION I share with one who asked (with a reference example link). Run what makes YOU feel good.

Case closed for this unit..

 

Poor fiona... I've never seen problems with running H20 by itself, so just do that. Im thinking of some coool cooling ideas as we speak....

 

i had my mini in jax fl and drove it between jax and ocala a few times i only ran water in mine and only time i had a issue with over heating it was do to the fact the the water pump was going out.

 

I agree 100%, no more than a 50/50 mix of antifreeze & water. Yep a higher pressure cap will raise the boiling point, but unless ones cooling system is 100% up to snuff most likely it would just be a way to find the weakest link in the cooling system.

I run what works for me & you run what works for you. Glad you ain't wrong. Why are ya YELLING any how Capt??

 

You should not experience this effect. Sounds like the fluid is boiling inside or there's air trapped in the system. On refill be sure to purge all air out. Watch your temps. I'm still willing to bet your rad cap is weak and needs replaced.