What could causes a car to munch through radiators?

[levymetal]

I've gone through 3 radiators in less than a year. Around the middle of last year the radiator that was originally in my car (no idea on age) sprung a leak. I bought an aluminium one off ebay (kingswoodcountry), and about 3 months after I had that it sprung a leak too. I left it because I'm lazy, but then the leak got so bad that I had to get a replacement. I fitted the replacement less than 2 months ago, and today I walk outside to see a small puddle of coolant under the car (directly under the radiator). The hoses are fine, the leak is definitely coming from the radiator. If the radiators were this shit then surely the manufacturer would be out of business, so I'm starting to think that something is wrong with my car that is causing it to pop radiators. But I have no idea what it could be. In the past year I've replaced top and bottom radiator hoses, water pump, 2 thermostats, the coolant I used said it was OK for aluminium/alloy, the radiator came with a new cap so that's fine, temp runs between 1/4 and 1/2...

Anyone have any ideas?

[social]

Have you possibly disassembled one to find out if its corroding on the inside?

[Dum*P*ster]

I would say, either its having massive temp changes..

Like when it's Hot,it being shocked cold or something..

Do you turn your A/C on and off sometimes when driving? :P

[SweetWagon]

Could also be electrolysis

[levymetal]

just checked for electrolysis, shows 0.30-0.35v in the coolant, same with engine on and off, is this too high?

Have you possibly disassembled one to find out if its corroding on the inside?

nah i just threw the old one out, and for the last one i sent it off to get it replaced so couldn't disassemble.

Do you turn your A/C on and off sometimes when driving? :P

don't even have air con

[levymetal]

would someone with a 5ltr please be able to check their electrolysis? i want to find out if mine's too high or all 5ltrs have this kind of current running through the system. for anyone doing a search in the future, grab your multimeter, set it on the 20v setting, and put the negative probe on the negative terminal of the battery and the positive probe into the coolant in the radiator (don't touch the radiator itself though).

[Dum*P*ster]

Is the radiator mounted properly maybe lol?

Like, it cant move or jiggle around?

[muttley383]

I think the max voltage level should be 50mV, not 350mV like you have got.
Have a look on the Tectaloy site for info on this.

Make sure all your earthing system is ok.

[wortus]

What sort of coolant did you use? Are any other aluminium parts in contact with the coolant corroded like the water pump etc?

[levymetal]

ah ok, yeah that document from tectaloy is pretty good, looks like aluminium is MUCH more susceptible to electrolysis than copper/brass (which are still susceptible though). haven't checked the water pump, too lazy to pull it off , but apparently electrolysis finds the 'tastiest' spot to corrode and goes to work there, which has always been my radiator so hopefully the pump is still ok. i'm using tectaloy 60 plus which says it's suitable for aluminium radiators.

here are some really good links about checking for electrolysis and finding the problem:
Electrolysis
Testing For Electrolysis

first thing i'll do today is test with the battery cable removed and see if the voltage is still there. i know the block is already earthed properly, yesterday i did a quick test and attached a jumper lead from negative directly to the block and the voltage in the coolant didn't change. it's weird how there is voltage with no accessories turned on. this is going to be a long and painful process.

[wortus]

Just a guess but maybe there are some electronics that are "leaking" and causing the voltage. Try disconnecting the alternator and the ignition module one at a time and check with your voltmeter.

[levymetal]

haha yeah i'll check it out, shame it's raining at the moment but when it clears up i'll disconnect some things and see what happens. thanks for the help

[levymetal]

alright, did some testing, completely inconclusive. voltage today magically halved to 150mv. before i wasted my time disconnecting accessories to find the problem, i just completely removed the positive power cable from the battery. so if every accessory is disconnected at once the voltage in the coolant should drop. well, i was wrong. 140mv with cable disconnected. according to this page, i have type b electrolysis. however their solution is some crazy ****ing flush. i don't even know if this will fix my problem, AND i still have to buy another radiator... i don't think i will bother.

[fergi]

just fiddling with my car so thought i would check for you,my reading with 20 v dc selected was .15. i have had this radiator for 5 years and all looks well.dont know if thats your problem though. i have a vp 5 litre.
cheers
fergi

[levymetal]

thanks for that mate, exactly the same as what i just got today (no idea why i got 350mv yesterday). is your radiator aluminium? i'm guessing not, maybe 5ltrs just have this voltage in the system, which means that aluminium radiators are not suitable...

[delcowizzid]

earth the radiator to the body

[fergi]

not sure if its ally. i think the top and bottom tanks are some sort of plastic if i remember correctly
fergi

[2DIE]

i didnt read through the other posts but..

dont buy coolant with antifreeze, it corrodes your radiator and also if you have a alloy head it could cause major problems.

most places in australia dont need antifreeze anyway so as long as you dont live where your car is frozen every morning just buy coolant and make sure it doesnt say or have antifreeze in it.

[purrVN]

have you been able to tell if maybe the radiator is cracking rather than corroding through? just thinking that maybe you might not have bled the air from the cooling system whenever it's filled up or something as this causes rapid temp and pressure fluctuations

[wortus]

i didnt read through the other posts but..

dont buy coolant with antifreeze, it corrodes your radiator and also if you have a alloy head it could cause major problems.

most places in australia dont need antifreeze anyway so as long as you dont live where your car is frozen every morning just buy coolant and make sure it doesnt say or have antifreeze in it.

I don't think that's right. How does it corrode the system? I recall reading that the V6's need anti freeze/anti boil due to the cylinder head design you can get boiling around the valve area and this can lead to damage without the proper amount of anti freeze/antiboil in the system.