Cause of rusting coolant pipes?

[steptoe]

I am beginnng to realise that all of the rusting coolant pipes of my/our Subes and other cars is not rusting away from inside at random in most cases, it is the mild steel (nice anode) rusting away at the ends that have rubber hoses clamped over them between the rubber and pipe!

Noticed that fellas?

I was thinking the cause was not good enough upkeep of the coolant/anti freeze/anti/boil anti corroson stuff but now thnking maybe just that tiny escapes of moisture at the hose loosening up in a spot not easy to retighten the clamp, bit of air as need for rust? so how do the rust inside at the welch plugs then?

Starting to hurt my brain...

Have also pulled components apart like Toyotas that have had their red kept up to them - so clean like new inside [says the one finger typer]

anyone try the sacrificial anode screw ins?

[TOONGA]

not tried the anodes myself but have seen the deposits in the bottom of radiators, associated hoses and motors when the engines are cleaned and the anodes (zinc strips placed in hoses) replaced.

All I could say was WTF, the engine might not corrode away but filling it with oxides and compounds of zinc might affect the cooling a bit.

TOONGA

[El_Freddo]

I'd just go with the notion of not keeping up with correct coolant maintenance. Are you sure it's rust or is it really a different type of corrosion? I'm sure you'll find that it is corrosion and if you've cleaned it up and seen rust this could be due to having cleaned the effected area then exposing it to oxygen...

My 2c anyway.

Cheers

Bennie

[steptoe]

OK, there is a difference between rust and corrosion? Or rust only applies to ferrous metals and corrosion to both ferrous and non ferrous? Mild steel is going to corrode by name of rust leaving orange oxides behind? Nice feeling cleaning up the crud to see daylight on the other side:) uh oh ! Who skipped chemistry ?

[discopotato03]

Welcome to the magnifiscience that is EA82dom . Yep , every piece of steel tube that sees water sees doom .
Dunno why , the OE clamps used on the things were those double wire hoop types and maybe they allowed water to creep in and keep all the barb fittings damp . Maybe the original coolant was a bit corrosive or people just decided to run without coolant additives .

Steptoe by now you've realised that the good ship EA82T is a bit like a space capsule that springs leaks anywhere and not with much or any warning .
Any EA82T veteran is paranoid about water leaks and those that keep them alive can claim to be Paramedics IMO .
You have to be absolutely sure that EVERY hose and every fitting is in top condition and even then you don't go anywhere without clamps screwdrivers and 10L of spare water .
It wasn't without reason that I suggested you replace that big steel pipe that runs from the water pump back to become a heater hose pipe with new rubber hose . I was sh*t scared it woulde leak on my original AC equipt engine and that I wouldn't be able to get at it with the compressor and bracket crap in place . This and the fact that seemingly 1/2 a tonne of iron mongery went over the shoulder when I removed all the AC hardware . The front of the car sat fractionally higher without it I kid you not .

And what joy it was in Spider mode not having the mongrel cold start air bypass valve on top of the thermostat housing , more hoses and pipes to perish and get in the way . Made getting at the thermostat a major operation too .

Leave no stone unturned with EA82 cooling systems because they are the things that can and do kill these engines .
Anyway hoses can be replaced one way or another but the barb fittings are a bit different . If you are going to strip your engine think carefully about removing them and replacing them with screw in fittings , I was lucky to have three lots of spider cast bits at one time and all the water fittings were good . The L throttlebody had crook water fittings and was bypassed with again EFI fuel hose because its tough stuff , Wurth stuff is anyway , and designed to live with EFI fuel pressure which is higher than cooling system pressure . Good hose/barbs/clamps are part of the eliminating green blood loss process . It goes without saying that an unknown water pump needs replacing even if it doesn't leak because again you know its new and has a life ahead of it . Rad hoses are easy and the radiators still available .

Lastly do not hesitate to stop and get the lid up if you have any inkling about engine temperature climbing about what it normally is .

A .

[steptoe]

Paranoid is the word , it is like that ain't it and glad I am not alone. Wasn't it your dad you took along on a coastal fuel economy drive? Little did he know he was there to mind Ellie in case she stopped and you needed to thumb a ride for help

enginewatchdog going in on this baby too!

Water pump, yes , gotta check out the deck height of the multi ribbed, thnk it is 110mm and convert a spare pump to suit.

On all these rusted pipes none had that green crystalised build up you get from antifreeze bleeding out - just orange rust crud.

New metal pipes components are still available genuine for all around the EA82's with a wait ex Japan via our Subies dealers, or about same from US.

.

[discopotato03]

No not me , my father has bigger issues that my old busses Houdini coolant supply . He goes for short rides in it often , coffee/paper runs to GJs .

Its not hard to see why as I keep saying that the better Americans at USMB pull the donk out and replace everything on it thats seen , in theory , coolant . By this I mean when they buy an unknown EA82T .
AND the turbos lower water hose pipe . Promise me you will beg/borrow/steal the lower water pipe of an early EJs VF whatever turbo and replace the complete standard original pipe on your turbo . It means removing the turbo from the manifold or manifold from the heads because the turbo in std form is too close to the engine to screw the associated water lines banjo bolt all the way out . Really - stupid - pathetic - design - .

I know its all a bit expensive but its the only way to have any chance of reliability . Its why my L RX owes me a fortune and I'm still driving the thing to get some value back out of it .
It didn't stop with its cooling system , new clutches and a tailshaft full of replacable uni joints and a three times rehashed exhaust to make it flow heaps and be quiet .
And then competition take no dollop LSD oil in the rear diff and Castrol hypoid spec synthetic in the gearbox . Engine gets a unique blend of Mobil 1 4T sport bike synthetic and their synthetic 0W40 car oleo .
I guess its like having an uptown bird with expensive tastes . Is it worth it ?
I think yes because I've learnt so much from this car but it was expensive because I built more life into it than I now aim to use .
The real eye opener was the transition from front wheel drive to all wheel drive which was something I hadn't had before . It really sinks home to have the FrWD traits and them see them disapear instantly , particularly when you factor in FrWD turbo traction/handling antics .
LOL I think those that went and bought an AWD Lib or Impreza got it too easily and may not appreciate the difference it makes . I can't begin to imagine what a FrWD Evo Lancer would feel like with all that torque , but anyway you people don't want to hear about Rex killers .

Long short , if you can survive EA82Ts and not lose them to coolant etc issues then you are a long way ahead in you attitudes towards all cars .
They teach you to be vigilant which is something sadly lacking in many of todays motorists . Its a sad thing that some modern cars can get by with little to no maint but it does catch up with them eventually .
Coxy has spent periods of his life doing general maint on customers cars and swears that between services the bonnet never opens . Cars come in with tyre pressures all over the place and people wonder why cars crack up occasionally . Alien to me but he reckons many out there regard the car as a house hold appliance and drive it till it won't go or something vital falls off .

I guess in a throw away society you aren't intended to have cars old enough to vote but I think its a challenge keeping these old girls going . With me its partly because I don't like the way cars are nowdays and the money they cost is plain stupid for what they are . Bent Greenie electronic systems intended to make people less accountable for their own actions - attempts to save cork heads from themselves .
I don't look forward to the day when an honest car is impossible to find even just to look at .

A .

[pitrack_1]

I was thinking the cause was not good enough upkeep of the coolant/anti freeze/anti/boil anti corroson stuff but now thnking maybe just that tiny escapes of moisture at the hose loosening up in a spot not easy to retighten the clamp, bit of air as need for rust? so how do the rust inside at the welch plugs then?

It may be the damage was already started/done by a previous owner(s).

Rust is generally hydrated Iron (III) Oxide. To form rust requires Iron (e.g. in mild steel), Oxygen and water. Take any of these away and it won't happen at normal temperatures.

Corrosion can loosely be defined as the chemical reaction of a material to break it down, often the reaction is with Oxygen. So rust is a form of corrosion relating to iron-based materials.

Coolant is a mixture of water and chemicals (mainly ethylene glycol).
Coolant is present in your cooling system and hence contains water, often as the main constituent. Water will dissolve oxygen and hence rust will form under water if Oxygen is available. Water can also dissolve salts and also forms the solvent for acids.

Salts and acids can accelerate corrosion, hence salty areas promote corrosion/rust.

So if there is a small air leak at your pipe connection, or your coolant system is not completely sealed, Oxygen will be introduced and corrosion (rust) may take place. Dissolution of various contaminants from the engine into the coolant will introduce salts and also form acids, exacerbating the corrosion.

Corrosion/rust is particularly critical if you have Aluminium in your engine, as that will corrode first. However, unlike rust, Aluminium Oxide will form a skin to protect the rest on the material from further attack. Rust flakes and is loose and so allows further attack of the base material.

So what can you do? the following are my opinions, based on some experience. I will also say I am unfamiliar with your particular engine type, my only experience with old Soobie engine cooling is my friend's old L-series which rotted through the heater core (apparently not uncommon).

Firstly, change your coolant regularly with a quality coolant that meets your manufacturer's standards (or better). I tend to mix my own from concentrate, I use a Castrol antifreeze/antiboil which is basically straight glycol +inhibitors and lists lots of standards. I use it in an N13 Pulsar, recommended is 30% but I use 40% to allow for dilution. How can dilution take place? By adding straight water to the top-up tank (this is generally recommended). I top up with pre-mixed coolant I keep in a container.

Run a slightly higher concentrate. If your handbook recommends 20% glycol and change every 24 months, don't be afraid to run 30% glycol and change every 12 months. They'll recommend higher concentrations for colder temperatures anyway. You may not want to go above 50% unless specifically advised, though.

But don't run 100% glycol. Not only does glycol have less heat capacity (the ability to absorb heat per unit mass) thereby reducing the efficiency of your cooling system, it's hygroscopic so will absorb some water from the atmosphere in any case. This small water amount will form acids/salts anyway which may be concentrated. The coolant has additives designed to function with water anyway. I don't know what the chemistry of the glycol in the system would do either, and rubber bits may not take kindly to it. And glycol will have different properties- viscosity, boiling point, expansion coefficient, possible cavitation, etc.

New/tight hoses and fittings will help.

Make sure your radiator cap is functioning properly. If it holds too much pressure when hot, it will (at best) leak coolant past the weakest pipes or seals (dilution through top-up). If it forms a vacuum when cold it will suck air into the coolant system, again from the weakest seals/joins. This may be a follow-up to the overpressure when hot.

There may be other galvanic effects happening, as you said the pipe stubs may be acting as sacrificial metal.

In any case, all this will only reduce/slow the corrosion. Time may have finally allowed it to catch up.

And don't ingest the glycol. It will do nasty, painful things to you as you slowly die.

Starting to hurt my brain...

And your engine!

Hope this helps,

[sven '2']

Steptoe by now you've realised that the good ship EA82T is a bit like a space capsule that springs leaks anywhere and not with much or any warning .
Any EA82T veteran is paranoid about water leaks and those that keep them alive can claim to be Paramedics IMO .

You have to be absolutely sure that EVERY hose and every fitting is in top condition and even then you don't go anywhere without clamps screwdrivers and 10L of spare water .

Can only agree 110%

Just top throw this in the coolant discussion mix (excuse the pun) is that of micro-currents.

Now I don't if this campfire urban myth stuff, but I had been told the mirco currents that exists due to bad earthing contribute to EA cooling failure & corrosion.

Fix? Simple earth to body and importantly neg terminal of the battery from the radiator. No need to buy the fleabay earthing kits.

Did this with all my EAs...hard to quantify results though.

[Venom]

Check for stray current in the coolant system to make sure you're not getting electrolysis. Usually its associated with alluminium radiators which can be damaged beyond repair in a few months, but maybe it can occur to other metals over a longer period of time? Maybe someone more knowledgable can confirm.

A proper earth doesn't necessarily fix stray current in the cooling system either.

I found this website after the radiator in my Liberty dissolved within a few months of topping up with too much water. Its interesting they mention it can damage all parts of the cooling system like rubber hoses and thermostat etc. http://www.qldstreetscene.com/forums/to ... radiators/

Stray Current explanation & testing procedure:

In simple terms stray current is a chemical/electrical process which causes an electrical current to pass through a vehicles cooling system fluid. It can cause rapid damage to radiators and will indirectly cause problems with other engine components such as water pumps, thermostat housings, etc.
This is brought about when one or more items such as a cooling fan or headlamp develops a problem in its electrical circuitry. This causes an electrical current to seek out an earth path via the radiator core through the engine coolant.


•Remove the radiator cap and run the engine to operating temperature. Do not rev the engine as this may cause the coolant to aerate. Note: Removing the cap will reduce the boiling point of the coolant. This may result in electric cooling fans not operating on some vehicles,

•Switch ON all electrical items including Items such as a mobile phone, rear demister, driving lights, etc.

•Switch an analogue multi-meter to a scale of 5 volts DC or less. Ideally the meter should be capable of reading millivolts. Do not use a digital multi-meter, as its internal operating characteristics are not suitable for this test.

•Place the negative lead of the multi-meter on the battery negative post.

•Dip the positive lead into the coolant without touching the filler neck or the core of the radiator

•A reading of more than .05 volts indicates the presence of a potentially damaging stray current passing through the coolant. Ideally the voltage should be 0 volts, however it is highly possible that some voltage level will be detected

•If no voltage or a very low voltage is detected, carry out the same test as in point 4, but with the ignition OFF.

•If voltage is detected, isolate the circuit by turning all electrical items OFF and switching each circuit ON individually.


Caution:

Refilling a cooling system with coolant will itself generate a current that lasts approximately twelve hours.
This can be avoided by refilling a repaired vehicle, for example, with clean water and then proceeding to test for stray current.

[steptoe]

Some really good authors above - keep it up

My recent experience both with 1987 subes, both stamped by sube service for much of their lives - their metal pipes are at either end of the scale. It may be stray current or maybe just 24 years and not the best coolant upkeep the main cause of the pipes rusting.

Will come back when engine is back together and in, runnng etc and check for stray current. Also have castrol coolant test strips like the ones the doc checks yer urine against .

[discopotato03]

I think the issue Jonno is getting at is the steel barbs pressed into manifolds heads etc and steel water transfer tubes .
A lot of it is probably the pure age of these cars - from the middle 1980s to the present for those still around .
I think the best idea is to replace these things where necessary and if possible with more commonly available materials . As I said to Jonno elsewhere I wouldn't wait for short bits of rubber hose or steel pipe to come expensively from the US or Japan . I'd get someone whos used to this kind of thing to make stuff up to do the same job .
No way I'd get that over engine steel pipe genuine , I'd just run a length of heater hose along the same path making sure nothing is likely to piece or abrade through it . If the territory is rugged slit another piece of hose and lightly cable tie it over the hose like a protective jacket . Things like this can be treated like a consumable part and replaced every year or so if need be .
The smaller water hoses are easy to examine regularly and replaced pronto if they harden up or fray at the ends . I wouldn't reuse any made up generic hose even if it was ok because the clamps compress the ends and thats where splits can form .

A big thing with a fully featured EA82 (EFI/Turbo/AC/Pwr Steer) is being able to see and get at everything to fault find "cardboard" hoses and paper thin steel tubes . If you were aware of the usual culprits you can get the compressor and bracket off to renew things but you can't see the beginnings of leaks unless constantly looking at temperatures and dark spots on the ground .
When my mongrel lower turbo water line sprung a leak it was pure luck that I'd backed around into a side street here and noticed the telltale trail of tiny drops in the street lighting as I walked away from it . Had it been raining ... well who knows . That repair put Ellie off the road for nearly a week and involved a lot of work pulling the turbocharger and downpipe . I struggled for half a day just getting the std lower hose off with the turbo still on pretty much knowing I'd never get it back together even if it was the shielded hose and I could get hold of one . Of course it was the steel line itself that had rusted through in a couple of places too close to the bend to just advance a new hose up a bit and reclamp . No room to work under the turbo let alone get a screwdriver in there to srcew up clamps . Of course the twenty something yr old originals were those wire band ones and buggered anyway .
THIS is why I implore Jonno you pull the turbo out and use the lower steel line off an early RS Libs VF turbo . Same sized banjo and bolt but the newer steel tube extends out from under the turbo where you can run a piece of EFI fuel hose to link the system up to the steel hose rising from the turbo side head . Then you can get at EVERYTHING meaning the new hose and both clamps and the steel line near the turbo copes easily with the localised turbo heat . Damned if I know why Fooey Heavy Industries didn't do it like this .

Jonno do it once and do it properly and remain vigilant , its the only way .

A .

[El_Freddo]

If the engine has sat dry for any period of time this isn't going to help things either

Loved the essay Disco - I miss them!

Cheers

Bennie