The V8 Owners Forum -

Isn't anti-corrosion one of the main jobs the coolant has to do

Have any other steel parts suffered the same?
Do you have an inlet manifold/heater take off? that's steel on my GEMS engine. Could check to see if it is as corroded as badly your core plugs?
Maybe you could do a test with some of your antifreeze in a bowl and drop in some steel parts to see if they corrode?
Could this be down to electrolysis? maye part of the core plug was uncoated and in direct contact with the aluminium block?

Tom.

It is all a bit mysterious.

I am going to switch to Ethylene Glycol based antifreeze, brass core-plugs, and use Permatex core plug adhesive.

I replaced one a month ago with black silicone as a sealant and it was very slightly leaking. So I hope that the Permatex will seal it as that is what it is designed for.

Chris.

stevieturbo wrote:It does look like plain and simple corrosion...

Either the part was damaged during fitting, or they're crap quality parts and the plating has come off allowing it to corrode ?


Could anti-freeze really cause such corrosion ?

Given that warranty sticker etc on the plug...I'd be asking the builder of why they think it's happening with their parts ?

Nothing wrong with OAT coolants I have used Quantum 5 year in many RV8's and when I built mine after using the stuff for 9 years I should have left the core plugs alone they had almost zero corrosion and the block is 95 if OAT dissolves steel I would see a lot of modern cars with dissolved water pump impellers I dont and I am on the tools, lots of scare mongering with OAT based coolants I have seen no proof including so called attacking brass and solder etc just my hands on experience chaps

stevieturbo wrote:Given that warranty sticker etc on the plug...I'd be asking the builder of why they think it's happening with their parts ?

I'd start there, too.

Engine builder says "Most probable cause is electrolysis and/or corrosive coolant. If it was a core plug problem it would affect every engine we supply which clearly is not the case. "

Perhaps my coolant wasn't as effective as it looked.....

Chris.

Interesting problem.

Would aluminium core plugs work ?
Anyone ever seen them for sale ?

At one time, you only used antifreeze in the winter. Plain water the rest of the year. And core plugs were plated steel, then as now?
So trying to think what would make one corrode away quickly - other than the antifreeze?

DaveEFI wrote:At one time, you only used antifreeze in the winter. Plain water the rest of the year. And core plugs were plated steel, then as now?
So trying to think what would make one corrode away quickly - other than the antifreeze?

Some years back, I replaced the water pump on my P6 and was recommended a product that came in a 250ml bottle to add as anti corrosive. We don't freeze in Cape Town, so all I needed was anti corrosion protection.
Time and a half goes by and I start the old girl to move to another garage and the cooling system is almost dry.... Bring on the garden hose and water is pissing out the front of the engine.
The NEW pump had corroded off in less than a year, at the end of the rubber pipes, both inlet and outlet.
I was less than impressed with that episode, and the rubbish called Aquaclear PX!

People often fail to realise that coolant/antifreeze is the only thing lubricating the pump seal using just tap water or soft water alone is asking for trouble, I have also witnessed additives and cheap coolants that IMO have contributed to premature cooling system issues i.e corrosion hoses rotting from inside out etc, get what you pay for I reckon