Stray Voltage/Current in the coolant water

[steveo Junior Member Find all posts View Profile Close steveo]

I was waiting at a Toyota dealer for them to replace a faulty reversing sensor when I noticed that the mechanic had a probe of a multimeter in the water of my radiator. Realising what he was doing (looking for excessive current/Voltage in the coolant) I asked him if the level was ok, he advised me that toyota had revised the acceptable level down to 0.4 Volts.

So heads up guys, with all your equipment on and transmitters transmitting the new level applies.

[speedcomm Senior Member Find all posts View Profile Close speedcomm]

Whattha ?

[steveo Junior Member Find all posts View Profile Close steveo]

Your alternator/engine is using your coolant to complete the earth return from the chassis which your electrical accessories use as the negative conductor to the negative engine block.

The maximum voltage allowed is 0.4V betwwen the engine block and the coolant, and from the coolant to the chassis.

If your measure value is greaater than 0.4 volts you need to review your negative conductor/chassis bonding.

The report effects of elivated levels are:

Excessive corrosion of the cooling system
Damage to the life and efficiency of the coolant

[Chippy Addicted PP Member Find all posts View Profile Close Chippy]

Hey Steveo

I had never thought about this, but is it because of the high alloy content in engines these days and the lower conductivity of alloy compared to the old cast iron blocks ??

Cheers
Chippy

[jeff s Avid PP Poster! Find all posts View Profile Close jeff s]

Hi Chippy.

the problem has allways been there.
Its just people know about it now, Or more people know about it now.
And radiator supplier would know it back to front.
After I bought a radiator for my Hilux a few years back there was a information booklet strapped to it.
The voltage was needed to be recorded and sent to the manufacturer of the radiator before any warranty period would be accepted.

Aparently that stay voltage (electrolisis) eats engines and radiators for lunch.
And yes, The newer alloy engines are effected more.

Go into a NatRad store and they can give you the pamphlet as thats were I got it from.

Jeff.