Rust in the block

[Ranga]

I seems I need to replace a front welch plug in the 300Tdi, despite it only being about 50,000km since the last one (is this too soon?). At least it's easy to get too, but I will be checking the others when I get a chance.

I suspect their may be rust inside the block. If so, what's the best remedy?

[slug_burner]

Keep good coolant in good condition by checking the pH and changing as required.

[Toxic_Avenger]

get a power flush of the block, replace welsh plug, and then use proper coolant as suggested.
How do you know there is rust in the block?

[Ranga]

get a power flush of the block, replace welsh plug, and then use proper coolant as suggested.
How do you know there is rust in the block?

Just an assumption given this is the second plug in about 50,000km

[gromit]

I'm guessing it was a different plug to the one you changed before ?
If so it's a sign that someone hasn't replaced the coolant at the correct interval or maybe hasn't used a corrosion inhibitor at all in the past.

With anti-freeze anti-boil you must mix at the suggested ratio otherwise you do not get full corrosion resistance. The same goes for corrosion inhibitor. You also need to change at the correct interval which is 2/3 years for traditional type coolants (IAT) and longer with OAT, HOAT etc. Check the brand you used for more details.

I've seen pictures on AULRO of cylinder heads where the aluminium has corroded in the waterways.
The block being cast iron will rust but should be OK. The core plugs/Welch plugs being thinner will rust out first.

I keep a log of when things like coolant was changed (too many vehicles to remember all of them) and I need to do my Defender & Series I in the very near future.


Colin