Cooling system flush - white jelly like substance!!

[MisterT]

After my recent overheating and leaking coolant escapades I got around today to taking out the rad to flush it out and have the leak repaired, to put it simply the core was stuffed and the fins shagged so Ive taken it to Serck in Peterborough for a recore.

Whilst removing the rad I noticed a whitish gel like substance in some of the waterways a bit like thick wallpaper paste, so Ive now taken off the thermostat housing and the water pump and there are further deposits of this stuff ranging in size from a small pea up to lumps the size of a thumb nail. (No wonder the rad was blocked!). Ive never come across anything quite like this before, so to my questions;

1 Has anyone else experienced this and if so what is it caused by? Is it something peculiar to alloy engines?

2 Could it be some kind of leak sealer put in by a previous owner?

3 What is the best way (and the best flushing solution) to flush the cooling system waterways to be sure of removing the offending matter, having just opted for a new rad core i dont want to block it straight away with this stuff. (I have dreaded visions of having to half dismantle the engine to wash this stuff out!) I also have the problem of how to flush the heater matrix cos I'll bet theres some in there too!

I should add that the engine has only 25k miles on it and in my ownership at least (last 6-7k miles) its always had approaching 50% antifreeze. It was maintained by TMS before I had the car so I assume it has had the correct attention!

[V8 GRF]

If you'd describe it a being like an 'emulsion' then I'd suspect oil and water mixing i.e. a head gasket problem.
The other suspect is 'Radweld' or simiar. The first can be expensive, the second less so i.e. small leak but sorted but might be masking another problem like a big leak.If I had a leaking Rad I'd change it.

[rev-erend]

Rather that try to figure that out - I would suggust you do a power flush with a hose pipe to get all that stuff out of the rad and engine..

[MisterT]

V8 GRF said:

If you'd describe it a being like an 'emulsion' then I'd suspect oil and water mixing i.e. a head gasket problem.

Definitely not oil/water emulsion, the oil is clean and if you look inside the rocker cover the surfaces are all like a new engine. There are no oily signs in the water I drained off either.

rev-erend said:

I would suggust you do a power flush with a hose pipe to get all that stuff out of the rad and engine..

Unfortunately this stuff sticks quite stubbornly to the inner surfaces of the water ways and the force of a hose isnt enough to shift it, thats why I have sent the rad for a new core.

I've spoken to Ray at V8Developments this morning and he thinks it could be some kind of sealer perhaps to hide a cracked block, and the only sure way to deal with it is to dismantle and clean out the components (apparently they have an acid dipping bath for cleaning ally components) and pressure test the block! Oh well looks like bread and water for the next month (or two!!)

Thanks for replies
Mike

[That Daddy]

I have seen this on late Renault,s a creamy sludge just round the neck of the rad expansion bottle(no not head gasket)not lots just a teaspoons worth,i think it may have something to do with the pink coolant they are now using,i have seen enough of them with this to say i think it is a by product of the coolants chemical/makeup, just trying to make a suggestion this may be your problem, if it is its not a worry.

[GreenV8S]

If it won't shift with flushing then you could take a view that it probably won't shift in use? After all, it's stayed where it is in a high flow area long enough for you to notice it, rather than get washed along and settle out in a dead spot.

You could take a sample and see whether it can be disolved in any commonly available detergents/soaps? If so, it would be possible (with a little work) to bypass the rad with an electric pump and just leave it gently sloshing round for a few hours and then flush it. Bit of a faff but a heck of a lot quicker/cheaper/easier than stripping the block. Bear in mind if it was put in to cure a leak then by stripping it out chemically you are likely to reintroduce the leak.