Coolant red gunk

[bluegrommet]

I’ve been getting the low coolant warning light in my WG 2.7 CRD. When opening up the cap I see some gunk on the inside of the cap and the coolant looks pretty thick and gunky. It smells a bit funky. Reminds me of when I used chemiweld to get a few extra months of life out of my 94’ Honda accord after the head gasket went.

Is this normal? I’m the second owner of this car and I’m not sure what the previous mechanic put in it.

The WG does’t seem to be leaking coolant but the level is below the min cold line. I’m not sure what coolant to top this up with either (red, green, water?).

[OffroadSpike]

That looks nasty, it is not normal. I don't know about the fluid inside, but that brown gunk around the cap is an unhealthy dose of rust/leak sealer. The OEM coolant should look pinkish but pretty transparent and "watery", not thick at all.

How long since you bought it and how long since you are getting problems?

I would test for a gasket leak first, put a latex glove on the reservoir hole and see if it blows up. Are you having overheating problems? Bubbles in the coolant fluid? White smoke out the exhaust?

You could also bring it to a workshop so they can do a coolant system pressure check to diagnose a gasket leak.

Anyway, after you're found what the issue is, you need to clean the whole coolant circuit since that gunk may have partially blocked the radiator. Drive it with plain water through multiple heat cycles, drain through the bottom radiator hose and repeat. I succesfully cleaned mine using citric acid solution, more info here:

https://www.jeepforum.com/threads/overheating-engine-and-clogged-radiator-how-can-i-unclog-it.4478571/

[layback40]

You need to first flush all that gunk out of the system. Use a garden hose with good pressure/flow. Once you only have clean water, you can drain it out & fill it with coolant at the correct ratio. You may need to fill with water & run it a few times to get it clean. The heater hose is a good place to connect the hose while flushing.

[FARWEST]

Thats nasty....'could be' a mix of 'rusty cooling system' and block seal....'somebodies' either made a very large error in mixing 'odd' coolants AND a block seal....or.....just a block seal and old coolant.....would use a garden hose to flush it, run it, flush it, run it until ALL that crud was no longer evident and you can make an informed decision into what condition your engine is in...yuk !!!!

[Classic Boy]

Looks like the cooling system of a 1965 morris paddock bomb I once bashed around the farm.