Cooling system paraffin flush

[juliethotel]

I'm doing the head gasket on a zafira, it's had horrible oil ingress into the coolant, Completely full of thick emulsified oil. Lovely mayo.

Trying to think of the best way to get it all cleaned out. I don't think a couple of bottles of rad flush will cut it.

Anyone got any suggestions? I'm thinking of running paraffin around the system for a couple of minutes, struggling to think of any good reasons why this is a bad idea (sensors should be fine, shouldn't damage waterpump etc)

Is this a stupid idea?

I'll take all the hoses I can off and clean them manually but I'm gonna need some way of clearing the rad, heater matrix, block and thermostat via circulation.

[anonymous-user]

I have read about people putting a dishwasher tablet in the header tank and running that for a while. Never tried it myself though.

[GreenV8S]

I would suggest disconnecting the top and bottom hose and flushing as much of the contamination out of the heater, engine and rad as you can with a hosepipe, then circulate detergent with the stat out to clean up what's left. It'll never be perfectly clean and doesn't need to be.

[227bhp]

What are you going to flush the Paraffin out with, because it isn't water soluble?
Try reading the last radflush thread that was posted up a few days ago.

[stevieturbo]

Yes it is a stupid idea.

In extreme cases, really radiator, hoses etc should be replaced, especially hoses as they will have been harmed by the oil, especially if it was run for some time.

And usually oil ingress isnt head gasket, it's the oil cooler.


There was another similar thread recently, but on top of that, you can buy good water solubile engine degreaser from any good motor factors in gallon drums. It is very good at cleaning oily parts, so whilst a slightly unusual use for it....you could try filling the system with this for a short period ( literally a few minutes at most ) and then thoroughly flushing the system with water a few times.

And possibly repeat.

It is a messy situation, and there is no simple fix. But some sort of good detergent will be needed.

[Sardonicus]

Washing liquid works (for washing cloths, not cutlery) works superb dont drive it though when in place just let it run up to temp when the liquid really gets to work and any oil residues just comes out as brown cloudy water with no traces of oil , however make sure you wash out completely including a warm cycle with just plain water so you know any detergent/chemical traces are diluted to nothing, I speak from experience with this method when Rover K series head gasket issues were at their worst ( lots of oil in cooling system ) worked well on failed Modine style oil coolers on VAG stuff mainly too it also bleaches the expansion tank back to clear also a real bonus and your just left with a spotless coolant system with no damage to gaskets seals etc , specific commercial/trade products for this job I found just crap really and I tried a few I'm on the tools for a living so would not recommend something I would not use myself , PARAFFIN just dont seriously its oil based for starters

[anonymous-user]

Why do you care if there's a bit of oil in the coolant? The engine doesn't.


(what i'd do, is fill up with some plain water, drive round till thermostat opens, then drop that water out whilst it's hot. Repeat a few times if necessary, then fill up with water / glycol mix as required)

[Sardonicus]

Oil attacks coolant hoses quite rapidly IME you need oil residue gone from the system , it can also attack the rad core end tank o'ring/gaskets also on plastic rads, neither are oil resistant , a little I wouldn't fret but if you have globules or oily digits when dunked into the coolant you want rid

Edited by Sardonicus on Saturday 14th September 14:10

[stevieturbo]

Max_Torque said:

Why do you care if there's a bit of oil in the coolant? The engine doesn't.


(what i'd do, is fill up with some plain water, drive round till thermostat opens, then drop that water out whilst it's hot. Repeat a few times if necessary, then fill up with water / glycol mix as required)

Ever worked on one that's had a cooler failure and the entire system is literally full of black gunge ? it is an absolute mess.

There is no doubt it will impact the ability of the system to work, and longevity of any hoses

[anonymous-user]

stevieturbo said:

Max_Torque said:

Why do you care if there's a bit of oil in the coolant? The engine doesn't.


(what i'd do, is fill up with some plain water, drive round till thermostat opens, then drop that water out whilst it's hot. Repeat a few times if necessary, then fill up with water / glycol mix as required)

Ever worked on one that's had a cooler failure and the entire system is literally full of black gunge ? it is an absolute mess.

There is no doubt it will impact the ability of the system to work, and longevity of any hoses

Sure, you don't want gallons of oil splashing round the place, but a hose pipe through the eng and/or rad for 5 min has always worked for me.

[juliethotel]

Max_Torque said:

Why do you care if there's a bit of oil in the coolant? The engine doesn't.


(what i'd do, is fill up with some plain water, drive round till thermostat opens, then drop that water out whilst it's hot. Repeat a few times if necessary, then fill up with water / glycol mix as required)

Oh it's not just 'a bit' of oil in there.

Whoever pointed out that it'll be a pain to get all the paraffin out well done to you, I won't be doing that then. I was told it's best not to use anything which foams up i.e. washing up liquid as it causes air locks.

I think I'll pump hot water through the matrix and rad and then do as you suggest, fill it with water, run up to temp, drain, repeat until it looks clean.

[Penelope Stopit]

juliethotel said:

Oh it's not just 'a bit' of oil in there.

Whoever pointed out that it'll be a pain to get all the paraffin out well done to you, I won't be doing that then. I was told it's best not to use anything which foams up i.e. washing up liquid as it causes air locks.

I think I'll pump hot water through the matrix and rad and then do as you suggest, fill it with water, run up to temp, drain, repeat until it looks clean.

What?

Free advice from someone that knows the job inside out

You can't be serious

Sardonicus said:

Washing liquid works (for washing cloths, not cutlery) works superb dont drive it though when in place just let it run up to temp when the liquid really gets to work and any oil residues just comes out as brown cloudy water with no traces of oil , however make sure you wash out completely including a warm cycle with just plain water so you know any detergent/chemical traces are diluted to nothing, I speak from experience with this method when Rover K series head gasket issues were at their worst ( lots of oil in cooling system ) worked well on failed Modine style oil coolers on VAG stuff mainly too it also bleaches the expansion tank back to clear also a real bonus and your just left with a spotless coolant system with no damage to gaskets seals etc , specific commercial/trade products for this job I found just crap really and I tried a few I'm on the tools for a living so would not recommend something I would not use myself , PARAFFIN just dont seriously its oil based for starters

[Sardonicus]

juliethotel said:

Oh it's not just 'a bit' of oil in there.

Whoever pointed out that it'll be a pain to get all the paraffin out well done to you, I won't be doing that then. I was told it's best not to use anything which foams up i.e. washing up liquid as it causes air locks.

I think I'll pump hot water through the matrix and rad and then do as you suggest, fill it with water, run up to temp, drain, repeat until it looks clean.

Hence why I said what I said washing machine cloths /detergents/liquids dont foam it just breaks the oil down to a brown dark non oily solution , a few capfuls is all thats needed , it sounds ridiculous to the layman but it works and like I say no damage is possible and the solution flushed out after , it wasn't my idea but was passed onto me from a commercial tech who does far more work than I on failed engines/head gaskets etc I have used it for many years and also had good feedback form other people I have passed it on to , I would also pit this method against many so called bonafide products intended for this problem it just works

Edited by Sardonicus on Sunday 15th September 12:00

[wolf1]

Garage owner here. We use dishwasher tablets (cheap aldi ones). Stick four or five in the system and run it for a day or so. Drain and flush with hose and then run another batch through. Make sure the engine isn't hot when you flush the system out or you may cause problems cooling the block too rapidly. This should get rid of any residue from the coolant galleries and especially the insides of any rubber hoses as they swell and degrade from prolonged contact with oil. Header tank may need one last clean out after a while but that you can usually do off the car.

[stevieturbo]

This sort of thing is extremely good at removing oil etc, and is fully water soluble, so rinses clean very easily.

https://www.amazon.co.uk/CarPlan-Ecl005-Engine-Cle...

[stevieturbo]

Cheaper option from Screwfix. But I've never sued this, so cannot comment on it's abilities.

I have used the Carplan stuff before.

https://www.screwfix.com/p/no-nonsense-heavy-duty-...

[Sardonicus]

Many solutions posted up that I'm certain work well (not paraffin) oil slicks in coolant never a welcome sight in any case , Diesels are just nasty with their often far blacker oil