Technical Super Coolant Flush

[Keepthe12alive]

Hello panda-maniacs!
Hope you are well and having a wonderful weekend so far!

Reaching out to document my attempt to SUPER flush my cooling system.

The previous owner of my 2011 1.2 petrol 169 Panda only ran the cooling system on JUST water, which resulted in a core plug failure, a water pump failure, and ultimately a head gasket failure within a month after I got it (mind, it only turned 45k miles the other day).

I’ve since changed the coolant twice and done a “flush” (didn’t do it the best, and didn’t have everything ready at once when I did it), but really want to make sure I’ve given the system as clean a bill of health as I can, and the timing seems right as I think my thermostat is bad (won’t heat to operating temperature unless slow or idling, and the system has been bled and the heat is relatively warm inside).



Additionally, the bigger faults about have since been repaired, and the history of that is well documented on this thread here: https://www.fiatforum.com/threads/head-gasket-blown-balancing-options-little-money.509978/

Another shout out to this amazing community which really saved me, as I absolutely could not afford to get another car. It really was do or die. Thank you.

 

[Keepthe12alive]

My SUPER flush plan—

I am taking inspiration from ChrisFix, specifically this video here:

Basically,
1. I want to add a flush cleaner to the existing coolant to clean it while I run the car for a while

2. I want to drain the old coolant+cleaner

3. I want to use a Prestone flush bottle + water to refill the the cooling system and then run the car for a little while

4. I will drain the Prestone flush+water

5. I will continue to fill, run, and flush the cooling system with water until the water comes out almost clear.

6. Then I will replace the old thermostat with the new, and then add the new Prestone all-engine OAT ready-mix coolant

7. Then I will bleed the air from the system as Fiat tells me to from the Haynes and the elearning links


————————————————————

I have the following items ready:
- Holts quick flush cleaning additive (I can add it to existing coolant and run the car for a little while)

- Prestone Radiator Flush (requires removing the old coolant, then dumping whole bottle in + water, then running the car a little bit)

- Prestone universal coolant (Organic Acid Technology, OAT)

- My new Febi thermostat: https://amzn.eu/d/cTvUo30

 

[Keepthe12alive]

My remaining question is this:

What water should I use?

The video above advises only distilled water, but then I have seen others advise only de-ionized water, and the Prestone flush bottle only says “water” on the back label instructions

 

[Keepthe12alive]

Additionally, if something about this super flush plan is bad or unadvisable, I would love to know!

 

[jrkitching]

What water should I use

If you have a dehumidifier, use the condensate from that. Just run it through a filter paper in a funnel to pull out any trapped dust.

The melt water when defrosting the freezer is almost as good.

Unlss you live in a very hard water area, you can get away with tap water. Boiling it first will precipitate out some, but not all, the hardness.

 

[Keepthe12alive]

If you have a dehumidifier, use the condensate from that. Just run it through a filter paper in a funnel to pull out any trapped dust.

The melt water when defrosting the freezer is almost as good.

Unlss you live in a very hard water area, you can get away with tap water. Boiling it first will precipitate out some, but not all, the hardness.

If I boil the water in the kettle, should I filter it?

 

[Keepthe12alive]

Thankfully, I live in a soft water area according to a post code checker

 

[jrkitching]

If I boil the water in the kettle, should I filter it?

Depends how much scale you've got it it. Does your kettle naturally tend to fur up? You could always just leave it in a jug to settle any sediment and pour the upper part off carefully.

Running it through a folded sheet of kitchen towel in a funnel will pull out any dust and solids.

 

[Keepthe12alive]

Depends how much scale you've got it it. Does your kettle naturally tend to fur up? You could always just leave it in a jug to settle any sediment and pour the upper part off carefully.

Running it through a folded sheet of kitchen towel in a funnel will pull out any dust and solids.

By the way, is de-ionized bad?

 

[Keepthe12alive]

By the way, is de-ionized bad?

Because I know I can pick that up from asda for cheap

 

[jrkitching]

Because I know I can pick that up from asda for cheap

ASDA deionised water will do just fine.

Don't overthink this; any type of clean water mixed with the right percentage of coolant will work, and it won't harm your engine.

It's the folks who use a plastic bottle they found at the side of the road to pour whatever they could find in the bottom of a ditch into an overheated engine that I'd be more concerned about.

 

[Keepthe12alive]

ASDA deionised water will do just fine.

Don't overthink this; any type of clean water mixed with the right percentage of coolant will work, and it won't harm your engine.

It's the folks who use a plastic bottle they found at the side of the road to pour whatever they could find in the bottom of a ditch into an overheated engine that I'd be more concerned about.

Thank you so much — and just to be clear my final coolant is ready mixed, so I don’t have to worry about water for that

Just the water that I use for radiator flushing

 

[koalar]

deionised in this situation is just as good as distilled

 

[koalar]

Remember when you disconnect the bottom hose

There's still roughly 1L left in the system

Not something that concerns most people in the UK as we don't go that cold

 

[Keepthe12alive]

Remember when you disconnect the bottom hose

There's still roughly 1L left in the system

Not something that concerns most people in the UK as we don't go that cold

If there’s still a litre left when I disconnect the bottom hose, won’t that be a problem if it’s just a litre of deionised water left there?

Like, that would throw the 50/50 coolant and water ratio, right?

is there any way to completely drain it?

 

[Keepthe12alive]

Remember when you disconnect the bottom hose

There's still roughly 1L left in the system

Not something that concerns most people in the UK as we don't go that cold

The online manual says to wait till it’s completely empty — is there a way to get it that way?

 

[koalar]

Nope

Some is always left in the block water jackets heater matrix and so on

If you use concentrate you can just put the calculated amount in first a top it off

Otherwise just live with it a bit weaker

It's no big deal

 

[Keepthe12alive]

Nope

Some is always left in the block water jackets heater matrix and so on

If you use concentrate you can just put the calculated amount in first a top it off

Otherwise just live with it a bit weaker

It's no big deal

Also, when I replace the thermostat, should I use any sealant or anything?

I can’t see anything in the Haynes or the online manual about it

 

[koalar]

No sealant needed, should come with a new gasket

There's at least three variation of the latter thermostats


Original has a black plastic spigot arrow below

Some third party use metal screw in spigot or cast in one price as below

The black plastic is a common failure point, so the all metal ones are preferred, again no big deal takes over 10 years to fail

 

[Keepthe12alive]

Sorry for how long it’s been!

Anyone know how to get the right replacements for these thermostat bolts?

(Stole koalar’s pic from HG repair thread)