Technical Black coolant

[Umitbat]

Hello
2016 1.4 lpg tipo has coolant that goes black
It started after a coolant change around 95.000km now 150.000. No oil loss.There is some Coolant loss from waste gate of coolant reservoir. We tried a new cap which was a cheap one it broke in a day which shows maybe pressure.
After changing coolant it goes black in a week.
Any ideas???

 

[StevenRB45]

Hello
2016 1.4 lpg tipo has coolant that goes black
It started after a coolant change around 95.000km now 150.000. No oil loss.There is some Coolant loss from waste gate of coolant reservoir. We tried a new cap which was a cheap one it broke in a day which shows maybe pressure.
After changing coolant it goes black in a week.
Any ideas???

I'd be getting a sniffer test and a compression test.

I think you've got combustion gases entering the coolant system via a probable head gasket leak which will be pressurising the system and the black tint is from exhaust.

It's likely a small leak that is getting worse as time goes on.

 

[Umitbat]

My catalysor was melted completely could it harm due to pressure before change?

 

[StevenRB45]

It's possible if the exhaust was blocked the back pressure increased and gases found a weak spot.

But in general I'd confirm if the head gasket is sound and go from there if the cat is sorted now.

 

[Umitbat]

No leaks on test interesting.They did it on idle no revving is it normal?

 

[StevenRB45]

How is the oil looking?

Combustion gases are one thing...oil is another both are kept out of the cylinders by the head gasket.

Although it pressurising the cooking system suggests exhaust over oil.

 

[Umitbat]

How is the oil looking?

Combustion gases are one thing...oil is another both are kept out of the cylinders by the head gasket.

Although it pressurising the cooking system suggests exhaust over oil.

Oil is always clean and no loss

 

[StevenRB45]

Erm, pass to me the symptoms are head gasket with the pressurisation of the system.

Hopefully someone will be along with a different idea...

 

[Umitbat]

Erm, pass to me the symptoms are head gasket with the pressurisation of the system.

Hopefully someone will be along with a different idea...

Yes looks like it but not tests like it. Is idle enough for test?

 

[StevenRB45]

Idle should be fine you're testing the coolant for combustion by products which would already be present not trying to break it.

 

[chris3234]

Do they know what caused the cat to melt
I'm guessing possibly the lpg running too rich?

 

[Umitbat]

I bought it second hand and it had an accident before maybe waited some time before I bought it. After buying I drove with benzin for a long time but I think it was melted already when I bought it.
Now we are looking after Lpg not to run rich.

 

[Umitbat]

No leaks on test interesting.They did it on idle no revving is it normal?

Can damaged hoses cause this black color?

 

[StevenRB45]

There's a possibility yes but it doesn't explain overpressure.

Unless of course the cheap radiator cap couldn't hold normal operating pressure and that symptom is a red herring.

 

[Umitbat]

There's a possibility yes but it doesn't explain overpressure.

Unless of course the cheap radiator cap couldn't hold normal operating pressure and that symptom is a

What else can cause pressure?

 

[StevenRB45]

You're looking at options of faulty radiator cap, head gasket or given you've changed the coolant recently I assume? Are we sure it's fully bled, if there's an air pocket that can lead to overpressure.

 

[Umitbat]

You're looking at options of faulty radiator cap, head gasket or given you've changed the coolant recently I assume? Are we sure it's fully bled, if there's an air pocket that can lead to overpressure.

We changed coolant 3-4 times in last year and mechanics did them and cooler fan vs looks fine. We even cleaned coolant tank to see exact results

 

[StevenRB45]

To be honest, the chances of me guessing correctly something via the internet having never seen the car that mechanics who've seen the car multiple times and likely done several diagnostic tests haven't thought of in that time is pretty slim.

All I can say I think is good luck.

 

[aschiuta]

We changed coolant 3-4 times in last year and mechanics did them and cooler fan vs looks fine. We even cleaned coolant tank to see exact results

Antifreeze coolant flow also through lpg regulator assembly and probably from others lpg components.
So , go to the service to disconnect all of lpg componets where the coolant flow, then wash all coolant circuit, then replace with fresh coolant and run few weeks only on gasoline. May be there is problem.

 

[Umitbat]

Antifreeze coolant flow also through lpg regulator assembly and probably from others lpg components.
So , go to the service to disconnect all of lpg componets where the coolant flow, then wash all coolant circuit, then replace with fresh coolant and run few weeks only on gasoline. May be there is problem.

Thanks
How can lpg make coolant black?