S54 Head gasket coolant leaks?

[ac427]

Is the head gasket ever the culprit for coolant leaks ?

Has anyone used leak detection dye with the cooling system with good results?

[Tbonem3]

Usually our HG issues are between cyl and you'll get worse leak down/comp #s, not oil in water or vice versa.

[sapote]

Is the head gasket ever the culprit for coolant leaks ?

Has anyone used leak detection dye with the cooling system with good results?

What symptom do you have? radiator hose too hard when squeeze?

[ac427]

What symptom do you have? radiator too hard when squeeze?

A month ago, i found a slight leak where a rubber hose from the heater matrix connects to the end of the black painted metal pipe that runs below the main cast return pipe.

I replaced the hose and pressure tested the system to two bar. It seemed to hold pressure and i couldn't see any leaks. The expansion tank is new (a year or two old) and looks clear of any pale blue coolant spatter.

I have an ongoing rough idle issue when the car is cold so the car has not been used for a few weeks. I started it up, it ran with a rough idle but the low coolant light illuminated on the dashboard cluster. So i turned it off and topped up the coolant.


"Radiator too hard to squeeze?" Is this a specific test, not sure what you mean. Something to do with the plastic ends on the radiator?

[ac427]

Usually our HG issues are between cyl and you'll get worse leak down/comp #s, not oil in water or vice versa.

Thanks, that's what i thought. I had a pressure test done earlier this year and was pretty good and more to the point, even across all six cylinders. I'll see about getting a leak down test done.

[sapote]

"Radiator too hard to squeeze?" Is this a specific test, not sure what you mean. Something to do with the plastic ends on the radiator?

My bad. I meant radiator hose. If hard then this means combustion gas entered the coolant.

[sapote]

I replaced the hose and pressure tested the system to two bar. It seemed to hold pressure and i couldn't see any leaks.
I started it up, it ran with a rough idle but the low coolant light illuminated on the dashboard cluster. So i turned it off and topped up the coolant.

No external leak, but low coolant light turned on in a short period, and rough cold idling. I would take a 30 minutes drive to get to operating temp, park overnight. Next cold morning, remove each spark plug and look carefully for condensation on plug tip. Yes means coolant leaked into chambers.

[ac427]

A week or so back whilst playing with DIS. I found a screen that showed misfires per cylinder. Cylinders 1, 3, 4 and 6 had zero misfires, cylinder 5 had 1 but cylinder 2 had 76. Strange because INPA always reported the issue to be with cylinder 1.

I thought it would be a good idea to swap the existing injectors around to see if the fault moved. So out with the fuel pump fuse and spin the engine over.

As i removed the fuel rail quite a bit of fuel came out as injector 2 was free from the fuel rail. I have replaced the injectors a long time back and not seen this amount of fuel. Anyway, i swapped injectors 1 and 2 with injectors 3 and 4.


Once i got everything back together i started the car and the idle was smooth. This was great and depressing at the same time, because i was expecting the fault to move.

Could there be some sort of fuel/airlock in the fuel supply?

Hopefully the coolant isn't in the cylinders but i wll check that and the radiator pipe squeeze test once the weather is drier.