Coolant system pressure "vs" gagging at high rotation

Hello,

Some time ago, when I was driving my 2000 110 TD5 SW, with 180.000 KM, for a few instants it suddenly lost power.

It happened a second time and this time I was able to see the temperature gauge going, momentarily, to the red.

When I stopped I found out there was, more or less, 1 liter missing from the coolant expansion.

(I don’t know if this quantity was enough to justify the overheating)

After refilling, everything seemed normal but when I stopped there was water leaking from the back of the head - Plug Core 37D2260L.

(2 photos)

After replacing and checking the coolant level, I went for a short ride.

At high rotation there was some gagging.

After stopping I took the coolant expansion cap off.

(2 videos)

TD5 1 - YouTube

TD5 2 - YouTube

There was a lot pressure inside and the water rose to the opening level.

I don’t know which should be the correct pressure value inside the coolant system, but I tested it for exhaust gas and the result was negative.

(1 video)

TD5 3 - YouTube

I’m not convinced everything is OK, the gagging at high rotation is still there and the coolant system is always with a lot of pressure in.

Can someone help?

Thanks in advanced.

Frederico

the system must work at 1.4 bar otherwise it overheats, first thing put a new tank cap cos if the valve it's blocked open or closed you'll get this symptom

1. if it's not tightened enough or not keeping the pressure in the coolant starts to make small bubbles above 90*C and it will presurise(=overheat) as then the boiling point of water is around 100*C according to the ambient pressure, that's why it's made to keep 1.4 bar in the system cos there the boiling point goes up to 125*C

2. if it doesnt open when it should and the pressure goes above 1.4 bar the temperature will rise too due to the pressure (thermodinamics law P/T= constant all the time)

so put a new genuine/OE cap and tighten it well to rule this out...and bleed it properly with the tank lifted above the bleed hole... if no joy there is a crack in the head somewhere ...sniff test on Td5 is not always relevant

Here goes a photo from the water pump.

The blades were completely rusted away.

I just hope the overheating didn’t damage the head gasket!

I will keep you informed.

Frederico

Looking to the elbow, the antifreeze also wasn’t any good!

Frederico

that was a neglected car filled with more water than proper coolant mix.... if you want a well maintained cooling system ALWAYS(regardless of season) use 50/50 mix of DISTILLED water with OAT... the OAT is not just antifreeze, it's there for anticorrosion and lubrication too....and 'lifts' the boiling point due to it's density