Coolant and heating issues

[nd-photo.nl]

My cap was weak when I tested it, when I was fault finding ultimayle having matrix issues - it leaked at around 10-12psi from memory vs the rated 24psi.


This blue circle is the overflow - If the system over pressurises and the cap vents, any coolant should vent out this spout. I would see a puddle of coolant on the metal work below this spout.

View attachment 50811

This was exactly why I thought of the coolant cap

 

[Compo1]

this is kind of where i go with it. i think i will do the full drain and flush, change the cam belt and pump and do the egr cooler at the same time.

i checked the pipes as you said and one gets warm quickly and the other warmer slowly.. its a hard one to test as 3 of the 4 heaters on the front are nice and warm. its just that far one! i believe its relatively easy to get at so might park this one for now and see if the flush does anything for now.

its the cooler thats the costly part as the other items dont help with exhaust gasses in the system. apparently the egr coolers on this model are quite common!

The Charge cooler is also a common problem on these.

If this was my car as the one martix pipe is only getting warm slowly I'd go about it like this, although id be doing it myself.

Power flush the whole system disconnecting pipes as i went as described earlier.

Heater Matrix swapped out.

Bypass the charge cooler, really easy to do to rule that out. Or Bore scope

And only then would a look towards the EGR cooler. It could well be that but thats an expensive job unlike diagnosing the charge cooler. Any garage should have a bore scope to look for water in there.

 

[OVB]

The Charge cooler is also a common problem on these.

If this was my car as the one martix pipe is only getting warm slowly I'd go about it like this, although id be doing it myself.

Power flush the whole system disconnecting pipes as i went as described earlier.

Heater Matrix swapped out.

Bypass the charge cooler, really easy to do to rule that out. Or Bore scope

And only then would a look towards the EGR cooler. It could well be that but thats an expensive job unlike diagnosing the charge cooler. Any garage should have a bore scope to look for water in there.

Yes I agree it's not the cheapest one to do however the issue still remains the exhaust gasses. From my understanding the charger will never mix to cause gasses in the coolant. The only 2 that can do this is the head gasket and EGR cooler from my understanding?

 

[Compo1]

Yes I agree it's not the cheapest one to do however the issue still remains the exhaust gasses. From my understanding the charger will never mix to cause gasses in the coolant. The only 2 that can do this is the head gasket and EGR cooler from my understanding?

The EGR valve sends a small amount of exhaust gases back through the intake manifold/charge cooler.

 

[OVB]

The EGR valve sends a small amount of exhaust gases back through the intake manifold/charge cooler.

You saying it could be the charge cooler? I thought only sees boost pressure, not exhaust gases so cannot cause combustion-gas contamination in coolant from the charge cooler?

 

[GlekkeMatrak]

Hi everyone! Seems like this is the thread I need for my issue. I've ran into the "loss of heating" issue last week. It seemed to be rather suddenly to me, although I hadn't driven the car for over a week during the new years' break. I only get some heat still, when I keep the engine in the higher rev range (2500RPM+) and the blower speed rather low. I've disconnected the heater matrix hoses from the engine bay, and gave it a flush. I must say I do get flow in both directions. I've refilled with fresh coolant and reconnected everything. Topped up the expansion tank (which is one without silicate, + I have the 1.4TSI so no regen). I still get the same symptoms. I can clearly hear a change in air velocity when I switch from high heat to cooling; which lets me think flaps are still switching around as well. Could this still be attributed to a somewhat blocked heater core?

 

[Compo1]

Hi everyone! Seems like this is the thread I need for my issue. I've ran into the "loss of heating" issue last week. It seemed to be rather suddenly to me, although I hadn't driven the car for over a week during the new years' break. I only get some heat still, when I keep the engine in the higher rev range (2500RPM+) and the blower speed rather low. I've disconnected the heater matrix hoses from the engine bay, and gave it a flush. I must say I do get flow in both directions. I've refilled with fresh coolant and reconnected everything. Topped up the expansion tank (which is one without silicate, + I have the 1.4TSI so no regen). I still get the same symptoms. I can clearly hear a change in air velocity when I switch from high heat to cooling; which lets me think flaps are still switching around as well. Could this still be attributed to a somewhat blocked heater core?

It could you carnt flush them properly, and you can still be 90% blocked and have flow.

Check the temp difference between the top and bottom pipes on the heater matrix itself after removing the kick panel in the passenger footwell.

Anything more the a 10 degrees difference, its blocked or partially blocked.

 

[SuperV8]

Hi everyone! Seems like this is the thread I need for my issue. I've ran into the "loss of heating" issue last week. It seemed to be rather suddenly to me, although I hadn't driven the car for over a week during the new years' break. I only get some heat still, when I keep the engine in the higher rev range (2500RPM+) and the blower speed rather low. I've disconnected the heater matrix hoses from the engine bay, and gave it a flush. I must say I do get flow in both directions. I've refilled with fresh coolant and reconnected everything. Topped up the expansion tank (which is one without silicate, + I have the 1.4TSI so no regen). I still get the same symptoms. I can clearly hear a change in air velocity when I switch from high heat to cooling; which lets me think flaps are still switching around as well. Could this still be attributed to a somewhat blocked heater core?

I flushed my matrix out something like 4 or 5 times.
I found my hose pipe adapter + oring fit nicely so I could flush it through with nice high pressure water, and I also vibrated it with a multi tool.

I lot of the 'detritus' I flushed out looked like very fine flakes - I think these over time build up and coat the inner surface of the heat exchanger, so restrict the heat transfer capability - as well as restricting flow.
I hoped that each flush would last longer before needing to do it again (every 6 months) to eventually 'clear out the system!' but it never did, was only ever temporary!
A new heater matrix fixed it and it has been great since (4 years ago)
Easy to DIY the matrix - it slides out from the side of the dash.

 

[GlekkeMatrak]

It could you carnt flush them properly, and you can still be 90% blocked and have flow.

Check the temp difference between the top and bottom pipes on the heater matrix itself after removing the kick panel in the passenger footwell.

Anything more the a 10 degrees difference, its blocked or partially blocked.

Just checked it from inside the car and it's clear. Bottom pipe untouchably hot. Top pipe lukewarm. Blower on medium speed. Just ordered the Nissens part and will sort it out when I have the time. Thanks!