Technical Punto 90 1.6 Overheating after new HG

Currently reading:
Technical Punto 90 1.6 Overheating after new HG

chesh

Established member
Joined
Dec 19, 2007
Messages
407
Points
206
Renewed my head gasket + 4 valves after timing belt snapped off.
Filled water, done air bleed by opening the 2 radiator and heating valves.
after water came out, closed them, and let the car run with radiator cap off.

https://www.youtube.com/watch?v=DIVWHRxji6o

Fan kicks in at half of temp, all hoses are hot.
Fan still kicks in every 30 seconds or so, but car is overheating to max.

I've done a test with crank sensor out,
filled the radiator with water, and cranked the engine.
I can see water is going in and not jumping out. does that say the HG is fine?
 
Have you tried it with the cap on?

Water boils at around 100 degrees. If the system is pressurised, this raises the boiling point. So the cap seals the system, with a valve in it to limit the pressure. With the cap off, the boiling point will be too low for the system, allowing it to boil at the hottest parts of the engine. That boiling is showing at the filler as bubbling.

Put the cap on and then see.

On the 1.1/1.2, the head gasket is coated with a sealant. The gasket is supplied in a sealed bag, and should only be opened just before fitting, fitted immediately, and the head placed on and torqued down. If the gasket is left out in the air for long, the sealant starts to harden, and will not seal as designed. It is likely that the 1.6 uses the same sealant. If you have taken the gasket out of its sealed packet some time before fitting it, it may not seal properly, and you'll need to do it again.
 
Head gasket is coated with sealant and was closed with sealed bag before I took it out.
I've installed it immediately.

When cap was off, and after 2 cycles of fan kicks in, I closed the rad cap.
Then the fan no longer started and engine overheat.

The next time I've done it like in the video, fan kicks in every 30 sec but water jumps out like that even the cap is closed.

------
I've contacted a friend and he said I should bleed the rap valve FIRST when the heater valve is still in the hose.

What I did was, I opened both of the caps, then filled water, then closed the rad first, then closed the heater one when I saw water is coming from it.

Do I need to leave the heater valve one closed when I do the rad cap first?
 

Attachments

  • 20200731_180944.jpg
    20200731_180944.jpg
    4.1 MB · Views: 34
With the rads with the integral tank, they can be a bit troublesome to bleed.

There are numerous threads about it, you'll need to do a search. I think it is possible for the rad to not be full, even when the tank appears to be full.

Problem appears to be air in system, so once bled properly it should be fine.
 
Ok!
I've bleed the air system twice and no luck,
Then when temp was half and the thermostat opened,
I slightly opened the heater air bleed valve when the car was running, air came out.
then filled coolant again, and bubbles came out for 10-20 seconds.

Then fan kicked in, closed the radiator cap and everything is ok!
 
Well
Car is still overheating...
It reached half, fan kicked in couple of times then overheated.
I connected the fan without the unit so it's always working. And still overheat to max.

What could be wrong when the rad fan is always on and still overheats?
 
Yes
Water is boiling in the coolant tank,
Its not wrong gauge reading
 
On the 1.2 the gasket directional issue restricts oil flow to the camshaft. Never seen a 1.6 block. Most waterways are somewhat similar on opposite sides, so I'd expect some flow.

When ticking over, heat produced is unlikely to be affected to any noticeable amount by incorrect timing, so this must be a coolant circulation problem.

There is either still air in the system preventing proper circulation, or the coolant is not circulating. Could be water pump or thermostat. Pumps with plastic impellers have been known for their impellers to let go of the shaft, so not turn much. Stat could be stuck, so should be removed to test.

Yes
Water is boiling in the coolant tank,
Its not wrong gauge reading

Any boiling will always appear in the tank, as that is where it has space to be seen boiling, and where pressure can be vented. If it boils inside the head, and it is hotter there, it cannot be seen, but this will push pressure out to the tank. The radiators with the integral tank can appear full when in fact not. There are threads describing filling procedures and tricks, mostly Punto, but might also be in Panda section.

First job, test the stat.

If ok, try bleeding and rebleeding as it heats up, especially just after the stat opens.

Is the heater getting hot? It should start to get warm very soon after a cold start, which could be a good measure of the pump working, or not.
 
I solved the problem today,
When I let the car run until fan kicked in, I did that with open rad cap.
Too much coolant came out of it, I believe it lost around 500ml or 1 ltr when the cap was open.

I then turned off the engine when hot, filled coolant until top of the rad,
opened the heater valve until coolant came out of it.
then CLOSED the cap and started the engine,
then no longer overheat.

I Don't know why this time it didn't work but I always waited for the fan kicked it with open cap.
In this case, it spilled too much coolant before fan kicked in.
 
Back
Top