overheating checks

[wull]

i've got some checks that i'm going to do today to try and figure out exactly what is wrong with the punto but does anyone have any simple checks that i can do?

i don't have any tools at my house so it needs to be simple checks,i asked on a fiat forum which i joined a few years back and amazingly there is no replies......

any ideas would be greatly appreciated :thup:

 

[brendy]

Wull, there are several things that can cause overheating these are below but can be attributed to a couple of main faults, lack of water or circulation.

Water pump failure
Head gasket failure
Water pipe leak
Radiator leak/airlock.
Thermostat stuck.

Most of these problems are diagnosed with a drop in water level so first thing to check is if you are losing water. Does the header tank need topping up?

While driving does the car start over heating while sat still but starts to cool a little after it has been moving for a while (water levels again or possibly pump)

I am not familiar with the exact layout of the Punto engine bay, there will be two main pipes running into your radiator, one from the engine and the other too the engine, do they both get hot to touch when the car has been warmed up?

The horrible check is to open the engine oil filler cap, if there is an excess of white/brown gungy mayo looking stuff, it could spell head gasket failure.

Check these in the mean time.

 

[wull]

cheers for the reply dude....

one thing i can answer is it keeps getting hot whilst you drive and it's very quickly.much faster than normal.when i drove it though samantha had not long came back from some where so that might of contributed to it heating up quickly.

the top hose coming into the rad was warm which i think means the thermostat is opening....i'll double check this today because the checks will be from cold.

 

[bladeplayer]

As well as the list Brendy mentioned Just check & see if the cooling fan is kicking in aswell , if its not running when engine is hot , could be the temperature sender , a relay for the fan or the fan itself , if engine is running hot this should be running .. hope its something simple for you man ..

 

[wull]

right i went out and did a few checks.

there is no signs of leaks at the radiator or hoses.they seem to be in good condition and the clips are nice and tight.

the coolant level was a bit below min but this was due to me opening the cap after driving the car 2 days ago.i topped it back up to the max line.

i started the car with the cap still off and within no time the level was rising,i checked the temop in the car and it was satrting to budge.awfully quick considering the car is stone cold and the temperature outside must be close to freezing.when the coolant level got close to the top of the filler neck i opened up the 2 bleed screws and the level dropped.

i then checked the temp gauge and it was close to 1/4(usualy is 1/2)and the blowers were blowing cold air.the coolant level was rising once again and when it was at the top again i did the same.this time the temp gauge was near the halfway mark and the blowers were blowing warm air,not hot but warm.it soon went cold again and the coolant level was coming up once again.

i then revved the car a bit and the temp gauge went from the halfway mark down to the 1/4 mark very quickly.

now after reading online a bit this seems to be symptoms of a failed HG

 

[USER1999]

If you pull out your oil level dipstick, is it black and oily? Any White gunk, and defo head gasket.

 

[USER1999]

​

With the water filler cap off, I would expect the water level to rise. It is a pressurised system, brought about by the hot water expanding. If it now does not have enough water in it to pressurise, it will over heat.

That said, if it rises loads, you do have a problem.

 

[wull]

the dipstick seems fine and the oil cap seems ok,it's hard to tell with the oil cap because it's a silly rubber thing.there doesn't seem to be any emulsification,maybe a slight bit but this can be caused from short journeys etc with condensation apparently.

the water rises to the point where it would overflow but i opened the bleed screws before it could do that.

 

[wull]

i've done some more checks and i'm no further forward.

i was asked to start the car and after a minute remove the coolant cap and what was expected was that the water would come pissing out.it never did!!!now if there was a build up of pressure after only a minute then hg would definately be at fault.but it never happened.

another check was to rev the car and see if the water level in the coolant drops which it never did.apparently this is a sign that either the water pump or possibly the thermostat has failed.

so i now need to remove the thermostat and check it but if it's either the hg or water pump then it's too costly.the water pump is a pain in the erse to do on the punto,i presume it will be on most cars but i don't have the resources to tackle it myself with lack of tools,time and a suitable area to work on it.

 

[thecraw]

May I make a suggestion please....

&

Woooooooooooooooooooooooooooooooooooooooooooooooooooosh

 

[wull]

May I make a suggestion please....

&

Woooooooooooooooooooooooooooooooooooooooooooooooooooosh

i think that's the best suggestion yet........will provide some heat aswell,jobs a good'un!!!!!

 

[Tommo21]

Sell it......fast. Get it cleaned up proper and fast. Cars are going at a good price this time of year if you shop around. Oh, if the temp gauge is high or the engine is really hot have the heaters on full blast, it helps to take some heat away.

Oh, I've got a nice 2009 passat TDI for sale. Still got some VW warranty left.

 

[Doc]

Hi Wull,

Engine cold and switched off - open coolant reservoir and bleed screws in coolant hoses.

When coolant comes out of lower bleed screw close it. If no coolant comes out then you need to raise the reservoir height to make gravity and laws of physics work for you.

When coolant comes out of upper bleed screw close it.

Top up coolant to max level, close reservoir.

Put heater on hot demist and blower on 2nd speed.

Start car and let engine run on fast idle, get someone to sit in car and keep revs at 1500 rpm.

One rad hose should get hot quickly, other should stay cold until thermostat opens, then should get too hot to touch almost immediately.

If one hose gets hot quickly and other stays cold then stat is stuck closed.

If one gets hot quickly and other warms gradually then stat is either missing or stuck open.

By time both rad hoses are hot the heater hoses should both be hot and heater should be blowing hot air.

Small inlet hose into reservoir should have fast flow into reservoir at fast idle.

If car doesn't overheat at idle but overheats when driving them water pump is prob at fault.

If you can see gas bubbles in coolant and reservoir over pressurises quickly then poss head gasket fault.

If coolant is escaping from reservoir cap then maybe just faulty cap.

There are numerous other possibilities such as blocked heater matrix or radiator, water cooled egr fault etc.

Hope this helps,

Cheers

Steve...

 

[Andy]

Gr8 repsonse Steve.

Know who to shout on when the car is goosed lol

 

[wull]

Hi Wull,

Engine cold and switched off - open coolant reservoir and bleed screws in coolant hoses.

When coolant comes out of lower bleed screw close it. If no coolant comes out then you need to raise the reservoir height to make gravity and laws of physics work for you.

When coolant comes out of upper bleed screw close it.

Top up coolant to max level, close reservoir.

Put heater on hot demist and blower on 2nd speed.

Start car and let engine run on fast idle, get someone to sit in car and keep revs at 1500 rpm.

One rad hose should get hot quickly, other should stay cold until thermostat opens, then should get too hot to touch almost immediately.

If one hose gets hot quickly and other stays cold then stat is stuck closed.

If one gets hot quickly and other warms gradually then stat is either missing or stuck open.

By time both rad hoses are hot the heater hoses should both be hot and heater should be blowing hot air.

Small inlet hose into reservoir should have fast flow into reservoir at fast idle.

If car doesn't overheat at idle but overheats when driving them water pump is prob at fault.

If you can see gas bubbles in coolant and reservoir over pressurises quickly then poss head gasket fault.

If coolant is escaping from reservoir cap then maybe just faulty cap.

There are numerous other possibilities such as blocked heater matrix or radiator, water cooled egr fault etc.

Hope this helps,

Cheers

Steve...

excellent post steve..

i plan on removing the thermostat to test it but i'll try all these again just to know for sure.from what you've wrote though i feel as if the water pump is at fault.

i'll try these first.....

 

[Philm]

on an old car, and often overlooked fault is the heater matrix, its probably in behind glovebox or dash, and you could swap everything under the sun and if you heater matrix is gunged up it wont make a difference.

like brendy mentioned, circulation.

at least a lack of mayo and white smoke means your headgasket is probably intact BUT driving with a coolant problem nomatter the weather(seriously) and you will overheat very quickly and you may be needing a headgasket and you still wont have solved the cause!

now you know you have an issue, work tirelessly to sort it quickly, before you have two or three knock on effects and no idea what caused what.

good luck with diagnostics pal. i know it can be painful.

Phil

 

[wull]

thankfully the car is not being used so hopefully there will be no knock on effects from whatever is the cause.

the downside with the thermostat on the punto is you can't remove it to see if the temp still goes up or not.

 

[CliveW]

Check the radiator fan is working correctly. A friend of mine had a Punto and it started having heating issues which were traced to a knackered fan motor. It would run but not fast enough to cool the engine.

 

[wull]

right,i went out with the intentions of removing the stat this morning but before doing this i decided to do all the checks steve posted.

firstly i bled the system butt the top one i couldn't do because i rounded the screw the last time:sbox: but i did it the last time so felt that was good enough and carried on.

i got the missus to rev the car @ 1500rpm whilst everything got upto temp and everything worked as it should.all hoses got warm especially the one coming from the thermostat.also the blowers were blowing hot air.....

so i decided to take the risk and go for a drive,i took it roughly 5-6 miles with both village driving,and out and about driving.

and it ran perfectly,the temp never went over where it should be and it never got hot enough for the fan to kick in.

unbelievable....i wonder if bleeding the system has made all the difference but could it be that it's early stages of HG failure?causing air to get on the system which over time causes what happened 3 days agp or whenever it was.

i'll get it checked when the mechanic gets back from holiday and in the mean time samantha can use the car in and around the village.......she'll just need to keep an eye on the temp gauge.