Overheating mystery

[Czechboy]

Hiya Everyone,

Here's one for you. My 1.4 is overheating but I'm not quite sure why. The headgasket isn't gone because there is no oil in water and vice verse. Also the expansion tank does not lose any water. The car made it to Manchester and back (500 miles) only overheating on the motorway when driving at 80 leptons for an hour with no heaters running. Doesn't really overheat in traffic. Fan still works. BUT when I changed the oil and filters I also decided to put in some Rad-weld into the expansion tank to stop the curry smell I get from a slightly leaking heater matrix. And now the car overheats even when going 70mph for 5 mins. When I stick the heaters on full blast the temperature drops back to operating temperature but I don't want to be driving with the heaters going constantly.

Thermostat??
Clogged up radiator??
any way of checking what it might be?

p.s the water pump was changed only 2 years ago.

Many thanks in advance

Mig

 

[F2 Ed]

is water getting into the rad? Stat may be stuck

 

[Czechboy]

is water getting into the rad? Stat may be stuck

is there a way of telling if it is??

 

[F2 Ed]

is there a way of telling if it is??

When the engine is hot squeeze one of the top rad hoses. You will tell if there is water flowing through it. Common sense

You can also take your stat out and drop it in almost boiling water to see if it opens

 

[KERMITCUPRA]

I think if you read in the handbook its standard on old 1.4 `s its a 1.4 thing............ See the 16v goes so fast it keeps it cool........

 

[Czechboy]

I knew you'd pop up on here Your coilovers have now done probably more miles in the boot of my car then they have done on the valver.

I will try the top rad hose thing. as for the thermostat I will have to try that out as well.

Any other ideas??

Thanks

 

[OllieL]

Does sound like the stat - same problem I had on my 1L polo. Want to get it sorted quick though cos I think that was what started the ball rolling on my head gasket giving up

 

[OllieL]

Why dont you just sell it and buy my 1.4 on sunday if I buy the valver tomorrow

Ollie

 

[Czechboy]

Nah, I secretly love the pimped out/chav'd up Polo, I seriously need to take it for a photoshoot but I have absolutely no spare time..........or its raining outside

Mig

 

[Czechboy]

When the engine is hot squeeze one of the top rad hoses. You will tell if there is water flowing through it. Common sense

Well I just drove back home (50 miles) and I tried squeezing the top rad hose. And its REALLY hard to squeeze and very damn hot. So either there is hot water flowing through it or its full of pressurized air. But I'm pretty sure it was full of liquid.

 

[m0rk]

whip out the thermostat. it will fail soon enough anyway. when mine failled I just took it clean out... takes the car a little longer to warm up - but worthwhile!

while you're there make sure the coolant is flushed round and eliminate any bubbles.

 

[Czechboy]

So can I just completely remove it then?? No other adverse effects apart from the car taking longer to warm up??

Ta

 

[m0rk]

none at all.

 

[KERMITCUPRA]

Mig... i know someone with a Beetle for sale. sorry.....
Jokes aside i bet your rad`s partley blocked. Wip off the rad hoses and give the whole system a good flush out with the garden hose. Bet youve got a load of cr**p in there.

 

[Czechboy]

Wip off the rad hoses and give the whole system a good flush out with the garden hose. Bet you've got a load of cr**p in there.

Will have to do that. I've got a pressure washer I could use to flush the inside, or do you recon a pressure washer is too harsh for the radiator?

Plan of action:

Buy some coolant
Drain old coolant
Chuck thermostat in the bin
Flush the system using a pressure washer
Fill system back up
Enjoy a motorway cruise without heaters at full blast

 

[m0rk]

flush it with a hose, no need to pressurise it... it'll likely just crumble!

Run the water round the block too - to flush that out too

 

[Pedro]

Chezchboy, if removing the thermostat does solve the problem then you may as well replace it with a new one. As M0rk says it won't harm your car running without, but in the middle of winter you will find it taking a good while to heat the heater matrix up, and with iced windows etc it's a pain in the arse!

 

[Czechboy]

Well I've just phoned up GSF and apparently they are only like £6 for a new one so will buy one, then buy some coolant (red one I think) and I can try and flush the system and replace the stat.

For the time being if there are any other simple things I could do that might be the cause then please fell free to tell me

Cheers

 

[Boi Ninja]

radweld? thats the problem, everyone that uses it has the same problem mate, its meant to block up the hole in the radiator but blocks up other things too.

 

[Chrisdaman]

yeh mig thermostats arent expenvise, one for my valver was only £7 i think from GSF