Engine overheating...thermostat changed???

[mmh]

Hi,

I'm fairly new to Polo's so any advice would be great.

The other day I drove my car for 10mins and suddenly the temp gauge needle went over 110 and the temp warning light started flashing on the dash.

Today drove it again same thing happened.

The coolant has gone high over max. the fan has not come on and the lower radiator hose was cold whilst the top hose was v.hot.

The thermostat was replaced with a new one today and it was fine the fan cutting in when needed.

Then the overheating started to happen again on the way home with the same symptoms.

Could anyone advise me on what it could be causing this? This is my 1st car and I'm quite worried

Cheers,
Mo.
1.6GL 1999

[ModifiedMadness]

One possibility may be a split water hose?

[mysteryboy]

Sounds exactly like the problem I had... ended up being the head gasket

[tupac2makaveli71]

or the radiator could be blocked so its not cooling properly? correct me if im wrong, but if the bottom is not getting hto then its not doing a good job cleaning so maybe you could flush it and get some kinda cleaner for it?

[mmh]

Hi,

There's no mayo in the oil and the car drives fine.

There's no sign of water leaking anywhere so I don't think it's a split hose.

The blockage in the radiator could be a possibility to investigate.

The car is low mileage under 40k so I hope its's not a head gasket, also there is no white smoke out the rear.

Someone suggested to me a broken thermostat housing or something like that... anyone had this problem?

Cheers, Mo

[mysteryboy]

Someone suggested to me a broken thermostat housing or something like that... anyone had this problem?

Cheers, Mo

Yes. Theres a little hole in the housing which shouldn't be there.

[mmh]

Someone suggested to me a broken thermostat housing or something like that... anyone had this problem?

Cheers, Mo

Yes. Theres a little hole in the housing which shouldn't be there.

Does anyone know if replacing the stat housing is a big job? and what sort of price would it cost?

Thanks

[mysteryboy]

Should be same price as getting the thermostat changed.

Here's a pic of a broken housing so you know what to look out for...

http://img136.imageshack.us/my.php?imag ... ng24gc.jpg

Good Luck sorting it out.

[mmh]

Should be same price as getting the thermostat changed.

Here's a pic of a broken housing so you know what to look out for...

http://img136.imageshack.us/my.php?imag ... ng24gc.jpg

Good Luck sorting it out.

Cheers for the pic mate, the car is giving me major stress at the mo

[willy g]

I had exactly the same prob mate and was very stressed. I chacnged thermostat and i was still overheatinf i had the hole in the housing!!
Its really easy to replace just two bolts on the housing. the only thing was i had to buy the rest of the gubbins that the housing is attached to (£40) but i think i was bummed!!
Good luck i reckon this is your prob

[test_richie]

Water pump

[mmh]

I had exactly the same prob mate and was very stressed. I chacnged thermostat and i was still overheatinf i had the hole in the housing!!
Its really easy to replace just two bolts on the housing. the only thing was i had to buy the rest of the gubbins that the housing is attached to (£40) but i think i was bummed!!
Good luck i reckon this is your prob

Cheers mysteryboy and willy g,

It was a thermostat stuck shut as well as a cracked housing. What a crap design all made of crap plastic!

All sorted now...though I think I'll get some AA just incase I get stuck anywhere further than my local area.

Thanks to everyone else with your suggestions, I was really bricking it a week ago.

Now the sun's out time to open the openair and enjoy some rays.

Cheers,
Mo

[martinjr]

I had/have the same problem. Some 4 weeks ago my Polo Classic 1.4 overheated. I checked the usual suspects but the only problem found was water was scarce, no sign of gasket leak etc. After the car cooled down I topped it up and drove it for a number of miles. It overheated again so I replaced the thermostat. I did notice during replacement of 'stat that there was a hole right through the housing retainer, as mentioned above. However I thought this may be part of the design so I ignored this. Within a further few miles of driving it overheated again. This time I replaced the water pump, took out the radiator and checked for blockages etc. The radiator was clean as a whistle. It overheated again so I replaced the housing. At this point I had replaced the thermostat, the water pump, the housing. Guess what? It overheated again and on checking I discovered the new thermo housing had a hole right through once again. I am now driving the car without a thermostat for the past couple of days without a problem. The only thing I can attribute the problem to is the fact that I did not put any coolant in while this checking process is ongoing. I know that the coolant is a vital requirement but would it be such that without it the car will overheat to the extent that it serially wrecks housings? I have a further replacement one but am reluctant to use it until I'm satisfied that coolant is the final solution to the problem. Any suggestions will be welcom.

[mmh]

The thermostat housing or casing was the problem on mine it is a very poor design and prone to breaking.

Check the thermostat in a pan of hot water to see if it opens and closes and then replace the housing.

Drain the cooling system and possibly flush it through too, and replace with VW G12+ Purple colour coolant and water mix.

VW used to have 2 types of coolant G11 blue and G12 red and these were not to be mixed in the same system. The G12+ Purple is compatable with both and should sort out any compatability issues with any coolant in the system.

[dragon_green]

thermostat housing is a common problem on mk4s