Overheating Problem? Help Needed.

[Guest Coopz]

Having a problem with the 205 at the moment (1.6 GTI 8v 1991) and hoping some of you guys maybe able to help.

 

So for a few weeks now the 205 has been overheating not when driving (on the move) but when in traffic and stopped a few times the needle is going in to the red and the stop light coming on. The fan hasn't been coming on! and I haven't lost any coolant, so as suggested I bleed the coolant system and there was quite a lot of air.

 

After bleeding I let her run and she overheated again red stop light and needle in the red. Then it pissed out boiling coolant violently from the header tank overflow and then split the matrix breather hose near the bulkhead with coolant coming out so i opened up the header tank cap to relieve the pressure while it chucked the coolant out.

 

I havent noticed any performance losses or smoke and any creamy muk or lost any oil for head gasket? although am bearing this in mind.

 

But a bit baffled of what it could be

 

Help much appreciated Cheers

[SurGie 54]

Water pump knackered, thermostat maybe or still some air trapped somewhere in the system, afaik.

[GLPoomobile 958]

You said the fan doesn't come on. Well there's your problem. you need to start looking at your fan wiring, switch etc. I'll let someone more knowledable take it from here...

[DrSarty 90 1 Cars]

Try a search using "+fan +not+ working" and you'll get a list of results. Fan faults are quite common and it's usually caused by the thermoswitch in the rad.

 

I'm not going to explain it here as it's been covered many, many times, and your search will show that. Just get a cuppa, stroll through the threads and you'll see the way to tackle it.

 

As usual though it's a process of fault finding by eliminating items to highlight the weak point. In your case it could simply be the fan not working for either one of three reasons: thermo switch, wiring or fan motor fault.

 

On the other hand, it could by as Surgie said a failed water pump or a bitch of an airlock. The worst case is the pump, but it's possible to see if it's functioning by running the car up to temp (i.e. not too hot) with the expansion tank cap off. This may well purge some trapped air too, but you should be able to see some swirl or movement in the coolant which would indicate the pump's working. It would also show the system is free flowing, i.e. there's no blockages in pipes or rad, which would leave the same water in the same place just getting hotter and hotter.

 

With these comments plus having a look through the search results you'll find a simple approach to fixing it.

Edited June 4, 2009 by DrSarty

[Tom Fenton 1,542]

Make the fan work first. Chances are with this working you have nothing else to worry about.

[Grim.Badger 15]

A pinhole leak in one of the hoses will cause the coolant problem you have, chances are it was the one that split.

 

Fans are easy to sort out; double check all the wiring (simple as the fan loom can be pulled out on it's own), clean the contacts and if need be replace the big blue sensor in the rad.

I also remove the resistor so the fans come on at high speed all the time, this is done simply by cutting the resistor off and connecting the thick blue wire with the thick white wire.

[Guest Coopz]

Ok cheers for all the info.

 

Update, I found that the rad thermoswitch had completely rotted away and snapped in two and radiator was in poor condition.

 

So far I replaced the breather hose to the heater matrix, fitted a new thermostat, a new coolant temp sensor, and fitted a new rad thermoswitch and a new radiator fan does work as tested on the battery.

 

Tomorow will replace the water pump also the bit of metal by drivers wheel arch connecting two bits of coolant hose can this be replaced? fit a new coolant level sensor then fill and bleed the system

 

And hopefully this sorts out the problem

[Tom Fenton 1,542]

Yes you can replace the metal water pipe, available from the main dealer for about £12 so don't be fooled into paying loads elsewhere.

[kyepan 291]

sounds very comprehensive, and pretty much what i ended up doing...

 

just so you know, the water pump is under the cam belt, so you'll need to take it off, but on an 8v it's pretty easy.

 

a cam belt and tensioner kit should not set you back too much and give you piece of mind on that front for another 40k-60k.

 

if you're in doubt make sure you inspect the belt properly for cracks when it's off

 

good stuff mate!

 

J

[EdCherry 34 1 Cars]

Doing the belt at the same time mate? Knew someone on here would give you a more of an answer than I could.

[Guest Coopz]

Doing the belt at the same time mate? Knew someone on here would give you a more of an answer than I could.

 

Cheers for the tip ed

 

Update time everything back in apart from I didnt fit the new water pump because I thought mine was ok is there actually any way of telling?

 

Coolant filled and bled the system. Started her left her running for about 20-30 mins temp climber up slowly and fan switched on so bingo was happy about that! Then turned her off and checked coolant level was good. Then went for a drive I thought she was still running quite hot where abouts should a warm 205 gti sit on the temp gauge mine sits not on the last bold line the one before?

 

Fan swtiched on when pulled over too so overall quite happy im back on the roads!