Technical Brava 1.6 Overheating - I think!

[ianto]

Hi
Am new to the forum, but have have driven a brava (1.4Sx) for over 4 years, this one blew an engine so decided to get a new one from auction (due to small budget!)

Anyway brought a 1998 brave 1.6 at auction, driving it home noticed that the temperature gauge shot up to red - Pulled in to petrol station water is oK, water boiled out as I opened the water cap. The water was not discoulured. There seems to be no water in the oil - the oil is not discoloured/emulsified. Anyway if I switch of the engine and restart the temp gauge is only half way - drive a bit it goes up!; switch off and on and the gauge is again on the half way mark!

Anybody had anything similar? Tell me what the problem is likely to be?

Thanks

Ianto

Have just checked again - the water when it boils out is cold!
The heater doesn't blow hot air,
The radiator is cool to touch, the pipes are very hot

 

[mountainmachine]

I'll let someone else shout at you for opening rad cap when its boiling, you could have trapped air in the system now.

To be honest sounds either like a faulty thermostat or head gasket, prob the thermostat, but wait for more opinions etc. Is the cooling fan kicking in? As you could have a faulty fan relay or fan resistor. (check fuses first!)

 

[ianto]

I found a bleed screw - undid it some air came out and the radiator is warming up, and it doesn 't seem to be overheating now - temp gauge seems constant at half way. Also heater is producing hot air - but seems to be intermittent - The radiator looks pretty new. Where are the other bleed screw - i found the one on the left side of the radiator )looking in to the engine bay). PS wher can I buy a haynes book?

I have absoulutely no mechanical knowledge whats the best way to learn about self servicing the car?

Any help most welcome

Ianto

 

[mountainmachine]

The water boils out when its cold, it soulds like exhaust or compustion gasses are entering the cooling system and thus bubbling out. Or it could just be trapped air pockets expanding. Best way is to open the bleed screw and squeeze the pipes to force air pockets out.

Again do a search on bleeding the radiator i couldnt explain it properly.

eBay or Halfords, or a motorfactors for a Haynes manual, any of the blue bravo/a ones also some more advanced manuals on here, do a search for bravo manuals.

 

[jug]

I'll let someone else shout at you for opening rad cap when its boiling, you could have trapped air in the system now.

:yeahthat:

if I switch of the engine and restart the temp gauge is only half way

that suggests it is not overheating, the gauge is simply not reading correctly, probably due to a corroded connector on the coolant temp sensor, or a faulty sensor, or a faulty temp gauge, or at least a fault in the circuit somewhere.

 

[bandido41]

Mine did that when i flushed the radiator. I didnt bleed the system so it wouldnt be long before the temp gauge was in the red but if you open the cap, the water is cold seing as you say the rad looks new chances are whoever replaced the rad didn't bleed the system the best way i found was before you start the car i.e when it is cold open the bleed screw on the left of the radiator and fill the radiator untill water starts coming out of the bleed screw then close up that screw and if you look behind the engine just above the exhaust manifold thaere is a black rubber hose that is cliupped onto a metal hose the secnond bleed screw is on the rubber hose (you will probably need to shift the rubber hose over to the right to see the bleed screw) use a flat had screw driver to loosen it and repeat the process as for the radiator bleed screw.

 

[steesh]

Quick question, where is the temp gauge supposed to read when at normal temp, is it at half way?

 

[bandido41]

Normally it should be at half.

 

[steesh]

Yeah thats ok then, the only thing is when it gets to half way thats when my car starts playing up, revs erratic etc. When the temp is just below its seems to work better, weird

I have disconnected my lambda and the problems still exist, so its either a knackered lambda or its nothing to do with it, time for a diag test me thinks......