General Over heating

[bravotony]

My 97 bravo hgt has been fine with no problems, then I stopped at a garage for a couple of mins, after bein out in car all day, then by the time I got home the expansion tank was boiling and hissing steam, but fan didn't seem to be on ! Does anyone know what could have caused this ? Cheers

 

[btmaldon]

It could be numerous things. I would start at the cheapest first by changing the expansion tank cap. Once these start loosing pressure, the coolant boils at a lower temp and doesn't circulate properly. Where the sensor for the fan is located, it could still be registering fairly cool.

Then run the engine with the heater on full to ensure the coolant is getting around the whole system. Run it till the fan kicks in, checking the top and bottom hoses to and from the rad are pressurised (not spongy) and are getting hot.

If the pipes are getting hot and the fan doesnt kick in, you probably need a new sensor/switch.

Hope its cheap to sort. It normally is unless its a head gasket. To check that,see if there is any oil in the water or what looks like maionaise on the oil filler cap.

All the best

 

[bravotony]

Hi guys, just had it runnin temp up to half way but heaters didn't get hot and the fan didn't kick in either plus the rad pipes were warm but spongy any ideas

 

[xander_trippin]

Any gunk under the oil filler cap? Could be an airlock, try bleeding the system first before lookin into anything else as its free to do. It could also be the temp sensor or rad switch or thermostat. Check al these as you go before looking into head gasket failure.

 

[bravotony]

Hi no gunk under oil cap, just topped up water went for drive all seemed fine running at correct temp and heater in car got hot as normal but when home I allowed temp to rise to check fan but as it reached half way coolant seemed to boil in expansion tank and when I loosened cap seemed to be no pressure, could the cap be faulty and not allowing temp to build up properly would this cause the problems I am havin ?
Cheers

 

[bravotony]

Would an expansion tank pressure cap from any bravo fit my hgt

 

[btmaldon]

For the cost of it' get down to Halfords and get a new cap. I would have thought the Bravo and Brava caps were the same.

 

[bravotony]

Hi all got a new cap on the expansion tank today, now its all pressurising properly but the fan doesn't seem to come on when it used to, when should the fan kick in mine used to be halfway on temp guage but thought it could be different wit new cap on ?

 

[Bexomater]

when the fans don't start, you should check the rheostats, they are two on your HGT, for it's two-staged.
for the first one, lower stage, it should kick in at about 92-96 degrees Centigrade, it is bolted near the right fan on the top right side.
for the second, which kicks in at about 100 degrees, and is ON whenever the AC is on. This one is on the down left side of the structure that holds the fans.
Good luck..

p.s. have checked the thermostat... (i did not quite understand)