Overheating

[soptom]

Evening all, my wife was driving the car today when it started getting hotter than normal, she turned for home and got there just as the red light started flashing and steam was venting from the cap. I've checked that the fan was running, which it was and now need some guidance, when it was running hot, the fan was continuous at its highest speed yet the gauge was still creeping upwards. The radiator didn't seem to be getting anywhere near as hot as the obvious temp suggested so does this mean the thermostat is at fault or the water pump, or could it be a blocked rad? I can see water flowing into the expansion tank so does this mean the water pump is working? Any help gratefully received. It is a 1995 2.0 petrol Galaxy and normally runs on the cold side of normal.

[Guest j_mchattie]

My mondeo had a major overheating problem (actually caused by the head gasket).

 

First thing to do (in my opinion) is change the thermostat. They are so cheap that its worth doing. Blocked radiators dont happen overnight, so the lack of heat can only be cause by either the pump or the thermo.

 

You say the pump is pushing round water, so you know it works ok. The radiator will (i imagine) get its sensor feed from the thermostat housing (via the ECU), which tells you that the thermostat is very hot.

 

If the radiator is cold (but was working last week in the normal temperature range), i doubt its blocked - i should think the thermostat isnt feeding that hot water out.

[Guest GT-Four]

yeah most people jump in feet first and go with the blown head gasket scenario

 

me i like to explore the more cheaper and quicker fixes

 

so in order

 

rad cap--chaep as chips and if it isnt holdng pressure the coolant boiling point will be lower.

 

a fragged rad cap can give symptoms very similar to a BHG

 

thermostat--- as mentioned a good cheap part and may cure probled

 

radiator ---could be blocked probably isnt but flushing it through both ways wont do any harm and if you have the stat out why not do it?

 

BHG---well it could be you never know but at least if you have done all of the above you have eliminated other causes of the overheating

 

let us know how you get on

 

john

[Guest j_mchattie]

Steam started venting after the temperature went red. So the rad cap was ok (granted, it may need replacing now that it has blown once)

 

Cylinder head gasket blowing often takes everything with it (it did on mine), but try the thermostat first.

 

Is there any water in the oil (frothy oil), or oil in the expansion tank?

[soptom]

The oil seems clear and so does the expansion tank so I'm hoping it's just the thermostat at the moment, I'll get a new one and flush through some new coolant tomorrow so I'll let you know the results after this, thanks for the suggestions so far.

[gregers]

i too have a 95 gal petrol and my temp gauge hardley moves unless im stuck in traffic then it creeps up slowly when driving goes down to the bottom any ideas chaps/chappetts me thinks it also requires new a new thermostat wot do u think?

kindest regards gregers

[Masked Marauder]

I would go with a thermostat that is not fully opening first, then the water pump.

[Masked Marauder]

i too have a 95 gal petrol and my temp gauge hardley moves unless im stuck in traffic then it creeps up slowly when driving goes down to the bottom any ideas chaps/chappetts me thinks it also requires new a new thermostat wot do u think?

kindest regards gregers

Sounds like a fully open stat or missing altogether.

[seatkid]

if the heater output is ok (hot,hot,hot) then thermostat, otherwise pump. Water flowing into the expansion tank is not normal, means its over heating and suggests its the pump failed. Change em both.

[soptom]

It seems to have been the thermostat that had stuck shut and was thus causing all my problems, changed it yesterday with all new coolant and it seems to be running okay so far, thanks for all the replies.

[Marky]

Good to hear you've sorted it.

 

 

Seatkid... u r watching too much CBeebies mate...hot,hot,hot Big Cook !!!

 

:(

[Masked Marauder]

Good to hear you've sorted it.

 

 

Seatkid... u r watching too much CBeebies mate...hot,hot,hot Big Cook !!!

 

:(

How do you know?

[Marky]

MM...with a 12 month old its on everywhere I'm afraid...I no longer rule

the remote !!!

[DubDriver]

Having read the posts on this topic there seems to have been some conflicting replies and misinformation.

 

Seatkid suggests - Water flowing into the expansion tank is not normal, means its over heating and suggests its the pump failed.

 

This is quite normal. Water is drawn from the bottom of the expansion tank and circulates back in at the top.

 

Masked Marauder suggests - Sounds like a fully open stat or missing altogether.

 

A fully open stat would if anything make the engine run cooler.

[seatkid]

Seatkid suggests - Water flowing into the expansion tank is not normal, means its over heating and suggests its the pump failed.

 

This is quite normal.  Water is drawn from the bottom of the expansion tank and circulates back in at the top.

I stand corrected. :huh: When the thermostat is closed, a small amount of water circulates as you say, in at the top, out of the bottom.

[Guest j_mchattie]

MM was replying to Gregers Post, about his 95 running cold