Coolant Tank Overheating Problem....
Discussion
Hi,
can anyone help with a problem that has been baffling garages around here with my P reg MGF VVC?
I am by no means mechanically minded so forgive my potential incorrect use of terminology!
The problem first started a week ago when after driving at 70mph for 35 miles, I dropped down to 30mph. The temp gauge started to rise, got to just underhalf way then stopped. Here's the first problem, apparantly the normal level for the gauge is one bar under the halfway mark, yet mine normally sits one bar above the lowest bar! A couple of mninutes later steam started to come out of the coolant tank. My first thought was HGF, so I checked the oil, no milkyness. I called out the AA, they did their pressure and chemical tests and the car was fine. They towed me to a local garage who said it WAS HGF and the head had to be sent off for the tests - ie £££.
I was not convinced so I got the AA out again, they did the tests again, the car passed again and with them following me, I drove 35 miles to another garage I had been recommended. They diagniosed a leak in the pipe taking the coolant from the back to the radiator. This was apparantly causing a loss of coolant, hence the problems. They changed the pipe, problem solved!
But unfortunately it is not! The same thing has happaned twice again, I drive at speed, slow down, the temp gauge rises to just under half way, then steam comes out of the coolant tank!
It is as if whenever the car has been warmed up and isnt travelling at speed, itsl liable to heat up, however the temp gauge never gets above just under half way, so is it really the engine overheating, or there too much pressure in the 'system'? Does the coolant need bleeding?
This morning I arrived at work after doing a 70mph stretch (no problem), drop down to 30mph - gauge starts to rise, get sto just under halfway and stops at that level. I pulled up at work and I assume the fan kicked in as the gauge dropped. I had a look at the cooland tank and despite the cap being tighly screwed on, there was a slight hissing noise coming out of it.
On my journey home, I was driving mostly at speed and therefore the airflow I suspect keeps everything cool, I pulled up and left the engine running. Temp gauge went up to one below middle bar - which is not something to worry about I believe - and I left the car running idle for about 8-10 mins. The gauge never went above this level, but sure enough, despite new cap, after 8-10 mins the steam begin to rise out of the back of the car again!
I opened the boot and it sounded like there was a 'gurgling' noise coming from the left hand side of the engine (sorry cannot be more descriptive than that) and the coolant level in the tank started to rise to above its normal 'cold' level. It was bubbling away.
I have changed the coolant cap so it cannot be that.
Turning the heater on and off seems to make now difference.
Does anyone know what is going on!!!
can anyone help with a problem that has been baffling garages around here with my P reg MGF VVC?
I am by no means mechanically minded so forgive my potential incorrect use of terminology!
The problem first started a week ago when after driving at 70mph for 35 miles, I dropped down to 30mph. The temp gauge started to rise, got to just underhalf way then stopped. Here's the first problem, apparantly the normal level for the gauge is one bar under the halfway mark, yet mine normally sits one bar above the lowest bar! A couple of mninutes later steam started to come out of the coolant tank. My first thought was HGF, so I checked the oil, no milkyness. I called out the AA, they did their pressure and chemical tests and the car was fine. They towed me to a local garage who said it WAS HGF and the head had to be sent off for the tests - ie £££.
I was not convinced so I got the AA out again, they did the tests again, the car passed again and with them following me, I drove 35 miles to another garage I had been recommended. They diagniosed a leak in the pipe taking the coolant from the back to the radiator. This was apparantly causing a loss of coolant, hence the problems. They changed the pipe, problem solved!
But unfortunately it is not! The same thing has happaned twice again, I drive at speed, slow down, the temp gauge rises to just under half way, then steam comes out of the coolant tank!
It is as if whenever the car has been warmed up and isnt travelling at speed, itsl liable to heat up, however the temp gauge never gets above just under half way, so is it really the engine overheating, or there too much pressure in the 'system'? Does the coolant need bleeding?
This morning I arrived at work after doing a 70mph stretch (no problem), drop down to 30mph - gauge starts to rise, get sto just under halfway and stops at that level. I pulled up at work and I assume the fan kicked in as the gauge dropped. I had a look at the cooland tank and despite the cap being tighly screwed on, there was a slight hissing noise coming out of it.
On my journey home, I was driving mostly at speed and therefore the airflow I suspect keeps everything cool, I pulled up and left the engine running. Temp gauge went up to one below middle bar - which is not something to worry about I believe - and I left the car running idle for about 8-10 mins. The gauge never went above this level, but sure enough, despite new cap, after 8-10 mins the steam begin to rise out of the back of the car again!
I opened the boot and it sounded like there was a 'gurgling' noise coming from the left hand side of the engine (sorry cannot be more descriptive than that) and the coolant level in the tank started to rise to above its normal 'cold' level. It was bubbling away.
I have changed the coolant cap so it cannot be that.
Turning the heater on and off seems to make now difference.
Does anyone know what is going on!!!
Sounds rather like mine after I had to replace the undefloor pipes and radiator. The main things to check before fearing the worst are (particularly if you no other evdience of HGF):.
1) Bleed the system , which can take two or three goes to get all of the air out. There are three main bleed points - a valve on the heater matrix, a plug on the radiator, and one bleed screw on the return pipe from the engine/rad. All three are highlighted on the site with the link posted earlier - suggest re-bleed the system.
2) Check that the fuse hasn't blown for the radiator fan and that it cuts in.
2) If you had leaking undefloor pipes, then check your radiator as well - mine was leaking from both!
MG Mark
1) Bleed the system , which can take two or three goes to get all of the air out. There are three main bleed points - a valve on the heater matrix, a plug on the radiator, and one bleed screw on the return pipe from the engine/rad. All three are highlighted on the site with the link posted earlier - suggest re-bleed the system.
2) Check that the fuse hasn't blown for the radiator fan and that it cuts in.
2) If you had leaking undefloor pipes, then check your radiator as well - mine was leaking from both!
MG Mark
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