help, again

[StevieDB9]

last weeks problem was a wrecked gearbox. this weeks problem is no heat from the vents in the cabin, which was handy for the icey windows yesterday.

i checked the coolant level which was fine tho i was very suspicious of the colour, very dirty dark red, usually bright red. the top radiator hose was hot to the touch and the bottom one cooler, so that seems fine. the radiator fan itself doesnt work (another thing to fix) but the engine never seems to overheat (touch wood). im going to flush the system at the weekend and fill with fresh coolant. my suspicion is the heater matrix although really ive no experience of these things so i was relying on your wisened minds here. any other ideas or does mine swing with yours?

[pgarner]

if theres no heat going into the cabin and your certian that the thermostat is working, which i guess it does if the cars not overheating, then i would say it would be the matrix away.

have you been losing oil or water lately ? just with the coolent being a bit darker than normal.

[StevieDB9]

not noticed any fluid loss, although im a bit suspicious after it came back from getting its new gearbox. heaters stopped working when i got the car back, foned the guy up and he said they didnt go near the cooling system when fitting the new box, which is, excuse the language, p**h since the gearbox lies direct under the radiator pipes

[HDi fun]

Perhaps they attacked it from the bottom?

It's not simply an air bubble or something is it. Try bleeding the cooling system first.

[pgarner]

if it was an air bubble would it not cause the engine to overheat ?

[HDi fun]

Not necessarily. The matrix could well be located higher in the car than the engine cooling circuit. If not the matrix, the control gear might be.

It's also possible to get air stuck in angled joints. pipework etc. where the surface tension of the water is enough to stop circulation.

[pgarner]

Ahh with you now. the air bubble may be caught up around the matrix and not in the engine cooling itself

[HDi fun]

Bleedling cooling systems - let's start again, that sounds wrong!!

It's often difficult to get to the highest points in the system, and car makers often don't fit bleed screws in an attempt to shave a few pennies from the production costs.

Years ago I had 2 Montegos in sucession, and the only way to remove air was to disconnect coolant hoses. Thus introduicng more air

Perhaps I should have been certified for buying the second one...

[billyo]

try shaking the car

[waynne]

Squeezing the coolant pipes might help move the bubble around. Its a good excuse for a spirited drive!

[StevieDB9]

well, going to flush out the system and renew the coolant and see whats whats. Someone said could be the head gasket which would cause oil to leak into the coolant which would explain the colour of it, though wouldnt the water be at a higher pressure than the oil and so it would be the water goin into the oil and not the other way round?

[HDi fun]

Originally Posted by StevieDB9

well, going to flush out the system and renew the coolant and see whats whats. Someone said could be the head gasket which would cause oil to leak into the coolant which would explain the colour of it, though wouldnt the water be at a higher pressure than the oil and so it would be the water goin into the oil and not the other way round?

If the coolant was leaking into the oil then the coolant level would drop. When you drain, flush, fill and bleed make sure to set temperature control to max if yours has manual controls.

Additionally, check with manufacturers spec for coolant. Lots of cars now use the OAT (organic acid technology) coolants and these should not be mixed with or replaced with Ethylene glycol or other non OAT coolants. Don't rely on the colour of the coolant to determine this.

[StevieDB9]

Could it possibly be the oil cooler?

[pgarner]

whats the car again ?

chances are the oil cooler wont affect the coolent as the water would just flow through it like the rest of the pipework