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Cooling system and heater diagnosis ?

HarryVY

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Hey guys got a couple of cooling system related problems...
1. About four days ago the heater stopped blowing hot air when turned on. I know the car should be up to operating temperature as I drive half hour to work, but when I turn the fan on it just blows cold air. I haven't had much time to attempt to figure out what's wrong as I've been doing a lot of overtime at work and don't have a garage to work on it at home, but the heater hoses appear to be ok.

2. On my way to work this morning, I noticed as I was going also through a roadworks zone that the temp. gauge had risen up to 3/4. I hadn't been working the engine hard at all leading up to this (was just cruising at 80kph and it was only 6°C this morning).
I took it easy the test of the way to work (60kph), and after Is parked the car, I popped the bonnet.and felt the radiator hoses. Top was at normal operating temps but the bottom hose and the radiator cap were cold, and the hose when squeezed felt like it had nothing in it.

The engine itself was no where near boiling temp when I felt the rocker covers.

Same thing happenened on the return journey home, and the temperature gauge returned to it's normal position (1/3) as I pulled into my street.

I figure that either the thermostat is blocked (though top hose was at normal operating temps.), or the radiator is blocked (stopping the hot water from heating the bottom hose)???

Any pointers would be much appreciated :)
 

edals

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Try bleeding the system first. Sounds like you have a air lock in the system. Make sure the cars up to temp, heater turned on max heat and open the bleed screw in the top of the thermostat housing, its just where the top hose connects to the block.

The bottom hose is the cool side, top hose is the hot side.
 

HarryVY

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edals:2838682 said:
Try bleeding the system first. Sounds like you have a air lock in the system. Make sure the cars up to temp, heater turned on max heat and open the bleed screw in the top of the thermostat housing, its just where the top hose connects to the block.

The bottom hose is the cool side, top hose is the hot side.

Ok then I'll give that a go. Thanks!
 

rambunctious

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Hey guys got a couple of cooling system related problems...
1. About four days ago the heater stopped blowing hot air when turned on. I know the car should be up to operating temperature as I drive half hour to work, but when I turn the fan on it just blows cold air. I haven't had much time to attempt to figure out what's wrong as I've been doing a lot of overtime at work and don't have a garage to work on it at home, but the heater hoses appear to be ok.

2. On my way to work this morning, I noticed as I was going also through a roadworks zone that the temp. gauge had risen up to 3/4. I hadn't been working the engine hard at all leading up to this (was just cruising at 80kph and it was only 6°C this morning).
I took it easy the test of the way to work (60kph), and after Is parked the car, I popped the bonnet.and felt the radiator hoses. Top was at normal operating temps but the bottom hose and the radiator cap were cold, and the hose when squeezed felt like it had nothing in it.

The engine itself was no where near boiling temp when I felt the rocker covers.

Same thing happenened on the return journey home, and the temperature gauge returned to it's normal position (1/3) as I pulled into my street.

I figure that either the thermostat is blocked (though top hose was at normal operating temps.), or the radiator is blocked (stopping the hot water from heating the bottom hose)???

Any pointers would be much appreciated :)

The heater tap is usually operated by vacuum, so if you have lost vacuum to the tap or to the control in dash then this could be the problem.
Have you checked the vacuum at the tap by removing the hose while the engine is running ?
Also, is the heater tap operating as it should when you use the dash lever to operate the heater ?
 

HarryVY

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VSHeaven:2838877 said:
Ok then I'll give that a go. Thanks!

Are you losing any coolant?

Pulled the bottom radiator hose off yesterday, and only 1 litre came out... Not sure where it's going, but I don't have any cross oil contamination so not a head issue.
 

HarryVY

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Ok I'll have a look at the vacuum lines running to the heater tap over the weekend thanks
 

Chetz

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Hi Guys

I have a problem with my Commodore Vyii Executive and ill try and describe it as best as possible.

So i was driving it around recently and i noticed that the temperature dial had crept up to about half way which is unusual as i had only driven it less than 5Km and usually the dial would not shift from the cold marker. I kept an eye on the dial as i was driving and all of a sudden the dial shot up to the top and the the dash board started telling me the temperature was too hot so i pulled over quick time and the temperature started to drop again. The top pipe from the radiator felt Hot and was under pressure and I believe that is normal and there is water in the reservoir but im really not sure whats going on. I was hoping that someone here might have had this same or similar issue ad will be able to help me out.

Thanks in advance
 

HarryVY

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Chetz:2840360 said:
Hi Guys

I have a problem with my Commodore Vyii Executive and ill try and describe it as best as possible.

So i was driving it around recently and i noticed that the temperature dial had crept up to about half way which is unusual as i had only driven it less than 5Km and usually the dial would not shift from the cold marker. I kept an eye on the dial as i was driving and all of a sudden the dial shot up to the top and the the dash board started telling me the temperature was too hot so i pulled over quick time and the temperature started to drop again. The top pipe from the radiator felt Hot and was under pressure and I believe that is normal and there is water in the reservoir but im really not sure whats going on. I was hoping that someone here might have had this same or similar issue ad will be able to help me out.

Thanks in advance

Sounds like you have a coolant leak mate. If it's leaking, the gauge will shoot up momentarily as the remaining water inside the system becomes very hot, before it then leak out. The temperature gauge will then plummet as there is no water surrounding the sensor for it 'sense the temperature of', if that makes sense.
If you didn't drive it too far following this event, then hopefully the engine will still be okay. I'd be draining the remaining coolant/water, and filling it with new coolant mixture before getting a cooling system pressure test done. You may well have a leaky radiator hose, or your water pump may have gone. Hope that helps let us know how you get on :)
 
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