Astra H 1.7cdti Expansion Tank

n1sar

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After driving for a while, i parked up my car. Once the it had all cooled down, i opened the coolant expansion tank and air and some coolant came out of the hole facing the windscreen. Ive done this several times now and its the same each time, is this normal or do i have a serious problem???

Thanks for any info in advance.
 
After driving for a while, i parked up my car. Once the it had all cooled down, i opened the coolant expansion tank and air and some coolant came out of the hole facing the windscreen. Ive done this several times now and its the same each time, is this normal or do i have a serious problem???

Thanks for any info in advance.
There shouldn't be a hole in your expansion tank its pressurised. Once cool, water shouldn't go anywhere.
 
There shouldn't be a hole in your expansion tank its pressurised. Once cool, water shouldn't go anywhere.

I have checked again and its the expansion tank overflow. it seems as though there is pressure in the expansion tank and when i open the expansion tank it releases pressure through the overflow???
 
I have checked again and its the expansion tank overflow. it seems as though there is pressure in the expansion tank and when i open the expansion tank it releases pressure through the overflow???

Either it hasn't cooled down enough or there's too much coolant in there...
 
I have checked again and its the expansion tank overflow. it seems as though there is pressure in the expansion tank and when i open the expansion tank it releases pressure through the overflow???

Are you filling the coolant up to the correct mark?. It's usually about half a tank on them. You don't need to take the filler cap off to check the water level especially if its hot this is very dangerous practice. Does the heater work in your car?. Does it lose any water apart from when you take the cap off.? This sounds normal for your car like him her states you are taking the cap off way to early before it cools down.
 
I have checked again this morning, and the car was left over night so should be cool. However there was still a little pressure when releasing the cap. What i also tried was driving the car between 70-80 mph once the car was warm, and when i parked up the coolant level had dropped and it looked like coolant had been pushed out the overflow. :Cry:


Someone suggested whilst i am driving to keep heaters on full, and if temperature drops i have problem, but the heaters seem to be working fine, however im not taking the car on long runs at the moment.

I am guessing this is not normal.
 
I have checked again this morning, and the car was left over night so should be cool. However there was still a little pressure when releasing the cap. What i also tried was driving the car between 70-80 mph once the car was warm, and when i parked up the coolant level had dropped and it looked like coolant had been pushed out the overflow. :Cry:


Someone suggested whilst i am driving to keep heaters on full, and if temperature drops i have problem, but the heaters seem to be working fine, however im not taking the car on long runs at the moment.

I am guessing this is not normal.

Try taking the oil filler cap off and check for any creamy white deposits, hopefully your cylinder head gasket is ok. If it looks fine then your thermostat could be faulty or the water pump is not circulating water around the engine.
 
Its normal. Unless its overheating its nothing to worry about.

When you top up the expansion bottle what happens when the car runs is that as the system heats up it pressurieses and put excess water into the expasion bottle. On some cars this bottle has a rlease valve which opens and lets excess water out if its too full.

When the system cools down it will then stuck some water back into the system and the expasion bottle will appear to have less in it than the should. Long as its in the middle of Max and Min you'll be fine.

If its constallanty draining it then i think you may have a leak and should get it checked.
 
Oil is not creamy and coolant is clean. all pipes are hot once car warms up, does that mean thermostat and water pump are fine?
 
It looks like its not draining any coolant however pushing it out the overflow?
 
Try changing the cap on your expansion tank. it has a valve in it that could be broken.
 
I have changed the cap on the expansion tank and no difference. However when i took the car for straight run on dual carriage way i noticed the heaters went cold when i increased speed rapidly, and when i went to 80mph the yellow spanner above the car light came on but went off later.

Well i then changed the Thermostat and have had a Block test done which came out fine. However i still have the same problem with coolant coming out of overflow when im driving on a long stretch of road. Also Heaters still going cold when speed is around 80 or speed is increased quickly.

Any idea, i am lost?:Smileysex
 
I have changed the cap on the expansion tank and no difference. However when i took the car for straight run on dual carriage way i noticed the heaters went cold when i increased speed rapidly, and when i went to 80mph the yellow spanner above the car light came on but went off later.

Well i then changed the Thermostat and have had a Block test done which came out fine. However i still have the same problem with coolant coming out of overflow when im driving on a long stretch of road. Also Heaters still going cold when speed is around 80 or speed is increased quickly.

Any idea, i am lost?:Smileysex

You either have an airlock in the matrix or radiator. Failing that your water pump is partially seized. get it checked out at your local garage and get the timing belt done, and the roller and tensioner replaced at the same time.
 
You either have an airlock in the matrix or radiator. Failing that your water pump is partially seized. get it checked out at your local garage and get the timing belt done, and the roller and tensioner replaced at the same time.


Water pump was changed not so long ago, but i have had it checked and it is working fine. How would i get rid of the air lock if it has one?? I suppose whilst changing the thermostat it could have created an air lock issue, however i have been to the garage and they assured me after the block test and changing the thermostat all will be fine. :handball:and still whatever the problem is it is definately persistant.
 
How well do you know the guy at the garage? I would take it back and tell him its not fixed. Try this test from cold tomorrow and let us know the outcome.

Start the engine from overnight stone cold and run for one minute then;
feel the top hose - is it hard?
Open the expansion tank cap - was the coolant pressurised?
Rev the engine, can you see bubbles in the coolant?

Yes to all three suggests the head gasket needs replacing.
 
How well do you know the guy at the garage? I would take it back and tell him its not fixed. Try this test from cold tomorrow and let us know the outcome.

Start the engine from overnight stone cold and run for one minute then;
feel the top hose - is it hard?
Open the expansion tank cap - was the coolant pressurised?
Rev the engine, can you see bubbles in the coolant?

Yes to all three suggests the head gasket needs replacing.


The mechanic i went to is very reliable and as far as i am aware. He said he can check out the problem for me but it will cost me quite a bit as the problem could be anything. Especially as he has done block test. However i tried your method several times and i had no bubbles in the tank from reving the engine but coolant flowed back into expansion tank via return hose. Also there was slight pressure in the expansion tank after 1 minute but nothing out of the ordinary.

I think the top hose does go hard though.

Head gasket?
 
The mechanic i went to is very reliable and as far as i am aware. He said he can check out the problem for me but it will cost me quite a bit as the problem could be anything. Especially as he has done block test. However i tried your method several times and i had no bubbles in the tank from reving the engine but coolant flowed back into expansion tank via return hose. Also there was slight pressure in the expansion tank after 1 minute but nothing out of the ordinary.

I think the top hose does go hard though.

Head gasket?

Its looking that way mate :( get it checked ASAP to confirm this get your man to do a sniff test on it. It could work out expensive though if it is the gasket so be warned. Head re-skim, gasket, water pump, timing belt, new bolts. It could cost you 600.00 upwards. :(
 
Its looking that way mate :( get it checked ASAP to confirm this get your man to do a sniff test on it. It could work out expensive though if it is the gasket so be warned. Head re-skim, gasket, water pump, timing belt, new bolts. It could cost you 600.00 upwards. :(

I asked for the sniff test to be done and he said it is the same as the block test we did. However it came out fine. But i asked him to do it again and it was fine again. Oh i double checked the top pipe is always hard even when the engine is cold. One thing i have been monitoring for a while is the fan. what temperature should the fan come on as mine comes on around 95-98. Is this also normal.
 
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