Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: Redeye on 30 August 2006, 07:43:12
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I had the Coolant Level warning displayed when I got in the car this morning and when I checked, the water was down to the bottom of the tank. I've noticed I've been having to top it up every week recently. I've checked the oil and that is fine, there doesn't seem to be any evidence of it leaking from the filler cap. How can I find where it's leaking from, are there any common places?
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Favourite suspect, if you have a/c or ecc, is the hbv (Heater Bypass Valve). On a V6 this is behind the drivers side bank of cylinders (whip the scuttle off to see).
Sometimes they only leak if on or if off, so you may get intermittent loss. Cost around £25 + VAT from dealer.
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Thanks for that, sounds promising, I'll check that out.
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If it is the HBV you'll want to get it changed ASAP because it may be dripping onto your dis pac, which will obvioulsy kill it eventually....
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Sadly, my money is on the oil cooler.... :(
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The HBV is likely to cause a visible leak going down the back of the engine and under the car (though it is true that if the leak is small it could still evaporate along the way, but then it wouldn’t be bad enough to have to top it up every week)
An oil cooler leak will transfer coolant into the oil because of the higher pressure in the cooling system, and the coolant will then evaporate when the oil heats up. Only if you run the car for short journeys with a cold engine will you see the mayo effect in the oil immediately.
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The HBV is likely to cause a visible leak going down the back of the engine and under the car (though it is true that if the leak is small it could still evaporate along the way, but then it wouldn’t be bad enough to have to top it up every week)
An oil cooler leak will transfer coolant into the oil because of the higher pressure in the cooling system, and the coolant will then evaporate when the oil heats up. Only if you run the car for short journeys with a cold engine will you see the mayo effect in the oil immediately.
Oil cooler will show signs of oil in coolant. The project car, which suffered oil cooler failure, showed no signs of water in oil.
You don't always see the hbv leak, as sometimes it only leaks in 1 position, sometimes only leaks whilst its changing position...
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Well I hope for Redeye's sake that it is the HBV and not the oil cooler....
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couldn't agree more....
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Thanks for the help guys, what I can say is, there are no signs of oil in the water and there are no signs of water in the oil, I'd say I lose about a quarter pint of water per week.
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When my HBV went, i had some water staining on the back of the engine and a drip underneath the car, some signs to look for !!!!
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Try and work out when the coolant leaks.. if it is the HBV then as Theboy says it may only leak on certain Climate settings (mine dumped the lot on Lo, no problem on Hi).
If you are able, remove the scuttle so you can get a decent sight of the HBV and then try the Climate in different settings. (putting it to Lo would be my first start). Then get a good light on the HBV and see if you can see the leak.
HTH
Merv
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Just changed my rad for the sole reason I was topping up quite alot, I found a small crack in the top plastic and it was trickling down the back of the rad leaving a nice little circular patch right under where the rad drain tap was.
Check all your pipe work possible cuts etc could be causing your problem.
Worth a look. :)
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The HBV is likely to cause a visible leak going down the back of the engine and under the car (though it is true that if the leak is small it could still evaporate along the way, but then it wouldn’t be bad enough to have to top it up every week)
An oil cooler leak will transfer coolant into the oil because of the higher pressure in the cooling system, and the coolant will then evaporate when the oil heats up. Only if you run the car for short journeys with a cold engine will you see the mayo effect in the oil immediately.
The oil pressure will be 30 - 50 lb/sq" and water pressure 7 - 15 lb/sq" so , with the engine running and a failed oil cooler you get oil entering the coolant and mayo in the coolant tank.
Hidden things to check:
Heater bypass valve and hoses
Coolant bridge seals
Oil cooler cover-block seal
Thermostat housing - block seal