Engine: 70: V70 Coolant Problem - help needed please

[Adriansewell]

hi, thanks for the replies. I bought a genuine pressure cap a few days ago. I slowly removed the old cap when the engine was warmish and the coolant level rose to slightly above the max line. I fitted the new cap. I checked the coolant level this evening (2days after fiting new cap) and the level was halfway between max and min. The engine was cold and the level rose slightly when loosening the new cap. So, it appears the problem still exists...any other ideas? I do no like the sound of micro cracks in the block! any furher help appreciated. cheers.

[Georgeandkira]

Hello, I'm not sure what a sniff test is. The thing I would expect done, in part because it's so easy to do, is a compression check. Remove the spark plugs. Screw in the compression gauge into cylinder #1 and crank the engine so the needle pulses 3 or 4 times. Do each cylinder the same number of pulses. Kira

[ShadeTek]

A sniff test test checks for any combustion chemicals from the chambers, which has leaked into the coolant. If the test is positive, then it can be the head gasket or cylinder block.

[Georgeandkira]

Hello, Thanks for the education, seriously. I had never heard of the "sniff test". To Adriansewell: You should do a compression check anyway. It's soooooo easy and cheap to do. Kira

[kicku]

If leaking water only, you will not find high pressure when remove the cap at COLD engine. High pressure means when remove the cap and water will rise more then 2-3 cm in the expansion tank. If this happens mostly you have an internal leak (head gasket hope). If this is not happening but the water continous vanishing without pressure in the tank (when at cold engine removing the cap) mostly you will have leaks on hoses or so.

[JXBURNS]

I had a similar problem but coolant dropped over 2-3 weeks; not days. When I took to garage they found, after several days, that the intercooler had moved back somehow and had been rubbing against the radiator resulting in a pin hole which was definitely not obvious. It was only when the pressure tested the system did they find the answer.

And the cause? I remembered accidentally hitting the front of the car at very low speed on a high step outside a house when getting out of a tight spot some 2 months earlier. Upon inspection the plastic grille under the numberplate was cracked. This had been pushed back into the air con condenser which in turn pushed into the intercooler and then into radiator. £500 quid worth of damage later...

Not saying this is the reason here but took ages to work out what it was.

John

[BarryCambs]

I had exactly the same symptoms and it turned out to be the head gasket. However, it did show up with a sniff test, which you have already had done. I don't know how sensitive they are, as it took a while to get a positive reading from mine. I'm not sure what else could cause the system to be pressurised, which it clearly is.

[Adriansewell]

thanks for all the replies. funnily enough John, our car also has a cracked grille under the number plate which was as we bouight the car so it could well be in the radiator...but I do not want to change the rad and still be left with the same problem.

so would a compression test show up a blown head gasket or, even worse, cracks in the block? i.e. what is the best way of determining a blown head gasket before looking at other things like replacing the rad?

cheers all.

[kicku]

Originally Posted by Adriansewell

thanks for all the replies. funnily enough John, our car also has a cracked grille under the number plate which was as we bouight the car so it could well be in the radiator...but I do not want to change the rad and still be left with the same problem.

so would a compression test show up a blown head gasket or, even worse, cracks in the block? i.e. what is the best way of determining a blown head gasket before looking at other things like replacing the rad?

cheers all.

Compression test will not let you see nothing until the leak is very big. Maybe remake the sniff test it's a good idea.

[Georgeandkira]

Hello, Having to do any diagnostic test a second time with a second tool or even a second technician wouldn't be a first. Yes, a compression test has a crude side. That's why you do them on the engine cold, then hot. If piston seal is in question, the test is done cold then with oil shot into the cylinder. In this case a leak down test with compressed air might be in order. The hose blowing off turns me away from a radiator with a hole. Is there any visible "frostiness" (evidence of coolant residue) on the lower reaches of anything? Kira