I have the 2002 XC70. Its leaking coolant (about 750 ml every 100 km), but there is no sign of a leak. The engine oil looks ok (not milky). There is no dampness under the carpets. Also when the engine gets warm the idle feels a little lumpy. The temperature gauge is normal, eeven when the coolant is low.

The other thing I noticed when I opened the hood was that the termostat (I think) kept on clicking on and off.

I had it in the shop and they cant find anything - but clearly there is a problem using som much coolant.

Any diagnosis? solutions?

 

I can only assume the leak is very slow. I would first suspect the radiator itself. However, the best thing for you to do is to have the cooling system pressure-tested at a reputable garage. This should reveal possible leak.

I can also suggest.....

- White powderish residue all along the coolant-carrying lines, especially the connections/seams.
- The reservoir cap.
- Water pump, which I assume is hidden by the timing belt cover.

I am not privy to the XC70s, so I'm moving this to the XC70 forum.


JPN

 

An old timers trick is to also place a big sheet of cardboard under the car when you put it away for the evening. In the morning you will be able to see if it is a static leak (i.e still leaks when the car is NOT running) and also it will give you a clue as to where it might be leaking from. I would also pull out the coolant reservoir bottle and see if it is leaking from the bottom of it

 

Another possibility is that the cooler in the radiator for the transmission has a small leak and coolant is getting into the tranny fluid.

 

I had a pressure test done, and the cooling system appears to hold pressure. I will try the cardboard under car trick to see if there is a static leak. However, I suspect that the leakage happens when the engine is hot.

I have noticed that the gear changes have started snatching a bit. Would this happen if coolant was leaking into the tranny?

Does the fact that the engine idle is uneven when hot provide any clues as to where the coolant may be going?

As I noted the oil looks fine, and the exhaust emission doesn't seem out of the ordninary.

Many thanks for the feedback, I feel like I may be making some progress at last!

 

The idle does not lead to anything. Sorry

How does the tranny fluid look?

 

Tech has a point, Check the tranny fluid. It should be a semi-bright red (if new) of reddish brown if it has a lot of miles on it. ALso it should not smell burnt

 

I got the test done to see is engine gasses were getting into the coolant. This was positive (liquid cahnged colour). Seems it was a blown head gasket - between cylinders 3 and 4.

However, I am wondering what caused the gasket to blow. The car has never overheated, and it has never been driven hard. Is it possible that there is an underlying cause for the gasket to blow?

I near changes have been a bit jerky and it seems to ****** a bit. Could that be related, or is my car just getting old?

 

Are you having transmission problems, too?
I was just reading about how there is a problem with the coolant leaking into the transmission on this particular car. It's a design problem. Something to look into anyway. Good luck!