I've got a 1998 V70XC with 144K. I've only had the car for a week (thought it was time to upgrade from my 850) and yesterday the low coolant light came on. It would come on if I needed anything past about half throttle and would turn off as soon as I let of the gas. To add to the situation, I had it idling for about ten minutes the next morning as I was installing a car seat in it and the idle started to drop low (between 500 to 0 RPM) and would correct itself every couple minutes. No check engine light or anything. Turned it on again tonight and had no problems, even after the engine was warmed up, and I'm thinking the cooler air tonight may have had something to do with it. No visible coolant leaks, no oil around the spark plugs, no smoke out the tail pipe or the dipstick tube. I'm stumped. Any help with this would be much appriciated.

 

Maybe heater core weaping.

 

I checked the carpet, no sign of coolant, and it doesn't smell like coolant inside. It is weird though that this happened the day after I used the heat for the first time. It went through the entire coolant overflow in one day. I guess I'll pull the carpet back and check the heater core itself. I'm thinking the coolant and the idle problem are unrelated, it just seams weird that they both started within 24 hours of each other.

 

Yes check the core itself.

 

i have a similar question re: my V70. not trying to hijack your thread just seeking additional info. my car doesn't seem to lose any coolant however when i turn on the heat it smells a little like coolant thru the vents.

i've been putting it off because it's probably a very tiny leak and i know what a pain it can be to get to a heater core. so how hard is it to get to the heater core?

 

So I went to Volvoworks and had them pull up the service history on the car from the previous owner. Go figure, there was a service note from right before I bought the car saying that there was a small crack in the block to the left of the water pump. Pulled the timing cover off and sure enough I could see a spot of coolant weeping from left of the water pump. Is it worth it to try some stop leak/Bars leak or should I write this one up as a loss?

 

I would try to trace and make sure it is just not a gasket.
I have never seen one of these blocks crack.

 

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. A compression test showed the sytsem was holding pressure. The other thing I noticed when I opened the hood was that the thermostat (I think) kept on clicking on and off.

The advice I have had is to run the car until the problem shows itself more clearly! Somehow I dont think that is the solution.

I am interested to know if you found the problem...

 

I'll let you know this week when I look at it more. I just had refractive surgery so I haven't been in much of a mood to work on the car.

 

Well I opened everything up last night and cleaned up the coolant that had pooled around the water pump and ran the car for about 30 minutes with the heat on full. No coolant leak, no idle symptoms. Weird. I guess i'll just drive it for a month or so and check it again. Now I get to replace that torn cv boot I found while I was under it...