Volvo Repair: Coolent warning light 960 1997 Sedan, blown head gasket, intake manifold gasket

Question
My wife and I bought a used (58,000 miles) 1997 960 (no turbo) Sedan from a local Volvo dealership two years ago. Had Volvo multipoint vehicle inspection. We have put on 25,000 miles and had gotten an additional two year/24,000 mile warranty (now up).  Starting in September the coolent warning light started coming on and going off when driving.  Coolent level OK and no overheating. My local mechanic (works on Volvos, BMWs, and Mercedes)changed the intake manifold gasket and changed the belts.  No improvement.   One month later found a coolent leak in radiator so with light coming on.  He replaced radiator.  Light then came on again.  He changed radiator cap and coolent reservoir.  Then the light came on all the time.  Took it to another Volvo dealership.  They tell me coolent was seeping from possible cylinder head.  Told me blocks have occasionally been found to be pourous.  Checked hydrocarbons in coolant system 1st it went to 3000 PPM came down to 696 PPM.  Warranty people wont pay to remove head and inspect.  Volvo wont help me either.  What should I do.  I don't want to buy a new long block or pay a lot of money.  do I dump the car?
Thanks
Zev

Answer
The coolant warning light isn't very smart, there's only one sensor that can turn that light on and thats the coolant level switch in the resevoir.  The dealer may have been taking you for a ride when they replaced all those other components.  Its true that it may have an internal leak into the engine but unless you are seeing white smoke out the tailpipe, its not that serious of a problem.  If it is though, you've got a blown head gasket and you're talking major dollars to get that fixed (especially since the heads usually crack at the same time the gasket blows).  The PPM numbers can only be made with an exhaust analyzer and all he did to get that number was open your radiator cap and stick the probe over it.  Those numbers aren't able to be very accurate.  If you aren't haveing to add coolant, be sure to triple check that sensor, it will stick sometimes and since everytime they do something to the car the condition changes it sounds like its just getting banged around.  You can try bypassing the sensor (either unplug it or twist the wires together, one will light the light, the other will turn it off can't remember which), or possibly replacing it but if that doesn't get it, i would consider dumping it cause it'll take too much to find the problem let alone fix it.  Hope that helps.

James