Welcome to the joys of classic Volvo ownership.
The method I use for a thorough coolant system flush is to disconnect the bottom radiator hose at the radiator and remove the thermostat, temporarily replace the thermostat housing, stick a garden hose in the bottom hose facing towards the water pump and run both the hose and the engine until the water flows out of the bottom of the radiator clear. Remember to have the heater control set to maximum heat to get water to flow through the heater matrix.
Google Gibbons Method for a similar approach to flushing the automatic transmission fluid. If the fluid is heavily contaminated it will be advisable to drain the pan, refill and run for a bit first to avoid shocking the system with brand new fluid. If you employ this method you will need considerably more fresh fluid than the capacity of the system. I usually use at least 2.5 gallons.
If your car has had a recent top camshaft seal the oil leak that preceded this is almost certainly responsible for the failure of the water pump top seal.
Replacing the water pump is quite an easy DIY task as it does not involve disturbing the timing belt. There is a bit of a knack to compressing the top gasket correctly and getting the heater bypass pipe to seal. I find the latter is best achieved by fitting the gasket onto the pipe dry and greasing the outside edge of the gasket and/or the hole in the back of the pump. I tend to use o-ring grease to encourage this gasket to swell a bit and create a more effective seal. Before refitting the pump with new gaskets ensure all the mating surfaces are completely clean with no traces of corrosion or old gasket otherwise you will get leaks straight away. I use a Dremel with a brass wire brush for this.
The biggest clue to HG failure is a smell of exhaust and retained pressure in the coolant header tank when cold. If you're getting this then the excess pressure is quite likely to be causing coolant leaks that you wouldn't have if the cooling system were working normally. Your car is at about the right mileage for its first HG failure. Is there any record of it having been replaced before?
I won't pass comment on your low idle on startup problem. If you read my recent saga you will see I'm still struggling with a similar problem combined with misfire and serious lack of power.
Good luck getting your issues sorted out. These cars are well worth the effort when they're working well. Many on here will sympathise with it seeming like everything is failing at once.
|