location for coolant drain plug ..but for engine

[akabond]

ya i just couldn't find the location for the coolant drain plug on the engine
side. does any know know and can share pictures?
thanks

[outnumbered]

don't think my wife will be happy
mike

[Georgeandkira]

Hello, The coolant drain is on the engine's firewall side near the oil cooler. Kira

[nickbw898]

You will not see it from above. You need to put the car on ramps and remove the under tray. View the rear (exhaust side) of the engine from below with a good LED torch. Be very careful NOT to use force or you will fracture this and repent at leisure. As an added not the HOAT antifreeze solution should be changed at the recommended interval or sooner. Failure to do so could render your auto gearbox failed as lack of anti oxidation can allow the coolant to mix with the gearbox transmission fluid. It is a very good idea to release the (water/coolant) pipes from the oil cooler because this ai the one known point in the system that collects chemical fall out - there is no known way of removing it otherwise! The other point to drain is the pet **** on the RHS of the radiator (as seen from viewing the car head on. Also be careful not top use any force on thei and do not overtighten it. Remeber that if the engine is not at working temperature the thermostat will be shut and thus there is a partial bar on draining the system. In any case for practical purposes it is impossible (DIY terms) to fully drain the system. Be sure to use demineralised water to make up new coolant mix with Vovo specified antifreeze>

[kiomarv]

Hi Nick,

I am flushing my 2001 S80 2.9 and I have a few questions for you.

(1) I emptied coolant through the block and the radiator. I noticed in your previous post above that you mentioned it was a good idea to clean out the oil cooler box. Should I remove the U-shaped return hose or the L-shaped inlet hose that attaches to a metal hose?

(2) To burp the system during the flush, should I run the engine with the expansion tank's cap loosened or even removed to allow air to escape the system? Or is it better to watch the level as the engine is running and shut off the engine once it drops too low and top off?

[nickbw898]

Sorry for delay in answering I have not had any alerts to your posting. Don't worry about burping your system these P2s sort themselves out without drama. Just make sure you have 50/50 distilled water and concentrates HOAT coolant on hand. Note you will never completely drain your coolant system, even if you disconnect the coolant lines to your oil cooler on the back of the block (facing the firewall) this is because the heater matrix will not get drained.

The "oil box" is part of the PCV system on a petrol engine. I see no connection to that system and draining/refilling the coolant system. The "L" shaped hose bundle does contain a coolant hose. This is to warm up the PCV system in low temperatures and prevent frozen pipes, but I do not think you should go there on a simple drain and fill of coolant.
I read you have an oil burner, I have never had (do not want) one of these so I will not advise you on this, except to say they have their own style PCV system and the dreaded EGR. Personally my take is oil burners are a menace to mankind and human health as should be disinvented!

[kiomarv]

Thanks for your reply, Nick. Since the system is never completely drained, is it better to flush the system with 50/50 antifreeze-distilled water rather than pure distilled water, to avoid throwing off the ratio?

[kiomarv]

Thanks for your reply, Nick. Since the system is never completely drained, is it better to flush the system with 50/50 antifreeze-distilled water rather than pure distilled water, to avoid throwing off the ratio?

[nickbw898]

I am not a fan of flushing the system but I don't really think it matters which.
It is a good move to disconnect the coolant hose connections to the engine oil cooler. The reason for this is that it is a point at which sediment is apt to collect. If you do this, even if you do not remove the oil cooler from the block you must use new seals and I prefer to use new clips too.
I think if one is removing the radiator it is worth reverse flushing it (with distilled water). The 50/50 mix is important of course. Too much antifreeze and you significantly alter the temperature at which the system reaches equilibrium. Too little and apart from risking freezing the system in winter temp (some places like Canada/North America get awful cold) but the real risk is from too little corrosion inhibitor in the system. I have had four Volvos and never had a moments worry about the coolant system. The water pumps are rock solid like the bomb proof old red block engines. I have towed boats and caravans with a 240, 740, 850 and my XC70 and never had a moments trouble with overheating.