Hi guru's,

My cars done 40k miles so I thought I'd better give my engine a coolant flush and then fill with fresh coolant.

I was able to start to drain the car fine (rubber screw on drivers (USA) side bottom of radiator in case people don't know) however only a gallon came out. Should i be concerned about that? I thought about 4 gallons would come out.

When I went to fill with distilled water for the flush (turned on the heaters full first), I started the engine, ran engine at 2000rpm, and the water is going into the expansion tank extremely slowly, I think I have either a blockage in the overflow to engine tube, I'm doing something wrong, or something else is wrong.

Hot air is coming out of the heater vents, the water in the expansion tank has steam coming off of it, and it's been running for about 1 hour now, and it's taken less than 1/2 gallon. Should I be concerned about this? It hasn't taken any more for 30 minutes.

Shouldn't the car have drained at least 3 - 4 gallons, instead of just a gallon? I did run the engine for 20 seconds twice to assist the draining. Could there be a coolant blockage somewhere?

I do realize now that I had topped it up with over a gallon of concentrate over the last 2 years, perhaps without adding distilled water. Could that have congealed the coolant? The stuff that drained was fairly watery (see pic)

Thanks in advance for any advice. I'm afraid to drive the car now until I know things are OK.

 

What engine is it ? Modern engines tend to have less coolant in them than the old "bruisers", but a gallon seems rather little. The only thing I find a bit disconcerting is you pouring in undiluted coolant into the engine. However, it would soon mix with the coolant already there, so I don't suppose it's done any harm. There are related threads lower down on this one that give clues on drain volumes.

 

Should have mentioned I have the 5.0L V8 (non-super charged).

After recalling that I had not added water when topping up previously, I added a gallon of distilled water only, no anti-freeze, today.

Other people have mentioned large drain plugs on the side of the block in other posts, but I saw nothing like that on my engine (2011 XF 5.0L). I did not remove the wheel well liner though, as some people have. Does it have one?

 

I just drained and refilled with new coolant my 2L petrol XF.
On that car there is a vent plug to purge air when refilling.
It is a plastic item fitted to a plastic pipe which looks like it goes thru the firewall for the heater.
You unscrew it maybe 3 or 4 turns and that allows air to escape.
I bet the V8 engine needs one too.

Very hard to figure out where the vent plug is without the workshop manual.
On refilling it took a lot of effort to eventually make sure the cooling system was 100% full of coolant.

 

Thanks, I'll look for the purge vent near the heater entry point. That would certainly assist with releasing more coolant.

I have the manual and it shows a plug on the block, but it was incredibly vague about where it was, and what it looked like, so i couldn't find it. The manual also didn't mention a heater valve either. Seriously, the manual is not that great.......

BTW anyone know where I can get a new radiator drain plug?, as the existing one is getting worn around the screwdriver slots. It looks exactly like this one for the XK of around the same vintage (2009 - 2015), but i can't be 100% sure.

 

The drain plug is a cheap piece of sh*t, the plastic far too soft so the slot can be easily damaged.
You could use JB weld or something to fit an extension to it, maybe a bolt or a bit of hexagon brass/aluminium.
If you shape the end that fits the slot of the plug should be fairly solid.
Make sure the extension will not foul anything as you try to put the plug back.
On my car that plug is very difficult to get at and no easy thing to put back either.