I changed my coolant the other day, bleed the radiator, took the thermostat housing off and jetted water both ways through the system to give it a really good flush. Unfortunately, I couldn’t get the bleed bolt off the back engine, but with the amount of water I got everywhere I’m sure the old coolant was well and truly flushed out. What I drained out looked nice and clean (translucent green and no oil) and there was only a tiny trace of rust in the bowl, so I didn’t bother with the Holts stuff I bought.

I left everything to dry out overnight and the next day I filled up with Honda premixed coolant (£16.90 for 5l). So.. I ran the engine, 25 minutes the fan came on for about 10 seconds, another 5 min another 10 seconds of fan. All the time I’m squeezing the top and bottom radiator tubes until no more bubbles and gurgles came out of the radiator. I switch off the engine and then I noticed I FORGOT TO TURN THE HEATER TO FULL.

Oh well, I topped up the radiator, everything was running well and I still had half a litre of coolant spare.

This morning I check the coolant level in the expansion tank and it’s gone down to the minimum mark. So, I top it up and go for a drive, pull into the shops and when I get out I notice the car stinks of like a burning oil. Later on at home after my car had fully cooled down I check the coolant level and it’s back down to the minimum line.

Is this smell / loss of coolant normal? I can’t see any leaks.

Do I need to start over because I forgot to turn the heater up? The fans are blowing hot air and the idling seems fine.

Have I put in enough coolant? The radiator is still full, I’ve used the whole 5 litres and it says it only takes 3.7l in the manual.

Sorry for the long rant, but I searched all the threads about this before and I’m worried as I haven’t got a lot of experience.

The smell would have been from the drained coolant evaporating off the engine block...unless of course under pressure you have a small seep from the thermostat housing seal (this is quite common).

The drop in coolant level is also common after a coolant change but should only really drop once.

Top it up, fire it up and get it fully up to temp and then thoroughly check around any areas that you disturbed. If 100% no leaks, take for a run and leave it to properly cool overnight. Check the level in the morning again if there are no leaks it should not have settled any more than it already has.

Thanks for the advice Performance Autoworks.
I just reread my post, can I wibble on after a couple of beers or what?
Well I think I found why I lost all that coolant, I didn't tighten the bleed bolt on top of the thermostat