accord type r cooling issues

Hey all!

I’ve got a really weird issue where I drive the car 30miles each way daily and I don’t get a problem. Soon as I drive to London from Swindon the car goes ¾ up to max temp when stationary. When moving again the temp goes back down. I've checked coolant etc and what I do notice is bubbling coolant in the expansion tank. I've now been monitoring it over a few weeks and from what I can see is the coolant is clearly evaporating somewhere in the system as I need to top it up. No white/black/blue smoke from the exhaust.

When I bought the car it had nothing but water in the cooling system so I flushed it and fill it with red coolant (I wasn't sure which one to use and had some of this left which i use on the skyline so thought if it's good enough for that, it's good enough for the 'R') and I've not had a single issue with it up until the other week where I topped it up.

Any help will be appreciated as I'm in the process of ordering a new rad cap and thermostat as I know Honda will give me the 'we don't stock these parts.......' line.

Cheers!

You have air in the system, its boiling, and its heating up. Its getting cooled down by airflow when moving with normal speeds Id take a look for a cracked/split coolant hoses. More likely the smaller ones, like the ones that pass through the throttle body for example.

Type R section posting, does this mean you have one?

Hi Marcus. Yeah I got one. Thought I'd payed it up a while ago. ... I've checked all the main hoses for leaks and did clean up the bay to potentially spot any leaking areas but it was a fail. I will check again but think I might just change the cap and stat to be sure. ..

Hi Marcus, I had the very same problem, and it did turn out to be air in the system. I had to bleed mine 3 times after I changed the coolant to get all the air out.

Best not to mix different types of coolant without knowing the composition of what you already have in the engine and what you're putting in... silicate/phosphate/OAT corrosion inhibitor types are incompatible and - worst case - can lead to sand-like particles forming in the engine waterways and causing wear (esp. waterpump).

If in doubt, drain the engine and then top up with phosphate or OAT type (avoid silicate types).