Rich's BB4

[Rich]

OK so I removed the radiator cap and it is full to the brim. The engine was cold so it wasn't expanded or anything. The white reservoir near the radiator had just a bit of fluid in it though... Is this meant to be full or is it just an overflow tank?

If that is sign of a leak then I can't one anywhere obvious but there was a little bit of moisture around the water temp sensor that the previous owner recently fitted (one of these):



If that reservoir is just an overflow then perhaps some air got into the system when he fitted the new hoses.

In any case, I am tempted just to re-fit the black hose until I am ready to wire the water temp gauge up.

[Merlin]

There is a max and a min on the expansion tank bottle. I think the max is where the bottle starts to get fat.

[Rich]

Cheers! I will take a look, I think it's low though (depends where the min/max lines are though).

I'm not sure if the previous owner used Honda coolant so I may need to flush it all out and re-fill, but to get me by I might just buy some cheapo stuff from wherever I can get it (unless you would advise otherwise).

If there is a potential air lock but no leak, I may just drain it and re-fill it with the existing coolant - is that safe?

[indigolemon]

IMO there's not any need for the Honda coolant. As long as you don't mix OAT non-OAT coolant you'll be fine to top up. I used the Halfrauds stuff for mine (get it cheap with the trade card).

[Rich]

IMO there's not any need for the Honda coolant. As long as you don't mix OAT non-OAT coolant you'll be fine to top up. I used the Halfrauds stuff for mine (get it cheap with the trade card).

Cool, shame I just bought 7 litres of the stuff then for £27 odd. Nevermind, it'll get used.

[BMCC]

I have taken the top hose off twice and never got any air in the system. Bottom hose is a different story.
As for your temp sensor you need to put a bit of PTFE tape on the threads and make sure it is tightened right up.

[Rich]

I have taken the top hose off twice and never got any air in the system. Bottom hose is a different story.
As for your temp sensor you need to put a bit of PTFE tape on the threads and make sure it is tightened right up.

Cheers, will do. But for now I'm just gonna stick the black hose back as the sensor is no use until I wire it all up.

The bottom hose has been changed too - they were both replaced with blue silicone hoses. I bet the gunk on my undertray is residual from when that bottom one was replaced because I've just checked & the coolant is at an ok level.

Before I check for air bubbles I'm just giving the IACV a clean out.

[Rich]

Just gave the IACV a clean, was a surprisingly easy job; just a couple of hoses, a couple of bolts and a harness to undo and it was off...

Looked like this when I first removed it:


Sprayed in a bit of this:


Then a few sprays later it looked like this:


Not perfect but much cleaner. I turned over and it seemed loads better; idle remained constant - even after a quick rev (it usually drops then conks out). Idle was at 1500RPM is that normal?

I had a few cans watching the England match so cannot take it for a drive yet, so will check it properly in the morning. Hopefully it has sorted it out! (fingers crossed)

[BMCC]

Fast idle is 1500 rpm ish (cold start) then when up to temp it should be 700-750 rpm. The revs should drop from 1500 to 700 ish over time (as the FITV closes) and the engine gets up to temp

[Rich]

Fast idle is 1500 rpm ish (cold start) then when up to temp it should be 700-750 rpm. The revs should drop from 1500 to 700 ish over time (as the FITV closes) and the engine gets up to temp

Nice one, cheers!