Doing my coolant change and cant find the drain bolt on the engine. I know i can just use the bottom rad hose but want to do a full wash out.

I have looked in the manual and cant figure out what it is pointing to can someone put up a picture pointing it out for me or describe it in the minutest of detail.

aftermarket rads like Koyo have a white screw plug drivers side you can reach it from underneath...IIRC stock rads dont have a plug you have to remove the lower hose to drain

Didn't know there was one.

Just take the hoses off the front of the engine and flush it through with a hosepipe.

Same for the rad.

I might change the coolant in mine.

 

I think it's a job plenty of garages ignore at service time or if they do it, don't use distilled water/antifreeze.

 

Old coolant or a regular water / antifreeze mix isn't going to do anything (especially the heater matrix) any good.

 

 

Is it a big job?

Will it all come out if you take the rad and engine bottom hose off? I guess the overflow bottle would need draining too?

a nice gentle way of doing coolant change and this will aviod blasting the system with a hose and possibly jamming gunk and particles into the fine water channels and blocking them up at the same time is to run the engine with rad cap off and a hose trickling into the neck after 1 hour of so the entire system should be purged with clean water...then drain rad and top up with 4-5 litres of coolant...job done

> cant find the drain bolt on the engine.

 

there are 2 on each side of the engine.

very hard to reach with the engine in the car.

You'll need to remove both alternator and aircon compressor to be able to access the drain bolts

My rad has the white drain plug near the bottom pipe but its a stock one i thought?

it is not the plug on the rad i am talking about but the drain plugs on the engine block so whatever is held in there after rad drained can be emptied, but by the sounds of it it is more trouble than it is worth. However, in the owners manual it does say anything about removing any components it just shows a pic where it appears to be close to the oil filter.

 

UNO's idea sounds good though but im not sure if i totally understand it. Running the engine with the rad cap of will make water pour from the top neck all over the engine bay so do you suggest attaching a hose to that neck to direct the water into a bucket? if so where do you drip the continuous stream of water in?

it is not the plug on the rad i am talking about but the drain plugs on the engine block so whatever is held in there after rad drained can be emptied, but by the sounds of it it is more trouble than it is worth. However, in the owners manual it does say anything about removing any components it just shows a pic where it appears to be close to the oil filter.

 

UNO's idea sounds good though but im not sure if i totally understand it. Running the engine with the rad cap of will make water pour from the top neck all over the engine bay so do you suggest attaching a hose to that neck to direct the water into a bucket? if so where do you drip the continuous stream of water in?

 

the coolant just trickles out when running the engine with the rad cap off so make sure the hose is trickling in at roughly the same rate...the overspill will run down the side of the rad neck and onto the floor....you shouldnt get a geyser erupting over the engine bay unless you floor the throttle or have some sort of air lock which burps up :hurl:

HTH

:)

Someone on here suggested flushing with Central heating 'Fernox' which reduces the build up of corrosion a while back. Not sure if it's safe enough, but this or rad flush for one decent journey after flushing with a hose would also be an idea before adding your antifreeze to the final coolant mix!

I would leave the drain plugs if i were you, they wont of moved for 15 years so if you turn them theres a good chance of them shearing, if they do this when they are loose youll more or less have a fooked engine.

 

If you take the stat out then re attach the metal pipes and put the top rad hose pointing up and blow down the hose (with your mouth) you will see the water gush out of the bottom rad hose.

 

It makes you go a bit light headed but its the best way i know of getting most of the water out.

 

Hope that makes sense

did mine a few weeks ago.

didn't bother with the block drain plugs just flushed it through at the top and bottom hoses.

Bit of advice... the drain tap at the bottom of the rad is a bugger to get at without elevating the car as the rad is quite far back almost out of reach, so i wouldn't bother with that either, just disconnect the top and bottom hoses, HOWEVER - detach the hoses at the rad and not the aluminium pipes as these pipes get corroded with age and I had to use a load of PTFE to get the hoses to re-seal on them :(

 

The other thing is when everything is back together you'll suddernly realise "SHIT! - I forgot about the expansion tank" - I syphoned it using a length of clear hose, refilling each time it got near the bottom untill the syphoned collant in the clear hose went from chocolatey brown to clear.... The syphoning only made me vommit twice :hurl:

did mine a few weeks ago.

didn't bother with the block drain plugs just flushed it through at the top and bottom hoses.

Bit of advice... the drain tap at the bottom of the rad is a bugger to get at without elevating the car as the rad is quite far back almost out of reach, so i wouldn't bother with that either, just disconnect the top and bottom hoses, HOWEVER - detach the hoses at the rad and not the aluminium pipes as these pipes get corroded with age and I had to use a load of PTFE to get the hoses to re-seal on them :(

 

The other thing is when everything is back together you'll suddernly realise "SHIT! - I forgot about the expansion tank" - I syphoned it using a length of clear hose, refilling each time it got near the bottom untill the syphoned collant in the clear hose went from chocolatey brown to clear.... The syphoning only made me vommit twice :hurl:

 

 

 

Detach the hose from the aluminium pipes, not the radiator, leave that hose attached, the reason for this is that the inlet pipe to the rad becomes extremely brittle with age and if you pull the hose off, often the pipe breaks.

Remove most of the corrosion from the aluminium pipe and seal it using sealant, obviously leaving it to let it set.

 

Never syphon using your mouth antifreeze is extremely toxic, if you had just let the overflow tank tube drop to the floor it would have drained out.

 

The reason why you gently flush the system while the engine is running is that, the thermostat will open and allow you to flush the block more readily. If you just stick a hose into an opening you will trying to flush against a closed thermostat.

 

Refill the cooling system with antifreeze to 50% of the coollant system capacity, as you will already have some of block containing unmixed water!