Head drain tap blocked

[quirky292]

Hi everyone

Thought i better service my moggie as shes been laid up in the barn for 4years so given her a treat as im the new owner.
Just flushing the radiator through and took the bottom hose off and the water is rusty colour brown, nothing unusual here, so i though i would just run water through until clear, then i put the hose back on and opened the tap on the block and to my surprise nothing happened. I took the tap off and blow out with air and a handful of debris came out. at this stage i left water in the rad but nothing came out, i had a good old poke around with a drill bit (using my hand not a drill) i managed to get the bit in as far as 3inches or so and with a 1inch of rubbish on the end.

Is there anything i could do or use to try n unblock this? ive been recommended to use costic soda

Thanks Jon

[bmcecosse]

Scrape about with bent wire (coat hanger) etc - if it won't come clear then yes try some caustic or drain cleaner but don't leave in for more than one heat cycle. And then flush a couple of times....and refill with antifreeze!

[quirky292]

Sorry i forgot to mention, i have been poking and prodding with wire and screwdrivers, and not even a trickle. Ok thanks BMC thats tomorrows job and aswell as brakes.

[linearaudio]

The tap being blocked solid is not unknown! Ultimately it doesn't matter very much- the radiator cores are more likely to silt up! You are doing the right thing reverse flushing, etc. A run-up with some caustic soda will help clear the muck out, but be very wary- it is nasty stuff cold, let alone hot & under pressure! The thing it likes eating most is aluminium, so be careful it is all flushed out, or the water pump housing, thermostat housing, and heater outlet tap may dissolve!!

[quirky292]

Thanks Linearaudio

Will make sure its flushed out a couple of times. Ive read that you need to wear gloves goggles etc as its nasty.
If it dissolves away, then im going to ask father xmas for new ones

[linearaudio]

If in any doubt about its corrosiveness, dilute some in warm water (as it tends not to mix well in cold), and drop any little scrap of ally you may have into it- DO NOT BREATHE IN THE FUMES!! It makes a fairly impressive demonstration!

[mike.perry]

Slightly off the subject but can I use caustic soda for clearing the sink waste pipe in the house or will it melt the plastic pipe?

[bmcecosse]

Perfect for the sink...... - stand clear though!

[rayofleamington]

back to the OP's question..
If you've managed to poke 3" around the tap hole in the block and not struck water yet - that becomes pretty worrying.
That sounds like the block is VERY silted up - I've never had to prod more than an inch or so

Did the engine have any overheating issues in the past?

[quirky292]

Um ive only just acquired the traveller and by the looks of things, it hasnt been serviced for at least 5years, as the plugs where black (i mean very black) and everything seemed to be worn out like the points, rotor arm etc. I did notice that 3 out of 4 HT leads where melted and sort of stuck onto the plug.

Does this have anything to do with overheating?? or is lack of maintenance

[bmcecosse]

Could be anything -best budget for complete new ignition components...... Top priority will be to find out if the oil filter is working as it should ! If everything is really horrible may be worth dropping the sump and cleaning the oil pick-up coarse filter and remove any sludge from the sump.

[quirky292]

Ok thanks BMC,

I have changed the plugs leads etc, but havent got round to the oily bits as it didnt run so i couldnt warm the engine up.
Hopefully costic soda will unblock the head and all be fine
Thanks Everyone

[Neil MG]

Don't use the caustic soda if the engine is not running! It needs to be pumped round and flushed out soon after so you need the water pump to be working, heat from the engine helps too.

[bmcecosse]

It's not the 'head' that's obstructed - it's the block! But don't worry too much - after all later engines don't have that drain - so there is no way of telling. And YES - the caustic needs running engine to circulate it - hence my comment earlier re 'one heat cycle' . If you are really worried about this - take the head off and then you can access the various water passages with pointy things and high pressure water jets !

[quirky292]

No luck.

Before i put the costic soda in my radiator has now decided to leak on me only a small one,

But i still went ahead and did it and kept an eye on the level, and after letting cycle round the engine etc, i took the tap off and .............. nothing happened, but i got a dribble which is a start.

Now what? do a second go?

[bmcecosse]

Take the head off and do it properly.......with pointy things.