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Car won't stop overheating!

Posted: Tue Sep 22, 2009 10:01 am
by stephh
Hi, sorry for my lack of technical knowledge before I start writing this, but I'm at my wits end as to what to do!

3 weeks ago I was driving home from Sheff to Leeds, and the car started to lose power (as though you are driving in too high a gear) and then there was a sweet smell/steam coming from under the bonnet. Cut a long story short, the head gasket had blown.

Got the car home, and got somebody to kindly change the head gasket for me, but when that didn't do the trick he changed the thermostat.

Car ran fine for about 20 miles, and then it started backfiring and jerking about as I drove (almost as though I was intermitently pushing the accelerator) and then I parked up at home, and the car started shaking when I turned it off water gushed out from the raidiator via the hose to the ground (for a lack of a technical term there!).

Its obvious its overheated again, but I don't know what has caused it. I've only had the car since July, so this is obviously a bit of a nightmare. I'd be really grateful for any advice on what to do next! Cheers!

Posted: Tue Sep 22, 2009 10:09 am
by ssnjimb
Hello Stephh

What condition is the cooling system in.

Have you ever flushed out the radiator as over time carp accumulates.

Is the fanbelt tight.

When you ever have the heater on does it get hot.

If yes to all of the questions consider flushing the block

What engine do you have

James

Posted: Tue Sep 22, 2009 10:23 am
by mike.perry
The delights of new Minor ownership! They can tell when there is a new driver and will develop some obscure fault just to annoy you. I have yet to drive a different Minor which hasn't broken down on me.
A blocked radiator core is a possibility, get it pressure checked at your local rad service agent. Running a hosepipe through it is not sufficient.
If the rad core is blocked then there is a good chance that the engine block is also full of crud and needs flushing. Meanwhile you can try running the engine without the thermostat to see if there is any problem in that area.

Posted: Tue Sep 22, 2009 11:14 am
by DAVIDMCCULLOUGH
Yes I agree, probably a blocked up radiator, probably will require a new core. Had the car been off the road for a while before you bought it?

Another thing worth checking is the timing. My mate bought a minor that that been off the road for a few years while being restored (messed about with....), overheated very badly on the way home and it turned out that the clamp holding the dizzy was loose causing it to heat up. that car also came from Leeds!!

Once up and running properly they are very reliable :D

Posted: Tue Sep 22, 2009 12:11 pm
by charlie_morris_minor
Did the person how changed the cylinder head check that head and block are still flat and true?

my wife once had a midget that would do 30 miles before overheating it turned out that the head was not flat, they skimmed it and all was fine after that..

Posted: Tue Sep 22, 2009 2:18 pm
by stephh
ssnjimb wrote:Hello Stephh

What condition is the cooling system in.

Have you ever flushed out the radiator as over time carp accumulates.

Is the fanbelt tight.

When you ever have the heater on does it get hot.

If yes to all of the questions consider flushing the block

What engine do you have

James
Hi James,

The heating is working a-okay and the fanbelt is definately fine, but I think the next step is to probably flush out the raidiator! I've got a 1969 2 Door trafalgar blue (1098)

Thank you for your help, I'll keep you posted!

Posted: Tue Sep 22, 2009 2:21 pm
by stephh
Thanks for all the brilliant advice everyone! I'll keep everyone posted as to whether I ever get further than Asda without overheating again. Ha!

Posted: Tue Sep 22, 2009 2:30 pm
by ssnjimb
Stephh the reason for the fanbelt and heater questions were to make sure the water pump are fine.

Drain cleaner and a box of kettle descaler work well.

As you are flushing the radiator and engine make it your job to replace all the cooling hoses as you do not know how old they are.

If its a 1098 engine on the right hand side of the block near the backplate there is a block drain plug take that out and watch the carp flow out. you may need a screwdriver to punch through the limescale.

James

Posted: Tue Sep 22, 2009 2:54 pm
by bmcecosse
Better get a compression check on the engine - it obviously overheated badly the first time around and although the gasket has been changed (has it been tightened down again?) - the damage may have been done to block/head/piston rings/bores. As others suggest - a good cooling system flush with drain cleaner could be an excellent idea - but just put it in - take the car for a 5 mile drive - return and drain out, and then flush through with clean water.

Posted: Tue Sep 22, 2009 5:08 pm
by cormorant
You may get some indication of how badly the rad is silted up if you do the following: get a length of soft iron wire e.g. garden wire and remove the rad cap, drain the water off and poke the wire gently down the slots that you can gain access to in the core. You may find that you are poking the wire through a mass of rusty sludge and the wire comes out coated in it.

If it's this bad probably nothing will shift it.

Posted: Tue Sep 22, 2009 5:49 pm
by bmcecosse
But it's worth a go with drain cleaner!

Posted: Tue Sep 22, 2009 7:33 pm
by stephh
Thanks guys,I'm going to attempt to get somebody to help me do all this over the coming week...hopefully I'll be back on the road before you know it!

Haven't had the head gasket adjusted again yet, as I only got 20 miles before it overheated again!

Steph x

Posted: Tue Sep 22, 2009 8:38 pm
by bmcecosse
First check really should be the thermostat - has it jammed shut ? They usually fail open - but you never know. I assume it has a fan fitted - not been removed by PO ? Has never happened to me - but others have reported badly rotted water pump impeller as a cause of overheating. So - if it all appears to be sufficiently 'flushed' - that may be a cause.

Posted: Tue Sep 22, 2009 9:27 pm
by charlie_morris_minor
to pick up on something bmc said.. i think the old ones failed "open" which is sensible but the new ones apparently fail "closed" or at least this is what i was told by somebody in the trade but that was 15 years ago so it could be that the new new ones fail "open"

the best way to test your thermostat is in a saucepan / kettle of water brought up to the boil.

Posted: Tue Sep 22, 2009 10:51 pm
by PSL184
The last stat I bought was about £2.50 so by the time you have gone to the trouble of getting it out to test you may as well stick a new one in anyway......

Posted: Tue Sep 22, 2009 10:56 pm
by bmcecosse
It now turns out this is a Charles Ware car - so why not take it back and tell them to fix it under warranty ?

Posted: Tue Sep 22, 2009 10:58 pm
by PSL184
Yes, indeed - I just noticed that fact on another thread..... :roll: