Tim
1850 posts
Joined: 18/10/2004 09:40:59
Location: Bournemouth United Kingdom (Excluding channel Islands)
Rad leak
One possibility is excess pressure in the cooling system caused by a blown gasket, which will force the water out of the radiator overflow when it gets hot (but doesn't cause white gunk on the oil filler cap). Have you got a pipe connected to the overflow outlet (on the neck of the rad, just undeneath the filler cap) that just disappears down the side of the rad? Stick the end of that pipe into a plastic bottle (a 500ml coke bottle should fit) and see if any water is going in there.
Posted: Dec 19, 2006 01:40 PM
josh blomfield
2 posts
Joined: 10/12/2007 00:41:03
Location: watford United Kingdom (Excluding channel Islands)
Radiator cap keeps letting out coolant!
Hi
Over the winter I had the radiator on my mini thirty blow and managed to replace it with a new one (which didnt come with a rad cap so I used my old one). It run fine for a bit but now wherever I go the coolant level seems to drop severely as it keeps leaking past the rad cap. Could this be my rad cap spring is giving up or could there be more to it; like pressure building up somewhere? Bearing in mind I did a coolant flush when I changed the rad so a blockage isn't very likely.
New rad cap?
thanks
Posted: Apr 20, 2010 08:01 AM
abs
98 posts
Joined: 08/11/2007 20:20:11
Location: cornwall United Kingdom (Excluding channel Islands)
Re.
If the heater is blowing cold first make sure you have a thermostat fitted as the lack of one causes poor circulation. Then check the heater valve in the engine bay is actually allowing water to circulate, finally you may have an air lock, if so pull the pipe off the heater valve and blow hard down the pipe with the rad cap removed, top the pipe up with water and quickly push back on and tighten, top rad up again. Job done. (hopfully!)
Posted: Dec 24, 2009 08:24 PM
John
1948 posts
Joined: 28/05/2006 16:49:46
Location: cambridge United Kingdom (Excluding channel Islands)
MY HEATER ONLY BLOWS COLD
might be an air lock in the system. try running engine without rad cap on for a few min hopefully it will go if it has one.
Posted: Dec 03, 2007 07:02 PM
J. Clarke
Which way do the heater hoses go?
its normaly hot in at top, as hot water cools it becomes less dence and falls to bottom where it goes out. but i think either way would work fine. after its refitted and fluid topped up run engine a min with rad cap off to release any air locks hopefully.
Posted: Oct 11, 2008 11:21 PM
Wesser
20 posts
Joined: 11/11/2004 13:32:42
Location: Milton Ernest United Kingdom (Excluding channel Islands)
Cooling
Got a 96 Cooper SPi, Temp sits just below the middle white line but on a longish journey yesterday when I switched off the rad started spitting out of the cap. My fans only for 4 out of 11 blades and the rad is a replacement without a place for the electric fan sensor. Getting a new 11 blader. So is there another place I can put a aux cooling fan sensor?
Posted: Sep 05, 2005 04:05 PM
pickme
672 posts
Joined: 08/09/2004 23:10:14
Location: Chippenham United Kingdom (Excluding channel Islands)
hot water
Sound like you need a new rad cap. You shouldnt be loosing that much water. When did you last change the head asket? Is there any oil in the water?
Posted: Jun 19, 2005 04:30 PM
Josh
31 posts
Joined: 31/10/2004 19:55:38
Location: United Kingdom (Excluding channel Islands)
hotness
New head gasket and rad cap within the last 4 weeks. No oil in the water.
Posted: Jun 19, 2005 07:06 PM
Blox
18 posts
Joined: 04/10/2004 20:05:44
Location: Newbury United Kingdom (Excluding channel Islands)
Runing hot
Ive found the MPi runs hotter because of the leaner combustion and lack of full time fan. The electric fan doesnt cut in when doing a decent speed as the front mounted rad should cope with the amount of air flowing through it at speed should be sufficient. After purchasing the MPI in 1997 I took it back to the dealer a couple of weeks later and said it ran too hot (comapred to my other minis). They returned it saying it was within normal range. It still runs hot on motor way speeds but does not give any problem however the expansion tank cap seems to leak!!! :(
Posted: Sep 12, 2005 04:57 PM
Oil pressure and water temp
too high an oil pressure will just make it more prone to oil leaks wont harm engine just make engine get covered in more oil. 60-75 psi is good pressure to aim for to give max protection if uv got ajustable pressure knob fitted. normal running temp around 200 F will vary a bit on ur setup, they can run fine past boiling point of water as its a pressurised system the max pressure varyies on rad cap fitted.
Posted: Jan 04, 2008 11:00 PM
Baza53
14 posts
Joined: 11/03/2013 18:23:59
Location: Spilsby United Kingdom (Excluding channel Islands)
mini timing
I have done all that but to no avail, It still over heats,I,ve done all the ovious things,ie, rad cap, flush rad, carb
Posted: Jul 05, 2013 10:16 AM
Well I,m now stumpt, The timing is bang on the marks,I,ve put a new rad,thermostat,pump,rad cap and tempriture gauge on and it,s still over heating.
Posted: Jul 16, 2013 12:56 PM
jr
5 posts
Joined: 18/06/2007 09:42:42
Location: Ashford United Kingdom (Excluding channel Islands)
Coolio
On mine l plumbed the heater take off into a new sandwich plate (stocked by MS or Moss) with a 12mm inlet, which sits under the existing housing on the c/head. l would also replace the fan with an electric unit. A high pressure rad cap is also worth fitting.
Posted: Jan 26, 2009 04:57 PM
Chris
131 posts
Joined: 18/02/2005 08:56:10
Location: Leamington Spa United Kingdom (Excluding channel Islands)
Overheating MPI
There are a number of reason that this could be happening and I would recommend checking the following: 1, The expansion tank RAD cap - this evenually leaks and doesnt pressurise the system, thus causing it to boil. 2, The thermostat may be sticking. 3, The water pump impellar may be faulty. Alternatively, the system may need a good flush incase there is any blockage stoping the flow through the radiator. I hope this information helps
Posted: Sep 08, 2005 01:51 PM
streetmonkey
6 posts
Joined: 13/04/2005 08:09:20
Location: Harlow United Kingdom (Excluding channel Islands)
I call her Alice...
Hey, Im new to this site and the forum, and well, im new to minis. My dad has always been on at me to buy one, so i did, On the 20th April, I got a 1982 Mini HL. 998cc. Cost me the grand total of £125.. Needs a little work doing to it, there is a hole in the A Panel, and rust around the headlights and petrol cap. It has had new floor pans and subframes before i brought her.. Took her out for her first spin on friday, to find she was leeking water, so today i fitted a new waterpump and thermerstat, just gotta get hold of the rad and rad fan then she will be on the road once more. Take a look see what you think. Dan
Posted: Apr 24, 2005 02:12 PM
alexs
7 posts
Joined: 26/08/2005 16:31:17
Location: Southampton United Kingdom (Excluding channel Islands)
Over heating
I agree entirely with Chris about thermostats. I would also add. next time you wash the car get the pressure washer in the engine bay and carefully clean through the radiator. this will hopefully improve the flow of air. Also make sure that the seal in the rad cap is not faulty.
If the problem persists you may need to back-flush your cooling system to bring it back to full efficiency.
Posted: Jun 29, 2006 12:56 PM
James
161 posts
Joined: 28/06/2006 11:39:53
Location: Downham Market United Kingdom (Excluding channel Islands)
Best way of cleaning rad?
Hi All, Matilda is having her engine rebuild next week, with work beginning tomorrow evening. One thing we need to look at, is the outside of the radiator, on the fan side is severely clogged with krud, owing to oil having been sprayed on it at some stage, and then getting caked up with dust.... Its gotten to the point whereby the boss pulled into the garage on her way home, to put some juice in, and Matilda, without warning, did a wee on the forecourt, blowing just over 2 litres of water out the filler cap! We know that the rad isnt working at full efficiency in this state, and in the morning, when the air is cooler, its not a problem... but in the mid day heat, when the boss knocks off work at 12, its a problem, as she has to keep the heater on full, just to keep the temp needle on the halfway line... turn it off, and the guage will just keep on a rising, with little air actually passing through the rad! Any ideas of the best way of cleaning out the vanes on the outside of the rad? I know its fairly fragile, so looking for a gentle way of doing it! Any advice appreciated! James
Posted: Jul 27, 2006 09:21 PM
It all helps, but using water wetter made the biggest difference.
Posted: Jan 27, 2009 01:09 PM
Allan Sherring
Joined: 30/03/2010 14:09:53
Location: Lymington United Kingdom (Excluding channel Islands)
hopefully sorted... argh
changed waterpump last night, finished gone 1am, work is not so hot today. thing is it was fine no damage at all and no build up of rust in there. going to change the rad cap anyway.
going to road test her tonight... re test tomorrow... wish me luck
Anyone got any other suggestions?
Posted: Aug 04, 2010 11:07 AM
Twixy
11 posts
Joined: 02/01/2005 18:11:35
Location: Wellingborough United Kingdom (Excluding channel Islands)
Chucking Water Out Of The Radiator....
Hiya,
it 1st happened on the way back from stanford hall (about an hour drive), and again on the way back from the MOT station (about a 20 min drive), where it passed the emissions the Hc was 900 and CO 2.5%, I'll try a new rad cap and thermostat this weekend, incidently when it 1st threw its water out it only emptied out the top header of the rad, no more than about half a litre, i only use the car in fine weather (about 4 days a year) so heater output isnt important, thanks for the ideas, i'll keep you posted...
Michael.
Posted: Sep 19, 2007 09:22 PM