12 replies to this topic

[natehall]

Model:Mini 1275 Rio
Year: 1994
Description of problem (please be as in depth as possible):

Just took the Mini for its first real drive since we owned it, nothing exciting just 30 mph stuff for about 5-10 miles to get it upto temp, let my wife have her first drive. Noticed the temp go to halfway betwen the mid way mark and the red zone and not drop back down. got home, parked it up and turned the engine off when masses of steam started coming from under the bonnet!

Took about 3-4 minutes to glove up, find a rag and open the bonnet, where I see it coming from the radiator cap and not our modification, once the steam had stopped massively escaping from the rad cap (a further 2-3 minutes we opened the cap and it was still coming out like a volcano

I have a couple of theories as to what it could be.. but I dont know if any of these are Mini Weakspots..

1. Thermostat stuck closed, I didnt get to feel the rad hose as there was a mass amount of steam coming from the rad. but last week the rad hose had got warm.
2. Water pump impellor failed.
3. Head Gasket Failure

Can anyone shed any light on the problem? Or spot anything I may have missed?

Any non-standard parts that might be involved with the problem?
Heater matrix water flow tap diverted back into the cooling system

[Beej123]

Stupid question but you never know, fan belt still there/not slipping?

See if the heater works, if it does its not the belt of water pump, past that im not sure

[natehall]

Stupid question but you never know, fan belt still there/not slipping?

See if the heater works, if it does its not the belt of water pump, past that im not sure

I will double check as There was so much steam finding the engine was tricky....

Heater wont work as it was leaking massively last week so bypassed it whilst my new one arrived (which was meant to be this week but I kinda forgot to order it..)

[AVV IT]

Yeah I agree it could well be the fan belt slipping so check that 1st. I'd probably then remove the rad & flush the cooling system, to make sure that the problem isn't caused by a blockage. If you don't know the cooling systems history then for what little it costs, I'd be tempted to replace the thermostat and water pump as a matter of course whilst you have the system drained down & the rad out (a waterpump is only about £15 from memory). After all, even if they are not the culprits you will then have eliminated them as the problem and to be honest it's only a matter of time until they fail anyway. (Oh & I'd also get your new heater matrix fitted at the same time, to "kill another bird with the same stone" )

The bypassed heater matrix certainly wont help with cooling, but it should in itself cause over heating, also it's unlikely that the thermostat is the culprit as they tend to fail open as opposed to closed, but then it's not impossible. Your model should be fitted with an auxiliary electric cooling fan in the near side inner wing, this wouldn't have necessarily stopped the car overheating, but it should have kicked in to help prevent it, so it might also be worth checking to see if it is working.

Edited by AVV IT, 06 February 2011 - 03:39 PM.

[natehall]

Yeah I agree it could well be the fan belt slipping so check that 1st. I'd probably then remove the rad & flush the cooling system, to make sure that the problem isn't caused by a blockage. If you don't know the cooling systems history then for what little it costs, I'd be tempted to replace the thermostat and water pump as a matter of course whilst you have the system drained down & the rad out (a waterpump is only about £15 from memory). After all, even if they are not the culprits you will then have eliminated them as the problem and to be honest it's only a matter of time until they fail anyway. (Oh & I'd also get your new heater matrix fitted at the same time, to "kill another bird with the same stone" )

The bypassed heater matrix certainly wont help with cooling, but it should in itself cause over heating, also it's unlikely that the thermostat is the culprit as they tend to fail open as opposed to closed, but then it's not impossible. Your model should be fitted with an auxiliary electric cooling fan in the near side inner wing, this wouldn't have necessarily stopped the car overheating, but it should have kicked in to help prevent it, so it might also be worth checking to see if it is working.

fan belt needs replacing as its not looking that new, but its still taught with about 1/4-1/2 inch deflection and with the engine on everything spins... so that is not the culprit.

I will get a thermostat, water pump, fan belt, rad cap, heater matrix and a electric fan switch, and give the rad a really good flush out. Are there any other common problems on the cooling side in a mini that I may as well replace whilst im in there...

[natehall]

oops double post

Edited by natehall, 06 February 2011 - 04:12 PM.

[AVV IT]

I will get a thermostat, water pump, fan belt, rad cap, heater matrix and a electric fan switch, and give the rad a really good flush out. Are there any other common problems on the cooling side in a mini that I may as well replace whilst im in there...

The bypass hose!! Definitely replace this whilst you have the water pump off (preferably with a Silicon Version or at least a small length of heater tubing, as the original "fluted" type item has a bad reputation.) I'd also use new jubilee clips and a new fitting kit for both the thermostat housing & waterpump that uses stainless bolts.

Apart from the actual rad itself, the other thing to consider are the hoses themselves. These can become brittle and crack when you remove them to do any work, again consider replacement silicon hoses as they are much more reliable and longer lasting (is your Rio an SPi or Carb model though, as the bottom hose for the late carb models is now obsolete and almost impossible to source )

Edited by AVV IT, 06 February 2011 - 04:25 PM.

[mikey72]

Jubilee clips as well. I've had ones that round off, had to be cut off, chew up when you try to retighten them...
Worth having some in just in case.

[starletman]

Model:Mini 1275 Rio
Year: 1994
Description of problem (please be as in depth as possible):

where I see it coming from the radiator cap and not our modification,

What modification had you made.

[natehall]

I will get a thermostat, water pump, fan belt, rad cap, heater matrix and a electric fan switch, and give the rad a really good flush out. Are there any other common problems on the cooling side in a mini that I may as well replace whilst im in there...

The bypass hose!! Definitely replace this whilst you have the water pump off (preferably with a Silicon Version or at least a small length of heater tubing, as the original "fluted" type item has a bad reputation.) I'd also use new jubilee clips and a new fitting kit for both the thermostat housing & waterpump that uses stainless bolts.

Apart from the actual rad itself, the other thing to consider are the hoses themselves. These can become brittle and crack when you remove them to do any work, again consider replacement silicon hoses as they are much more reliable and longer lasting (is your Rio an SPi or Carb model though, as the bottom hose for the late carb models is now obsolete and almost impossible to source )

My Rio is a carb model I believe, so that makes that soo much more difficult to get the replacements.

I will look up the silicone hoses, never had a problem with them other than the odd split on any other car before, but if there a known weakeness, ill price up the replacements, preferably a full hose kit for the car.

Also another question, how do I know if I need the water pump with bypass tube or the one without the bypass tube?

[natehall]

Model:Mini 1275 Rio
Year: 1994
Description of problem (please be as in depth as possible):

Any non-standard parts that might be involved with the problem?
Heater matrix water flow tap diverted back into the cooling system

Model:Mini 1275 Rio
Year: 1994
Description of problem (please be as in depth as possible):

where I see it coming from the radiator cap and not our modification,

What modification had you made.

That is the only modification from standard.

[AVV IT]

My Rio is a carb model I believe, so that makes that soo much more difficult to get the replacements.

I will look up the silicone hoses, never had a problem with them other than the odd split on any other car before, but if there a known weakeness, ill price up the replacements, preferably a full hose kit for the car.

Unless I'm very much mistaken, then you have a HIF38 carb model. I therefore doubt that you will be able to buy a full hose kit for it, as the standard GRH1289 bottom hose is now obsolete. You may well still find it listed in most of the mini suppliers listings, but it's generally very expensive & always out of stock. To my knowledge a silicon version of that hose hasn't ever been made, so a silicon kit hose kit won't be an option either (although minispares have been talking about introducing one for a while now). You can get around this by fitting the Standard Earlier Hose instead and either replacing your heater hoses with the earlier & smaller 1/2" heater hoses, or connecting it to your cars wider 5/8" heater hose using a Reducer. If you do decide to go down this route then I can probably help you out with the reducer pipe, if your interested. I have new one somewhere, that I bought but never fitted as I then decided to replace my heater pipes instead.

Also another question, how do I know if I need the water pump with bypass tube or the one without the bypass tube?

I'm fairly sure that you will need the version with the bypass hose, but the easiest way to confirm this is to look at your existing water pump. You should be able to see if it has a bypass hose fitted to the top of the pump, just by opening the bonnet and looking down the side of the engine at a bit of an angle.

[natehall]

My Rio is a carb model I believe, so that makes that soo much more difficult to get the replacements.

I will look up the silicone hoses, never had a problem with them other than the odd split on any other car before, but if there a known weakeness, ill price up the replacements, preferably a full hose kit for the car.

Unless I'm very much mistaken, then you have a HIF38 carb model. I therefore doubt that you will be able to buy a full hose kit for it, as the standard <you>GRH1289</you> bottom hose is now obsolete. You may well still find it listed in most of the mini suppliers listings, but it's generally very expensive & always out of stock. To my knowledge a silicon version of that hose hasn't ever been made, so a silicon kit hose kit won't be an option either (although minispares have been talking about introducing one for a while now). You can get around this by fitting the <you>Standard Earlier Hose</you> instead and either replacing your heater hoses with the earlier & smaller 1/2" heater hoses, or connecting it to your cars wider 5/8" heater hose using a <you>Reducer</you>. If you do decide to go down this route then I can probably help you out with the reducer pipe, if your interested. I have new one somewhere, that I bought but never fitted as I then decided to replace my heater pipes instead.

Also another question, how do I know if I need the water pump with bypass tube or the one without the bypass tube?

I'm fairly sure that you will need the version with the bypass hose, but the easiest way to confirm this is to look at your existing water pump. You should be able to see if it has a bypass hose fitted to the top of the pump, just by opening the bonnet and looking down the side of the engine at a bit of an angle.

Thank you very much, that is very usefull information and I think i will be putting in a rather large order to mini spares in the next few days as I have some body panels I was going to be ordering from them once I found out about my TMF+ discount, just need to get the full list of panels and we shall get started.