Hello.. I’m a new mini owner. I’m usually in a ford Ranger but my kids love the mini.

Concerned about a possible blown head gasket.
1.overheating after 6-8 min water is going out reservoir and that discharge hose.
2. That tank is chirping and banging and making all sorts of noise.
3. Engine oil looks perfect (no signs of coolant)
4. No smoke from rear or funny smell
5.Engine felt good and seems like it runs well
6. I turn it off after temp starts to climb
7.water pump disassembled and looks good
8.thermostat replaced (had a code for it)
9.evac code was only other code

What are my chances that it’s that reservoir or cap not holding pressure?
Im super stressed out bc my wife and 2 kids can’t fit in the ranger bc it’s standard cab.

I’m not having much luck finding competent affordable mini repairmen in the Knoxville area.

I know you get what you pay for I just have to draw the line between overpaying at a dealership ( I can’t afford that) or paying a still considerable amount towards a non mini mechanic. I need to find a common ground.. decent mechanic but no fancy showroom to help pay for.. I can do the expansion tank or reservoir whatever it’s called but if it’s a blown head gasket I’m in deep poo 💩

Any advice? Would the oil have coolant in it if it was blown? I’m a nervous wreck right now.


The oil seems ok


Blowing white stuff out.. seems like isn’t holding pressure

Pump fins seem ok

 

What is that stuff coming out of the coolant tank? I would flush the cooling system really good.
It could be the cap on the tank but highly doubtful at this point. I would replace the water pump since you already have it off. These things are a bear to purge the air out of the cooling system. I ended up using a syringe to put coolant into the bleed hole on the upper radiator hose. Close the valve, run a minute or so and repeat. Once I felt I had enough coolant I ran the car and used the bleed screw to remove the excess air. 6 to 8 minutes is really quick to start overheating so it sounds like trapped air in the cooling system to me. Usually but not always, a blown head gasket will turn the engine oil into a milkshake.

 

I would replace the thermostat again. You could have gotten a bad one. Also make sure you bleed the system really good. Open the plastic screw on the top radiator hose until a steady stream of coolant come out.
I actually do the first start in stages. Cap off refill and bleed until level stops going down. Cap on run uNeil bleeding is steady stream and temp is about 200. Let cool then refill/bleed as necessary and then cap on let the hot until fans come on and off. Monitor temps at all times with scan tool.

 

It's entirely possible to have a blown head gasket and NOT have oil and coolant mixed.
Start the engine cold with the coolant tank cap off. Do you see an excessive amount of bubbles even when you're sure you bleed the system adequately? Put the palm of you hand over the opening and try to make a tight seal (make sure the coolant isn't hot!). Do you feel pressure fluctuations?
If either of these is yes then invest in a hydrocarbon test for the coolant. If it's positive then you almost certainly have a bad head gasket.

The fact that you're boiling over in 6-8 minutes makes me think it's the head gasket. A bad pump, bad thermostat, or air in the system would take much much longer for the engine to overheat.

 

I’m certain I didn’t properly get air out of system. I’m trying to learn how to work on it as I go. I’m unfortunately not a mechanic and strictly relying on YouTube videos currently. I’m comfortable with things like water pumps and thermostats.. really wasn’t difficult at all on the mini but diagnosing problems takes someone who knows what they are doing. Mechanics in my area aren’t even doing thermostats or water pumps on minis so as simple as that was I’m scared to have one of them diagnose or repair something complex. I’ll be working on it tonight but the good thing I’ve found is some stuff on the mini isn’t as difficult as you would assume especially if you don’t give up immediately but a head gasket would be way beyond what I could do.

 

knoxville
Don't 'fill' the expansion tank - it only needs one inch or so of coolant in it when cold.

 

thank you. I’ve had radiator completely off 2 make it easier to work on.. it starts banging and making so much noise in expansion tank that its actually a little scary but I’m gonna research up on how to properly bleed it tonight.

is it better to use hydrocarbon test or a scope to see if pistons are cleaned off?

 

MVPeters is correct. Also, when bleeding the system, try to get the car on an incline, nose high. If you have access to a cooling system pressure tester (try an auto parts store for a loaner) and it has an adapter for the MINI radiator cap, you can actually pressure the system from the reservoir, then open the bleed screw and you'll see the air come out until nothing but coolant. Then close the bleed screw.

 

If the rad is still off, flush, flush & flush the system while it's easy.
Looking at the spark plugs should be enough to tell if there's water in the cylinders. If not, a 'sniff-tester' isn't expensive.

 

so the bumper plastic is broke and radiator has a small crack in it so need to replace that (I know throttle body is cracked too from age) unfortunately everything on the car is old.

just an update and trying to get 2 root of problem.. car can be saved if it’s not a head but hopefully will know after pulling plugs and getting sniff test

1.idles good
2.starts up great
3. ran for 20 min no overheating yet but with radiator leak if I put cap on reservoir it does spray it out radiator crack faster.
4. It’s not making the banging noise in radiator and loud fan isn’t kicking in like it was.
5. I did bleed some from front bleeder but with radiator leaking idk if once it’s replaced if banging in reservoir will come back.
6. So with radiator leak the engine isn’t overheating now or making noise?? Very weird

 

Sure looks as though there's an obstruction in the system. Thermostat not opening or blockage, faulty water pump?

 

knoxville
See if the attached file has anything useful:

 

thank you I’ll be going over this tonight. Unfortunately with my radiator having to be replaced now idk until a day or two from now if that’s part of problem but bc the front end plastic broke out to begin with (radiator support bracket) I have to order that in and then a radiator and then get it all attached so could be a week or so delay in getting everything but I can’t imagine how a radiator leak would prevent overheating.. even typing that sounds stupid. I’m having to learn as I go since I’m not a mechanic. I can replace wear and tear items and stuff like radiators alternators and basic stuff but this more complicated stuff really is for the professionals unfortunately.

 

https://youtube.com/channel/UCYGH-J61knl15mVYqTbfHIQ

added a couple videos.. my son thinks it would be fun to make a few videos and learn how 2 do that too

found radiator leak- my fault condenser tightened down 2 much into the radiator

 

Might try Aaron at Outmotoring, they're in Knoxville. He may know of a good shop (or have some advice) in case you're still having trouble with the leak / overheating issues.

[Also a good parts vendor.]

 

Your cooling system has to be intact before you concern yourself with overheating. A crack in the radiator is basically cooling system failure. I'm guessing your expansion tank cap isn't holding pressure or sealing and that is why you have coolant all over it.

I recently went through an overheating diagnostics and ended up having 2 issues (besides the broken coolant tee that started it all). First, the cap on my expansion tank would not hold pressure. My first clue was prior to the broken tee, when I checked my oil level while I was filling my gas tank, I noticed some coolant on the top of my expansion tank and I knew for certain that my expansion was not cracked. That cap was only about 4 months old at the time. I have the tools to pressure test my cap and used it to find that indeed, my cap would not hold pressure. It may go without saying but some people do not understand that a pressurized cooling system raises the boiling point of the engine coolant mixture, so if the cooling system is not pressurized, the coolant will boil at a temperature that it should not boil.

I replaced the cap (and verified my new cap does hold pressure) and my engine still overheated.

I then replaced my thermostat (which was only 1 year old but in the car when it overheated) and that was the final piece of the puzzle to correct my overheating issue. The heater core is the only part of my cooling system now that has not been replaced in the past 18 months/8000 miles.

 

the expansion tank (at least the cap) is 100% leaking for sure.

I did jb weld the radiator until Tuesday when new radiator is supposed to show up and that is holding for now but yeah the expansion tank is banging hissing and whistling.. the mechanic down the road from me is gonna do a sniff test Monday or Tuesday (charging the same as if I bought the tester and fluid) $40 so just gonna let him do it and if head isn’t bad I’ll have used up all of my luck. I really enjoy this car and my kids love it so I’m really hoping it’s not the head

 

I went thru everything you are going Thru , you know what it was for me? Bad cap, anything that doesn’t you the oe cap your good, and if it still leaks you have issues, now i also have my heater core bypassed right now cuz that was a issue with my cooling system.

good luck

 

Just curious any update on the coolant bleeding situation? In a similar situation here, did some work on the system - resistor, hoses, pump, aluminum housing & gasket during a supercharger oil service - upper gets hot (and empty with the bleed screw removed, nothing coming out at idle) and lower stays cool. Cabin gets hot as blazes on 'Hi' while idling. Starting to worry...

 

Hey bud , I have a expansion tank with a new coolant cap , a radiator and water pump... if you need them ,drop me a pm... I can give them to you free if you just cover shipping...
also it's very important the air is bled out or you'll get boilover just like your car is doing.. I make a little funnel and 1st I fill up the expansion tank( to the top, helps push out air bubbles and keep full while filling ) I squeeze the hoses to help suck the coolant down and once I've done that a bunch of time I remove the air bleeder plastic screw on the coolant hose and I fill through that ( takes abit as the holes small ) but once it's topped off through that hose and the reservoir still is about 1/4 way filled. Then make sure the coolant caps on and the bleeder screw tight and fire it up , squeeze the radiators hose too a few more time while it running just to help eliminate any air.. it's vital none is in there....
Wish you the best of luck with it...
i seen you need a raditor too .. i have a radiator also , off my car known good.. if you can cover shipping ille give it all to you

 

i think minimanadam hit your problems on the nose , you def need a new expansion tank and rad for your cooling issues to go away, if you have a coolant pressure tester you can also pressurize the system from tank and bleed out the air that way too