First, big shout out to WMW for catching the fact that I ordered the wrong head gasket kit. You don't get that service from large chain outlets. I'll continue to shop with these folks. Anyway, onto the successes and failure....

My son overheated the heck out of my 2006 MCS. I think its related to a small head gasket leak, the low speed fan not working, and those two possibly compounded with a Forge Aluminum tank that isn't threaded correctly for the stock radiator cap. Not his fault, he's a new driver and I sent him out with subpar equipment. I'll take the blame. Long story short, head gasket was toast, coolant in oil....game over!

Prior to pulling it apart, I had an intermittent EML light and code P1498 (usually at idle, the light would come on and then go off next time I started it), so I had a vacuum leak somewhere. To find it, I made a smoke machine with a pickle jar, a cotton sock missing its pair, baby oil, and a cheap soldering iron from Autozone. Total cost, 8.99 and spare crap (including epoxy) I had laying around. Holy ****, that thing works AWESOME. There was a tiny little hose that connects to the back of the blow-off valve on the side of the throttle body that wasn't connected. Would've never found that. Must've disconnected it when I serviced the Super Charger. Foreshadow, EML light and P1498 have not re-appeared. If you need to find a vacuum leak, its hard to beat. Watch the video, I did the exact same thing using the rubber glove with a finger cut off. Easy and worked great. Even my wife was impressed, lol. So, success #1.

Next, I suspected the low speed fan wasn't working. So, I grabbed some wire I had left over from installing lights on my Jeep and connected one wire to the + battery post located next to the air filter and electric taped the other wire to (negative) to a bolt. Went to the plug on the driver side that goes to the fan, unplugged it, and touched the negative to the negative wire and the positive to the thicker of the two red wires. ZOOOOM, high speed came on. Touched the + to the smaller red wire, nothing. Well, thats not working. So, I replaced the low speed resistor. After replacing the resistor, I touched the (+) wire to the smaller red wire in the plug and zoooom, low speed came on. Checked my fan relays, they tested good. Low speed fan back in business. Success #2!!!!

With those two easier projects solved, I began to tear the engine apart. Took me about 8 hours taking my sweet time and putting bolts and nuts in labeled zip lock bags. I pulled the head and sent it to Womack engine repair (local shop) and for $300 had a valve job and resurfaced the head. New head bolts and gasket kit from WMW arrived. I followed the installation in the mini-manual and min-mod on YouTube, all went well. Only took me about 4 hours to get it all back together. Hardest part was the dang exhaust manifold bolts. Tip on timing, mark with paint pen AND NOTE LOCATION OF CAM SPROCKET KEY. I took a picture. When I got it back from Womacks, the cam was forward about 30 degrees from when I took it apart. All I did was line the sprocket back up with the chain using the paint pen marks (one link painted, tooth painted, mark on sprocket side). Then used a breaker bar to turn the crank pulley clockwise until the sprocket fit onto the cam key. Just try to keep tension on the front side of the chain. Not likely you'll jump a tooth but that just helps to make sure. Oil was changed, filter changed, new radiator, thermostat, hoses, new water pump from when I serviced the super charger...new new new new new. New Forge expansion tank and OE cap as well.

After it was all together and I bled the system for about a half hour, i wanted to be 100% sure the head gasket was not leaking. So, I got block test kit from autozone and the blue indicator fluid. Tool was free and fluid was 13 bucks. It said to get the engine up to temp, apply suction on the bulb for 2 minutes. Did that, stayed blue blue blue. So, not satisfied I kept at it for 8 more minutes. Stayed blue blue blue (see picture). Ok, no combustion gases in coolant!! Woot!! Success #3.


Now it was time to bleed. I already had this OEM kit for my Honda Odyssey and Jeep. Unfortunately, it didn't have a fitting for the Mini. So, I took the old cap and drilled a hole in it using a step drill it until the long funnel like adapter fit through the interior hole of the cap snuggly. Then I attached the funnel and filled it up to the step with coolant.


I bled it for about an hour and a half. Revving, cracking the bleeder screw, watching for bubbles. With it this high, you can sit in the mini and watch for bubbles, which is great. Had the heater on high, fan on low. The bubbles stopped at about the 45 minute mark. I mean, no bubbles at all. But, I'm like, well...I'll have a beer and see if we can't find any more. After relaxing and enjoying a beer or two...nope, no more bubbles. I shut off the engine. When you shut off the engine, the heat in the metal will continue to transfer to the coolant and cause it to expand since you aren't passing it through the radiator any longer to cool it. The marks you see on the funnel are prior to shutting off and how far it expanded after I shut it off. That's quite a bit of volume!! A bit more than Half the capacity of the Forge tank. I measured. So, if I fill the tank appropriately and everything is working like its supposed to, I should never see a drop of coolant outside of that tank. But, it did. After reducing tread life for about an hour and returning home, I shut off the mini and popped the hood. Coolant spitting out of the tank cap. Failure #1.

If there is no air in the system then something else is happening. Air is either getting in or the laws of physics don't apply to mini coopers. I measured the volume of expansion and removed that volume of fluid from the tank. Plus a hair more. No way the fluid should get out. I don't think the cap fits the tank correctly for starters and its maybe letting the coolant boil causing air to develop in the system. I can't seem to get any OE cap to screw onto this damn expensive under-hood ornament worth a turd. Maybe its me, but I doubt it. I'm going to first test the pressure holding capability of the coolant system and if that is good, I'll slap back on the plastic tank and cap and see if I have the same problem...I'll report back.

 

Resolved I sent WMW an email about what was going on. Essentially, all that bleeding I did was unnecessary. Just need to fill it from the reservoir, then purge air using the bleeding screw.

Clearly I was losing coolant, so I ordered another new radiator cap and the OE expansion tank. Fixed. Zero problems. The Mini had been running great ever since.

 

Sounds like success to me. Nice work