Testing Thermostat on R56?
 

Is there anyway a DIYer can test the crazy "pigs heart" thermostat used on the R56 Minis?

The local Mini dealer tells me I urgently need a new thermostat, at only 42K miles. unfortunately I was not present when they did the inspection but when I examined it myself later I could find no visible leakage. no error codes when scanned and the heater works fine as usual, making it hard to know if I am being scammed or not.

What year/model R56 do you have? How did they come to this conclusion if there were not faults thrown for the thermostat? Why were you in the dealer (i.e. oil change, check engine light, etc.?) If there was no fault it makes me believe that they saw it leaking. You can get into it and inspect to see if you see any coolant coming from it. Is your vehicle overheating? You can plug into your OBDII and watch your temp. It should read about 220F at operating temperature. If it's below, let's say around 190F, you could have an issue, but I'd think a fault code would be present.

Depending on if it's a Cooper or Cooper S, and its year, this article here can help you find the location of the thermostat to inspect it: MINI Cooper R56 Turbocharged Engine Thermostat Replacement (2007-2011) | Pelican Parts DIY Maintenance Article.

2010 base Cooper. I was in the dealership to get my key read to find out what routine maintenance I might be missing, they offered a free checkup. The $2K list of things to do it needed came as a surprise, and they didn't offer to bring me in back to see the process, and the service writer was a bit surly about answering questions, though he did say the conclusion was based on "leakage and faults".

I checked cafefully for any leakage and so did a friend who is much better at such things that me, neither of us saw any leakage. I replaced the thermo sensor last summer myself, so I am fairly familiar with the thermostat and how it fits in.

My cheapo Autel scanner doesn't seem to do temp, so no idea of that.

Oh, and I parked it hot over a clean piece of cardboard last night, no drippage all.

I suppose it is possible that the dealer has a much better scanner than I do? Or that they erased the faults and they have yet to return?

Was your check engine light on when you went into the dealer? It could be that they cleared the faults, but I'd assume you'd have a CEL on for a thermostat issue. Thermostats, when leaking, do not have to show signs of leakage on the ground. They can seep/leak and the liquid can get burnt off before reaching the ground. Seeping wont show up on the ground until it acquires into a drip. Does the vehicle gauge on the cluster show any signs of overheating? I'd ask the dealer exactly what they saw that lead them to believe you have a t-stat issue. Otherwise, I'd take it to a MINI indy shop for a second opinion. It could be they're recommending it due to the age of your MINI. However, it's a part that people typically don't replace until it is not functioning right. Some replace for preventative measures, before any signs of it being faulty.

If there are absolutely no sigs pointing to a thermostat issue, you could leave it be or get a second opinion. MINI indy shops tend to be more truthful about service repairs. Can track one down in your area by plugging in your postal code here: Mini Cooper Repair Shops - Find a Mini Cooper Mechanic | MiniRepairShops.

I have read elsewhere that there can be stains on top of the transmission under the area where the thermostat lives. Those would be coolant stains; the coolant drips down and then evaporates before it can land on the ground.

--DD

CEL was never on.

I find when there is steady leakage as there is almost always some discoloration even if no liquid coolant is present. Besides, the coolant level in the tank has been steady.

I'm leaning towards just driving it, but checking regularlly for fault codes or leakage. And keep looking for a good indy.

Thanks for your help, it was very useful!

Oh, borrowed a scanner that read temp, coolant temperature (on a 20 F morning) was 219 F (104 C).

Nothing leads me to believe you have a t-stat issue, but just keep an eye on things and report back if anything changes. :)