'07 Mini Cooper coolant problem

mini
cooper

#1

I’ve got a 2007 Mini Cooper (regular, non-S) with almost 130k on it. I’ve already replaced the timing chain in 2014 (ouch!!), but now there’s issues with coolant disappearing from the reservoir and burning (never leaking on the ground, btw). I took it to my mechanic on Friday, he found the temperature gauge/sensor was leaking so they replaced, it all seemed good.

A day or two later, coolant levels were low again and there was some smoking and burning. I plan on taking it in on Friday this week for another look, but I fear the worst – especially after chatting with an acquaintance who does his own car work. From what I told him about the symptoms, he thinks the head gasket needs to be replaced. If so, this will likely cost more than what we can afford (the timing chain was rough enough on us). We still have a couple/few years left on car payments, but might have to swallow hard, trade this in and get a beater instead.

Any thoughts on this?


#2

These are notorious for bad head gaskets. Just make sure you confirm the problem by testing the coolant for acidity from exhaust gases (you can buy a test kit and do it yourself) or remove the radiator cap when cold, start the engine, and check for bubbles in the coolant from exhaust gases when you rev the engine.

If you still owe on the car, dumping it may not be the best move. You might be able to borrow some $$ to get it repaired and still come out ahead, vs selling at a big loss and then buying a crappy beater that will need replacing soon.


#3

Thanks, jesmed. I already borrowed some for the timing chain fix in January (bad timing for a major repair to come up at that time), doubt I could do the same now (especially with it being maybe twice the cost or more). I still owe over $7k on it, too. Quite a jam, if it is indeed the head gasket. Oy…


#4

Ouch. Well, run the numbers and do the tradeoffs. You might be able to save some $$ by paying a competent friend to do the job. But don’t cut corners, and be sure to check the head for warpage and have it machined if necessary. You don’t want to have to do the same job twice.


#5

I obviously can’t say from here what is going on. But nothing about your description makes me think of a head gasket. If you lose coolant via a head gasket problem, the issue is normally that it ends up with the oil - inside of the engine. (Have you checked your oil? What does it look like). You mention losing coolant and some burning going on. Head gaskets can leak externally, but its more typical for external leaks to just come from normal cooling system leaks (e.g. hoses)

Has the car overheated? Or has the temp gauge done anything abnormal otherwise? What are the symptoms other than losing coolant and burning?


#6

Actually, the most common breech of a headgasket is between the cylinder and the water jacket, because the massive pressures that blow the hole are the combustion pressures from the cylinder and the water jacket intentionally surrounds much of the cylinder to dissipate the heat, whereas the oil passages are proximate to the cylinder only incidentally. Rarely is an oil passage involved. This sounds very much like a possible head gasket to me.


#7

I get the breach between the cylinder and water jacket. I’ve actually had one of those. But that’s also an “internal” leak so it doesn’t produce any burning (at least not directly. Burning would come from having it leak onto something hot and external like the exhaust manifold. (I’ve had that one too with heater hoses). Of course if it is combustion gases shooting into the water jacket that can overpressurize and make other things leak. And it can leak externally. But I would have expected that the post description would include some reference to overheating - or at least some wonky temp gauge behavior.

I guess we’ll wait and see…


#8

Point made about leaking.
Generally, however, the loss of coolant happens when the piston draws coolant through the breech and vaporizes (burns) it. The OP’s description sounded to me like that’s what’s going on.

However I see your point about the overheating. Generally the hot combustion gasses heat the coolant more than the cooling system is able to dissipate. Generally the engine overheats.


#9

Ah…I get you. I have the “smoking and burning” under the hood, but maybe you have it out the tailpipe.

So @bgart13, where is the smoking and burning happening?


#10

And I see your point about there being no mention of overheating.

OP?


#11

It sounds like you owe more on the car than it’s worth, even if it was in sound operating condition…It’s going to be difficult to get past this without a lot of blood being spilled…


#12

Good comments above, but don’t assume it is a head gasket. It could be something simple, like a leaking hose or block freeze/drain plug. Or something not quite as simple, but still fixable, like a leaking radiator or water pump. A careful look-see with a flashlight, your mechanic can usually tell for certain if it is any of those. If the leak is minor, you could well notice loss of coolant and steam from the engine compartment but no dripping of coolant onto the ground.

When head gaskets fail they can fail in various ways so to confirm you’d check for exhaust gasses in the coolant, oil and coolant mixing, & white smoke out the tailpipe.


#13

Hi all, thanks for the comments, etc. Here’s the general symptoms as simply put as I can do:

  • Coolant level in reservoir drops down to well below “low” after a 30-45min ride in the AM.
  • Over the last two mornings, the coolant level in the res was down to nearly empty (just a little in the bottom of it).
  • There is now a puddle left underneath the car after sitting overnight (and a smaller one if left for a few hours while at work). I saw the dripping too when I looked underneath after getting home last night.
  • There are some puddles forming on a flat surface connected to the engine (don’t know what to call it).
  • The area it’s all happening at is to the right of center (while facing the car from the front).

Also - there’s no smoke or condensation from the tail pipe. The smoking is all coming from under the hood (and it does it only occasionally, not constantly). I see no milky substance when taking the oil cap off, nothing out of the ordinary with that (as I’ve read and stated here can be seen with a blown head gasket). No overheating or temp lights have come on at any point, ever. The car is actually running really well, besides this problem. The only issue is it sometimes hiccups when accelerating after taking my foot off of the pedal (around 2k rpms). I told my mechanic about this after the timing chain was replaced, he took a look – but the computer is not reporting any problems. He’s told me to pay attention to it and that if it gets worse, let him know (he suspects a couple of things, ie sparkplug(s) needing to be changed).

I’ve attached a couple of pictures, but they probably aren’t too helpful. For the wider shot, the pooling of fluids is right about in the center of the picture itself where I’ve circled in red. The second shot is that area but closer up and a slightly different angle.


#14

Here’s the first pic - it didn’t attach to my last reply.


#15

Sure looks like a bad hose. It’s leaking where the hoses meet the block. I don’t know if the thermostat is ther, but the gasket could be leaking.


#16

The puddle under the car and on the engine is good news. Also the fact that it’s not overheating. I agree, maybe a leaking thermostat gasket if that’s in fact where the thermostat is.

Here’s someone who had a leak from the temp sensor on top of the thermostat housing, so check that too:


#17

Yeah. You just have a coolant leak. Take it in before you do manage to overheat it and end up with bigger troubles.


#18

Thanks again, everyone. I’ll be spending my day with my mechanic tomorrow. Wheeee!


#19

Most coolant leaks onto the ground are not from head gaskets.
The Mini Cooper is not an economy car when it comes to maintenance.


#20

Ok, so the mechanic looked on Friday, found it to be the housing for the temp sensor/gauge/whatever. He knocked the prior week’s labor charges off this bill since it was all related. Fingers crossed I don’t have to see him for the rest of the year (except for an oil change, perhaps). Thanks again, everyone!

oldtimer11 - nope, it sure ain’t an economy car! Great mileage, though. This last tank I averaged over 31 mpg. In the past, I’ve done a six hour road trip (340-350 miles, each way) with half a tank. I do love that aspect of it.