I'd appreciate any input you all might have...

From a cold start, letting my 2003 MCS idle for a little over 5 minutes brings-on an overheat condition (per the MINI's "gauge"). Also, I am not getting any cabin heat. I fear this might be a failed water pump, or drive gears, not being able to circulate the coolant...

Some more info:

- The fan is operating as designed, low on at 220F and high at 233F, or thereabouts...

- No external leaks visible. There were from the expansion tank (cap), but I replaced it with a Canton, and all is tight there... Coolant level in the expansion tank remains at mid-level, not dropping during testing, further convincing me of no leaks

- Attempts to bleed air out of the system at both locations yields only water.

- Installed a new t-stat and housing recently as I had a leak there, and that resolved the leak. So, I don't think it's a t-stat failure. Even if the t-stat were stuck closed, I believe I'd still get cabin heat...

- I just installed a new belt tonight as that might have been the culprit (slightly less than half of the first hole visible). Same issues after the install though...

- The car runs smooth, no codes, no loud or unusual noises. I tend to believe that if the water pump drive was bad I would have heard something, or still hear something. Maybe there were such noises, unnoticed, and now it's all disintegrated, and quiet. Not sure...

- If not the water pump gears, maybe some airlock in the system or blockage. Thoughts?

 

Has the car ever run right right since the new thermostat was installed?
Just wondering if it might have been installed backwards.

 

I'd be tempted to go with this and if you install if on the wrong side, the bleeder hole would be at the bottom rather than at the top.



If the coolant level is good and that the system is properly bled, the main reasons for the engine to overheat with no heat in the car would be either a thermostat preventing the coolant flow or a dead water pump. If the stat was stuck closed, it would overheat and also prevent enough hot coolant from going in the heating system. If it was stuck open, it would take forever to get to normal coolant temp and also affect the heating inside.

 

I appreciate the feedback guys.

I installed the t-stat about 3 months back, and while I had no reason to use the heater, it didn't run bad or strange in any way. If backwards, I would imagine I'd get an immediate overheat situation....

So, maybe the new t-stat somewhat suddenly stuck closed. I believe that is it, or there is some blockage there. I did some shop vac work last night:

1. Sucked what I could out of the new expansion tank, opening bleed points...
2. Disco'd the the top hose above the radiator and fan and sucked there...
3. Disco'd from below at the radiator and suck there...
4. I also then blew air through these openings...

I had all of these open at the same time, to get out what I could. When attempting to blow air from the top hose above the radiator, I got resistance.

Is the capacity about 6 quarts? I forgot... Would a blockage of the heater lines, or in its core be the culprit? Maybe I can disco a line there and use the shop vac...

Looks like I won't be making a college football game today. Oh well... Thanks again.

 

^
Are you saying bleeder hole is correct on bottom side?

 

Are t-stat failures common on these cars?

All of the troubleshooting ruled-out the t-stat as it was purchased earlier this year, and I drive at most once a week, so it has seen little use...

Well, after spending a few more hours checking into more things that could be the culprit, I decided to remove the t-stat and drop it into a pot of hot water. It did not open. What temp should it open?

Oh, to the earlier question, the weep hole is typically on the top, at least it was on mine and other cars that I had over the years... The image shows it correctly, I believe.

 

No.

 

The thermostat should open in the 180F range...

Your photo shows it is mounted correctly.

When you filled and bled the air out of your cooling system, did you remember to turn your heat temp to full hot? (fan does not need to be on)

Best of luck with it.

Motor on!

 

Thank you JABowders.

I found that the stock MINI T-stat is a 195 degree open one. The one I have here states such as well. So, it should be open at that temp.

Yup, heater has been on high the whole time, at various fan speeds. A/C works fine, FWIW.

 

I decided to rev the car during heat-up this morning, and got the death rattle from the SC / water pump area. Damn. I made a video, but off to the airport on biz travel... I'd otherwise upload.

I will not go back to stock, but with an EWP, either of these two:

http://www.daviescraig.com.au/Electr...5-details.aspx


http://www.cvproducts.com/Products/SC-E558A-BK.aspx

Anyone know the size of our radiator hose, 1.5" maybe? The 2nd pump is at 1 3/4"....

 

Sounds like a thermostat

 

The water pump gears were pulverized into a dust.

Installed an EWP 80, and all is fine now. I had installed a new t-stat, with housing, earlier in the year...

During this project, I also replaced the radiator with an aftermarket, all aluminum one. I ditched the A/C as well. And with the SC out, I removed the OEM water pump and sealed it off. Oh, I also put new SC oil in the unit.

Runs like a champ and there is cabin heat again.

 

Interesting (and terrifying) that the WP gears ate themselves without any audio tell-tale. Glad to hear you're up and running.

 

You got that right. Good to hear from you Eric...

It was my pop, who was outside my MINI upon start-up who heard what sounded like metal-on-metal issues. From inside, and my MINI is quite loud, I could not discern a difference.

Even after I managed to get home one night with coolant temps too high, I couldn't hear the issue with the car idling in the driveway. It was only under throttle, which got me back inside the cabin to not hear so well... I finally opened the doors and leaned out while working the accelerator, and I could hear it; and I then knew it would be no small project.

It seems that I suffered no major damage, maybe none at all. While I drove home with high coolant temps, I was also watching oil temps, and they were still in a safe range, but were also going upward...

The EWP mod was something I had wanted to do anyways.

 

Glad it all worked out. As I approach 80K, and have a friend at 100K+, I wonder if it's not time to do a SC R&R and make sure everything is lubed up.

 

If you plan to keep the MINI for a while longer, I would, plus other things too possibly. Apparently our radiators tend to fail (the plastic ends), around 10-12 years, of normal driving.

My MCS has a little over 60K miles, none of the track, but some fairly hard miles in a canyon. To have the water pump go, or the drive gears, is totally unacceptable, and a major flaw. There was no way I was going back to stock...