Christmas Day Overheating Adventure

[davintosh]

We had planned to head to my wife's parents' house bright & early yesterday for Christmas, and I had cleaned up & gassed up the X5 for the hour drive. Got the family and loot all loaded up X5 with plenty of time for us to get there for the Christmas morning church service, but about 3 blocks from home, I look down at the instrument cluster & see the temp gauge pegged to the right. Crap. So we turned around & went back home, transferred everything from the X5 to the e32 and headed out again. Didn't lose much time, but I was stressing out about the thing all day yesterday.

We haven't had the X5 for very long, but I've never seen the temp gauge move past the 12 o'clock position. In fact, on Monday I ended up sitting in it with the engine idling for about 15-20 minutes waiting for a car wash, and the temp gauge was right about the 10:30 position the entire time. We also drove it around a bit that night, about 20 minutes total, and the temp gauge stayed where it should be for that. Yesterday morning it was plenty cold out -- about 0°F -- but it had been parked in the garage overnight, with the heat on all night (to make sure the doors & locks dried out properly after the cold-weather wash), so it was a balmy 60°F in the garage. I left the engine idling about five minutes while we loaded up, so the total running time before I noticed the temp gauge was well under 10 minutes.

I'm thinking/hoping the problem is something simple like the thermostat, or maybe even a misbehaving temp gauge... Any thoughts on that? I haven't had the time to take a closer look at anything; we got back late last night and I'm back at work now, but will definitely break out the Bentley and my meager troubleshooting skills when I get home.

One other thing really had me worried, at least until I did some asking around earlier today; when I checked the oil at the gas station on Monday it was quite low, so I picked up a couple quarts of synthetic 5w30, and it took both of them to get back to the full line. The inside of the oil filler cap had some white/yellow pasty crap on it too. My first thought with that in mind on top of the overheating was "head gasket" so I checked the coolant too; level was fine, and showed no signs of contamination. The pasty stuff is likely just the result of some condensation in there, as it's been quite cold lately, and my wife does a lot of short trips with the X5. Then I found this thread about the oil separator; makes perfect sense that that thing would be acting up & causing high oil consumption, and is due for replacement.

[brokenbmx06]

Im going to go with the thermostat. Oddly enough mine was stuck open and never threw a code however when scanned with PaSoft it showed that it was stuck. The car wouldn't warm up for a VERY long time when it was running. Sometimes when it was running the temp gauge would randomly go completely in the red. I would simply pull over and turn the car off then back on and it would show the correct temperature on the gauge. If you have someone in your area that has something like PaSoft or a GT1 is should be able to tell you if your thermostat is ok or not.

[Christiano]

The overheating could be the thermostat for me too. The oil consuption could be a "bible" of troubles... Start checking the spark plugs to see where is the problem. Maybe could be a valve seal (or rings), or a simple oil leak. If seals or rings, you gonna find some oil on exhaust, for sure (put a finger inside the exhaust to see). Check the upper gaskets too... who knows.
Good luck,
Chris

[Ricky Bobby]

I'm guessing you have CCV problems, which sometimes leads to oil consumption from what I read, the short trips in the cold that your wife does don't help. If you have paste under your oil cap its not being run long and hard enough to burn off the condensate in there.

As far as oil consumption, clean your engine out well, take a look for leaks around the oil filter housing, as well as feel under the valve cover to see if you can visually or by touch find any leaking spots, take out the spark plugs and see if they have oil on them at all, and obviously get under the car and check for oil spots by the oil pan gasket.


The M54 does consume oil, as far as I remember a quart every 1000 miles was within BMW spec believe it or not. I was about 3 quarts low on my last oil change, I drained out just under 5 and put in 8. However, my indy says no valve cover leaks, no under body leaks, no oil filter housing leaks. So if I'm losing oil it means i'm burning it within spec or through the CCV.

[RickM5X3]

Sorry to hear about the E53 adding stress to your Christmas day! Hope you had a great day with the family anyway.

But your X5 would be giving high fives to other E53s if it could. Nothing makes an E53 more happy than ruining a family outing with a sometimes bizarre and/or urgent repair issue. Since you are new to the E53, just know that if you are so lucky to get a year end bonus or take a profit from your business, your x5 KNOWS this, and will reward you with a big ticket repair item. Additionally, if you do something smart like reduce your cable bill to save money, the X5 will retaliate with a leak of some sort, maybe just a coolant leak, but perhaps an oil pump seal if it feels like you have too much cash in your pocket. And forget it if your kid needs braces, the E53 will sense this and definitely want a transfer case or transmission!

[JCL]

The CCV does not cause increased oil consumption over time. If it is full of condensate (the white paste) and it then freezes, it can either freeze in the open or closed position. In one of those, with high vacuum conditions such as on overrun, the CCV can draw oil out of the sump into the intake, creating large clouds of blue smoke. In the other scenario, the crankcase can be pressurized and then oil will be pushed out the weakest point, usually a valve cover gasket. So both can lead to oil loss, but both are drastic, not something that results in the loss of a quart over hundreds of miles.

If the CCV has frozen, you will know it as the vehicle isn't driveable.

[davintosh]

Well, I checked things out a little more closely when I got home tonight... There was a spot of coolant on the floor of the garage under the front of the X5, near the radiator cap. That and the evidence of coolant spray near the cap suggest that something likely did go awry with the thermostat, and it was in the process of overheating. But, after starting the engine, letting it idle for a good ten minutes, then taking it out for a somewhat spirited drive, I was unable to get the temp needle to move past the 11 o'clock point on the gauge. I'm wondering if just the sudden 60° temperature drop from garage to the 0° driveway maybe made things act up. Or maybe the issue is just as Rick described it; the car is out to ruin me (hilarious comment, BTW. I loved it, as did my wife & kids. )

At any rate, I'm going to have my wife drive it as-is, but give her strict orders to keep an eye on the temp gauge when driving; if it acts up again, I'll probably start by replacing the thermostat, and maybe the water pump to start with. I only have maintenance records going back so far, and don't see any work done on the cooling system, but the hoses all look fairly fresh. As for the oil business, I've never noticed any blue smoke on startup or load with it, and the inside of the exhaust pipes is clean. I'm going to hold off on the CCV replacement, as it sounds like it's quite involved; maybe wait until spring on that. But I will definitely be checking the oil more often than I had been, especially this winter, and get in the habit of getting the engine good and hot every couple days or so, especially this winter.

Thanks to everyone for their replies; all very helpful, and/or humorous.

[Ricky Bobby]

As far as I can remember, coolant expansion tank, thermostat and hoses (and water pump too if you are so inclined) are almost a regular maintenance item, i know when I bought my car the PO said he replaced everything but the water pump at 60k miles.

Cooling systems on BMWs from what I gather on here can be finicky, hope it was just a gremlin for now but maybe you are in for some preventative cooling maintenance in the future!