Coolant Leak !!!

briandwlee · #1 12-12-2010, 12:42 PM

My X5 keeps displaying 'Coolant Level Low.' There must be something going on.

About two weeks ago, the warning came on, and I brought the vehicle to service dept. The service tech said coolant level was really low, and it was refilled.

In about a week, the warning came on again. This time the service dept performed 'Pressure Test', but they could not find any leak. Coolant reservoir was refilled.

Five days after, the warning message was displayed again. Service department refilled the reservoir again with 1L(apprx. 1 quart) and booked it in for service.

The same frustrating message was displayed again last night in three days. It's very frustrating.

The service department says if the Pressure Test doesn't find any leak, there is no leak. Is it true? Is there some other leak that cannot be found by 'Pressure Test'?

Where are common leak points in X5s?

Thank you very much in advance for your inputs.

DeanLinAZ · #2 12-12-2010, 02:12 PM

I had the same issue with the engine in my motor home for over a year. It kept losing coolant, the low coolant light would illuminate, and I had to add more coolant after each outing.

After several "pressure tests" by Caterpillar techs found no leaks, and no drips were ever noticed, a dynomometer test revealed a leaking (read, blown) head gasket at the number 3 cylinder. The warranty claim paid for several thousand dollars of labor to replace the $150.00 head gasket. Because the problem lasted for such a long time, the number 3 piston also had to be replaced.

Don't let this issue slip past your end of warranty date as the labor to change out the head gasket on any engine is prohibitive to pay out of your own pocket.

This may or may not be the problem with your vehicle, but ask to have it checked out the next visit to your dealer's service center.

Good luck--from experience,

ard · #3 12-12-2010, 02:41 PM

^^^ +1

The coolant system can leak to the 'outside' which is what a pressure test will detect.

However it can also leak into the motor, into the oil or combustion chambers...in which case a pressure test will never detect this since both of those are 'sealed' and will hold test pressure.

You could test the oil, it will show coolant contamination. Or maybe do the coolant pressure test with the spark plugs out.

No idea what kind of car you have nor if it is a BMW mechanic or under warranty or what...but I'd be VERY concerned with a "mechanic" that is having problems with this diagnosis... tell us a bit about the 'human' side of this diagnosis, and what is going on with that...

A

Penguin · #4 12-12-2010, 04:48 PM

Quote:

Originally Posted by ard

You could test the oil, it will show coolant contamination. Or maybe do the coolant pressure test with the spark plugs out.

I agree. But would add that with a head gasket leak it often goes both ways, getting some exhaust gases dissolved in the coolant. Any competent garage can also do a simple test for exhaust gases in the coolant, which would also indicate a head gasket problem. I believe nowadays they even have some simple test strips to test coolant for exhaust gases, sorta like litmus paper or the strips you use to test for ph.

I would think any competent technician when faced with a chronic loss of coolant and good pressure test results would test the coolant.

dbox · #5 12-14-2010, 01:52 PM

took the dealer 13 times to finally figure this out with my 2004. I bet this is the posters issue as well.

Quote:

Originally Posted by Penguin

I agree. But would add that with a head gasket leak it often goes both ways, getting some exhaust gases dissolved in the coolant. Any competent garage can also do a simple test for exhaust gases in the coolant, which would also indicate a head gasket problem. I believe nowadays they even have some simple test strips to test coolant for exhaust gases, sorta like litmus paper or the strips you use to test for ph.

I would think any competent technician when faced with a chronic loss of coolant and good pressure test results would test the coolant.

joeboch348 · #6 12-12-2010, 02:48 PM

i had a small crack in the reservour. it held pressure when testing but once warm it must have expanded the crack and it would steam. a good pressure test would be pumped up and left to check for a drop in pressure then started to see if there is a head gasket problem the pressure would rise . if they mechanic is worth anything he would have done that. outside leaks could be anywhere including the alternator.

xoutpostking · #7 12-12-2010, 03:05 PM

Open your engine oil filler cap, see if there's condensation under the cap and around the neck/opening. If no, small leak somewhere not important, still needs to get fixed. If yes, you are in serious trouble with blown head gasket/s. We talking tens of benjamins!!!

joeboch348 · #8 12-12-2010, 03:26 PM

just dont take the cap off when it's running! no coolant in your garage or driveway?

Weasel · #9 12-12-2010, 08:20 PM

What year is the X and which engine?

drx2 · #10 12-12-2010, 11:19 PM

You can test the coolant for exhaust gasses. Take the radiator cap off and use the same sensor they use for emissions testing. It will "sniff" the gasses coming out of the radiator and it will detect if there are any hydrocarbons. If so, them the head gasket is the logical answer.

I even heard the guys on Car Talk a couple of weeks ago say they use this method. They said there is another test for the coolant and it is positive if the coolant changes color. It was not very reliable because it is technique sensitive, and coolant can come in different colors, changing the end color giving a false positive or negative.