Coolant leak
07-26-2011, 11:48 AM
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My Ride: Black 2006 BMW 530i with sport and prem package, staggered 124 wheels, 50% tint, AC Schnitzer aluminum pedals, black interior w/ alum trim set, M style body kit and sound upgrade: Alpine PDX-5, PXE-H660, sub, MBQuart speakers.
A couple of months ago I got the "low coolant level" warning so I took the car to the shop. The guy looked all over and couldn't find any leak, and everything was dry. He then proceeded to fill it with coolant and end of story.
Now 2 months later I start the car yesterday morning and I get the same warning. I open the trunk and look down with my flashlight and there's a lot of coolant leaked at the bottom of the engine, so i filled it with water and ran to the shop. They mechanic then did two pressure tests, one with the engine cold and another with the engine warm and there was no leak. Obviously there must be a leak somewhere and it's not a regular leak, but it's puzzling and we have no idea what could it be.
If we don't do anything then it could get worse and the repair could be thousands, but what else is there to do? anybody had any similar experience?
Now 2 months later I start the car yesterday morning and I get the same warning. I open the trunk and look down with my flashlight and there's a lot of coolant leaked at the bottom of the engine, so i filled it with water and ran to the shop. They mechanic then did two pressure tests, one with the engine cold and another with the engine warm and there was no leak. Obviously there must be a leak somewhere and it's not a regular leak, but it's puzzling and we have no idea what could it be.
If we don't do anything then it could get worse and the repair could be thousands, but what else is there to do? anybody had any similar experience?
07-26-2011, 11:50 AM
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I suggest lift it up, clean up everything and leave it there to locate the source of the leak. Pressure test does not always locate the leak since it could be very small and accumulate over time on the undercarriage cover.
07-26-2011, 12:04 PM
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My Ride: Black 2006 BMW 530i with sport and prem package, staggered 124 wheels, 50% tint, AC Schnitzer aluminum pedals, black interior w/ alum trim set, M style body kit and sound upgrade: Alpine PDX-5, PXE-H660, sub, MBQuart speakers.
It hadn't leaked (or leaked very little) for a while since the last time (2 months ago). The fact there was a lot of coolant at the bottom of the engine yesterday it means there was a huge leak all at once and it happened overnight, otherwise it would have dried out.
07-26-2011, 12:10 PM
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may be someone else can chime in with different experience but with my previous cars and my current one, the way I usually do is jack it up inside my garage, remove the undercarriage, wipe everything clean, and keep an eye on the floor to see if there is a wet spot. Then from that wet spot, I look straight up to narrow it down before proceeding. Yes coolant tend to dry up fast so you have to pay attention to the dark spot on the ground. That's what I did to my E60 when I had the tranny seal leak several months ago.
GL
GL
07-26-2011, 02:16 PM
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A couple of months ago I got the "low coolant level" warning so I took the car to the shop. The guy looked all over and couldn't find any leak, and everything was dry. He then proceeded to fill it with coolant and end of story.
Now 2 months later I start the car yesterday morning and I get the same warning. I open the trunk and look down with my flashlight and there's a lot of coolant leaked at the bottom of the engine, so i filled it with water and ran to the shop. They mechanic then did two pressure tests, one with the engine cold and another with the engine warm and there was no leak. Obviously there must be a leak somewhere and it's not a regular leak, but it's puzzling and we have no idea what could it be.
If we don't do anything then it could get worse and the repair could be thousands, but what else is there to do? anybody had any similar experience?
Now 2 months later I start the car yesterday morning and I get the same warning. I open the trunk and look down with my flashlight and there's a lot of coolant leaked at the bottom of the engine, so i filled it with water and ran to the shop. They mechanic then did two pressure tests, one with the engine cold and another with the engine warm and there was no leak. Obviously there must be a leak somewhere and it's not a regular leak, but it's puzzling and we have no idea what could it be.
If we don't do anything then it could get worse and the repair could be thousands, but what else is there to do? anybody had any similar experience?
Was your mechanic checking it with engine hot and running? than after engine was shut off and cool down?
When engine is running and pump circulates coolant, pressure in system is lower and there is no leak. Once you shut the engine off - pressure builds up (temp) and somewhere leaks....
If there is a small leak (damaged hose possibly ) and coolant actually leaks (sprays?) on hot engine and quickly evaporates. Once engine cools down - it drip on the floor...
07-26-2011, 02:23 PM
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and if you have not replaced the water pump - do it (thermostat as well). Had similar issue with 2002 530i - was loosing coolant a little for a month or so with no leak indication and with no smell (except early in the morning when pulling from garage) and one day got temp warning than cloud coming from under the hood - > water pump blew on freeway... as always in least convenient time = lost appointment, mess, towing etc... etc....
07-27-2011, 12:01 PM
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My Ride: Black 2006 BMW 530i with sport and prem package, staggered 124 wheels, 50% tint, AC Schnitzer aluminum pedals, black interior w/ alum trim set, M style body kit and sound upgrade: Alpine PDX-5, PXE-H660, sub, MBQuart speakers.
Was your mechanic checking it with engine hot and running? than after engine was shut off and cool down?
When engine is running and pump circulates coolant, pressure in system is lower and there is no leak. Once you shut the engine off - pressure builds up (temp) and somewhere leaks....
If there is a small leak (damaged hose possibly ) and coolant actually leaks (sprays?) on hot engine and quickly evaporates. Once engine cools down - it drip on the floor...
When engine is running and pump circulates coolant, pressure in system is lower and there is no leak. Once you shut the engine off - pressure builds up (temp) and somewhere leaks....
If there is a small leak (damaged hose possibly ) and coolant actually leaks (sprays?) on hot engine and quickly evaporates. Once engine cools down - it drip on the floor...
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