Coolant LEAK or Sensor Problem???
 

I just bought a used 2001 4.4 x5 with 58k on it...I did alot of research here and on other forums before buying...I realize the 2001 8 cylinder has some issues, but this is my dream car and the budget would not permit a newer model year...sooooooo...the issues begin!!! The car drives and feels awesome and looks brand new...however it keeps displaying the "check coolant level"...The engine temperature guage seems to ALWAYS be straight up the middle...I would NEVER run it if the needle were heading to the red...So alright...I check the coolant and the little red buoy is floating...so I jiggle the bouy around a bit and the coolant level goes down substanstially...so I figure it needs topped off and add about 10 ounces of distilled water...light disappears...I am now feeling satified that I fixed my car and I drive it about 30-50 miles (not all at once) and the light re- appears...I return home immediately and let the car cool off...open the expansion tank hours later and the coolant explodes out...just a bit...perhaps it did not need topped off originally...but I jiggle the little buoy again and the level goes down again...hmmmm...now I have no idea what to do...So I head inside to do some research on the problem...I have read a million posts and am confused so here it is...MY FIRST X5 POST...

-The car does not VISIBLY appear to be leaking fluids...

-Water does puddle under the center of the vehicle , but from my reading here that seems to be A/C condensation (correct me if I am wrong please)

-I can smell coolant when I look under the hood and the car is hot

-No smoke and the car feels great when driving

So my questions are...

How much coolant is too much and should the level change when you jiggle the red buoy??? (We had a 328i that we could NEVER get the coolant level light to go off despite replacing ALL coolant components...apparently they are notoriously hard to bleed properly???)

I read here on the forum that the engine temperature guage is a "dummy guage"...does that mean I cannot rely on that to tell IF my engine is over heating??? I am so freaked out right now I am afraid to drive my dream car for fear of destroying it...please help!!!

I first thought that there was a leak between the top and bottom halves of the expansion tank but now that does not seem to be true...

Is it possible this is JUST the sensor having gone bad???

Can you refer me to the appropriate links that help me determne IF this is a sensor problem, a water pump problem an expansion tank problem or the dreaded valley pan gasket...

I am trying hard to learn fast and have doen a bunch of reading but instead of eliminating things I seem to be adding things to my list and just creating general confusion for myself...so rather than lsoing my mind I thought I would ask those of you who have more experience and expertise where to start...My husband and I have some DIY skills, but with this car being so new to us, we need advice before we start tearing it apart:D

Thanks in advance for any and all advice...This is a GREAT FORUM...so much information...

I too have this problem in a 2001 4.4i X5 - I purchased mine with 80K miles. Low Coolant all of the time. The searching I did here points to the Coolant Reserve Tank. Yours is probably cracked. I don't have fluid anywhere (leaking out) either, but I do smeel coolant. The car looks and drives like new, but I hate that error. One of these days I will bring it to a shop for the repair.

Do a search on the coolant reserve tanks cracking...

p.s.
Next mod, crack open the headlights and ger rid of those wafers!!! (if you have HID)

Thanks so much for the response...I am DESPERATE to get this fixed...it is FREAKING me out because I am afraid I may do some damage...because I am fearful it will overheat...I have lloked at the expansion tank and cannot detect a leak or crack...unless it is ridiculously minute...I will do some more searching about the expansion tank upon your advice...I have to say I LOVE this car...It drives as well as everyone said it would...I have found the advice of members to be extremely helpful in the past with our E39 and our E36...

Since I am a newbie, I am not sure what you mean by "wafers"...I have lights that are far brighter than my E39 lights and are bluish white in color, but I like the face lifted look on the 2004's and sort of wish I had those...That would be an awesome mod...but first I need to get the coolant light out...it will make me crazy...

How many posts until I can post photos of my new to me x5?

Thanks for the advice I will keep reading!!!

Jammer..you have HID's or more commonly known as xenon bulbs for your headlights from what you describe. The Wafers or waffles are the things over your highbeams and partially around your low beams around the projector lens. You can remove them for a more cleaner look...

The temp gauge is pretty imprecise indeed but if your engine was over heating it would go to red so I do not think you have an overheating issue...at least not yet. It you smell coolant then you do have a leak somewhere. Here are possible caused on this car: A cracked expansion tank, leaking water pump, a cracked hose or hose connector. The hose connectors are plastic and do not age well at all.
Here is what happened to me 18months ago. It started with a low coolant issue for few days that I could not locate and then it turned into a more obvious problem. Here is the post.
http://www.xoutpost.com/x5-e53-forum/...t=coolant+hose

First make sure the puddle is coolant (BMW coolan is blue), so place a clean paper-towel underneath the parked X5 and see what color the paper towel turn into. A/C condensation is just water to no color.

For coolant leak, check the reservoair tank, hose in engine compartment, the easiet to check.
Next (if the above items look good), I'll suspect it's the valey pan gasket, very labor intensive to replaced.

How often do you get the warning message(assuming you top of the coolant with distilled water)?

I agree with the others. If you can smell coolant, then you probably have a leak somewhere. The red buoy floats on the coolant, so it should not go down when you shake it. I am thinking that it could be going down when you shake it becasue the coolant level is low and the buoy is sticking.

My initial thoughts are water pump or valley pan gaskets, which are unfortunately expensive reapirs. I had those items replaced on my 02 4.4 under warranty at about 80k miles. I would suspect that if you had a top side leak such as a hose or expansion tank, that you would see a white residue from dried coolant on the affected areas and the hood insulation. I know I did when my expansion was leaking.

You should not have to add coolant at all after the system is topped off and all the air bubbles are worked out, so you may need to get your system pressure tested to find the issue.

Good luck

Wow these are all great answers...Thanks so much for the quick replies...

HPIA4v2...the puddle is DEFINITELY water...it just scared me because the car is new to me and I was not sure since my coolant appears to be going somewhere...I did the paper towel test and there is NO COLOR to the liquid...clearly water...it just seemed like a lot and from an odd place...I would have thought A/C condensation would have been in the front of the car...go figure..

primetime...thanks for the headlight clarification...I do have xenons but thought xenons and HIDs were two different things...I am still learning...I definietly like the facelifted headlights...but it sounds like I have a more pressing issue right now as I am afraid to drive my x for fear of blowing up the engine...

alpac...my hubby had an e36 that suffered from the infamous plastic parts coolant failure so common to those vehicles and indeed drove it with the needle buried in the red...I am girl but even I knew better than to do what he did...hahahaha...I believe you are dead on as the engine has not overheated to date...I am fearful however that it will and I do not want to cause further damage so I aim to get this corrected IMMEDIATELY...but would prefer to attempt to fix it myself if possible and if I can diagnose it...I will be referring to your link as soon as I post this...

I have added coolant after driving about 50 miles...I am wondering though IF I may have not added enough...what would cause the coolant to appear full then when I jiggle the red buoy the level goes down and then I can add more fluid...why is it doing this???? Is this a significant symptom or more likely just me not entirely knowing when my expansion tank is actually full??? If the red buoy supposed to stick up above the neck of the expansion tank when the lid is removed???? Thanks for the help...I am going to keep researching and hope to add more clues to my mysterious disappearing fluid...Are there any definitive signs that it is the valley pan gasket...I am hopeful to eliminate thaat one first...Thanks for all of your expertise adn related experiences!!!

Fseth...Just to clarify...the red buoy does not go down when I jiggle it the COOLANT LEVEL goes down when I jiggle the red buoy....like jiggling the buoy displaces air or something causing the fluid level to go down thus allowing me to add more fluid...does that make better sense? I am assuming topping off the expansion tank requires no more skill than just opening the lid and pouring in BMW coolant or distilled water...PLEASE ADVISE if I am doing this incorrectly...

I have noticed some dried salt looking residue on the expansion tank arounfd the neck where the cap screws on and a little where the top and bottom half of the tank meets...is that an indication that the tank is leaking??? I thought initally that there was a leak where the two halves of the tank are joined but if so it is tiny...I have tried turning the engine on and watching to see if the pressure of the running engine causes a leak but to no avail...although I only did it for a few seconds...as I have mentioned I am worried about damaging the engine itself...Aside from the low coolant level light the car has a few dead pixels (something I factored into the purchase price of the car) and a passenger side burnt out turn signal...being fixed as we speak...It drives perfectly the interior looks BRAND new and there are about three scratches on the exterior...you would NEVER know it was a used vehicle by looking...I have been wanting to buy this car for three years and I HOPE I am not going to be sorry!!!

You could have a leaky cap on the expansion tank or the tank itself could be leaking. Do you see any evidence of fluid or residue on the hood liner near where the tank would be when the hood is closed? If you see residue on the tank itself, I would think that the cap or tank would be a good place to start.

Also, I thought the dead pixel issue was something that BMW recalled and should be fixed for free? Someone else may be able to chime in on that.