Coolant Temp Overheating
 

Hello All,

So for starters I definitely missed out on the Midnight run a little while back but now I've moved from queens to jersey which gives me space to actually work on my car now rather than doing everything on the street.

So here is my dilemma:

Yesterday I was driving back from work which is approximately 25 miles. Somewhere in between I get a check coolant sign while I'm driving approximately 45-50 mph. Immediately after that maybe 2 minutes later I get check coolant temperature sign. Now the car starts overheating so I pull over immediately at the first chance.

The last thing I changed on this was the lower rad hose from engine to the radiator. Now I remember how hard it was getting that hose off and then getting the new one to get in there. Anyhow that hose came off from the radiator and had spewed all the coolant out. I was able to hammer it lightly and get it to be in there again and re-filled the coolant that I picked up from a Sears nearby. (Originally when i had flushed and re-did this job I have only used the BMW coolant but I had no choice and bought the prestone and put that in). Turn the car back on all seems normal the temp gauge is right in the middle and so I start driving immediately it shoots to the red area and I pull over again. So luckily I was only a few miles from home and crawled home letting it cool every 1/2 mile - mile before it shoots to red. Now I re-checked that hose and its still connected and no coolant dripping after I re-filled it. Also at this point now before I get home I also have the SERVICE ENGINE SOON light on which im guessing might be from turning it on and off or probably a sensor.

I am wondering if the sensor that is attached in that hose that I also replaced is the culprit. I wonder if it fried when it detached itself and started overheating.

I do not have warranty so I'm on my own on this. My first guess is to change that sensor or perhaps the sensor and the entire hose itself.

Please give me suggestions as to what I should do. Again the car keeps overheating but I do not see any coolant loss.

Recent changes:
New Expansion Tank with thermostat
New hoses all of them

In my recent post i posted pics of all the changes

When you refilled the coolant, did you bleed the system? You might be overheating because there is a ton of air in there.

That hose coming off is not good. How did it do that anyway. Did you put the clip on when you installed it? You should read the codes, and see what is going on. Maybe your t-stat is busted again.

there are multiple problems - first you need to properly bleed the system, and as a matter of fact you can look up the procedure either here or on E39 forums - the engine is the same between the platforms.

once you bleed the system, read the codes from the engine to see what threw the code...

report progress, we will help you from there on...

I think that might be the problem I did not bleed the system. The air might be the issue. I know that the last time I was bleeding the system I made sure the temp was to max 90 and at the lowest setting. Then adding coolant with the vent open and I started getting coolant flying out of the vent at which point it seemed clear of bubbles. I did not do that this time when filling it up. I will do that as soon as I get home.

The hose was in tight for sure because i could not do it with bare hands so i used a rubber mallet to slowly push it in all the way until it was on just the way the previous one was. Then i closed the clip and did not have trouble until this.

As far as codes go I can read the one on the obc but I do not have a reader. Any suggestions on one that I can pick up from perhaps a pepboys? or an Autozone?

I am gonna research again the correct procedures on bleeding and make sure its done the right way and see what i get back on it.

The "codes" you need to read are not associated with the car's OBC. You need an OBD II scanner/reader that will give you the codes for the vehicle's electronic emissions system (which OBD II is federally mandated to be installed in ALL car mfg's vehicles in the USA).

Once you have the OBC II "DTC" (diagnostic trouble codes)...you can usually find the code, its meaning, and possible fixes online. There is so much OBD II info online its not even funny. For instance, just type "OBD II codes" into a google search box and see what I mean. :)



Since OBD II is a federal mandate for the same criteria for all car MFGs...in most states you can go to places like AutoZone, Advanced Auto, Pep Boys etc...and most will read your OBD II codes for free. All they need to do is hook up to the OBD II connector on the lower left of your instrument cluster (between the steering wheel and driver's door...there's a small flip down door).


And now that your over in Jersey...consider picking up a simple OBD II code reader (as a Xmas present for yourself) :) ... you can find simple ones on eBay or Harbor Freight for approx $25. You can also pay much more money if you desire more info etc...but a simple $25 reader works fine for quickly hooking up and finding out what any OBD II code(s) that may pop up...and allows you to reset them if possible.

This is the one I have (Autel Maxi Scan MS300)...and keep in my trunk tool kit in case needed...again, I paid approx $25 for it a few years ago on either eBay or Amazon.com. I just checked and it's going for $19 on Amazon :wow::

Your best bet is to fill it with an Air Lift:

Air Lift Cooling System Refiller : Amazon.com : Automotive

You do need shop-air to use this. It uses the shop air pressure to create a vacuum, and it will then suction in the pre-mixed BMW Coolant/Water mix. Don't forget to use only distilled water, not tap water.

I'm gonna try to bleed it without this for now and see where it goes and then take it to a local spot for diagnostics.

Well, the auxiliarly cooling system pump can circulate the water a bit. Turn it on while filling the car, (hit the Max button when the car is off and key out, I believe there is a time limit from when the car was shut down. I think it will also go on with the ignition in ON but car not started as well.)

But these cars can be quite difficult to get out all the air pockets without an Air Lift. And if you run the car with an air pocket, you do run the risk of overheating the car.

Nah. Key in position 2, heat at 90, slowest fan speed. I can actually hear the pump, and hear it circulating water. It will do this as long as your battery has juice. So ridiculous easy to bleed system fully without anything special. Never had an issue.

Update:

So finally I bled the system and it started pouring out clear antifreeze through the bleed hole. I filled a gallon of antifreeze and then also went through almost a gallon of water feeding it slowly through the expansion tank. Once it started flowing through the expansion tank I stopped the process.

Speaking of juice I got back in the car and it was dead. :stickpoke

I jumped the car and then let it warm up - it did not overheat. Unfortunately I saw some steam coming out of the hood. Opened up and I saw that there was coolant leaking from the bleeder screw despite it being tightened.

any suggestions before i do anything else?

take a look at the exhaust - does the smoke "steam"? you might have an internal leak of the coolant into the engine... if the car "steams" the internal leak might be an issue...

otherwise - the are airpockets... one of the burping procedures involved rolling the front of the car on a curb and doing the burping procedure several times... even after doing that, there still might be air bubble somewhere in the system, and as it travels around the system, it burps... even after it looked like it already burped once or twice...

two cents...
 

you should order and install a new bleeder screw and expansion tank yesterday. Meaning at the very least get a bleeder screw immediately and order an expansion tank and just replace it. I apologize if you wrote that you had already done so, but if you did I overlooked it.

From the year of your X if you are not sure about the battery I'd go ahead and replace that now. I just went through a battery fiasco that you can review the thread if you like but here are the take aways for you-

1) If you are purchasing the battery from auto parts store and you do not have a charger I would strongly recommend purchasing the battery and having the store charge the battery for four hours (no matter what the charge says) prior to installing ( read X_Mesiter's thread).
2) you may want to get the 9v cig charger to potential avoid any dash lights during the swap
3) lastly remember that the electrical will be off after the battery is out so don't close the trunk gate/lift.

Anyway the bleeders fail and due to the pressure in the system even a .000004mm gap in the thread could cause trouble.

Yah I checked the exhaust it was normal as it would on any given day but the steam was definitely the antifreeze and I only drove it around the block to warm it up a little. I noticed that it was leaking out and once I popped the hood I saw it was leaking out of the bleeder screw assuming its touching something to heat it up and create the steam. What is burping? I will def order new bleeder screws and the expansion tank was just recently changed before this whole new ordeal. The battery hasn't given me any issues besides this now for sitting bleeding the system but I will definitely look into that and see if I can get it changed at the shop. I'm hoping this resolves the matter but will keep you guys posted. Appreciate the help.

Will be installing new bleeder screw - make sure its on not too tight and then leave the expansion tank open and start the engine with the normal procedures - saw this video also so will follow through and hopefully its nothing else.

Bleeding the air out.wmv - YouTube

I was concerned about driving with it overheating but I had pulled over immediately as soon as the warnings came on and I noticed it going into red. While crawling back I only drove about a half a mile before it would go up to red and let it cool at least 5-10 minutes in between and at times more wherever it was safe to pull over. I hope there is no engine damage as it seemed to be running fine when i took it for a test drive around the block.

Once this is done I am going to the local Autozone to get a read out and will post the findings here. Was hoping to drive it over to New York once this is done but I want to make sure its proper before I take a risk.

thanks again

Bleeder screw still letting out bubbles
 

Alright so i've followed all the bleeding procedures.

Truck was cold when I started so it took approximately 10-15 minutes to come up to proper temperature. I have uploaded 2 videos to youtube and checkout the link. At first I would say it took some time for the expansion tank throwing out coolant inside. Every so often the bleed screw and the expansion tank would let out coolant as if breathing.

After running this process for 25 minutes the coolant expansion tank had stopped letting out coolant shooting through. This entire process ive had the bleeder screw on.

The fan was set to the lowest point and set to 90. Once the gauge reached the middle temp it was hot in the car so the heater is working.

Now my question is that do I need to keep doing this to get all the air out? The bleeder screw is still spewing bubbles out and a little bit of coolant. I drove around the block and the engine sounds good - its shifting well but I have not taken it on to the highway yet because I am not sure if thats gonna put a lot of strain on that bleeder screw. Once parked I opened the hood up again and checked the bleeder screw - thats the second video of it spewing out bubbles and coolant.

Please tell me if you think this may be another problem. There is no leak from anywhere else. I am wondering if the hose that has the bleeder screw may have bad threads on it. But then again the old bleeder screw looked good and so did the washer on it. Again all of this is fairly new within the last 3 months. I am sure when its cold again the coolant level should drop from the amount it threw out but that I can fill again or just do a total flush again but I want that air out and im wondering why there is still air coming out of the screw.

Bleeding
BLEEDING X5 - YouTube

Post Bleeding
POST BLEEDING - YouTube

thanks

Keep the expansion tank filled up. Is the bleed screw still open that it keeps spewing the coolant?

I see your setup is different than mine. You can't bleed system with engine off? Either way the system needs to pressurize, so top off fluid, close cap and bleed screw. Take a drive and see if it over heats.

Let it cool, pop bleed screw, you should hear air. Close it top off fluid.

Yah it's a 3.0. Did you get a chance to see the videos? The bleeder screw is closer and I'm debating whether I should now throw in coolant or water? Because I have already gone through a gallon of the Preston and water. But I'm also losing alot with it spewing out. Should i fill it up with water and then Should I drive it a bit and then open up the bleeder? I have also not done this on an incline. The screw is new and there was still bubbles and coolant coming out of there. It comes out in intervals. Also when I unscrew it should I leave space or remove the entire screw? Because it keeps throwing out coolant. The reason I didn't do it with the car off is because I didn't want battery to die and the other video I posted showed car on.

Ok so now topped off with a little bit of water. The indicator showed that coolant is topped off well but I got my check coolant sign again so it might need a little more coolant. I have some bmw coolant now so I may top it off with that. Drove it around locally for a few until temperature gauge was to middle. Did not go past that and heat was hot inside.

Parked the car jumped out - checked under the hood - no leak. Gave it a few minutes to cool down and turned the bleed screw. A little bit of coolant came out and then bubbles and shooting out some air and coolant and then stopped.

Waiting for it further cool down and will top it off with coolant and then take it for a longer drive to test out the function.

I am still worried that originally my hose popped off on the highway. any suggestions on why that would happen? I am pretty sure when I installed it, it was in tight and had not given me trouble for quite some time. That hose was installed under 4 weeks and have driven a minimum of a couple hundred miles on it.

Are you using regular green Prestone? If so, you really should flush the whole system and fill with the proper mix of BMW blue coolant and distilled water.

Not the regular green one but an orange one that I picked up at Sears when all of this began. But at home now I do have a backup gallon of BMW coolant and i can definitely flush it all out and refill with it. I was thinking about doing that also but I will definitely do that now first thing in the morning.

I know that you can fill the coolant in a X5 without an Air Lift as Slick confirmed. (Some cars are virtually impossible to get filled without an Air Lift...like certain VWs). But this post really shows the difference. It takes about 2-3 minutes to fill the car with no air pockets with an Air Lift. For a pro, time is money. For a non-pro like me....I just like to make my life as easy as possible.

Since you already 'corrupted' the system with prestone (using the term mildly) I wouldn't bother getting the BMW coolant in until you are definitive on the problem being solved. That is, what's done is done and you should only be using BMW coolant. But since you aren't sure the problem is solved, I'd wait until you are sure the problem is fixed at this point to bother to 1) do a complete flush and 2) use only BMW coolant on the re-fill. That being said I'll just throw this out there to the group and it may seem dumb, but is there a bleeder screw washer? I didn't think there was one on the bleeder. If I am correct, and again not sure I am, that may be your problem, or at least one of them. I am posting without checking the manual so could be way off. As far as your hose disconnecting this sit is riddled with hundreds of people that were positive that things were tightened properly or to spec only for them to fly off- it just happens. Anyway replace the expansion tank so you can rule that out. They inevitably fail anyway at some point. And in many cases you can't tell they have failed -- threads off, small crack at seem only evident under pressure etc..

Also, since you are knee deep in a coolant issue it may help you to observe a few other YouTube videos on BMW coolant re-fill for perspective if you have not already. Sometime you pick up on that one thing that you may have overlooked, even thought it is simple/straight forward. ( the car experts, and mr. bmw from recollection have a few, but search on YouTube and you will definitely find it)

Wait the screw is closed in the second vid? And it still does that? Are you sure that expansion tank is still good. It should not do that, especially with cap open too. Also if the car sits in above freezing temps , like garage, you can just use distilled water to do all this. Change your expansion tank.

I see Slick's point that there's no reason to switch to the proper coolant until the system is 100% ok. Except that it's very hard to get ALL the old coolant out of the system in one shot. You may need to flush and refill more than once.

Also once you're sure the bleeder screw is not leaking, did you pressure test the system? It's better than taking a long drive and having to limp home if there's a problem. If it can't pass a pressure test, no reason to go anywhere. It's also safer; while cold, you can bring it up to pressure. It should hold pressure. You can also leave the gauge attached, and warm up the car, to make sure the pressure generated by the system is correct.

+1 what skyline said.

When you replaced your expansion tank initially, was it OE, as in dealer, or did you buy something cheap on eBay or something. Also, when it was changed, did someone forget to close the bleed screw for a while? You changed the bleed screws, but the issue seems to be with your tank threads for that screw. Quick way to test is remove the screw, and apply some Teflon plumbing tape to the threads. If it stops leaking, your tank is shot. Do not leave the tape there, it is only temporary, and not meant for plastics.

Alright guys so coolant is topped off after its cooled down - and I allowed it to heat up to normal operating temperature - and drove it at least 15 miles of which 10 was on th highway at a constant 70 mph. Got a hand on an obd code reader and here's the output

Engine coolant temp sensor 1 circuit low input
P0117

Any suggestions? Everything else seems ok so far will drive to work on Monday and see how it does on long run.

Also used 50/50 Preston to top off with. Will flush and put in bmw coolant next chance I get after the holidays. All else seems good no leaks from expansion tank either. Also clamped that hose that had come off

Have you typed "BMW OBD II code P0117" into a google or bing search box yet? If not, as mentioned in my previous reply...there is more than enough info already on the interwebs about OBC II codes.

You'll find info as to what sets this code off...why it sets off...what you should look at and consider for repair...what may be the issue if you've changed stuff and the problem continues...etc, etc, etc.

Well you already know you overheated your car, and that fault is what set the SES light. Clear the code, and if will probably will stay away.

But BMW motors don't take kindly to overheating, so you'll have to keep a close eye out for symptoms of a damaged head gasket or even ruined cylinder head. From what you've said, it seems that neither is the case, but you need to really keep a close eye on your coolant level and your temperature gauge for a while.