545i Overheating

[ultradriver1000]

My friends 545i is overheating. Is there anyway to diagnose the problem or should the water pump and thermostat just be changed?

Is there anything I should be looking at that could be a simple fix?

Thanks!!

[SHEBUILT]

Any codes?

[ultradriver1000]

No it just sent a "drive at moderate speed to help cool engine" then "stop immediately".

I'll check again for codes though.

[skylolow]

Being that its 2004 or 2005 and chances are a 60K or so in miles chances are very high the water pump or a stuck thermostat. Many times when these water pumps fail they leak. So you may want to start first with the thermostat as that is cheap and quick fix. Make sure the fan is running also.

Also get down in front of the car and check the front of the radiator. Lost of leaves and crap like to pile up in there. Not out of the question you could have an issue with the radiator.

[ultradriver1000]

Well I ripped apart the front and pulled off the water pump and thermo.

Dead on man it is a 2004 with 65K miles lol.

In between the rad and a/c condenser there were a TON of leaves. Waiting on parts to come in but keeping fingers crossed that a new pump, thermo and cleaning out the leaves solves it.

[skylolow]

Make sure you use BMW's coolant when refilling.

[DavidF]

Make sure you use BMW's coolant when refilling.

May I ask why? All modern coolants are phosphate free and safe for aluminum engine components. BMW does not have the aluminum engine market cornered and thus the only aluminum safe engine coolant.

[ultradriver1000]

Ok new problem. I replaced the pump and thermo but the hose that goes from the reservoir to the pump leaks. Is there a O-Ring I can replace or do I need a new hose? The hose itself is not damaged, just where it connects to the pump drips. UGH

[supra94tt]

Ok new problem. I replaced the pump and thermo but the hose that goes from the reservoir to the pump leaks. Is there a O-Ring I can replace or do I need a new hose? The hose itself is not damaged, just where it connects to the pump drips. UGH

New hose.

[mikeyoung]

Yeah with those hoses the sealing is built into the hose itself, the clamp just locks it on so, when it leaks there is something wrong with the hose....make sure the fitting and hose is clean though no debris - that can cause leak.
I just replaced the water pump on my 545 last weekend. probably it was the thermostat that was bad on your friends. Water Pumps are very simple mechanisms and its easy to tell when they go bad...they leak and become noisy..thats because the only thing they are is a propeller and a shaft with bearings. The bearings fail which makes noise and then the slop in the shaft causes the seal to fail and they leak.
That said, I have always felt like replacing a water pump is a good 'preventative' maint task because they always seem to fail at the worst time...and they WILL fail doesn't seem to be any common mileage once you get past 60K or so. Mine lasted almost 160K miles while my buddy's 325 lasted 60K.

[matthewt]

To Mikeyoung, I notice your 545 has 160k...have you had any problems with the coolant pipe under the intake manifold? I just bought my 05' 545 with 83k on it, and have heard that this is an issue on these cars. I have found the collapsible pipe from AllGermanauto, so if it does go, I'll save about 3k over the dealer repair. No problems yet, just wonder how much of an issue this really is, as an occasional problem can be inflated to a chronic problem on auto forums. Thanks

[mikeyoung]

no, I haven't seen an issue with that, If I understand I think you are refering to one of the 2 pipes that are exposed when you remove the watter pump - there is a small one and a large one circled in this pic : http://mikescoolworld.files.wordpres...ling-tubes.jpg

[thundermax]

The failure of a pipe under the valley pan is actually rare, but I've seen a few. There really is no pattern as far as mileage or anything that would contribute to a failure. The car I replaced that pipe on only had 90k miles and was the only thing leaking on that car.

[matthewt]

Yeah, the one under the valley pan. Good to know it's fairly rare, Thundermax, buut at least i have a lower cost alternative to the stealer if it does fail!! I LOVE this car, this will be the 3rd Bimmer I've owned, had an e21 320i, and currently have an 84' 745 turbo as a project! Thehandling of a 3er with the power of a 7er!!

[ultradriver1000]

This car is a total mess.

I ended up replacing the one hose, pump and thermo this time. Before I had to replace the overflow tank and the cross over tube above the radiator.

Now the car is leaking oil out of the alternator bracket. Why did BMW put a oil seal gasket there? Possible oil cooler?

This car only has 75K miles.... I don't think the previous owner took care of it at all.

Love the car and it drives great but way too many issues.

[DavidF]

I think the oil seal under the alternate bracket is for cars requiring a dry sump oil system. The oil tank would be connected to the block/oil passages located under the alternator bracket.

[turbovrGTI]

alternator bracket seal is for cars with a factory oil cooler..

[SaxonFS]

My friends 545i is overheating. Is there anyway to diagnose the problem or should the water pump and thermostat just be changed?

Is there anything I should be looking at that could be a simple fix?

Thanks!!

New to the Forum...This is my second BMW and first problem I have experienced. I had the same overheating warnings come up with the "severe overheating stop engine now" coming up 2 minutes after initial warning. Had to have it towed to dealership and just found out it was the electronic waterpump. I knew BMW repairs were more expensive than most other but WOW $1100 to have a new waterpump replaced!!! I talked to an independent certified BMW mechanic and was told that a lot of waterpumps were giving out on this year and model at around 45k miles. Was hoping it would be just a simple thermostat, but oh well. Still love the car.

[ultradriver1000]

New to the Forum...This is my second BMW and first problem I have experienced. I had the same overheating warnings come up with the "severe overheating stop engine now" coming up 2 minutes after initial warning. Had to have it towed to dealership and just found out it was the electronic waterpump. I knew BMW repairs were more expensive than most other but WOW $1100 to have a new waterpump replaced!!! I talked to an independent certified BMW mechanic and was told that a lot of waterpumps were giving out on this year and model at around 45k miles. Was hoping it would be just a simple thermostat, but oh well. Still love the car.

$1100 ouch! Sorry to hear it, I only charged about $450 to replace this one for my friend. He is trading the car in on a new one now. Oh well.

[Joker2004545i]

even after replacing the water pump and the thermostat, I still get the warning message...any idea?

[White94RX]

Electric fan has failed? Usually will store a fault code in the DME. That's why it's important to properly diagnose a car before throwing parts at it.

[jk3007]

Oil Level Sensor could throw a warning of Overheating also. There would not be a way to diagnose it to the sensor, but it happened to me. I got the same warnings, replaced the Water Pump, Thermostat, Temp sensor and hoses...Recommend checking the radiator and fan 1st though. BMW kept my car for a week before taking a chance on changing the Oil Level Sensor and that fixed it. Apparently, if the sensor malfunctions it will send a faulty signal to the DME that the oil is low and that the car is in the process of overheating. Mine was throwing the overheated message after about 2 mins of operating.

[Joker2004545i]

thank you for the info guys. I'll check that out.

[intercool]

can anyone help with this check engine code(PO597 thermostat heater control circuit open) i am not sure what or where this is and how to test it.i have check all the fuse found ok.looking under the hood driver side ,i found two solenoid with 3 wire plug connected on the heater hose .or are they taking about the heated thermostat.thanks in advance.

[gio8]

I had the same problem, car overheated to the point it was spilling the antifreeze. What can the problem be? Or what should i be looking into to identify the problem?