1998-540i-250,000mi. Just had new water pump radiator and thermostat replaced after overheating. waterpump was gone,radiater damaged.-; also replaced sensors. While driving now the temperature gauge will shoot over to hot. I stopped the car and restarted in 5 min. The gauge is right back in the middle. this was happening after replaced water pump,radiator and thermostat; the mechanic then relpaced the sensor. Did not happen until today,one week later. car is not overheating . mechanics think it is gauge cluster or computer. these are experienced mechanics but not at BMW dealership. thanks Nick
Country: United StatesMake: BMWModel: 540 iYear: 1998
Hello and welcome to JustAnswer BMW,My name is XXXXX XXXXX it will be my pleasure to assist you today. Has it been verified that the engine is not in fact overheating, and that the overheat warning is in fact an error?
yes! after stopping the car ;turning it off and restarting the guage is normal. i also was near the station and stopped in and it was not overheating. thanks
Before reading my answer below, please note that you must take correct action to complete our question. If you do not rate as one of the top three ratings, I do not receive any credit or compensation whatsoever from the deposit you have paid. The higher the rating the better and I strive to provide the best answers that I can.If you need more information please use the "reply" or "continue the conversation" link, please do not select a low rating - please just ask if you have additional questions.If you select one of the two left most ratings, this is a negative for me and I am not compensated for my answer, so please reply if you have additional questions.Also please note that even if you were hoping for more in terms of good news, if you do not provide a positive rating, this PUNISHES me for my honest answer.Just answer is an honor system. Thank you.I would replace the temp sensor again and very carefully check its wiring and connection. Since the sensor solved the issue for a week, I think the problem does lie here. Also, it is common for the sensors to go bad after an overheat, not the computer or cluster.If the wiring checks out and the problem keeps occuring, then it would have to be either the computer or the cluster (more likely the computer). You are talking pretty big money either way so before biting off on either it would be prudent to have a bmw dealer scan the car to see if their factory equipment can verify the cause for you. A cluster or computer replacement will require dealer equipment to accomplish anyways, so it will be hard to avoid the dealer if it gets to this.Please use the "reply" or "continue conversation" link if you have further questions. Otherwise please select a positive feedback rating (far right options) so that I may be credited and compensated for the assistance I have provided. Please do not select one of the two left most ratings - please simply reply if you require anything additional and I will be happy to answer any follow up questions you may have. Thank you and best of luck with your vehicle.
Thanks Steve. which sensor would that be;I think there are two? the recent replacement eas the radiater sensor. I also have noticed that it has happened twice whe i go down a steep part of the road and then come up at the top. The mechanics have a man who has a diagnostic computer for a 100 dollars.Should i give that a shot after the sensor check.
Okay, they replaced the wrong sensor. The sensor by the radiator is only to influence the speed of the eletric auxiliary fan.
you need to change the sensor at the water pump / front of engine
also make sure there is no air in the system and that the cooling system has been properly bled
I would only invest in a computer diagnosis if it is using a BMW factory scan tool.
Please use the "reply" or "continue conversation" link if you have further questions. Otherwise please select a positive feedback rating (FAR RIGHT) so that I may be credited and compensated for the assistance I have provided. Please do not select either of the left hand ratings - please simply reply if you require anything additional and I will be happy to answer any follow up questions you may have. Thank you and best of luck with your vehicle
Hi Steve. can i continue to drive the car until they replace the sensor? just spoke with them and they replaced both sensors. If i drive and and guage goes over to hot can i contiue to drive and see if it returns to center,or dooes shutting off the car and restarting have to happen to have the guage back to neutral.
I would pull over immediately if you get an overheat warning.
Normally, you do not need to turn the car off to reset the guage, it will move as the temperature of the engine goes up and down. So if the engine gets hot, it goes up, if the engine starts to cool, it goes down on its own.
If it spikes to hot on you, then it goes back to normal after turning the engine on and off then it should be fine. If not, then you may have an actual legitimate overheat so I would not drive it in that condition. So, the answer is, do not drive if the guage is in the red.
So your best is that its the sensor, because it spikes hot and the returns to normal? a couple of times before the sensor replacement at the waterpump it did the same thing. thanks Nick
yes the sensor (or its wiring/connection) or possibly air in the system is what I suspect.
Steve, how to i put in a great rating for you.
you should have five selections, either stars or smiley faces, please select the best one.
or, if you just have an "ACCEPT" button, please just click that.
Thank you, XXXXX XXXXX luck with your vehicle.
Steve, dont see any info with stars etc
there should be an accept button or something for you to click to "give your expert credit" or something to that effect - maybe "ACCEPT" or something like that.
If not, please let me know and I can have the site moderators resolve the issue.
thank you again.
Steve, there is no accept or area for rating. i do accept; and rate you at 5 stars. Got the job done.
okay, thank you for that.
I will have the site admin fix the issue
good luck with your vehicle.
Thanks Steve. mechanics will check sensors and bleed systems tomorrow.the Best Nick
best of luck