# 1999 740iL whining sound



## namidub (Jul 14, 2009)

My car started developing a loud whining sound coming from under the car. I tried pinpointing the source, but it seems to be from the rear area. It started when the temperature went up in summer. It doesn't always come on. The car performs as usual. I would appreciate any thoughts.

Also, my nav (MKI, I think) started having problems and it seems to also coincide with the high temps of summer. The audio would cut out and the screen freezes. Turning off and back on would allow the CD player to resume but the screen stays frozen. The screen would be OK after stopping and restarting the engine.


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## CodyItaliano (Feb 19, 2009)

your nav unit is fried. i've already went through like 4 or 5. got my new one installed today. its a newer unit. 

as far as the noise its making, it could be anything. you say its from the rear of the car? might be a fuel pump going out.


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## Kevin Serra (Apr 10, 2009)

namidub said:


> My car started developing a loud whining sound coming from under the car. I tried pinpointing the source, but it seems to be from the rear area. It started when the temperature went up in summer. It doesn't always come on. The car performs as usual. I would appreciate any thoughts.
> 
> Also, my nav (MKI, I think) started having problems and it seems to also coincide with the high temps of summer. The audio would cut out and the screen freezes. Turning off and back on would allow the CD player to resume but the screen stays frozen. The screen would be OK after stopping and restarting the engine.


The cellulnoid in your gas tank is stuck open. Cant buy one seperate as it comes as an essembly to the gas tank. Just had the same problem..... Had my mechanic take it out of the gas tank and cleaned it..... The car now sounds great. Only took three differenct fuel pumps and four visits to finlally diagnose the problem...oh yea and $1,400 to find out it was a simple fix....


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## HELLROT750 (Jun 29, 2009)

YEA,, YOU'RE NAV IS DONE. REPLACE MINE ALREADY FOR ABOUT 3G'S. NO EASY FIX. WISH HAD BETTER NEWS


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## CodyItaliano (Feb 19, 2009)

personally, i would recommend going aftermarket for a new stereo/nav system. less expensive initially than something new from BMW to replace whats broken. if mine goes out again, i'm probably going to go with an after market component system.


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## namidub (Jul 14, 2009)

I noticed that the power steering fluid level was a little low (ATF). Refilled with DEX type and the whining seems to occur less and not as loud. Could the power steering pump be going bad? I don't see any leaks.

So far, the nav is holding up. Keeping my fingers crossed. I have heard that with the E38, there is tendency for ffluids to reach the electronics, possibly the affecting the nav/ CD player. This leak" supposedly is located from the inside seam of the rear windshield. I've read that some electrical problems occur when tinting is removed (which usually involves wetting that area).


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