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Smartcar fortwo

I have purchased a 2005 smartcar fortwo( 3 cylinder turbocharged diesel ). Recently there is a loud buzzing noise( like a swarm of angry bees) being emitted from the engine area. This noise is intermittant and of course when I took it to the dealer, the noise quit and they were unable to reproduce it. I was wondering if it might have anything to do with the turbocharger-maybe some bearing?

I have never heard of a turbocharger buzzing.  They may whine, but but buzz.  

When it does it does it continue to do it for a while?  

I am suspecting an electric fuel pump maybe or a loose heat shield on the exhaust.

You have not been specific enough regarding the noise. Yes, you said that it was intermittent, but…
Do you hear it when the engine is:

shut off?
cold, and idling?
hot, and idling?
while driving at a steady speed?
while accelerating?

Or, all of the above?

OK.I have investigated and have more data. When the glow plugs are warming up, there is a 5-10 second period when there is a high humming or buzzing noise emitted from the engine area. I assume this is an auditory signal to tell you to wait until starting. There is also an icon of a coil on the dash. When the icon is gone you may turn the key to start the engine and the humming(buzzing) stops. My problem is that the humming returns for no apparent reason randomly. Could this be a problem with a sensor of some type? Thanks,

there is a 5-10 second period when there is a high humming or buzzing noise emitted from the engine area. I assume this is an auditory signal to tell you to wait until starting.

I doubt it. LIkely it is just the fuel pump and that would be normal. Some are a little noisier that others.

No it is not the turbo as it is not doing anything yet.

I did not know they had a diesel version of that puppy. How do you like it?

I don’t think that the OP is posting his question from the US. To the best of my knowledge, the diesel version is sold only in Europe–and possibly in Canada.

Yes, I am from a small town 40 miles west of Ottawa, Ontario, Canada. I find that this little diesel is really peppy and has an optional standard transmission along with the auto. I get over 65 miles to the gallon and the diesel is clean, not smelly like when we think of buses or transports. It is quite roomy inside and one can do a modest grocery shopping. The Passion model, is fully convertible, so I am looking forward to the summer to appreciate this feature, since I bought it last fall. Anyway, I spoke to the service guy this morning, and he said unless an Icon stays on in the dash( ie. glowplug indicator, or service engine light) wait until next servicing to get it checked out. I also run this puppy on synthetic oil. The reason this diesel version is not available in the United States is because of different laws on emission standards.

That sounds interesting.  If they bring it into the US I might consider one for my next car.

I was wondering since it is winter, if the diesel needs to be preheated when it comes cold from the tank. Could perhaps the buzzing noise be the glowplugs preheating the fuel entering the combustion chamber? I guess I’ll find out in spring and summer when the fuel is warm. Then I have to keep the engine running for awhile after coming off the highway so that the turbocharger can cool down. Karl

OK, I would guess that may be the glowplug circuit buzzing. Likely it should not do it but if a relay is going out, it might be that. It also could be a fuel pump buzzing while it builds up pressure. Anyway those would be my guesses.

How about this. Get a length of garden hose and use it like a stethoscope and have someone turn on the car and use the hose to find the noise.

Really it does get to 65 miles to the gallon?

I get over 60 mpg (highway) with my VW Beetle Diesel. It is not all that hard to do.

And you can haul more than one other person, or a couple bags of groceries. No no, I dare say you could haul more than one more person AND more than a couple bags of groceries.