Technical Humming noise after short journey.

[halli]

Hi,

My car has started making a loud humming noise when the engine is on and when off with key removed. The noise seems to be coming from the lower rear of the engine. The noise stops after a few minutes.

This noise only occurs when the car is not up to temperature. If the car has reached operational temps the noise does not happen. I therefore guess it must be something to do with a sensor.

Diesel consumption has risen though performance doesn't seem compromised. There is no black smoke for the exhaust other than the usual which might arise from an "Italian tune-up"

Can anyone shed some light on this? The car is a 54 plate Ulysse 2.0 HDi

I don't fancy going to a garage for a diagnosis as I have been stung in the past and would rather turn up with the relevant knowledge (or do it myself if it is easy enough!)

Cheers

-halli-

 

[jarred]

Sounds like the auxillary heater under the car. This Is normal.You will find a smell that goes with it (parrafin burning ). When the engine is very cold A extra heater under the car burns small amounts of diesel to aid heating the engine only comes in use in cold weather. Do a search using Auxillary heater/webasto/smell whine noise you will see lots of posts on this subject

 

[halli]

Sounds like the auxillary heater under the car. This Is normal.You will find a smell that goes with it (parrafin burning )

Cheers, is it normal for it to stay on after the ignition has been switched off then? Bit weird for it to be heating the engine after the engine is switched off, but then this car seems to have a few weird things about it! Like the clonking rear suspension that Fiat said was normal "It's not a saloon car, mate. It's more of a van, you've got to expect these sort of things"

Will this heater explain the rise in diesel usage for short journeys then?

 

[jarred]

Get out lock the car and it still makes the noise for about a minute. I think its to overun the heater to burn off the last bits of diesel.Yes when it gets cold outside your fuel bill goes up cause on short runs the engine uses the underfloor heater more. Clonking noise sounds like you need new drop links.Makes the noise when you go over speed bumps hit small potholes or over a uneven rd?

 

[halli]

Clonking noise sounds like you need new drop links.Makes the noise when you go over speed bumps hit small potholes or over a uneven rd?

I thought it was rear suspension, but when it was in for the brake servo recall I asked Fiat to have a look and they couldn't find anything wrong. I'll jack the car up and have a look when the weather gets a little better. Are the droplinks the ones with the stupid aln key slots in them that always chew up when you try to remove them?

Thanks for the help

 

[jarred]

Yes thats the ones. But you say the noise is coming from the rear? Sure the spare wheel is in tight?

 

[halli]

Yes thats the ones. But you say the noise is coming from the rear? Sure the spare wheel is in tight?

Aren't there rear droplinks? I've only ever worked on the rear suspension of my MX5 which has them.

I'll check the spare wheel too, good idea