Hissing Sound from Engine
 

Hi All
I have Mitsubishi Outlander 2008 with 65K on it. Since last 6 months I am facing with an issue which no dealer can identify. After the car engine is at it's normal temp. i.e. after driving it for 10 min there is a hissing sound that comes from the engine side only after the car is running above 70KM. The hissing sound comes and goes in short intervals when the car is running above 70KM and when I put on the brakes or if driving at 60KM or lower then there is no sound.

Showed it at couple of dealer service centers but all linked this sound from different outer body parts like side mirrors, bug deflector but after checking all that nothing changed, same sound. Simple logic is that it has nothing to do with outer body sound as if it had been it would give a contineous sound and not after the car gets hot.

Called the head office after taking it twice to Oakville Mitsubishi and they said to take it to Dixie Mitsubishi but have taken it 3 times there and still nothing resolved.

Is anyone facing the same sound problem as it is a nuisance when you are driving on the highway and listening to this sound. Not a very loud sound but still annoying.

I know you don't think it's coming from outside, but there has been problems with wind noise/vibration coming from the outside mirrors, and mitsubishi has a fix for it.

I had the noise problem on my 08 ES and the dealer took the bottom cap off of the mirror and put in some foam to stop the noise. In my case the noise was only coming from the passenger side outside mirror, but I would think it could happen on either side.

The "mirror sound" on my Outlander would come and go also depending upon speed and how smooth/rough the road surface was.

Egr
 

Just a thought

The EGR system on most vehicles only starts working at operating temperatures and with the engine running at a reasonable speed (highway, etc) so as not to effect drivability. IF you've got a leak in the recircualtion pipe it'll only show up when the EGR solenoid opens which would "cycle" somewhat.

Yes they did this fix to my side mirrors too but no difference in sound. If it had been outside body parts then as I said the sound starting only when the engine is hot would have not relevance.
Thanks

Thanks a lot wish the mechanics at the dealers could be as smart as you are. You are the first one to say something different than just being wind sound.
Will surely ask the dealer to check EGR on my next visit.

Hi All,

Just wanted to update all that I am at 83000 KM now and still the dealers have not been able to fix the problem as they agree that there is sound coming from the engine side but cannot identify the problem.
Has anyone faced this problem yet ??? Any advice and help will be appreciated.
Dealer was telling me that your car will be out of warranty after 100K but I clearly told him that I need this problem fixed as have reported it at 50K ... if nothing works out will go to Mitsu. HO for getting this problem covered after warranty

hissing sound
 

Mine does exactly the same as yours and I am convinced its the brake servo
press the brake pedal and it stops? sounds like the vacumn going through the brake servo

Yes when u press the brake pedal it stops. But why does it not do when the engine is cold the hotter the weather louder the sound.
Took it last week again to the dealer and gave them the copy of one response received last year from member called tcp.
The EGR system on most vehicles only starts working at operating temperatures and with the engine running at a reasonable speed (highway, etc) so as not to effect drivability. IF you've got a leak in the recircualtion pipe it'll only show up when the EGR solenoid opens which would "cycle" somewhat.
Dealer is saying that have found some fault in the same area and have ordered the part. Lets see if this is resolved after changing that part. Otherwise the next step would be to tell them to look into what you have informed.
Do let me know if your problem gets resolved.
Thanks

ok but I cannot think of any link of the egr and the brakes so if pressing the brake stops the noise why would you link it to the egr?

The sound finishes whenever I go below 60 km/hr so irrespective of applying the brakes the sound never comes when I am at slow speeds and only starts coming after driving for about 10 min. and above 60km/hr .... if it had been the brakes then it would be contineous irrespective of the speed.
Lets hope for the best that this problem is resolved when they call me in to get the part changed. Will keep you updated .... do let me know if anything works out for you