Rainbow_Rising
Hi all, haven't been here for a while, got a question about a problem that really bugs me, after changing all my engine mounts ( two of them twice in last year) I still get this weird noise which I am puzzled where it is coming from.
I am 100% sure that it is not engine mount after replacing them all.
It starts when engine reaches exactly 2500 rpm and stays there till around 3000rpm.
It is a very loud noise like an elephant blowing into a trumpet :)
When driving in city, it only happens when you are driving uphill which cause engine stays on that 2500rpm to get the car going or just when gear is changing and after that it stops because engine rev drops to 2000. if I am driving in freeway,when driving 120km which on that speed engine rev is 2500 it makes the same noise.
It doesn't vibrate the car but the noise is very loud and annoying.
2 days ago I replaced bottom right mount and top torque rod mount and still same thing.
Mechanic thinks it might be the driving shaft but to be honest I am not willing to spend 1 more dollar on the car anymore.
I don't think turbo makes that noise, that is one thing I can think of that is related to the engine speed.
So here I am again stuck with this XC90 that killing me slowly.
I drove from Brisbane to Sydney and that noise drove me nuts beside the panel beater who failed to aligned the driver door properly and I have that stupid noise from the car and wind whistling from the driver door all the way back to Brisbane.
Thank you guys in advance, any though ?
Regards,
Mo
jamesinc
You can do some work to further isolate the source of the noise:
- Does it make the noise in neutral with the car stationary and the engine revved to 2500RPM?
- Driving at a speed that causes the noise, if you shift into neutral without slowing down does the noise immediately stop?
VolvoDeger
You sure you don't have a air leak at turbo pipes kit sounds like a pressure noise the way you are describing it Mo.
Philia_Bear
Mo, Where in australia are you located?
VolvoDeger
He is queensland
Rainbow_Rising
Hi guys and thank you very much for your replies,
The engine doesn't make the noise in neutral and I will do the other test when I am driving in freeway again tomorrow.
I am not sure about the turbo pipe, I will check that too and I live in Brisbane but currently holidaying in NSW. :)
Thanks,
Mo
diecast
Hi guys, i think i have the same thing going on with my 2010 D5 XC90 for the last week or so.
I have a whistling sound that only occurs when the engine is under load from about 2000rpm upwards, as soon as i lift the accelerator pedal the noise stops. I also did "Old Mates" tests and can report the following:
1) Does it make the noise in neutral with the car stationary and the engine revved to 2500RPM? - NO
2) Driving at a speed that causes the noise, if you shift into neutral without slowing down does the noise immediately stop? - YES
I nipped up the 4 big hose clips on the intake hoses but that didn"t fix it. I looked around engine bay with paintbrush and a soapy water solution looking for leaks and couldn't see anything obvious.
Couple of questions
Any ideas on what the problem is?
Am i doing engine damage driving it like this?
Thanks in advance
Diecast
timbo
Its fairly common for the plastic turbo outlet to intercooler pipe (runs under the engine) to deteriorate. I would check that first. You can test it by putting the handbrake on, gearbox into D, foot on the brake and then hold the revs at 2,000rpm. This actually loads the turbo up more than just revving it in neutral. You will hear a whoosing/hissing noise
Driving with boost leaks can cause excess soot buildup in the particle filter
Rainbow_Rising
I changed the gear to N while driving and it stopped the noise but it is a bit difficult to determine because as soon as I did that the engine rev went up to 3000,I read somewhere that turbo kicks in in 2500 rev, but this noise is not the whistle kind, I guess I have to wait till I go back to QLD and talk to GLT guys.
Ex850R
I may be wrong but I believe it's not a good idea to hit N while at speed?
Anthony
It starts when engine reaches exactly 2500 rpm and stays there till around 3000rpm.
It is a very loud noise like an elephant blowing into a trumpet :)
(Obviously) some form of venting is taking place under load.
(eg. small hose that connects to relief valve, turbo hose, one way valve, leaking diapragm / gasket ).
Surely you would be losing power when the trumpet sounds.
Sorry not a diesel expert.
Feedback when solved will be interesting.
VolvoDeger
can you record the noise for us to listen
diecast
Thanks for the replies, i'll try Tim @timbo's idea tomorrow. I have not noticed any power loss, as my leak sounds like a rising whistle not an elephant.
diecast
Follow up to the noise, It turned out to be the seals on the intercooler, now replaced when car in for a service, all quiet now.
VolvoDeger
are they the large orange seals you talking about as have had those leaked for sure
Anthony
So in the end it was a leak most noticeable when turbo compressor generates boost rising around 2,500 rpm.
diecast, any chance of posting a pic of the old seal(s)?
diecast
I didn't see the seals as the car was serviced at a dealership, but on the invoice they have listed the following Volvo p/n's 30778628, 30778629.
Yes, leak/whistling sound most noticable when on boost. Must have been a really small leak as there was no drop off in performance etc.
Philia_Bear
diecast
I think they charged me $10 each plus labour, so happy with that.
VolvoDeger
yep there the ones I have changed plenty of very common and at least you all fixed.
