Technical HELP Whistle sound JTD

[daggyboy]

Hello..Some days ago from time to time gently pressing the accelerator is heard whistling, howling sound.
After some time disappears .. then again .. for example after passing 15 km, there was no howling .. I stopped, do not turn off the engine, wait a few minutes ... I press the accelerator gently and then starts the howling. After some time disappears ..
VIDEO
https://www.youtube.com/watch?v=jHY4EC2b_8Y&feature=youtu.be

Turbo..? Timing belt alternator belt and pulleys are fine..the intake system also good..

 

[mhowse]

to my ears sounds like could be belt screech..you say belts are ok but how old are the aux/alternator belt..you could try dripping some water onto the aux belt and see if the sound goes away and know if it is belt screech..could even be one of the pulleys to alternator or air con if you have air con or auto belt tensioner if air con model...rubber in bottom big pulley can cause problem but not something have had on my jtd.

if you open bonnet you may get better idea to area of noise

 

[daggyboy]

Same sound without alternator belt..timing belt kit, water pump replaced before 20k..Today I took off the timing belt..water pump, tensioner, idler, belt everything nice.
After fitting the timing belt back. I tried, but nothing has changed.
I've done several tests to check the intake system all sistem is fine..And it seems the sound is coming from the turbine..

 

[richydraper]

turbine or compressor side?

my initial thoughts were boost leak but you say you've checked your boost system... turbo failure is pretty uncommon in JTDs from what ive picked up on here, could it be an intake manifold gasket??

how did you check your pressure side of the inlet?

iirc there was a guy on here not so long ago that had similar issues im off to see if i can find his post

 

[daggyboy]

I made something like this in the garage boost leak test tool. Remove intercooler hose from turbo..put that tool in hose..and blowing air to the system about 1.3 bar..and just spraying water with soap all over hoses, pipes, intercooler..find leaking EGR and a few original clips..(Before test, remove engine oil cap) https://www.youtube.com/results?search_query=boost+leak+test some videos with tests.
Manifold gasket..:worship: one more thing to check, before restore or buy turbo! Thank you richydraper for idea.

 

[richydraper]

im impressed! looks like you did a thorough test.

it may well not be a gasket but i, for one, would be checking EVERYTHING before condemning a turbo the noise does seem to be boost related, it doesnt seem to happen much before 1200rpm. im gonna tag sussexa in, i hope he doesnt mind but i know he has a vast knowledge of FI, more so than me, he MAY be able to shed some more accurate light on it or offer more tests that might help you out!

 

[sussexa]

nothing from me im afraid other than guesses also.
ive heard turbines can sometimes loose a tip of the fin and create some noise anomaly that can sound a bit screechy or sireny but id guess they would make the noise all the time.
as above there could be a small gap in cylinder head to exhaust manifold gasket or even from between manifold and turbo flanges, this might be leaking when cold and self sealing when expanding with heat.
what about map sensor o'ring.
I have something similar noise to that but I only get it once per journey on first bit of boost, nothing after so ive not taken too much time looking for it.
mine sounds nearer the back of the dash board near the hp fuel pump area maybe, just had a new inlet manifold and mines still there same as before.
have a close listen around hp pump ? as its altering fuel quantity and fuel pressure as you rev even parked up (whereas boost doesn't so much with no load parked up)
although
looking through some you tubes this sounds similar to yours

looks like his was inlet manifold / gasket

 

[daggyboy]

Today i found leaking manifold gasket..but or leaking gasket can make that sound..?
This week I tried to replace the gasket..could someone advise what sealant i need to use for manifold gasket..?
And one more question, removing hose from turbo to intercooler..press the accelerator gently till 3000rpm..turbo sprays engine oil..its normal..?

 

[sussexa]

if I remember right your tuned up pretty high for an 8v power wise ?
cant remember if your still on a standard turbo ? the seals could be a bit worn as well as having the recirculated crankcase oil vapour fed back in before the turbo inlet, so youll be seeing some of that also.
you seem pretty handy so if your worried about turbo you could drop the turbo inlet rubber pipe and also the exhaust downpipe to access both sides of the shaft you could then push back and forth to feel for excess play in the thrust bearing (should be very little play this direction maybe a few tenths of a mm(0.1-0.2mm)) then wiggle opposite ends up and down to feel for radial play(this will have more play, a new turbo may have 0.3mm so id expect 0.5mm on an old turbo, if it feels really sloppy might be worth a trip for a second opinion.
here are some vids for visual comparison(pretty good condition but my removed turbo at 30,000 miles but high boost use)


might be worth fitting an oil catch tank on the breather line before turbo, that might cut down some especially if your running high boost/power.
have a read in here
http://www.alfaowner.com/Forum/alfa...-line-mini-oil-catch-tank-rutland-motors.html
its a nice small unit should be easily placed somewhere on the stilo, and if you check it regularly the small size shouldn't be an issue.
if you go that way make sure you get something similar to the sintered bronze filter near the end not the foam filters .
well done for finding the leaking gasket , ive heard they can resonate like a reed valve and make this noise.
im not sure if they use any gasket sealant at all ?
seen people mention hermitite red on gaskets (light smear ) but not specifically on jtd inlet manifolds.
just had mine replaced on the jtd16v and there was no sign of sealant on the old manifold face?
a phone call to a local specialist would best confirm.
heres a pic of mine as it came off






no pics further away sorry and cleaned now anyway

 

[daggyboy]

This is a standard 85kw no changes, just removed egr, blocked on the exhaust manifold.
Tomorrow i will take down the turbo and see what is going on.
My other stilo was with chip box..but i have removed it.

 

[richydraper]

a lot of the ebay specials seem to be the coated steel type gaskets rather than the compressed metallic fibre gaskets which most petrol engines use, probably due to the higher pressures + temps in a diesel.

theres no need to use any kind of sealing compound on these as the coating does the job for you. just make sure your mating surfaces are clean and even... 400-600 grit emery/wet and dry or even a medium wire wool would suffice. no need to worry about discolouration either, as long as the surfaces are free of crud you'll be good!

on a side note i can think of 1 place where no gasket is used... the Merc Econic (refuse truck) has no gasket between manifold and turbo. the machining doesnt appear to be particularly precise but it seems to work and i cant think of an instance where i've known them to leak.

 

[jatkinson]

This is the exact squeal I had, wish I had seen this earlyer, mine was the exh gasket, I got told it could be belts so replaces all them, bought a new turbo fir it and on strip down to replace the turbo seen black soot around the ports, so replaced the gasket between head and manii with a gasket from Euro car parts and all sorted now, no squeal and back to running like a new UN

 

[jatkinson]

Draggyboy, forgot to tag you
blu73 remember me telling you about the squeal this guy has exact same,.... Saves me uploading a vid fir you

 

[blu73]

oooo that is a nasty noise :yuck:

 

[jatkinson]

thats why it was annoying me so much ... , but finnaly found out it was the gasket after a messing about ... simple way to find out it it is .. , Take your heat sheild off and see if you can see soot around it or get a spray bottle and mix water and a little bit of washing up liquid , and spray it on around were the 2 serfaces meet , and if if it is blowng , you will see it bubble / get blowen away when some one revs it

 

[blu73]

are the old find a leak in a tyre trick - i wouldn't have thought of that

 

[daggyboy]

jatkinson i have found yesterday leaks in exhaust manifold ends, same way as you say..
sussexa i do not have that tool like yours, but i take some video. movement back and forth is more than 0.1-0.2mm.
a few photos from today's work.

 

[jatkinson]

your Gasket looks like its Blowing in Exact same place as mine ,, what milage is yours on ?

 

[sussexa]

looks to be leaking past the position the bolts hold flange down, id be looking at checking the flatness of the exhaust manifold face as it would be a shame to put a new gasket in and find it leaking again, if warped or recessed on that end a skim on a milling machine is ideal but possibly a reasonable job could be done with hand file and sheets of wet and dry if you have a good flat block to work the manifold across.
im not a specialist but that turbo doesn't look too bad for some ive seen on you tube, the original clearance in the housings around the fan blades is approx. 0.5mm so if theres no sign of metal on metal contact in the turbine housing or compressor inlet its probably not been touching also bear in mind the oil pressure will sort of self centralise the shaft and reduce that play when in use.
you already have turbo off now is time to consider rebuild or best to leave completely alone and refit as is.
googled for some actual garrett specs none found via garrett but did find these in a thread( and added metric conversions)
GT-15
Axial End play:
Minimum: .001" or 0.0254mm
Maximum: .003" or 0.0762mm
Eccentricity:
Maximum: .0004" or 0.01mm
Radial:
No Min/Max specified (no contact with housing allowed)
Balance:
0.65G entre 0 - 90.000 rpm
2.0G entre 90.000 - 168.000 rpm

VNT-15/GT-15V/VNT-17
same limits as specified above
Balance:
0.6G entre 0 - 90.000 rpm
3.0G entre 90.000 - 168.000 rpm

these look pretty tight tolerances but I bet theres plenty on the road running fine that are outside these specs.
the axial play of 0.02-0.07mm is barely feelable by fingers,

 

[daggyboy]

Sorry for long pause..
So, I checked the flatness of the exhaust manifold face and found roughness.
But now everything is fixed.
This week i'm thinking to rebuild a turbine..