New Member - Loud Whooshing Noise from turbo on acceleration

[Dorset Elan]

Dear All,
I would like to say Hi first of all as this is my first post.
I bought my Elan M100 S1 in Calypso Red in April and have loved the open top driving experience very much -we drove it to Castle Combe and also recently took part in the London to Brighton Classic and Sportscar Run too.

Your forum is great and I have learnt so much already especially regarding the servicing as I have managed to do lots of maintenance myself including the dreaded gearbox oil change from following the advice on the forum.

However recently my Elan has developed a very loud whooshing noise on acceleration and only when the turbo boost is engaged - the loud whooshing noise is definetly only related to when the turbo boost is engaged and only when I accelerate .
If I accelerate very gently without engaging the turbo the whooshing sound is not present.
I had a look at the hoses from the top of the engine bay and everything seems in order + I also carried out the wastegate wiggle too which did not have any issues .
I have searched the forum but as of yet cannot find any identical issues that have happened to other members so therefore I am a bit stuck and hoping someone can help advise on what the problem could be ?

Thanks in advance for any help....

[Enright]

Welcome. Thanks for the intro and adding your location to your profile.

It sounds to me as though a boost hose might have just popped off the charge-cooler. Or at least I hope that's the answer, because I started to get nasty noises from my daily driver's turbo (an MG ZS TD) just before Christmas, and the result was a most spectacular diesel runaway as I came off the M1! I had to stall it in 3rd as removing the ignition key had no effect.

So, are you getting any boost pressure when you accelerate?
If the answer is "no" (or very little) then you need to get a 2ft piece of hose, and use it as a stethoscope to find the hiss/whoosh. The odd rev while under the bonnet may help you to do this.

But if the answer is "yes" and you can't find any hiss, check your oil (check it anyway) just in case you have dramatically increased oil consumption. Then take off the concertina intake pipe in the middle of the turbo inlet and try to wiggle the shaft. Obviously this needs to be done with the engine off.
There should be no play, and no marks on either the impeller blades or the housing. If there are then you MUST NOT use the car any further until you can get your turbo off and reconditioned, and you should thank your lucky stars that you caught it just before a catastropic failure wrecked it and possibly your engine.

That's why I hope for your sake that it's just a popped-off pipe - please let us know the result.

[Elanlover]

One other possibility is that someone installed a dump valve. Depending upon how it was plumbed you could hear a whoosh after heavy acceleration once you lift off the throttle.

[epipete]

One other possibility is that someone installed a dump valve. Depending upon how it was plumbed you could hear a whoosh after heavy acceleration once you lift off the throttle.

good point, check the plumbing behind the filter housing

[Enright]

The bit I picked up on was that the car had recently developed the noise on acceleration. As Dorset Elan stated that "the loud whooshing noise is definetly only related to when the turbo boost is engaged and only when I accelerate", I reckon a dump valve can be discounted. With those you only get the whoosh at the point of lift-off. However, just in case the car has a recirculating dump-valve, if the activation hose had come adrift then it would vent pressure during acceleration. But the idle speed would be higher. Question is, is it? If idle speed is affected then a bung or pipe may have been blown off the plenum.

[lotusflasherman]

The bit I picked up on was that the car had recently developed the noise on acceleration. As Dorset Elan stated that "the loud whooshing noise is definetly only related to when the turbo boost is engaged and only when I accelerate", I reckon a dump valve can be discounted. With those you only get the whoosh at the point of lift-off. However, just in case the car has a recirculating dump-valve, if the activation hose had come adrift then it would vent pressure during acceleration. But the idle speed would be higher. Question is, is it? If idle speed is affected then a bung or pipe may have been blown off the plenum.

He said it had developed and was on acceleration not lift off. When I saw the title I thought of dump valve too, but then I read it fully.. Got Recirc' Bailey on mine - when hose came out of air filter cylinder it sounded like it had asthma.

[Enright]

Nah, hayfever - "Atishoo!"

[Dorset Elan]

Many thanks for the responses so far....just to confirm whooshing noise only under acceleration and when turbo boost gauge has been engaged. Idle speed is normal and also when driving gently through the gears without engaging turbo boost everything sounds normal too.
In addition the noise does seem to be more pronounced on the left front (passenger) side of the car.

[Elanlover]

Maybe a loose, ill fitted or punctured intake hose coming into the throttle body perhaps?

[Andy_J]

I suspect Enright is correct, sounds like either a hose on the pressure side of the turbo to me or a damaged intercooler. Intercooler and pipework are all on the left side of the car.

Dorsetelan - if you take the passenger side arch liner out you should be able to see the plumbing for the intercooler

[Dorset Elan]

Hi everyone,
I was in the garage earlier checking the hoses in particular the large black hoses going from the turbo via the intercooler ending at the inlet manifold .

I am so pleased to announce that I have fixed the issue ...thankfully it was very straightforward in the end ...strangely the back of the jubilee clip connecting the large black hose to the inlet manifold had partially slipped off the hose which was not visible to me from the front and the front of the jubilee clip seemed secure so therefore not easy initially to spot... so as a result it looks like that is where the air leak was coming from.
I repositioned and tightened the clip checked all the others then took the car out for an evening drive to test it all out..

I am now very happy to announce the cat on skates is now back in business no more loud whooshing noises...everything is now back to normal

Thank you everyone for your assistance and advice