Help! Turbo whoosh!

[Malc]

I haven’t really put my foot down recently on my S2 as I’ve only had it six months, but when I did over the weekend, I got a loud ‘whooshing’ when the turbo kicked in, rather like steam escaping from a relief valve. The turbo only got to around a quarter on the gauge (around 0.2?) although I didn’t want to floor it further just in case. When I lifted off, it stopped immediately (almost ‘clicked off’). I have had turbo cars before and recognise the gently whoosh and whir of the turbo but this was loud and unnatural to me. Anyone got any idea what it might be? The car’s only done 40,000 miles and was last serviced by Paul Matty 300 miles ago. I don’t think it is a dump/blow off valve as my understating is that this allows excess pressure to escape on the overrun not on acceleration. I don’t think it can be natural as I’m sure I would have heard it before . A couple of photos of the engine bay are attached if of any use. (No they’re not as it doesn’t want to upload them! Will keep trying…).

[Rambo]

Have you checked your wastegate actuator rod is moving freely? I think you should be up to approx. 0.7 bar on full boost. Can you hear the wastegate flutter?

[Malc]

Not too sure how I check the actuator rod? Would post a video of boost gauge and sound but this facility seems to be disabled! Boost is probably 0.4 max.

[Rambo]

Have you checked the Wiki?

http://wikilec.com/view/Wastegate:_Releasing

[johnj]

I dont know about the sound, but I found the easiest way to move the wastegate activator was using the pump method. Check that the throttle cable has been properly adjusted.

[Rambo]

I dont know about the sound, but I found the easiest way to move the wastegate activator was using the pump method.

It is. I just wanted to show the guts of the actuator module so the OP knew what was what.

PS the bike pump and football adaptor is also useful if your petrol overflow is blocked with gunky slime.

[Malc]

Went to see my local garageman (who I know) and although not a Lotus specialist, has rebuilt an M100 so knows a thing or two. Thinks it is either an air leak from the hoses etc, or, as you say, a problem with the actuator rod. So now booked in to him next week and hopefully will be sorted - at a reasonable price! Will show him the Wikilec info. Thanks for your advice.

[Simon_P]

Loose hose clamp.

Take a flat bladed screwdriver and tighten them up
Right in front of you on the big smooth black pipe from the wing to the intake one on either end. (Most likely)
An on the one from the turbo to under the headlamp ( not the one from the dustbin to the middle of the turbo)
There is another one in the wheelarch.

[Rambo]

Can you post a photo of the engine bay (RHS) or is LEC still misbehaving? Just need to check if you have a dump valve spliced in somewhere.

[Malc]

Can you post a photo of the engine bay (RHS) or is LEC still misbehaving? Just need to check if you have a dump valve spliced in somewhere.

Have tried to post a couple of photos but it says no file selected when trying to load so assume problem with site still existing.

[Malc]

Can you post a photo of the engine bay (RHS) or is LEC still misbehaving? Just need to check if you have a dump valve spliced in somewhere.

Have seen a pic of a dump valve on a Lotus spares website and it appears to be a shiny ‘funnel’ and as far as I can see there is nothing like it on my engine. From what I understand a dump valve releases pressure on the overrun, whereas the pressure seems to be escaping on acceleration and immediately stops on lift off. The loose fitting idea seems to be the most logical, letting air escape under pressure. Second possibility actuator rod (although not certain this would have the same effect), third possibility intercooler problem. (Please no!). Will check all the connections/hoses/clips first before it goes into the garage - is it too much to hope it is such a simple fix?

[Rambo]

I'm sure it will be a simple fix. I can't recall anyone having intercooler problems.

The loose hose is the most obvious as Simon has already stated. Worth you checking the hoses he mentioned before it goes to your mechanic.

I assumed you might have a wastegate problem (perhaps sticking due to lack of use?) as you aren't registering full pressure on boost

[Dave Eds]

E mail your photos to me and I'll see if we can upload them....

Have you checked the vacuum hoses are all connected and in good condition?

[HJ2]

I'm sure it will be a simple fix. I can't recall anyone having intercooler problems.

The loose hose is the most obvious as Simon has already stated. Worth you checking the hoses he mentioned before it goes to your mechanic.

I assumed you might have a wastegate problem (perhaps sticking due to lack of use?) as you aren't registering full pressure on boost

I have seen a cracked duct before, bu most likely a hose or hose clamp indeed.

[Malc]

E mail your photos to me and I'll see if we can upload them....

Have you checked the vacuum hoses are all connected and in good condition?

Hi David. Have emailed you the photos of the engine. Going to check all the hoses and connections tomorrow - here’s hoping!

Malc

[Dave Eds]

Got them, can't upload them either.. .

Nothing appears to be untoward from what I can see on my phone.

[Malc]

Well what a wonderful facility this site is! Checked all the pipework and connections and found that joint on the top pipe that runs along the back of the engine to the wheel arch was loose. It had been attached to the wrong side of the ‘lip’ and had worked itself loose. Repositioned the pipe, did up the jubilee clips and, hey presto, problem solved. Thank you all for your assistance and advice.

[HJ2]

Cheap fix!