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It doesnt matter. Probably better doing it when its hot do any water will evaporate. Ive seen a 1.2 with a hole in the bottom of the plastic intake manifold.
 

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Discussion Starter · #82 ·
It doesnt matter. Probably better doing it when its hot do any water will evaporate. Ive seen a 1.2 with a hole in the bottom of the plastic intake manifold.
@marks152 Thanks I tried it this morning when the engine was hot and like you I think there is an air leak but it wasn’t possible for me to narrow down its location. That being said, when I moved the pipe highlighted in red it seemed to cause it to rev a little bit so I’m wondering if this may be connected:



I can see me asking a local garage to take a quick peek as they can obviously get under the car and to the pipes and manifold all the way round but before I take it I’ll see what you think and have also had a chance to look at the latest data I uploaded in case you think it may be the MAF.

Cheers.
 

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Discussion Starter · #84 ·
That pipes the brake servo pipe. Ive not had chance to look at the data yet. Been mad bust with work.
@marks152 Thanks and no worries mate I know the feeling!

I can’t help but wonder if the air leak may be connected to the brake servo itself or possibly the pipe as the revving usually happens just after I’ve stopped but then again the booster does seem to be working as I’ve done a test I saw on another post although it could be a minor one still letting air in I suppose.
 

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Disconnect it from the manifold and block the hole in the manifold up. Remember the brakes will be poor so be careful.
 

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Discussion Starter · #86 · (Edited)
Disconnect it from the manifold and block the hole in the manifold up. Remember the brakes will be poor so be careful.
@marks152 Thanks so if I disconnect the pipe by unclipping from the right hand side where the yellow clip is and put my thumb over the hole it was plugged into and the hissing stops then it would point to either the pipe or servo itself is that right?
 

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Discussion Starter · #88 ·
@marks152 Thanks again I’ll give it a go this morning and I also noticed earlier that when I had stopped if I press my brake when it’s idling a second or 2 after taking my foot off it caused the revs to increase to over 1k so I’m starting to think it may be the servo itself but I’ll check the pipe more thoroughly as well once it’s disconnected and report back.

This would also be consistent with on my first live data the revs went to its highest just after I’d come off the motorway so had to press my brake for longer which may have let more air in.

Not wishing to tempt fate but think I might be getting close to nailing this issue….
 

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Discussion Starter · #89 ·
@marks152 Here is a video of what happened when I disconnected the pipe:



I think it’s definitely air being sucked in where the pipe connects that is the hissing sound I can hear when the engine is running normally.

The pipe itself doesn’t seem to have any splits or holes in it and here are a couple of pictures from what I can see of what I think is the servo although they don’t really show much:






As I mentioned in my last post I’m wondering if there may be an issue with the servo.

What do you think and would it cost much to replace it?

Cheers.
 

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It shouldnt be sucking in air when its running. Thats the problem. Just need to work out why its leaking. I cant remember if the connector has a gromit that pushes into the manifold. Im sure uve got a manifold somewhere. Let me get a picture of it.
 

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This us the stub as it fits on the manifold. Id make a blank by using a rubber tube with a bolt in the end and fit it to the stub. Then try the water trick with it running. If it doesn't leak then its the servo pipe thats at fault. If it leaks its the seals on the stub. They look like they may be o rings at a guess. Ill see if I can remove the stub from the manifold ive got here to confirm
 

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Discussion Starter · #92 · (Edited)
@marks152 Thats great thanks I’m pleased it seems to at least be narrowed down to a couple of possible issues.

Just to make sure I understand what I need to try are you saying if I block off the hole at the top of the stub in red with a bolt and try the water test and if nothing happens then it’s an issue with the servo pipe but if it revs then its either or both of the 2 o-rings in green:



I don’t think you’re suggesting an issue where it connects to the manifold in yellow but please correct me if I’m wrong. Does it just pull out at that point to be replaced if required?

Cheers.
 

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Dont screw a bolt into the bit in red. It will damage it. I usualy use a bit of rubber or silicone pipe on it with a boot in the other end.

The part in green isnt o rings. Its just shaped plastic.

The part in yellow could be a source of a leak. Spray this area with water while its running and the red bits blocked.
 

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Just re watched your video again. Does the air sound the same with the servo pipe connected as it does with is disconnected and the port blocked with your finger.
 

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Discussion Starter · #95 · (Edited)
I’ll have a look if I’ve got some pipe to use but not sure I have is there any other way to block it up safely?

I’d say you cant hear the air as much with the servo pipe disconnected and my finger covering it.

Out of both possibilities I’m starting to think it may be the pipe as it revved more when I was braking during idle yesterday so wonder if the one way valve within the pipe has just gone and it’s letting some air through.

However if it is the other part in yellow does this just unplug from the manifold and can it easily be replaced?
 

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Defo needs investigating. If you cant block the hole with a pipe then put your finger over it and spray around the joint. Might be a bit awkward doing it this way.
 

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Discussion Starter · #98 ·
Ok so I tried covering the hole with various things including foil wrapped round it etc. When I sprayed water near the part in yellow it didn’t seem to get any worse or start revving but as I started to reconnect the vacuum pipe it started to rev quite a lot.

Would it be easy enough to replace the pipe and yellow part connecting it to the manifold just to be on the safe side?

Also as I’ve not had any issues with the brake pedal going hard or anything like that is it unlikely to be the servo itself do you think?
 
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