Corsa C air leak?

gjs6385

Hi I’ve had some trouble with my corsa c revving high when the engine is warm when idling or in neutral. I’ve found this when looking under my bonnet could this be causing an air leak and how do I remove the gunge?

https://vimeo.com/457416194

JustAnotherSaver

To me it looks like your jubilee clip needs tightening.

Although while it's wiggling around like that and all loose, i'd pop it off and see how clean or filthy your throttle body looks.

As for the gunge, a squirty bottle of degreaser and a brush as well as some old rags.

I would hazard a guess at this either being the 1.3/1.7 diesels or actually my money would be on the 1.2 petrol?

gjs6385

JustAnotherSaver said:

To me it looks like your jubilee clip needs tightening.

Although while it's wiggling around like that and all loose, i'd pop it off and see how clean or filthy your throttle body looks.

As for the gunge, a squirty bottle of degreaser and a brush as well as some old rags.

I would hazard a guess at this either being the 1.3/1.7 diesels or actually my money would be on the 1.2 petrol?

You’re spot on it’s a 1.2 petrol.

Could this be causing my problem and should I also get some carb cleaner to wipe the throttle body if required?

I was thinking of just using a toothbrush to clean the gunge off would that work best and getting a new jubilee clip is this the correct one 8mm?:

https://m.ebay.co.uk/itm/Jubilee-Type-Worm-Drive-Clips-Hose-Clips-Stainless-Steel-8mm-To-360mm-Diameter/123028709520?ul_ref=https%3A%2F%2Frover.ebay.com%2Frover%2F1%2F710-53481-19255-0%2F1%3Ftype%3D4%26campid%3D5338645461%26toolid%3D10001%26afsrc%3D1%26customid%3D%26mpre%3Dhttps%253A%252F%252Fwww.ebay.co.uk%252Fitm%252FJubilee-Type-Worm-Drive-Clips-Hose-Clips-Stainless-Steel-8mm-To-360mm-Diameter%252F123028709520%253Fhash%253Ditem1ca5152090%253Ag%253AfQgAAOSwa59aroQN%26srcrot%3D710-53481-19255-0%26rvr_id%3D2601713438488%26rvr_ts%3D8faeae641740ad3921d395ffffc5c659&_mwBanner=1&_rdt=1&ul_noapp=true

Goudy

If it's drawing in/leaking air between the MAF (top of the airbox) and throttle body/inlet manifold it'll run rough.

The MAF measues the air entering the engine so it can fuel correctly, if extra air is bypassing the MAF and entering the engine it'll run lean with a bouncing idle. If it's leaking out air after the MAF it'll run rich with a dull, heavy idle.

It looks like the hose from the airbox to throttle body needs a clean, reseating and tightening, but check all the other hoses attached aren't split and leaking. All that oil is from the crank case breather, it's plumbed into the air intake from the top of the engine so it burns off in combustion, it's pretty normal after all these years to see this, just use carb cleaner to clean the pipe and throttle body and tighten it all back up, the clip appears to be still there, just screw it up tight.
 
Another common air leak with the Corsa C is the vacuum pipe from the brake servo, I've seen plenty that have cracks around where the pipe fits to the servo it's self, I've even suffered from this one myself.
This pipe is a hard plastic pipe and can go brittle and facture with age, when it does it can draw in air but it'll also cause you to lose brake servo boost when it gets bad enough, but have a good check around the other hoses and pipes attached, it's at that age now where rubber and plastic perish.

gjs6385

Goudy said:

If it's drawing in/leaking air between the MAF (top of the airbox) and throttle body/inlet manifold it'll run rough.

The MAF measues the air entering the engine so it can fuel correctly, if extra air is bypassing the MAF and entering the engine it'll run lean with a bouncing idle. If it's leaking out air after the MAF it'll run rich with a dull, heavy idle.

It looks like the hose from the airbox to throttle body needs a clean, reseating and tightening, but check all the other hoses attached aren't split and leaking. All that oil is from the crank case breather, it's plumbed into the air intake from the top of the engine so it burns off in combustion, it's pretty normal after all these years to see this, just use carb cleaner to clean the pipe and throttle body and tighten it all back up, the clip appears to be still there, just screw it up tight.
 
Another common air leak with the Corsa C is the vacuum pipe from the brake servo, I've seen plenty that have cracks around where the pipe fits to the servo it's self, I've even suffered from this one myself.
This pipe is a hard plastic pipe and can go brittle and facture with age, when it does it can draw in air but it'll also cause you to lose brake servo boost when it gets bad enough, but have a good check around the other hoses and pipes attached, it's at that age now where rubber and plastic perish.

That’s great I will get on to cleaning and tightening the clip up thank you. It sounds like this could be causing my problem.

At the risk of asking a stupid question where is the vacuum pipe from the brake servo and can I replace it if it’s gone or is it a tricky one for a garage to do?

Goudy

On these the Servo is under the scuttle panel, driver side. Right beneath the master cylinder reservoir.
The pipe comes out the bulkhead to the back of the engine/throttle body.

It's not a big job to get at, though you really need the wiper motor out.

If you're worried about a Servo leak, try this

1. Sit behind the steering wheel and start the engine. Let it idle for two minutes and then shut if off.
2. Pump the brake pedal at normal foot pressure three or four times and hold your foot on the pedal pressing down slightly on it.
3. Start the engine. As you start the engine, you should feel the brake pedal moving downward slightly, about an inch or less. 
4. With the engine still idling, remove your foot from the brake pedal and turn off the engine.
5. Depress the brake pedal (using normal foot pressure) three or four times. If you notice the pedal rising after the second or third you depress it, the booster is more likely holding vacuum. 
6. Start the engine and let it idle.
7. Now, push down the brake pedal and turn off the engine, but hold the pedal depressed , it should hold for around 30 seconds after shutting off the engine before it uses up all the stored vacuum.

JustAnotherSaver

I had the 1.2 so could tell it a mile off. I mentioned the diesels as I was hedging my bets. 
The noisy tractor like engine is perfectly normal for the 1.2 engine. Its a timing chain, not belt on these and changing chains belts and tensioners will not eradicate this noise for very long. 

Unless your clip is goosed then it just needs tightening, not replacing. 

The throttle body is a piece of piddle to remove. Once off you can properly inspect and clean. The gasket is a rubber like one, not paper and would probably be OK to reuse. 

If you have soaking wet passenger footwells up front then this is normal on this Corsa and is related to the seal on the brake servo having perished. 

Not quite as common but normal all the same are the 'needles of death'. I drove some 200 mile with no temp, revs, speedo or fuel because the clocks had died. Very very annoying. Its a poor design where its just male and female connectors that just sit in place rather than being locked in place as in the Astra G. You can try padding them out and electrical spray but it'll only be temporary if it works. 

JustAnotherSaver

Also if you get gunge under the oil filler cap in these, it doesn't necessarily mean your head gasket is going either. 

gjs6385

I’ve tried cleaning the throttle body inside and out and tightened the jubilee clip and it seems to have possibly improved slightly.

I also tested the brake servo and wonder if that might be the cause of the air leak. When I turn the engine on when warm it revs up slightly and idles at about 1000-1100rpm and if I press the brake pedal a few times it then goes up over 1500rpm. Do you think it could be the brake servo vacuum pipe that needs replacing?

gjs6385

I managed to remove the vacuum pipe yesterday and ran the engine but the issue still occurred so doesn’t look like it’s the brake servo.

Interestingly though literally the second the engine temp needle started to rise the revs increased along with it so I’m wondering if it might be an engine temp sensor issue or similar what do you think?

Also I have a separate issue with the heating I’ve had the matrix flushed and a new water pump also tried running with the cap off incase there was an airlock in the cooling system having had some steal seal in previously to stop a coolant leak but the air still doesn’t blow through very warm at all however if I rev the engine then it comes through hot. I think the only option left is to replace the heater matrix which hopefully shouldn’t be too costly unless anyone has any other ideas.

MinuteNoodles

If you removed the vacuum pipe and ran it without it in place then you will get the same problem.

Before you go replacing the heater matrix disconnect both hoses to it. Run a hosepipe through one of the connections and see what comes out of the other. If you get water flowing it doesn't need changing. Unfortunately stuff like that sealant you used can cause blockages. When you're driving around where is the temperature gauge? It should be around the halfway mark. If it's at a quarter or less or drops significantly when on the open road it's likely the thermostat that needs changing and that's a quite cheap job as the part is less than £10 and easy to access. Coolant leak sealants can knacker a thermostat.