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Need help with a 4g93 GDI vacuum leak
Posted: May 1st, 2015, 1:13 pm
by alleykat2020
Looking for a competent GDI mechanic to locate and fix an intermittent vacuum leak.
Noticed the problem when I started running out of brake assist.
Changed booster. Same problem.
Installed a vacuum gauge and realised it was a vacuum leak.
Checked booster hoses etc. All good. All check valves good.
Also checked the vacuum hoses I can reach but nothing.
The engine holds 18 to 20 when cold. Drops to about 14 as it warms up and by the time it reaches operating temperature, sometimes drops as low as 4 when the brakes are depressed (hence no brake assist from booster).
Managed to construct a vaccum canister which helps but still runs out every now and then.
Idle is also all over the place.
Anyone who knows of a competent mechanic who has a smoke machine or uses vacuum dye, could you please give me a contact number so I can get this problem solved.
Thanks.
PM, call, text, whatsapp..... 685-7809
Re: Need help with a 4g93 GDI vacuum leak
Posted: May 3rd, 2015, 8:11 pm
by alleykat2020
Re: Need help with a 4g93 GDI vacuum leak
Posted: May 4th, 2015, 3:45 pm
by alleykat2020
Re: Need help with a 4g93 GDI vacuum leak
Posted: May 5th, 2015, 9:50 pm
by deivid
i use water or anything that comes out of a can at high pressure around suspected hoses....if there is a leak it will suck in the water.....use a spray bottle an listen for the water being sucked in....
Re: Need help with a 4g93 GDI vacuum leak
Posted: May 5th, 2015, 11:57 pm
by cinco
YouTube a homemade smoke tester. A rubber glove and cigar are all u need
Re: Need help with a 4g93 GDI vacuum leak
Posted: May 6th, 2015, 5:10 am
by 1UZFE
In for info.
Re: Need help with a 4g93 GDI vacuum leak
Posted: May 7th, 2015, 9:32 pm
by alleykat2020
deivid wrote:i use water or anything that comes out of a can at high pressure around suspected hoses....if there is a leak it will suck in the water.....use a spray bottle an listen for the water being sucked in....
Tried that around all hoses and gasket that i can get to. No dice.
I believe the vacuum leak may be somewhere i can't get to.
Wherever this leak is, I believe the seal/hose only becomes pliable when the engine bay temperature increases.
Re: Need help with a 4g93 GDI vacuum leak
Posted: May 7th, 2015, 9:42 pm
by alleykat2020
cinco wrote:YouTube a homemade smoke tester. A rubber glove and cigar are all u need
Also tried this as well.
The rubber glove inflated and didn't go down at all. No smoke seen leaking out anywhere.
One of the reasons I think it may be the intake manifold gasket or some gasket that's able to sucked inward with the engine vacuum but cannot be pushed out using positive air pressure. At least not with lung power.
Still on the fence about using a small tire air compressor and a homemade smoke canister or soapy water. Don't want to damage anything in the engine by using one of those small air compressors.
The small amount of positive air pressure should have been enough to force air out of an open vacuum leak is what I'm thinking.
I stand to be corrected.
So need a mechanic whose willing to go through the engine (including willing to remove intake etc.) until leak can be found and everything can be properly resealed etc.
Re: Need help with a 4g93 GDI vacuum leak
Posted: May 17th, 2015, 9:07 am
by alleykat2020
Re: Need help with a 4g93 GDI vacuum leak
Posted: May 26th, 2015, 8:00 am
by BoostJunkieXL
try 2954982 his name's MIK
Re: Need help with a 4g93 GDI vacuum leak
Posted: June 1st, 2015, 7:28 pm
by alleykat2020
Okay guys.
Consulted with a mechanic who has a smoke machine and after describing my problem was told that the engine just was not producing enough vacuum, not that there was an external vacuum leak so using the smoke machine would be a waste of time. He said due to the intermittent /sometimish nature of the "leak", something internal was causing the engine not to produce enough vacuum.
Did some online research and realised that a dirty EGR Valve could be causing the erratic idle and possible vsacuum loss if it failed to close properly.
Using this guide by raybic
viewtopic.php?f=33&t=453517 , i decided to remove the intake mainfold today, clean it using throttle body cleaner, purple blaster and water and finally delete the EGR.
After reassembly, the engine erratic idle has steadied and the vacuum gauge reads a steady 24.
However, once the AC is on, the vacuum gauge starts behaving erratically again.
So back to the drawing board. Improvements but still the problem persists.
Re: Need help with a 4g93 GDI vacuum leak
Posted: June 21st, 2015, 10:52 pm
by de_dougla_smurf
Call Mik. He could sort u out