Vacuum leak - Reduced engine power - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Mr Jos · 07-19-2015, 03:06 PM

Hi,

I have a vacuum leak somewhere in the PCV area. When the hose is pulled off and closed no leaks anywhere, only when it's connected. All tested but there seems to be a leak somewhere in the engine itselve (not intake side,but crank side).

Any possibilities where it could be so I don't have to tear the engine apart to find the leak.

It goes in reduced engine power and idles very bad cold, long starting time etc. Also throwing code for low fuel pressure in rail 1 (No idea if related with vacuum leak).

Greetings,

Mr Jos · 07-24-2015, 02:30 PM

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Pathogen · 07-24-2015, 03:29 PM

I have a vacuum leak tester. If you want to pay shipping, you can have it. PM me.

AITI · 07-24-2015, 04:09 PM

You have the V6 LFX engine I assume? If so, the PCV foul side line is simple. It goes from the center top of the intake manifold to the barb on the rear of the passenger side valve cover. Check the valve cover side of it. If you have the LS3 it connects to the valley cover vent under the front of the intake manifold accessible from the passenger side front of the engine. If the L99, it connects to the rear of the drivers side valve cover. Did you add a breather to the valve cover by chance? That will act as a vacuum leak as your bypassing the MAF so the air entering is un-metered. Give us more info and we can try to help.

Mr Jos · 07-25-2015, 07:50 AM

Hi,

I have the LFX yes.
I know where the PCV line is, and checked it for leaks and there are none in the line. The leak (it is audible) is somewhere in the engine block itselve, somewhere on the side or rear, but I can't find it. The sound is gone when the PCV line is pulled of and closed with a finger. I just don't know what parts are after the click-one connector, is it just a hole in the aluminium block itselve, or some replaceable part?

lawdog · 07-25-2015, 09:23 AM

I presume you don't have any Chevy dealers thee in Belgium ? I would be taking it in to a dealer for this problem. They can do a fog test which may find the leak in 5 minutes. Or find a mechanic around your place that has a fog tester.

MrChrisLS3 · 07-25-2015, 10:03 AM

You could also get a mechanics stethescope (looks like a doctor's, except it has a rod at the end) pull the hose off the rod and listen around the area. If there is a leak, you'll definitely hear exactly where it's coming from.

Mr Jos · 07-26-2015, 05:02 AM

I'll have to look monday. This year they stopped selling Chevy (and never sold V6 Camaro's in Europe) but I'll go for a fog test. Only problem is that all shops are on 3weeks holiday with reduced work being done.

Mr Jos · 07-27-2015, 03:17 PM

Problem is solved. [Edit: Issue came back, see next post]

Low fuel pressure codes (on startup) are gone, no more bad idle/die at cold start.
Good old accelerating.

If someone gets the same, as hissing noice at passenger side around pcv, and goes into limp mode, this solved it for me:

Blowing air in the crankcase where normally the hose is attached. I don't know if the metal tube has a valve in it, but something happened and now no more vacuum leak.

I still have to put back the VTC (removed it few days ago) and the catchcan, I don't know if I'll put that one back, removed it out of the line 1week ago after I forgot to empty it (full can cause of everything perhaps?).

MrChrisLS3 · 07-27-2015, 05:02 PM

Maybe caused a blockage in the PCV system and you blew it out with the air?

Mr Jos · 07-28-2015, 05:14 AM

After driving 200miles with no problem it came back while driving on the highway at a constant 75mph. Same vacuum hissing sound, gotta look at it when it stops raining.

Mr Jos · 07-28-2015, 09:58 AM

Seems to be that it is pulling to much air from the dirty side PVC hose. With motor off and closing the clean side with my finger I can put it under pressure/vacuum by blowing on dirty side, so seems that there is no leak.

Could it be pulling to much air from the clean side somehow?

MrChrisLS3 · 07-28-2015, 10:11 AM

Quote:

Originally Posted by Mr Jos

Seems to be that it is pulling to much air from the dirty side PVC hose. With motor off and closing the clean side with my finger I can put it under pressure/vacuum by blowing on dirty side, so seems that there is no leak.

Could it be pulling to much air from the clean side somehow?

Well, I'm not real up to speed on the LFX engine, however maybe you should refocus on that low fuel pressure code. I know that's a pretty big deal on the DI engines, and it may have nothing to do with the PCV system.

Mr Jos · 07-28-2015, 02:03 PM

The low fuel pressure code went away when the 'vacuum leak' was gone yesterday.

Seems that it pulls so much air that it's way to lean, and it tries to correct it but can't get there and trows low pressure code.

Is the PCV system on these engines without any valve at all? Just open clean side before throttle body, (I dont know what the big thing is in the line). And no valve either on dirty side? It is just pulling way to much air from the crankcase.

07-19-2015, 03:06 PM	#1
Mr Jos Drives: '13 2LT RS Join Date: Dec 2013 Location: Belgium Posts: 49 View My Garage	Vacuum leak - Reduced engine power Hi, I have a vacuum leak somewhere in the PCV area. When the hose is pulled off and closed no leaks anywhere, only when it's connected. All tested but there seems to be a leak somewhere in the engine itselve (not intake side,but crank side). Any possibilities where it could be so I don't have to tear the engine apart to find the leak. It goes in reduced engine power and idles very bad cold, long starting time etc. Also throwing code for low fuel pressure in rail 1 (No idea if related with vacuum leak). Greetings, __________________ Black '13 2LT RS Thé only one 2013 LPG converted Camaro in the world MRT V2, VTC Last edited by Mr Jos; 07-24-2015 at 02:31 PM.

07-24-2015, 02:30 PM	#2
Mr Jos Drives: '13 2LT RS Join Date: Dec 2013 Location: Belgium Posts: 49 View My Garage	- __________________ Black '13 2LT RS Thé only one 2013 LPG converted Camaro in the world MRT V2, VTC

07-24-2015, 03:29 PM	#3
Pathogen Drives: 2014 1LS Camaro Join Date: May 2014 Location: Cincinnati, Ohio Posts: 653	I have a vacuum leak tester. If you want to pay shipping, you can have it. PM me. __________________ Nobody with a good car needs to be justified. -Flannery O'Connor

07-25-2015, 07:50 AM	#5
Mr Jos Drives: '13 2LT RS Join Date: Dec 2013 Location: Belgium Posts: 49 View My Garage	Hi, I have the LFX yes. I know where the PCV line is, and checked it for leaks and there are none in the line. The leak (it is audible) is somewhere in the engine block itselve, somewhere on the side or rear, but I can't find it. The sound is gone when the PCV line is pulled of and closed with a finger. I just don't know what parts are after the click-one connector, is it just a hole in the aluminium block itselve, or some replaceable part? __________________ Black '13 2LT RS Thé only one 2013 LPG converted Camaro in the world MRT V2, VTC

07-26-2015, 05:02 AM	#8
Mr Jos Drives: '13 2LT RS Join Date: Dec 2013 Location: Belgium Posts: 49 View My Garage	I'll have to look monday. This year they stopped selling Chevy (and never sold V6 Camaro's in Europe) but I'll go for a fog test. Only problem is that all shops are on 3weeks holiday with reduced work being done. __________________ Black '13 2LT RS Thé only one 2013 LPG converted Camaro in the world MRT V2, VTC

07-24-2015, 04:09 PM	#4
AITI Account Suspended Drives: 2015 LFX Auto Join Date: Apr 2015 Location: US of A Posts: 280	You have the V6 LFX engine I assume? If so, the PCV foul side line is simple. It goes from the center top of the intake manifold to the barb on the rear of the passenger side valve cover. Check the valve cover side of it. If you have the LS3 it connects to the valley cover vent under the front of the intake manifold accessible from the passenger side front of the engine. If the L99, it connects to the rear of the drivers side valve cover. Did you add a breather to the valve cover by chance? That will act as a vacuum leak as your bypassing the MAF so the air entering is un-metered. Give us more info and we can try to help.

07-25-2015, 09:23 AM	#6
lawdog Drives: 2010 SSII w RS & Sunroof Yellow Join Date: Aug 2009 Location: West Suburbs of Chicago, in a Courthouse Somewhere Posts: 953	I presume you don't have any Chevy dealers thee in Belgium ? I would be taking it in to a dealer for this problem. They can do a fog test which may find the leak in 5 minutes. Or find a mechanic around your place that has a fog tester.

07-25-2015, 10:03 AM	#7
MrChrisLS3 Drives: 2018 1SS M6 Join Date: Nov 2014 Location: Houston Posts: 2,617	You could also get a mechanics stethescope (looks like a doctor's, except it has a rod at the end) pull the hose off the rod and listen around the area. If there is a leak, you'll definitely hear exactly where it's coming from.

07-27-2015, 03:17 PM	#9
Mr Jos Drives: '13 2LT RS Join Date: Dec 2013 Location: Belgium Posts: 49 View My Garage	Problem is solved. [Edit: Issue came back, see next post] Low fuel pressure codes (on startup) are gone, no more bad idle/die at cold start. Good old accelerating. If someone gets the same, as hissing noice at passenger side around pcv, and goes into limp mode, this solved it for me: Blowing air in the crankcase where normally the hose is attached. I don't know if the metal tube has a valve in it, but something happened and now no more vacuum leak. I still have to put back the VTC (removed it few days ago) and the catchcan, I don't know if I'll put that one back, removed it out of the line 1week ago after I forgot to empty it (full can cause of everything perhaps?). __________________ Black '13 2LT RS Thé only one 2013 LPG converted Camaro in the world MRT V2, VTC Last edited by Mr Jos; 08-27-2015 at 03:04 PM.

07-27-2015, 05:02 PM	#10
MrChrisLS3 Drives: 2018 1SS M6 Join Date: Nov 2014 Location: Houston Posts: 2,617	Maybe caused a blockage in the PCV system and you blew it out with the air?

07-28-2015, 05:14 AM	#11
Mr Jos Drives: '13 2LT RS Join Date: Dec 2013 Location: Belgium Posts: 49 View My Garage	After driving 200miles with no problem it came back while driving on the highway at a constant 75mph. Same vacuum hissing sound, gotta look at it when it stops raining. __________________ Black '13 2LT RS Thé only one 2013 LPG converted Camaro in the world MRT V2, VTC

07-28-2015, 09:58 AM	#12
Mr Jos Drives: '13 2LT RS Join Date: Dec 2013 Location: Belgium Posts: 49 View My Garage	Seems to be that it is pulling to much air from the dirty side PVC hose. With motor off and closing the clean side with my finger I can put it under pressure/vacuum by blowing on dirty side, so seems that there is no leak. Could it be pulling to much air from the clean side somehow? __________________ Black '13 2LT RS Thé only one 2013 LPG converted Camaro in the world MRT V2, VTC

07-28-2015, 02:03 PM	#14
Mr Jos Drives: '13 2LT RS Join Date: Dec 2013 Location: Belgium Posts: 49 View My Garage	The low fuel pressure code went away when the 'vacuum leak' was gone yesterday. Seems that it pulls so much air that it's way to lean, and it tries to correct it but can't get there and trows low pressure code. Is the PCV system on these engines without any valve at all? Just open clean side before throttle body, (I dont know what the big thing is in the line). And no valve either on dirty side? It is just pulling way to much air from the crankcase. __________________ Black '13 2LT RS Thé only one 2013 LPG converted Camaro in the world MRT V2, VTC