Oil in the cold air tube
10-17-2014, 03:07 PM
#1
Thread Starter
Join Date: Oct 2014
Location: ca
Posts: 47
Oil in the cold air tube
I appreciate the membership to this forum. I have been helped by the experience and expertise on this group many times in the past by way of internet search. I have an issue with my engine that I hope you will consider. If I have posted this question in the wrong place, please notify me and I will remove it and post it correctly.
I have a 2006 Mustang GT 4.6L with a Roushcharger supercharger Kit that I installed around 2008. The kit and the support have been excellent and I don not think the problem is from the kit.
About 2 years after the install of the supercharger kit and flawless performance, a problem began to show whereby when I would start the car (after the engine being at full operating temperature), right after startup the engine would stumble for about 2 seconds then immediately correct itself. This would only happen after the car was fully warmed up. The other issue was that after extended freeway driving, and after pulling onto a freeway off-ramp and the engine going down to idle, it would stumble for several seconds and sometimes even shutoff. Again this is at full operating temperature.
This problem would happen but I was not getting a check engine light. After doing some research, I found that oil was getting into the cold air tube and fouling the MAF sensor. I also discovered that the tube from the passengers side valve cover which goes to the cold air intake tube was clean and dry but the tube going from the drivers side valve cover (where the PCV valve is inside the valve cover) was the culprit for the oil travel.
The tube from the drivers side VC connects to the back side of the intake manifold (behind the supercharger) in a high point on the manifold. The oil residue that enters into the manifold appears to run right down the inside of the manifold, through the throttle body and into the cold air tube and pools under the MAF which seems to be causing the trouble of the stumbles from inaccurate data collected by the MAF.
I came to that conclusion after I had removed the cold air tube, cleaned all of the oil residue out of it, and cleaned the MAF with a MAF cleaner and cleaned the throttle body. When I would do this, I would have no stumbling issues for a month or two until the oil would re-collect in the cold air tube and ultimately foul the MAF again.
After checking the PCV valve by connecting a hose and finding it would let air pass one way and not the other, I concluded that the valve was OK. After doing some more research, I got an oil separator (catch can) from Summit and installed it between the drivers side VC and the inlet behind the manifold (as I have seen some do on the forum and going by examples I have seen which were shared by guys with this same issue I have).
This fixed the stumbling issue for several months. The strange thing is that about every month I would flip my drain valve on the catch can but I would never get any oil drain, only maybe a drop or two at most. This puzzled me because I read where guys were getting about a tablespoon or so a month,but since the car was running fine, I let it go.
So now, about a week or so ago I got a check engine light and borrowed my friends OBD 2 checker and found that I has 2 codes. P0171 and P0174 which are a lean condition in banks 1 and 2. Upon doing some research, one of the issues that can cause this is a dirty MAF. I took the cold air tube off and again, I have oil in the tube and pooling under the MAF.
I opened up my oil separator and found only a small residue inside it but heavy oil on the side of the separator (in the tube) that goes to the back of the intake manifold (the tube that shouldn't have any oil in it) and again it appears to be running down inside the intake manifold, through the throttle body into the cold air tube and pooling under the MAF.
I realize that there are a couple more issues that can cause those error codes like 02 sensor or fuel pump and filter, but I cannot understand why no oil is collecting inside my catch can and why it is making its way back into the manifold.
I have a 2006 Mustang GT 4.6L with a Roushcharger supercharger Kit that I installed around 2008. The kit and the support have been excellent and I don not think the problem is from the kit.
About 2 years after the install of the supercharger kit and flawless performance, a problem began to show whereby when I would start the car (after the engine being at full operating temperature), right after startup the engine would stumble for about 2 seconds then immediately correct itself. This would only happen after the car was fully warmed up. The other issue was that after extended freeway driving, and after pulling onto a freeway off-ramp and the engine going down to idle, it would stumble for several seconds and sometimes even shutoff. Again this is at full operating temperature.
This problem would happen but I was not getting a check engine light. After doing some research, I found that oil was getting into the cold air tube and fouling the MAF sensor. I also discovered that the tube from the passengers side valve cover which goes to the cold air intake tube was clean and dry but the tube going from the drivers side valve cover (where the PCV valve is inside the valve cover) was the culprit for the oil travel.
The tube from the drivers side VC connects to the back side of the intake manifold (behind the supercharger) in a high point on the manifold. The oil residue that enters into the manifold appears to run right down the inside of the manifold, through the throttle body and into the cold air tube and pools under the MAF which seems to be causing the trouble of the stumbles from inaccurate data collected by the MAF.
I came to that conclusion after I had removed the cold air tube, cleaned all of the oil residue out of it, and cleaned the MAF with a MAF cleaner and cleaned the throttle body. When I would do this, I would have no stumbling issues for a month or two until the oil would re-collect in the cold air tube and ultimately foul the MAF again.
After checking the PCV valve by connecting a hose and finding it would let air pass one way and not the other, I concluded that the valve was OK. After doing some more research, I got an oil separator (catch can) from Summit and installed it between the drivers side VC and the inlet behind the manifold (as I have seen some do on the forum and going by examples I have seen which were shared by guys with this same issue I have).
This fixed the stumbling issue for several months. The strange thing is that about every month I would flip my drain valve on the catch can but I would never get any oil drain, only maybe a drop or two at most. This puzzled me because I read where guys were getting about a tablespoon or so a month,but since the car was running fine, I let it go.
So now, about a week or so ago I got a check engine light and borrowed my friends OBD 2 checker and found that I has 2 codes. P0171 and P0174 which are a lean condition in banks 1 and 2. Upon doing some research, one of the issues that can cause this is a dirty MAF. I took the cold air tube off and again, I have oil in the tube and pooling under the MAF.
I opened up my oil separator and found only a small residue inside it but heavy oil on the side of the separator (in the tube) that goes to the back of the intake manifold (the tube that shouldn't have any oil in it) and again it appears to be running down inside the intake manifold, through the throttle body into the cold air tube and pooling under the MAF.
I realize that there are a couple more issues that can cause those error codes like 02 sensor or fuel pump and filter, but I cannot understand why no oil is collecting inside my catch can and why it is making its way back into the manifold.
10-18-2014, 10:33 AM
#4
^^what he said. Call UPR at 561.588.6630 and we can set you up with an EXCELLENT catch can. You'll be blown away when you see how much oil vapor it traps. I've filled my 7oz can in one oil change.
10-19-2014, 01:47 AM
#5
If you have forced induction, that's the way to go. By venting both valve covers via catch cans to breather filters with the crankcase completely divorced from the intake system, you'll have no more oil contaminating the intake and fouling the MAF sensor.
10-19-2014, 07:53 AM
#6
3rd Gear Member
Join Date: Jun 2010
Location: RI
Posts: 690
If you are FI, be aware that if you run a breathers only, and bypass the PCV system, you will risk pressure build up in the crankcase which leads to oil seepage past gaskets and seals. Putting a breather on the PCV valve side of a 3v does absolutely nothing - the valve never opens. The valve is built in to the underside of the valve cover and if you don't remove it, it will never open. The only place for the pressure to go is through the dinky 3/8" vent on the passenger valve cover and even the addition of a CFM filler cap/breather may not be enough.
The better solution is to run a good catch can in the PCV line, whatever brand you may choose. It always better to keep the crankcase under vacuum for N/A driving and when you get into boost the PCV connection behind the throttle plates will help open the PCV valve and suck the vapors (and crankcase pressure) through - thus still keeping a vacuum on the crankcase. The PCV connection behind the throttle plate is before the S/C rotors, so it doesn't see "boost" - the air rushing past the connection into the S/C will create a siphon effect on the PCV line. But bottom line is that you need a catch can that effectively pulls/seperates the oil out of the PCV vapor. Sounds like the Summit catch can kinda sucks at that and it also sounds like the PCV connection on your S/C isn't located in the greatest of places if it lets oil run all the way down to your MAF location. With a good catch can you won't have to worry about that anymore anyway.
The better solution is to run a good catch can in the PCV line, whatever brand you may choose. It always better to keep the crankcase under vacuum for N/A driving and when you get into boost the PCV connection behind the throttle plates will help open the PCV valve and suck the vapors (and crankcase pressure) through - thus still keeping a vacuum on the crankcase. The PCV connection behind the throttle plate is before the S/C rotors, so it doesn't see "boost" - the air rushing past the connection into the S/C will create a siphon effect on the PCV line. But bottom line is that you need a catch can that effectively pulls/seperates the oil out of the PCV vapor. Sounds like the Summit catch can kinda sucks at that and it also sounds like the PCV connection on your S/C isn't located in the greatest of places if it lets oil run all the way down to your MAF location. With a good catch can you won't have to worry about that anymore anyway.
Last edited by jpplaw; 10-19-2014 at 08:17 AM.
10-19-2014, 09:43 AM
#7
^^Agreed. FI modulars tend to make quite a bit of blow by. A good quality can (UPR) makes a big difference. Also, it's good to keep the PCV system functional since it aids cylinder seal by pulling vacuum out from under the pistons.
10-21-2014, 07:41 PM
#8
Thread Starter
Join Date: Oct 2014
Location: ca
Posts: 47
Thanks for the replies to my question.
I checked and the catch can I installed is indeed a UPR can. 05-10 Mustang Oil Catch Can.
Heres a link:
http://www.uprproducts.com/mustang-b...driver-05.html
I checked and the catch can I installed is indeed a UPR can. 05-10 Mustang Oil Catch Can.
Heres a link:
http://www.uprproducts.com/mustang-b...driver-05.html
10-21-2014, 10:28 PM
#10
Thanks for the replies to my question.
I checked and the catch can I installed is indeed a UPR can. 05-10 Mustang Oil Catch Can.
Heres a link:
http://www.uprproducts.com/mustang-b...driver-05.html
I checked and the catch can I installed is indeed a UPR can. 05-10 Mustang Oil Catch Can.
Heres a link:
http://www.uprproducts.com/mustang-b...driver-05.html
