JLT catch can causing vacuum leaks?

[mrgtx]

IIRC, JLT makes a similar catch can for pretty much every S197 version so it seems like this question would be best asked here...

One of the first mods that I did to my 2011 GT was to add the JLT catch can. While they make them for both cylinder banks, I read that the passenger side was the more critical one so that's the one I installed.

Sure enough, it collects oil that would otherwise be lining the intake manifold and the backs of the valves over time. I typically collect a few milliliters every thousand miles...not as much as some other folks report but that could be due to a lack of effectiveness of the catch can as much as a lack of oil getting sucked through. In either case, it seems worthwhile to have the catch can in place.

I have heard complaints that these things can cause vacuum leaks. So far, I hadn't seen any signs that mine was leaking but noticed that the hose clamps (OEM/clasping type) between the hose and the can unit were no longer snug. That certainly could be the start of a problem (if it wasn't already).

It has been on the car for ~24,000 miles so it's possible that the hoses are deteriorating (and collapsing?) but they look fine.

What is the failure mode for these catch cans? How do folks figure out that they have a vacuum leak? Do you always get a CEL?

Any thoughts, insights, opinions are very welcome and appreciated.

-Mike

 

[Mystickeith50]

They can. If the cap isn't closed all the way, the fittings Crack or become loose, etc. Do you have the metal male adapters in both sides or plastic?

 

[mrgtx]

They can. If the cap isn't closed all the way, the fittings Crack or become loose, etc. Do you have the metal male adapters in both sides or plastic?

Excellent question. I assumed they were metal fittings but I will pop the hoses off and take a look.

Are there different versions of the JLT unit?

 

[stkjock]

the first units had plastic IIRC and they broke, the design was updated and older units could have the fittings replaced by JLT for free in the past.

 

[07 Boss]

IIRC, JLT makes a similar catch can for pretty much every S197 version so it seems like this question would be best asked here...

One of the first mods that I did to my 2011 GT was to add the JLT catch can. While they make them for both cylinder banks, I read that the passenger side was the more critical one so that's the one I installed.

Sure enough, it collects oil that would otherwise be lining the intake manifold and the backs of the valves over time. I typically collect a few milliliters every thousand miles...not as much as some other folks report but that could be due to a lack of effectiveness of the catch can as much as a lack of oil getting sucked through. In either case, it seems worthwhile to have the catch can in place.

I have heard complaints that these things can cause vacuum leaks. So far, I hadn't seen any signs that mine was leaking but noticed that the hose clamps (OEM/clasping type) between the hose and the can unit were no longer snug. That certainly could be the start of a problem (if it wasn't already).

It has been on the car for ~24,000 miles so it's possible that the hoses are deteriorating (and collapsing?) but they look fine.

What is the failure mode for these catch cans? How do folks figure out that they have a vacuum leak? Do you always get a CEL?

Any thoughts, insights, opinions are very welcome and appreciated.

-Mike

Shouldn't it be on the driver's side? I know on the 4.6, the pcv valve is on the drivers side, is it not the same on the 5.0?

Is the car running rough at idle?

 

[mrgtx]

Shouldn't it be on the driver's side? I know on the 4.6, the pcv valve is on the drivers side, is it not the same on the 5.0?

Is the car running rough at idle?

I followed the advice of some other (admittedly lesser) Mustang forums and the advice of American Muscle...so I think I got the correct side. It is interesting if they swapped from one generation of modular motor to the next since I gather that they share a lot of the same tooling.

Idle was fine (good question) and I didn't have any solid signs of a leak...I was brainstorming when I noticed what I thought might have been a change in the exhaust note (more of a "wub wub wub" in there) and what seemed like a slight loss of power. A vacuum leak seemed like a reasonable enough place to start...

In the end, I'm pretty sure it was just that I had been driving more with the windows up and the power loss was in my head but the loose hose clamp was an important find (IMO) since this is a known failure point with that mod.

 

[SNKPWR]

Shouldn't it be on the driver's side? I know on the 4.6, the pcv valve is on the drivers side, is it not the same on the 5.0?

Is the car running rough at idle?

Pcv is on the passenger side on the 5.0

 

[Fullboogie]

Spray brake cleaner around the unit while the car is running - that will tell you if you have a leak.

 

[Kylar]

Spray brake cleaner around the unit while the car is running - that will tell you if you have a leak.

Use starter fluid instead, same effect and doesnt include chemicals that will discolor/damage plastic/painted finishes

 

[mrgtx]

So I definitely have the plastic fittings on my JLT catch can.
I will be making a call today to see if they'll help me out.

 

[Sky Render]

Sure enough, it collects oil that would otherwise be lining the intake manifold and the backs of the valves over time.

I'm not so sure this is as big an issue on cars that aren't direct injection. The fuel mixture in the intake manifold keeps the valves clean.

 

[Pentalab]

So I definitely have the plastic fittings on my JLT catch can.
I will be making a call today to see if they'll help me out.

Mine came with plastic..pita. I swapped em both to brass....end of problems.

 

[MechE]

I followed the advice of some other (admittedly lesser) Mustang forums and the advice of American Muscle...so I think I got the correct side. It is interesting if they swapped from one generation of modular motor to the next since I gather that they share a lot of the same tooling.

Idle was fine (good question) and I didn't have any solid signs of a leak...I was brainstorming when I noticed what I thought might have been a change in the exhaust note (more of a "wub wub wub" in there) and what seemed like a slight loss of power. A vacuum leak seemed like a reasonable enough place to start...

In the end, I'm pretty sure it was just that I had been driving more with the windows up and the power loss was in my head but the loose hose clamp was an important find (IMO) since this is a known failure point with that mod.

Passenger side should be correct. That side returns to the intake after the throttle plate which is a lower pressure than the feed side that connects to the intake before the throttle plate.
I read somewhere that the oil system was completely reworked for the coyote; this probably has something to do with the change from the 4.6L

 

[BruceH]

FWIW the manual provided to us by Louie in Dubai shows air coming into the RH valve cover from the airbox and out through a pcv valve in the LH (driver side) valve cover. This is how the 3v is routed also.

Has something changed from the 2011 5.0 that this manual describes?

http://iihs.net/fsm/?dir=892&viewfile=Evaporative Emissions.pdf

 

[MechE]

FWIW the manual provided to us by Louie in Dubai shows air coming into the RH valve cover from the airbox and out through a pcv valve in the LH (driver side) valve cover. This is how the 3v is routed also.

Has something changed from the 2011 5.0 that this manual describes?

http://iihs.net/fsm/?dir=892&viewfile=Evaporative Emissions.pdf

That or the manual is wrong.

I am plumbed airbox to driver side cover.

 

[BruceH]

That or the manual is wrong.

I am plumbed airbox to driver side cover.

That has to be how the crankcase breathes then. From the air intake after the maf to the motor and out the other side through a pcv to the intake manifold.

 

[travelers]

The PCV valve (blue) is in the right (passenger) rocker cover.