[NakaiCougarV6]

Hello! I smoke tested my Cougar trying to find a vacuum leak. Three areas have smoke coming out: Intake manifold lines, the throttle body where the springs lead to for the pulley, and the EGR holes (which was replaced a few years ago).

My Cougar still idles lean when you put it in drive or reverse on a cold start. Once it warms up the idle is normal.

Does anyone know what these lines do? Did the circle inserts wear out? I push down on them to make sure they are snug but they still leak with the test.

I honestly do not know what to do next. Should I look for these parts to replace or come up with a temporary fix, like a sealant?
I would appreciate any help, regards.

 

[NakaiCougarV6]

Thank you 1999mercv6! That is a great idea for the intake hoses. I will buy some RTV sealant. As for the throttle body and gasket I'll see if I can get a better view of why there is a leak, but I'm definitely pricing them out online now.

 

[NakaiCougarV6]

Okay, I just uploaded a short video of it on YouTube:

 

[NakaiCougarV6]

Thank you for finding that! I will focus on the intake vacuum lines first and see if that fixes the cold start-lean idle. I'll update soon.

 

[NakaiCougarV6]

Status update: I gently pulled out the P444C line by pushing it up and down and it came off without breaking anything. I can confirm after reading this forum: vacuum clips on upper vac lines, going into UIM?
That it is held in by a black plastic piece that's surrounded by a gold or brass cover. You can slightly pull out the plastic piece with your finger nail and try to apply RTV sealant. I just need to find a tooth pick to spread the sealant and it's supposed to take 24 hours to cure. I will try it again soon.

Anyways, this vacuum leak also explains why this engine becomes easily heat soaked since it's sucking hot air directly from the top of the engine bay. The intake manifold valves open at 4000K+ rpm and that's exactly when it struggles to accelerate on 90+ degree days. Once this issue is fixed I'm hoping this Cougar will perform better.

 

[NakaiCougarV6]

Thank you guys for the help! I decided to order a throttle body from a lower mileage donor Cougar with a new gasket. I want to have a second one I can take a chance with that could work fine and to understand what it looks like inside with its O-ring and bushing before restoring the first one.

Also I finally understand the O ring on the UIM line ports that keep it sealed, which means I should apply RTV sealant to the bottom inside circumference.

Quick question: How do I remove that brass sleeve?

I think I'll fiddle around with it carefully to see if it comes out for better access to apply sealant.

 

[NakaiCougarV6]

Thank you B3NN3TT, I was able to order the automatic throttle body for my AT Cougar. I also ordered a used manifold intake that includes two vacuum clips/brass sleeves that could work better than my current ones, and so I can also have an extra pair that I can restore with RTV sealant since it's not sold anywhere anymore.

 

[NakaiCougarV6]

I used this "Automotive EVAP Smoke Machine Diagnostic Vacuum Leak Detection Tester" from eBay:

I stuck it into the throttle body opening and I held the throttle pulley back to open the valve. I did have to take off the air filter box to access that.

Also I'm glad there are still ways to improvise. I hope all of our Cougars stay alive over this century.

 

[NakaiCougarV6]

Okay, I will do that 👍. I remember AutoZone has those angled picks, I will pick that up too. Thanks, I wasn't sure if it was possible.

Also hello SpaceCatsAz! Vibrant white is a great color with its albedo effect.