Engine Air intake manifold leak advice

[mikeah]

Hi all,

I fixed up a vacuum leak today (or mostly did at least) at my A/C vacuum reservoir (picture attached). Along with that, I finally got a chance to run a leak check on my air intake manifold with the MAF port covered with a glove. I saw a fair amount of smoke seeming to seep out of the front part of the manifold, but honestly it seems to be coming from a few spots.

My guess so far is the air intake manifold gasket(s) at the least is shot or worn out and needing replacing, but I am also curious about the other various components going in.
Attached is a video and some pictures of the smoke output (unfortunately I couldn't personally find a clear indication of where it was coming from, but it mostly seemed at the initial connections and sensors there.

As of right now, these leaks are what is causing the rough idle and cold start for the first 1-2 minutes. 1500-2000RPM for 1-2 minutes will keep the car from fluctuating idle and stalling. After this, subsequent starts are flawless.

Any ideas on a better way to test for leaks or identify specific leaking points in my scenario, or does the video/image provide enough insight on the leak? I can definitely run another leak test if there's any advice on areas for improvement or focus.

Happy to provide a video of the cold start also if that'd help.

Leak video:
View: https://youtu.be/5_GcoC3sf7s


Thanks as always and hoping I can sort this ordeal out.

 

[General karthief]

I can't tell, too much camera movement
Did you have the throttle blade open?

 

[mikeah]

Sorry, it's a pain to get a good shot of the smoke as it seems to be starting from around or underneath the EGR valve/solenoid I think. Hopefully this video does it a bit more justice and thanks for taking a look.

I did catch a vacuum line leak for the 2nd A/C line going back through the firewall, but I just fixed that with some tighter hose from my LMR hose repair kit and it's good now. So now the main leak seems to be from the EGR area.

I didn't see additional leaks with the throttle blade open FWIW, but I only briefly ran that.

Any thoughts here on where to start? Thanks again.

View: https://www.youtube.com/watch?v=qFb5L9f3Y7E

 

[Mustang5L5]

I can’t really tell where it’s coming from. It kinda looks like some is getting by the glove. I usually put the glove on, then put the intake tube on as well.

Regardless, throttle body, IAC, and egr spacer gaskets are pretty cheap. Wouldn’t hurt to just refresh all of that.

 

[mikeah]

I can’t really tell where it’s coming from. It kinda looks like some is getting by the glove. I usually put the glove on, then put the intake tube on as well.

Regardless, throttle body, IAC, and egr spacer gaskets are pretty cheap. Wouldn’t hurt to just refresh all of that.

Thanks, I'll give those a refresh. I'll report back with another test once I've given those gaskets a swap and hopefully we'll be in a better spot.

For the throttle body gaskets, 65mm should be okay for the stock intake manifold, right?

I think https://lmr.com/item/AF-F65G/93-mustang-cobra-accufab-65mm-throttle-body-gasket-86-93 has all the gaskets I'd need for this refresh (unless I missed one)?

 

[Mustang5L5]

Should be fine.

I’d even be tempted to just go to the local Autozone and see what they want for some Felpro gaskets. Even Amazon might have these cheap.

These are all the p/nS for stock HO manifold gaskets.

 

[General karthief]

The majority of gaskets for these engines can be had from the local parts store. No shipping.

 

[mikeah]

The majority of gaskets for these engines can be had from the local parts store. No shipping.

Yeah, unfortunately when I checked for various ones they weren't near me at my usual stores (Autozone and Advance).

I just checked with NAPA and they have them all, so I'll scoop those tomorrow and get around to swapping them soon.

Should be fine.

I’d even be tempted to just go to the local Autozone and see what they want for some Felpro gaskets. Even Amazon might have these cheap.

These are all the p/nS for stock HO manifold gaskets.

This is great, thanks a ton. I got the exact models for each at my local NAPA.

 

[mikeah]

I'm back with good news! Removing the front of the intake (EGR spacer, throttle control, etc) and replacing the gaskets was an incredibly worthwhile effort. The gaskets were all shot, there was a coolant leak in the EGR spacer, and additionally, there was a full coolant blockage in the EGR spacer going towards the firewall. The amount of carbon in the air intake was truly wild. I spent a fair bit of time with mass air flow sensor cleaner and throttle body cleaner getting it into a better spot. Here are some of the pictures of the carnage.

I did end up replacing the EGR valve as it was pretty much totally seized from carbon build up (I tried and tried to clean it, but the movement was super tight, so replacing seemed wise).

After putting it all together, I reset the idle (I actually I think backed out all the way on the throttle cable) and I've got an idle around 900 RPM I think (sounds good to me).

I did have to double-nut the studs to be able to actually remove the EGR spacer (tried a fine point chisel to no avail). I put some anti-seize lubricant on the original studs that I reused since I couldn't find any of those studs at my local stores (all of them were too short it seemed).

The only remaining issue is the bottom bolt of my IAC solenoid snapped so I need to order some replacement bolts and also remove that bolt. The top seems to be providing a solid enough seal for now.

 

[limp]

I'm back with good news! Removing the front of the intake (EGR spacer, throttle control, etc) and replacing the gaskets was an incredibly worthwhile effort. The gaskets were all shot, there was a coolant leak in the EGR spacer, and additionally, there was a full coolant blockage in the EGR spacer going towards the firewall. The amount of carbon in the air intake was truly wild. I spent a fair bit of time with mass air flow sensor cleaner and throttle body cleaner getting it into a better spot. Here are some of the pictures of the carnage.

I did end up replacing the EGR valve as it was pretty much totally seized from carbon build up (I tried and tried to clean it, but the movement was super tight, so replacing seemed wise).

After putting it all together, I reset the idle (I actually I think backed out all the way on the throttle cable) and I've got an idle around 900 RPM I think (sounds good to me).

I did have to double-nut the studs to be able to actually remove the EGR spacer (tried a fine point chisel to no avail). I put some anti-seize lubricant on the original studs that I reused since I couldn't find any of those studs at my local stores (all of them were too short it seemed).

The only remaining issue is the bottom bolt of my IAC solenoid snapped so I need to order some replacement bolts and also remove that bolt. The top seems to be providing a solid enough seal for now.

Mustang5L5 ALWAYS has good advice.....

 

[General karthief]

Mustang5L5 ALWAYS has good advice.....

That's why he gets the BIG cookies!

 

[limp]

That's why he gets the BIG cookies!

I thought that was the window guy here in Florida??

 

[General karthief]

I thought that was the window guy here in Florida??

Huh???

 

[limp]

Huh???

The guy who has the commercials about his window company during the 6 o'clock news that always has the giant cookie.. He always tells you to " remember the cookie..

 

[General karthief]

The guy who has the commercials about his window company during the 6 o'clock news that always has the giant cookie.. He always tells you to " remember the cookie..

he wants you to bring HIM cookies.
Ain't happening