Stupid foam under LQ4 Intake manifold

[nixit]

I guess they put these here to keep stuff out, but it's doing the opposite. I also found the knock sensors ate the F up and the wells they sit in full of water. This is why the LQ4's have such a big probem with knock sensors. And without the foam there a nice air gap under there

You can't tell in the picture but it was about an inch deep in some spots

 

[K85 Octane]

eww
My foam was in good shape, so I figured I'd leave it since the manufacturer put them there.

What exactly is the crap that's there? Mud?

 

[nixit]

Mudd and leave, and I've only been in the mudd twice and it wasn't that deep

 

[sweetk30]

lot of guys relocate sensors 1 per side of block .

 

[K85 Octane]

Is there a problem with the knock sensors or their location in this motors?

 

[nixit]

They sit in these wells, under the plugs on the wiring harness. And the gunk that foam traps eventually gets under the plug.

 

[nixit]

And if it gets past this grommet... bam right on top of the cam, I haven't heard of it happened. But the possibility is there

 

[92yamaha]

I've heard that they knock sensors (foam or not) love to trap water since they're recessed and have no weep holes.

I suppose if you ever plan on crossing water, it's good to move them elsewhere. Also, never wash the engine...I had a neighbor kill both sensors at the car wash.

 

[Babaganoosh]

Lots of people rip them out when the intake gaskets leak. At the same time it is worth putting a bead of silicone on the knock sensor boots to seal to the valley cover

 

[folkenheath]

The primary purpose of the foam is so you have less engine noise in the cab. If you don't care about that, you can remove it, no worries.

 

[63chevyll]

I coat the knock sensor and wiring with dielectric grease. Seems to work ok

 

[diesel4me]

I bet the foam also was intended to prevent rodents from nesting in the valley..

I have seen lots of mouse nests in Northstar and older 3.0 V-6 mitsibushi engines in Caravans,among others, that have a valley (like a 6.2 diesel!)--and their urine and poop rusts up and rots things badly in a very short time..they chew up the wiring too..

 

[folkenheath]

Foam does not stop rodents, they like to chew on it.

 

[diesel4me]

Agreed,but it does slow them down,and tends to discourage them,they'll look for an "open" valley usually.....too bad they didn't lace the foam with D-con !..

 

[MAX89K5]

Those things are long gone for me, i wish i had sealed the knock sensors when my intake was off....