Boost Leak around MAF.

[saleen37804]

Hey guys, wondering if anybody has ever dealt with with a boost leak around maf? I have paxton novi 1200 sl with a blow through set up. I found a moderate boost leak around the maf after performing a boost leak test. I've tried everything I can think of to fix it. I tried using rubber gasket cut to set in the slot of the maf bung and black rtv gasket maker. Nothing seems to work. The rubber seal around the maf is in good shape.

Any advice?

 

[MrBhp]

It can be over tightened to its receiving flange. When it's mounted, is it flat across the top?

 

[saleen37804]

Yea is flat across top. Appears to be setting perfectly flush. I thought the gasket may be getting pinched from over tightening it so I put a small bit of machine pull on the seal and moderately tightening it, but still leaks. I'm waiting on Lito to get back to me to see if he's dealt with something like this before.

 

[saleen37804]

I'll get a couple of pictures and post them tomorrow after work.

 

[07 Boss]

Have you tried a new maf sensor? It's plastic, maybe there is a crack in it or it's leaking internally somewhere. If you tried rtv around it I would think the seal is good.

 

[MrBhp]

Have you tried a new maf sensor? It's plastic, maybe there is a crack in it or it's leaking internally somewhere. If you tried rtv around it I would think the seal is good.

I thought that too. It's an odd place to leak.

 

[saleen37804]

Have you tried a new maf sensor? It's plastic, maybe there is a crack in it or it's leaking internally somewhere. If you tried rtv around it I would think the seal is good.

I hadn't thought about that. It's a pmas so not exactly cheap if that is the case. I still have the original maf. I'll give that a try once I get home. I'll let you guys know

 

[saleen37804]

I couldn't find the original maf, but did have a second pmas that was damaged in a freak cleaning incident. Story for another, but certainly worth hearing lmao. You can see in the attached pictures that flange is clean. Both maf's appear to be setting flush. I swapped out the gasket I used previously with the one from the damaged maf. Actually appears to leaking worse that last time though

 

[saleen37804]

Here is a video. If those links don't work for some reason, I'll try uploading it to you YouTube or something.

Quick Share

1 file (104.9 MB)

quickshare.samsungcloud.com

20260720_205813_1.mp4

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[MrBhp]

It looks like it's sitting on the stud.

 

[saleen37804]

Yea the maf does touch the studs when it snugged down. The maf flange came On3. I have another flange somewhere, but I'm pretty sure it looks exactly like that one.

 

[MrBhp]

That thing is just not seating. How odd that you added rtv and it still leaked.

 

[saleen37804]

That thing is just not seating. How odd that you added rtv and it still leaked.

Yea idk. Maybe I didn't use enough. Was a little worried about getting it on the maf and messing this one up. I've not herd back from Lito in nearly 5 days. Do you think I should try thr rtv again? Be liberal with it this time

 

[MrBhp]

Are you using this kind of gasket?

 

[saleen37804]

No, rubber one that came with it.

 

[MrBhp]

Try that other gasket.

 

[saleen37804]

I didn't know they made one like that. Ordering it now!

 

[MrBhp]

I'm pretty sure my mega maf or the weld-on bung came with that gasket. I'll take a picture for you tomorrow.

 

[Midlife Crises]

File the studs flush with the flange and do not over tighten the bolts.

 

[whitmanink]

File the studs flush with the flange and do not over tighten the bolts.

another thing to test is the welds around the maf,,
if you got a pinhole crack in one ,, that will cause it .,.

i only say that because it should seal with what you've done ,
unless the studs are too big and not letting the gasket compress , but it still looked like it was..

that is of course, if a thicker gasket dont solve the problem