Need Help! 'pop corn' noise from engine after chaging inlets

[Fluxuk05]

As above, just swapped my inlets for matched ones, put everything back together - started up, engine rev to 5k on its own and then drops to a very rough idle and makes VERY nasty sounding pop corn bangs from the engine.

Any ideas? dont really want to send the pistons into the roof of the garage...

 

[Cup_Phil]

Inlet leak - did you put all the gaskets on and tighten everything up?

 

[Fluxuk05]

Yea just been reading up, almost certainly an air leak.

Gaskets are on, looking like it could possibly be the rubber seal on the bottom of the plenum.

Could also be the TB to plenum join? is this meant to have a gasket?

 

[Chrisjk]

Could also be the TB to plenum join? is this meant to have a gasket?

Yes it is, you can use silicone sealant though i believe.

 

[Cup_Phil]

Unfortunatly that's the length of my knowledge mate as I've only had my clio a month and not taken the inlets off yet

If you get yourself a can of carb cleaner or WD40 - while the car is ticking over spray it at the joins
When it sucks the WD40 in the revs will go up

 

[Fluxuk05]

Just been looking, tested the eye shaped seal under the plenum by putting oil on the rubber then seeing if when removed any was on block. Seems like the plenum wasn't sat correctly.

I'll report back....

 

[Fluxuk05]

Great Success!

Turns out you can mount the plenum so that the back of it sits up slightly and the bolts still screw up. Surprising how such a small gap of only a few mm can bugger things up.


Also managed to shear off a bolt, so that took another 20 mins to get out. What a day/

 

[Cup_Phil]

Glad it got sorted in the end