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Author Topic: Hot inlet manifold  (Read 2035 times)

Offline dub whore

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Hot inlet manifold
« on: 16 September 2012, 11:31 »
I've recently put a new engine in and in the process deseamed my inlet mani and polished it. I dunno weather it's coinsidence or wot but now my inlet gets really hot which you all know ain't a good thing. And ideas?
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Offline Chris#101

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Re: Hot inlet manifold
« Reply #1 on: 16 September 2012, 11:37 »
When you polish something you remove all the pits (which makes that mirror effect?) that dispurse heat Which in turn attracts and holds alot of heat due to it not being able to escape aswell !

its hard to put into words  :grin: but I know what I mean
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Offline oceanic-green

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Re: Hot inlet manifold
« Reply #2 on: 16 September 2012, 11:37 »
This happened to me, I didn't clean or take it off, it just started getting really hot after driving it for a couple of mins. I replaced my maf with a new one, and it sorted the problem out!
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Offline dub whore

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Re: Hot inlet manifold
« Reply #3 on: 16 September 2012, 11:41 »
Quote from: oceanic-green on 16 September 2012, 11:37
This happened to me, I didn't clean or take it off, it just started getting really hot after driving it for a couple of mins. I replaced my maf with a new one, and it sorted the problem out!

My maf is pretty new. I don't see how the maf can affect the temp of the inlet tho??   :huh:
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Offline Wazzzer

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Re: Hot inlet manifold
« Reply #4 on: 16 September 2012, 12:40 »
MAF controls the fuel. Fuel cools the mixture. If it runs lean due to a dodgy MAF, it runs hotter
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Offline Prawny

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Re: Hot inlet manifold
« Reply #5 on: 16 September 2012, 13:28 »
I think if the only thing you've changed is the polished inlet then that's where the issue lies.

The inlets are a textured finish for a reason, the textured surface has a greater surface area over which heat can dissipate away. polishing it reduces the surface area and it won't cope with heat that well.

That said, if you're inlet is getting ultra hot then you probably need a better intercooler setup or WMI. The inlet on my 300bhp 1.8T feels like an icy can of beer after a thrashing, it's actually freezing, even on a hot summers day!
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Offline jamie1989

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Re: Hot inlet manifold
« Reply #6 on: 16 September 2012, 15:58 »
As above my THS intercooler keeps temps down all the time when thrashed  :cool:
It does get hot once stood still on idle though lol
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Offline dub whore

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Re: Hot inlet manifold
« Reply #7 on: 16 September 2012, 21:58 »
Quote from: jamie1989 on 16 September 2012, 15:58
As above my THS intercooler keeps temps down all the time when thrashed  :cool:
It does get hot once stood still on idle though lol



Yeh mine isnt hot all the time. My front mount does the job but when stood on idle it's too hot to touch!
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Offline shaft69

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Re: Hot inlet manifold
« Reply #8 on: 17 September 2012, 10:06 »
If cars not moving intake temps be pretty hot no flow through cooler to cool it so thought temps be 60-70degrees if not higher. mine when driving are low 20's with wmi on seen 4degrees.
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Offline Prawny

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Re: Hot inlet manifold
« Reply #9 on: 17 September 2012, 10:17 »
what does it matter how hot it gets on idle? on idle there is no airflow, and the bay gets red hot, plus heat conducting up from the engine, it's always going to get hot.

to find out if you have an issue, do a few hard pulls on boost, then pull over straight away and see how hot the manifold is then. if it's still red hot, then your intercooler is crap :)

IAT's of sub 10 degrees are not uncommon when using WMI :) even after a pull through the gears to 140mph on a hot day mine only peaked at 21 degrees!
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