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Model specific boards => Golf mk4 => Topic started by: dub whore on 16 September 2012, 11:31

Title: Hot inlet manifold
Post by: dub whore 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?
Title: Re: Hot inlet manifold
Post by: Chris#101 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
Title: Re: Hot inlet manifold
Post by: 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!
Title: Re: Hot inlet manifold
Post by: dub whore on 16 September 2012, 11:41
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:
Title: Re: Hot inlet manifold
Post by: Wazzzer 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
Title: Re: Hot inlet manifold
Post by: Prawny 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!
Title: Re: Hot inlet manifold
Post by: 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
Title: Re: Hot inlet manifold
Post by: dub whore on 16 September 2012, 21:58
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!
Title: Re: Hot inlet manifold
Post by: shaft69 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.
Title: Re: Hot inlet manifold
Post by: Prawny 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!
Title: Re: Hot inlet manifold
Post by: jamie1989 on 17 September 2012, 12:35
I need WMI in my life  :evil:
Im well happy with my THS intercooler though, best mod Iv done by far!
Title: Re: Hot inlet manifold
Post by: Granta Gti on 17 September 2012, 21:22
I need WMI in my life  :evil:
Im well happy with my THS intercooler though, best mod Iv done by far!

They nice but pricey  :sad: mk4 modding eats your can and gets us into trouble!