intake air temps?

Diagnostic Trouble Codes (DTC) / VCDS (VAG-COM) forum
Post Reply
buzzard
4th Gear
Posts: 586
Joined: Fri Mar 11, 2005 11:50 am

intake air temps?

Post by buzzard » Tue Nov 20, 2007 11:20 am

reading of 45C on vagcom

this is never right is it.---- its 5C outside.

currently lookin for a boost prob.
done a log 003 for maf and this seems ok. 215g/s for standard car
but 115 log --boost actual and required is all over the place.
think i might have a leak appeared.
will check all the usuals.
(feelings of ticking time bomb.)
S4 B5 long gone
S4 B8 Stage 2

User avatar
CliveH
Cruising
Posts: 4754
Joined: Sat Oct 02, 2004 12:07 pm
Location: Yorkshire, UK

RE: intake air temps?

Post by CliveH » Tue Nov 20, 2007 1:00 pm

It's possible if you're not getting proper cooling.

Can you post your logs up please?
Clive

S2 ABY coupe, S4 B5 saloon, S4 B6 avant
RS4 B7 phantom black saloon, mint, fully loaded, low mileage - FOR SALE!- http://www.rs246.com/index.php?name=PNp ... ic&t=88981
S8 D2 facelift, RS6 C5 saloon, both gone but not forgotten

User avatar
shineydave
Cruising
Posts: 2561
Joined: Sun Oct 16, 2005 10:22 am
Location: Bradford, Yorkshire, UK
Contact:

RE: intake air temps?

Post by shineydave » Tue Nov 20, 2007 7:26 pm

whereabouts is the inlet temp measured?, if it's after the intercoolers (as i would think makes sense) then the air has been through the turbos so it's not surprising it's warmer than ambient
Dave

"if that's the Turbo Fairy knocking tell her i'm not in"

http://www.ukchat.com/home/setnick.asp?room=RS2346

User avatar
Jarv
5th Gear
Posts: 1243
Joined: Wed Mar 22, 2006 9:44 pm
Location: North London
Contact:

Post by Jarv » Tue Nov 20, 2007 9:29 pm

I'm watching this thread with interest as I am very keen to find out what intake temp levels other SMIC equipped cars are running.

On my FATS run after my dyno session at Thorney on Saturday, I got a peak intake temp of 45 degrees, bang on what you got Buzzard. I also had my intake temps logged on my dyno session, and it peaked at over 90 degrees due to the inability of the fans to get sufficient air through the SMIC's.

I'd also like to know a bit more about what is an acceptable variance between actual and specified boost, and what the causes and consequences are of exceeding the recommended variance. Be interested to see your logs to see if your variance is similar to mine.
Mike

Q7

User avatar
CliveH
Cruising
Posts: 4754
Joined: Sat Oct 02, 2004 12:07 pm
Location: Yorkshire, UK

Post by CliveH » Tue Nov 20, 2007 11:56 pm

The Intake Air Temperature Sensor (G42) sits after the intercoolers (in the inlet manifold), which is why such high temperatures are being observed (as Dave says, air cooled after being through the turbos).

During the FATs runs at Thorney, typical IATs were in the range of 29 to 45C on the K04/RS4 cars.
Clive

S2 ABY coupe, S4 B5 saloon, S4 B6 avant
RS4 B7 phantom black saloon, mint, fully loaded, low mileage - FOR SALE!- http://www.rs246.com/index.php?name=PNp ... ic&t=88981
S8 D2 facelift, RS6 C5 saloon, both gone but not forgotten

buzzard
4th Gear
Posts: 586
Joined: Fri Mar 11, 2005 11:50 am

Post by buzzard » Sun Nov 25, 2007 1:33 am

sorry for the interlude guys but i’m off my feet at the mo.
and yes...you’ve guessed it.
she is back on form.(always the same when your trying to draw a conclusion or a diagnosis of any kind)
temp logs were an average of 30 down to 26 on wot and can only think that heat sink caused the 45C temp.... but interestingly coming down hill for a while on overrun you would expect the temps to fall (reduced forced induction temps and all) but temp still stayed at 28-30)
boost figures for aquired and actual have also returned to within a smidge of each other so
seems that my boost prob has also vanished..and as before the air flow is 215g/s(normal for stock)

i hate speradic faults....

(have to let it develop)
i do run a cheese style air filter box though(full of holes) and i think that this is definately more suseptable to heat sinking than a standard airbox...if the turbo fairy comes i’m going to improve the intake for this reason..
S4 B5 long gone
S4 B8 Stage 2

Blue_Thunder
Top Gear
Posts: 1963
Joined: Wed Nov 22, 2006 10:54 pm
Location: UK - Liverpool

Post by Blue_Thunder » Tue Jan 08, 2008 5:08 pm

buzzard wrote:interestingly coming down hill for a while on overrun you would expect the temps to fall (reduced forced induction temps and all) but temp still stayed at 28-30)
Once the inlet manifold gets warm, would this affect the measured IAT?

The last time I ran FATS in my K04'd S4, I think my IAT's were around the high 40's.

Post Reply

Return to “DTC / VCDS”

Who is online

Users browsing this forum: Google Adsense [Bot] and 34 guests