E46 BMW Social Directory E46 FAQ 3-Series Discussion Forums BMW Photo Gallery BMW 3-Series Technical Information E46 Fanatics - The Ultimate BMW Resource BMW Vendors General E46 Forum The Tire Rack's Tire Wheel Forum Forced Induction Forum The Off-Topic The E46 BMW Showroom For Sale, For Trade or Wanting to Buy

Welcome to the E46Fanatics forums. E46Fanatics is the premiere website for BMW 3 series owners around the world with interactive forums, a geographical enthusiast directory, photo galleries, and technical information for BMW enthusiasts.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Go Back   E46Fanatics > Tuning & Tech > Driveline, Engine & DME Tuning

Driveline, Engine & DME Tuning
Talk about driveline improvements, NA tuning and DME tuning your E46 BMW here. This includes diffs, intakes, exhausts, chips, software and OBD tuning.

Thread Tools Search this Thread Rate Thread Display Modes
Old 06-03-2010, 09:04 AM   #1
Registered User
Join Date: Jun 2008
Location: Toronto
Posts: 168
My Ride: 330ci
heat soak? car feels weaker when hot

Hey guys,

Ever since I got my headers, cams and AA tune installed, when the car heats up, and I mean in 25+ degree celcius weather (85-90farenheit? lol), I feel a significant loss in low end power.

The headers are ceramic coated, but have peeled a bit so some parts are exposed. I'm also running a Dinan CAI. Anyone have an idea of what this could be? Is it heat soak? The engine bay does get pretty hot, but I'm not sure if its hotter than before the mods. Is there a way the tune can be the culprit (somehow?)

Any suggestions as to how I can keep temps down are appreciated. (air scoops maybe?)

Michel is offline   Reply With Quote
Ads by Google

Guests, get your FREE E46Fanatics.com membership to remove this ad.
Old 06-06-2010, 02:38 AM   #2
Registered User
Join Date: Dec 2008
Location: Anacortes Wa
Posts: 62
My Ride: 2005 330i ZHP -Imola
It is probably caused by heat soak of your inlet air temp sensor. If the inlet air temp sensor is heated while sitting still for a period of time, it will indicate to your ecu that the air going into your engine is much hotter than it really is. When the ecu gets this info, it will retard the timing in order to prevent detonation. This is a bigger problem for cars like the e39 M5.....but it happens to all FI cars. Try insulating the MAF sensor, where the IAT sensor is, and see if the problem goes away.
davematuska is offline   Reply With Quote
Old 06-08-2010, 09:24 AM   #3
Registered User
Join Date: Jun 2008
Location: Toronto
Posts: 168
My Ride: 330ci
Thanks for the advice. Any suggestions as to how to insulate the MAF?
Michel is offline   Reply With Quote
Old 06-08-2010, 09:30 PM   #4
Registered User
Join Date: May 2004
Location: Bethlehem, PA
Posts: 918
My Ride: 2004 330i
One other thing to consider is the oil temp. Years ago I never ran an oil cooler and when we'd go to tracks like Homestead or Phoenix, the car would start to lose power after the first 30 minutes. When we'd come in for a pit stop, the car would start pushing water out of it within 30 seconds of sitting in the pits. The first thing I did was remove the whole electric fan and shroud. That helped but the problem was still there. Once I installed an oil cooler, the problem went away. now the oil runs around 230 F instead of 290 F. I did notice that on the dyno, the power did drop off once the oil temp went above 240 F.

As for the intake temp sensor. If you have a MS 43.0 ECU, then the sensor is in the intake manifold. If you have a MS 45.1, then it's in the MAF.

I do suggest buying this Thermo Tec Aluminized Adhesive Heat barrier for the shielding for the CAI. Then buy Thermo Tec Aluminized Wrap (about 1.5" wide) and wrapping the complete intake boot all the way to the throttle body. It works and lowers the intake air temps. Only takes about an hour and $100 (Jegs carries the stuff). I would put a few long zip ties around the boot once you are done. This will keep the wrap in place over the long haul.

One other thing. Get the Stewert High volume water pump and use the stock pulley. The stock pulley is small and will allow the water pump to deliver enough volume at low rpm's to keep the head cool.

Also, put in a new radiator. While the radiator is out, clean out the condenser with a water hose. You'd be amazed the amount of garbage that gets stuck between the condenser and the radiator. If the air flow is cut off, that just means a less efficient cooling system.
mrshelley is offline   Reply With Quote
Old 06-10-2010, 08:32 AM   #5
Registered User
Join Date: Jun 2008
Location: Toronto
Posts: 168
My Ride: 330ci
^thanks, that's great information. I'll look into these options.
Michel is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Censor is OFF

All times are GMT -5. The time now is 12:38 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
(c) 1999 - 2016 performanceIX Inc - privacy policy - terms of use