My lower radiator hose is always cold, even after t-stat replacement - BMW M5 Forum and M6 Forums

Go Back   BMW M5 Forum and M6 Forums > BMW M5, M5 Touring, M6 and Z8 Forums > E39 M5 and E52 Z8 Discussion

E39 M5 and E52 Z8 Discussion 1998-2003 Advertiser's Forum


Reply
 
LinkBack Thread Tools Rate Thread Display Modes
Old 3rd February 2012, 02:57   #1
Dob3rman
Member
 
Dob3rman's Avatar
 
Join Date: Jun 2011
Location: New York

Garage: 2001 BMW e39 540i Dinan

Sales Feedback: (0)

Thanks: 3
Thanked 4 Times in 1 Post
My lower radiator hose is always cold, even after t-stat replacement

Hi guys!

Please help with my thermostat problem. My lower radiator hose had always stayed cold and I thought my t-stat stuck closed so I ordered a new t-stat from pelicanparts and had it replaced. Now, my lower hose still stays cold... The engine temp gauge is at the middle, so I guess nothing is overheating. My upper radiator hose is always hot (as I should be). Do you guys think it's normal or not? My old t-stat was dead for sure (I boiled it but it never opened).
(e39 540i M62/TU)

Thank you for help!

Last edited by Dob3rman; 3rd February 2012 at 02:59.
Dob3rman is offline   Reply With Quote
Old 3rd February 2012, 06:17   #2
x-fire
Member, Sport: On DSC: On (>100 posts)
 
x-fire's Avatar
 
Join Date: Aug 2011
Location: Perth, Australia
Age: 48

Garage: 2001 M5 E39 in Silverstone Metallic

Sales Feedback: (0)

Thanks: 41
Thanked 12 Times in 12 Posts
Quote:
Originally Posted by Dob3rman View Post
Hi guys!

My old t-stat was dead for sure (I boiled it but it never opened).
(e39 540i M62/TU)
Have you boiled the new T-Stat to check it opens?
__________________
Objects in the Mirror are Losing


26 Aug 2014 - 172852kms - New Bank 1 VANOS Unit and replaced Bank 2 Intake Camshaft Sensor
18 Aug 2014 - 3 years of ownership
16 May 2014 - 169882 kms - New Front shock absorbers, Front Thrust Arm bushes, Rear upper control arm bushes, Suspension level sensor, Rocker Cover Gaskets, Engine Vent Pipes & Breather Hoses, and RHF Door Seal. Reseated LHF Spring Pad and Both Rear Brake Discs replaced under Warranty. Full Wheel Alignment
08 Apr 2014 - 168104 kms - 2 New Front Tyres (Bridgestone Potenza RE50A RFT)
01 Apr 2014 - 167779 kms - Inspection 2 Service
19 Dec 2013 - 163365 kms - Replacement Front Tow Eye Cover
03 Oct 2013 - 160663 kms - New Front Discs & New Rear Discs/Pads. New Wiper Blades
10 Sep 2013 - 160000 kms Milestone (less than 1000 kms to the 100,000 mile mark)
01 Jul 2013 - Puncture - 2 New Rear Tyres
(Bridgestone Potenza RE50A RFT)
25 Mar 2013 - 150000 kms Milestone

04 Mar 2013 - 148435 kms - Repaired broken cup-holder
28 Feb 2013 - 148355 kms - New Stock Clutch and Flywheel, jetwashed fuel tank, new fuel pump and filter, and replaced hazard button in console
05 Feb 2013 - 147659 kms - New Tailshaft Artic Disc (Guibo)
19 Jan 2013 - 147212 kms - New Stock Airfilters and Cabin Filters
22 Dec 2012 - Obtained Peake Code Reader
23 Apr 2012 - 146003 kms - Replaced Rear Wheel Bearings
06 Feb 2012 - 141515 kms - New Front Brake Pads and Sensors
28 Dec 2011 - 138938 kms - Oil Service and Safety Check
18 Aug 2011 - 125412 kms - Purchased Car (Replaced 2 rear tyres shortly after purchase)
x-fire is offline   Reply With Quote
Old 3rd February 2012, 21:57   #3
Sailor24
M5 Expert (>4000)
 
Sailor24's Avatar
 
Join Date: Oct 2010
Location: Corner Brook, NFLD, Can
Age: 52

Garage: 2000 Anthracite,

Sales Feedback: (0)

Thanks: 789
Thanked 1,173 Times in 933 Posts
540 has something different about it, can't remember what it is. If Matt does not respond you will not likely get much other expertise. Your car is not the same as an M5 for many reasons and the cooling system is one. Sorry wish I could help.
Sailor24 is offline   Reply With Quote
Old 4th February 2012, 02:25   #4
Dob3rman
Member
 
Dob3rman's Avatar
 
Join Date: Jun 2011
Location: New York

Garage: 2001 BMW e39 540i Dinan

Sales Feedback: (0)

Thanks: 3
Thanked 4 Times in 1 Post
Quote:
Originally Posted by x-fire View Post
Have you boiled the new T-Stat to check it opens?
Nope I definitely should have done it.
Today I ran OBC test #7 at idling and the engine temp was 108-109C maximum but my main fan never sped up.
Our t-stats are electronically controlled, so can it be that they open a little to pass a little amount of coolant just to keep engine temp stable? If so, the lower hose wouldn't really have time to get warm... Otherwise I don't know what to think.

Last edited by Dob3rman; 4th February 2012 at 02:28.
Dob3rman is offline   Reply With Quote
Old 4th February 2012, 02:38   #5
x-fire
Member, Sport: On DSC: On (>100 posts)
 
x-fire's Avatar
 
Join Date: Aug 2011
Location: Perth, Australia
Age: 48

Garage: 2001 M5 E39 in Silverstone Metallic

Sales Feedback: (0)

Thanks: 41
Thanked 12 Times in 12 Posts
It sounds plausible. If you are not registering hot on the dashboard, then it might be normal operation.

Have you asked your local dealer/mechanic?
x-fire is offline   Reply With Quote
Old 5th February 2012, 07:10   #6
Dob3rman
Member
 
Dob3rman's Avatar
 
Join Date: Jun 2011
Location: New York

Garage: 2001 BMW e39 540i Dinan

Sales Feedback: (0)

Thanks: 3
Thanked 4 Times in 1 Post
Quote:
Originally Posted by x-fire View Post
It sounds plausible. If you are not registering hot on the dashboard, then it might be normal operation.

Have you asked your local dealer/mechanic?
Yes, I have. He said as long as my aux fan doesn't engage and the temp is not getting over 110 degrees Celsius, everything is fine.
My new t-stat actually opened once but to make it open I had to run my engine at 2500rpm straight for 10 min and only after that my lower rad hose got hot.
Dob3rman is offline   Reply With Quote
Old 5th February 2012, 07:17   #7
68FB
M5 Guru (>2000 posts)
 
Join Date: Mar 2011
Location: Ontario, Canada

Garage: 2001 M5 Ti Silver

Sales Feedback: (0)

Thanks: 308
Thanked 989 Times in 696 Posts
Check out the info on this site.

http://www.meeknet.co.uk/E31/M62B44_Engine.pdf

It looks like for the M62, the wax pellet on its own doesn't open the t/s until 103 deg C, so the boiling water test is no good for testing it. Looks like there was anything wrong with your old t/s.

The above also shows the normal part-load coolant temp being 109 deg C, exactly what you are seeing. It is not unusual for a t/s not to open at all in cold climes like NY under light driving conditions, especially with an aluminum engine.

What puzzles me is that you are feeling the upper rad hose hot. It shouldn't be if the t/s is not opening. It should also be cold or maybe warm, not hot . How hot is it?
68FB is offline   Reply With Quote
The Following User Says Thank You to 68FB For This Useful Post:
Sailor24 (5th February 2012)
Reply

Bookmarks



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
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 On
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Changed stat.. still running cold? pyro225 E39 M5 and E52 Z8 Discussion 6 6th November 2010 23:40
WTF?! Coolant return hose blew off radiator?! xplodee E39 M5 and E52 Z8 Discussion 5 2nd May 2010 03:57
Feedback on replacing broken radiator hose? farrell E34 M5 Discussion 10 21st June 2007 23:50
high pressure on the radiator hose mohamad baajour E39 M5 and E52 Z8 Discussion 22 27th April 2007 23:14
Fan Blade Cut Radiator Hose!!!! stever E39 M5 and E52 Z8 Discussion 8 13th June 2002 03:12

Loading...

All times are GMT +2. The time now is 13:26.



Everything Copyright 2000-2008. Do not use ANYTHING from this site without written permission. All images, graphics, sound files, video files and text appearing on this web site are the exclusive property of m5board.com and are protected under international copyright laws. All images, graphics, sound files, video files and text on this site are for on-screen and on-site viewing and listening only. No part of this web site may be reproduced, copied, saved, stored, manipulated, or used in any form for personal or commercial purposes without the prior written permission of m5board.com. Use of any image or graphic as the basis for another photographic concept or illustration is a violation of the copyright. Any copyright infringement will be prosecuted to the full extent of federal and international copyright laws. M5board.com is an enthusiast board and we don't condone any dangerous activity. Our airfield events are completely safe based on years of experience, we conduct them during clear visibility with mature participants that have several years of experience with high-performance automobiles, large unobstructed run-off zones on sealed off private former military airbases and we clearly mark the braking zones. If inexperienced with high speed driving we do not recommend organizing your own event but attending a high-performance driving school. The use of the term "BMW" on this site is for reference only, and does not imply any connection between m5board.com and BMW AG or BMW North America.