3.5 Overheating/Thermostat Change - Oldsmobile Forum - Oldsmobile Enthusiasts Forums


Intrigue Talk about the Oldsmobile Intrigue within...

Reply
 
 
 
Thread Tools Search this Thread
  #1  
Old 01-22-2018, 12:12 PM
Junior Member
Thread Starter
 
Join Date: Mar 2007
Location: United States
Posts: 15
Default 3.5 Overheating/Thermostat Change

I apologize up front if what I'm entering is repetitive; but I thought I'd like to share my most recent incident with my 2000 Intrigue with the 3.5 L V6. This should be applicable to an Aurora with a 3.5 L V6 or a 4.0 L V8 as well.
The darned thing started to overheat-not exactly overheat, but having an extremely high water temperature hysteresis during operation. Temperatures would rise erratically to as high as 225 F and then drop back to the 180 F range. Fan operation was just too often taking into account the cold (40 F) relative current ambients. I suspected a thermostat issue; so I ordered an ACDelco OEM from RockAuto. This was as a result of information I had learned from other people who had used "will-fits" that fit, but didn't work. Well, the ACDelco thermostat arrived in the box and when I changed it, I noticed that although it was reportedly OEM, it "didn't look like" the one I took out. It was clearly missing a molded-on seal on the sealing portion and "looked different" in other less critical aspects. It was also identified as "made in Israel."

Cutting to the chase, I "boiled" the part before installing it. It opened as designed at approximately 180 F (using a meat thermometer to measure water temperature.) The removed thermostat could best be described as "lazy." It opened eventually, but well above the 180 F point and had to be in water at a rolling boil for a considerable period of time before finally extending. I installed the replacement thermostat following the shop manual instructions and it just did not fix my issue. Others have reported problems bleeding the trapped air in the cooling system-I merely followed the shop manual instructions with one small deviation-as written, I couldn't get the coolant to statically bleed out the bleed vent in the radiator. Covering the surge tank opening and applying a slight pressure to the overflow line with the surge tank filled to the cold-hot level readily addressed this issue and I could quickly get a reasonable flow out the bleed vent.

I then ordered an ACDelco 15-10570 thermostat/housing assembly. When it arrived, I was initially skeptical; because it came in a non-descript box and was marked "made in Brazil." However, the thermostat had the requisite molded-on seal and "looked considerably more like" the thermostat I removed. When I subsequently changed it out, I likewise found that all the casting marks on the thermostat housing matched up with the ones on the housing that was on my car. So I guess I was a little gun-shy, but once burned, twice cautious. This change-out was a success and simple. I'm now quite adept at changing a thermostat. I replaced the assembly in it's entirety, bled the system as per the shop manual using a slight pressure assist, and the car is now cooling like a champ. It warms up quickly and once warm, the water temperature hysteresis during a 40 F day is only about 5 F.

...So that was my experience and what I learned. I hope others will find this helpful.
Thanks.
Reply With Quote
  #2  
Old 04-22-2018, 08:43 AM
Junior Member
 
Join Date: Apr 2018
Posts: 1
Default Extremely helpful

I have been tearing my hair out over here, going through pretty much the same steps you described, and reaching the same basic conclusions. I wasn't sure of any of the mess until I read this- simple, to the point, solidifies and summerizes my own woes- and I'm absolutely elated that you even listen the part numbers!...BUT ...I did a search for the therm/housing you ended up using (the ACDelco 15-10570 thermostat/housing) and it is most certainly the one I need as well, however, every website I checked said "not cureently available" or showed they longer carried or it! I mean, I can't find a replacement for this thing ANYWHERE on the fraking Internet! and I have been searching /researching myself into a migraine! Am I missing something? is there a site you might be able to recommend? I feel so totally overwhelmed by this whole thermostat hunt, like NO ONE sells the right one! They all say they fit, but, they dont! Or thier missing the gasket, or thier the world shape, size, ect....it just maddening.. Sorry if this was a little melodramatic, but I never run into dead ends like this with my Olds (and I have run into PLENTY of problems and replaced tons of parts with only minor bumps and headaches), and I need my car back in shape as soon as possible, and at this point i am sick to death of the whole "changing the damn thermostat" process, especially when it ends in frustration and more research....so any info you could give me, or any direction you could steer my quest would be amazing!
Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Thermostat kyleo51 Aurora 1 02-03-2008 07:09 PM
external thermostat sticking wc878 Intrigue 1 12-21-2007 05:36 PM
Thermostat replacement 3.3 jayciera General Tech Help 2 03-05-2007 05:01 PM
No Thermostat...But running Hot!!! 00alero Alero 15 01-04-2007 09:18 PM
3.1 thermostat Rawdoncierra General Tech Help 1 04-16-2006 04:31 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Advertising
Featured Sponsors
Vendor Directory

All times are GMT -5. The time now is 07:40 AM.


© 2018 MH Sub I, LLC dba Internet Brands
We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.