Jump to content
CaddyInfo Cadillac Forum

2002 deville overheats when a/c is turned


gone12

Recommended Posts

2002 deville oveheats when a/c is turned on .Does not overheat when no a/c is used. Fans run when a/c is turned on pass fan runs have speed drive fan runs full is this normal for fan speed.

Antifreeze is full

radiator flows was flushed

thermastat new

water pump new

temp sensor works when fans go on

high speed relay was changed

What can be the cause???

Edited by gone12
Link to comment
Share on other sites


Also, you can run the OBD codes on a 2002 Deville. Run the codes and post them here, and the codes will probably tell us most or all of what needs repair.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

Link to comment
Share on other sites

The only codes that come up which I think have nothing to do with overheating is

IPM Bo429

RFA Co760

I dont know should both fans run at same speed ?

Driver side runs 2 time faster then pass side.

Link to comment
Share on other sites

B0429 Temperature Control #3 Rear Circuit Range/Performance
C0760 Tire Pressure Monitor (TPM) system sensor not transmitting

There are two things that you haven't listed that may cause overheating but won't throw a code: a radiator cap that doesn't seal (could be the wrong type!) or a leak in a hose clamp or elsewhere in the coolant plumbing, and stopped up by-pass hose. Other general things to check are obstructed radiator (leaves, etc), clogged radiator, etc. I don't have anything specific on the 4.9 so I'll defer to those who do have experience and manuals with that engine.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

Link to comment
Share on other sites

The Northstar came out for the ETC/ESC and STS, along with continuing in the Allante, in 1993. The 1992 had the new E/K platform, and the STS was Road & Track's Car of the Year, but another year later came the Northstar except for a very early introduction of the 1993 Allante with a Northstar in the Spring of 1992.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

Link to comment
Share on other sites

Yeah, his signature block shows a 1992 ETC, apparently with a 4.9, but he's asking about a 2002 Deville.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

Link to comment
Share on other sites

Check your tensioner pulley to the waterpump to make sure it is not stuck and not giving you the proper tension on the waterpump belt. Pull the hose that goes into the top of your surge tank (bypass hose) coolant should be peeing out of this when the engine is running.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...