 Can a CHT sensor go intermittently wonky? |
|
|
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
|
| Robson51 |
 Oct 14 2021, 01:32 PM
Post
#1
|
|
Member  Group: Members Posts: 88 Joined: 18-November 19 From: seattle Member No.: 23,654 Region Association: Pacific Northwest  |
I was watching Dr 914s walkaround of a D Jet 2.0 motor, and he makes a comment that the Cylinder Head Temp sensor causes a lot of problems, and can get wonky.
Is it possible for one to test out fine (2750 ohms) and then act bad? I have a strange syndrome where the car was running fine, but developed a rich syndrome very suddenly. Haven't had a chance to check it again, but it was almost new. TIA Rob |
   |
 
|
  |
Replies(1 - 7)
| Superhawk996 |
Oct 14 2021, 02:08 PM
Post
#2
|
|
914 Guru Group: Members Posts: 5,906 Joined: 25-August 18 From: Woods of N. Idaho Member No.: 22,428 Region Association: Galt's Gulch 
|
Yes. They don't have good stress relief. Intermittent shorting between lead and ground is possible. Likewise because of lack of stress relief, it's possible to have the copper conductor break, and result in an intermittent open which will lead to rich condition.
|
|
|
|
| DRPHIL914 |
Oct 14 2021, 02:59 PM
Post
#3
|
|
Dr. Phil Group: Members Posts: 5,768 Joined: 9-December 09 From: Bluffton, SC Member No.: 11,106 Region Association: South East States
|
QUOTE(Superhawk996 @ Oct 14 2021, 04:08 PM)  Yes. They don't have good stress relief. Intermittent shorting between lead and ground is possible. Likewise because of lack of stress relief, it's possible to have the copper conductor break, and result in an intermittent open which will lead to rich condition. (IMG:style_emoticons/default/agree.gif) but in 12 years of having a d-jet car i have see the suddenly or even intermittently rich issue tied to a MPS issue more than a bad CHT recheck the MPS, Phil |
|
|
|
| Robson51 |
Oct 14 2021, 03:29 PM
Post
#4
|
|
Member Group: Members Posts: 88 Joined: 18-November 19 From: seattle Member No.: 23,654 Region Association: Pacific Northwest |
QUOTE(DRPHIL914 @ Oct 14 2021, 12:59 PM) QUOTE(Superhawk996 @ Oct 14 2021, 04:08 PM) Yes. They don't have good stress relief. Intermittent shorting between lead and ground is possible. Likewise because of lack of stress relief, it's possible to have the copper conductor break, and result in an intermittent open which will lead to rich condition. (IMG:style_emoticons/default/agree.gif) but in 12 years of having a d-jet car i have see the suddenly or even intermittently rich issue tied to a MPS issue more than a bad CHT recheck the MPS, Phil MPS freshly rebuilt professionally |
|
|
|
| tvdinnerbythepool |
Oct 14 2021, 03:40 PM
Post
#5
|
|
Member Group: Members Posts: 310 Joined: 24-July 18 From: Olympia, WA Member No.: 22,336 Region Association: Pacific Northwest
|
@Robson51 Absolutely! I was just a victim to this heinous crime. $20 part can ruin an otherwise wonderful car (IMG:style_emoticons/default/lol-2.gif) (IMG:style_emoticons/default/headbang.gif) (IMG:style_emoticons/default/driving.gif) I was randomly going VERY rich and huge bogging issues. Tested fine then tested WAY off spec the next time. Easy to test but test a few times.
|
|
|
|
| 76-914 |
Oct 14 2021, 03:51 PM
Post
#6
|
|
Repeat Offender & Resident Subaru Antagonist Group: Members Posts: 13,512 Joined: 23-January 09 From: Temecula, CA Member No.: 9,964 Region Association: Southern California
|
Might check the CHT wire to the ECU also. Do you have a known good MAP to cross check? Or carry an ohm meter to check the sensor output next time it gives up the Ghost. These type headaches are why I converted to water cooled. (IMG:style_emoticons/default/headbang.gif) GL
|
|
|
|
| Olympic 914 |
Oct 14 2021, 04:26 PM
Post
#7
|
|
Group: Members Posts: 1,677 Joined: 7-July 11 From: Pittsburgh PA Member No.: 13,287 Region Association: North East States
|
I had one go out intermittently. usually if it goes "open" the engine will quit. The ECU needs to see some resistance.
Mine went rich because I was running a 1 k parallel resistor, so it was reading as if it was still cold. But better than sticking me on the highway, made it home and put a new one in. |
|
|
|
| Superhawk996 |
Oct 14 2021, 04:32 PM
Post
#8
|
|
914 Guru Group: Members Posts: 5,906 Joined: 25-August 18 From: Woods of N. Idaho Member No.: 22,428 Region Association: Galt's Gulch
|
QUOTE(76-914 @ Oct 14 2021, 05:51 PM) These type headaches are why I converted to water cooled. (IMG:style_emoticons/default/headbang.gif) GL I gave up water pumpers due to coolant leakage. (IMG:style_emoticons/default/splat.gif) (IMG:style_emoticons/default/aktion035.gif) |
|
|
|
|
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 12th June 2024 - 03:18 AM |
Invision Power Board
v9.1.4 © 2024 IPS, Inc.