Temp gauge goes HOT- suggestions?

Why do I have to unlock my doors through my trunk?
User avatar
vvurdsmyth
E30 Guy
Posts: 58
Joined: Fri Jul 13, 2012 4:40 pm
AntiSpam: No
Location: Bronx, NY

Temp gauge goes HOT- suggestions?

Postby vvurdsmyth » Sat Sep 01, 2012 2:04 pm

Starting it ('86 E30) the first time after doing a clutch job, the temp gauge starts out cold then as it is warming up the temp needle buries itself on the HOT side... Before I tear into it, any suggestions as to the fix..?
User avatar
Yoshi
Site Admin
Posts: 9093
Joined: Thu Feb 26, 2009 7:47 pm
AntiSpam: No
Location: North VA
Contact:

Re: Temp gauge goes HOT- suggestions?

Postby Yoshi » Sun Sep 02, 2012 1:30 am

Just after a clutch job? Something isn't right. Maybe your clutch fan is shot?
Image
Status: HG repair. 488wtq though!
User avatar
vvurdsmyth
E30 Guy
Posts: 58
Joined: Fri Jul 13, 2012 4:40 pm
AntiSpam: No
Location: Bronx, NY

Re: Temp gauge goes HOT- suggestions?

Postby vvurdsmyth » Sun Sep 02, 2012 3:06 am

Yoshi, thank you for the suggestion, but if it were the fan or thermostat, the gauge would creep to hot, but it snaps to hot a minute or so after starting; my first guess would be the temp sensor on the radiator, but are there any other engine temp sensors..? of course check the wiring first...
User avatar
Nsquared97
I <3 E30's
Posts: 2889
Joined: Mon Jul 25, 2011 7:08 pm
AntiSpam: No
Location: Grand Rapids, MI

Re: Temp gauge goes HOT- suggestions?

Postby Nsquared97 » Sun Sep 02, 2012 4:02 am

There are 2 temp sensors, the one on the radiator and one on the thermostat housing. Can't remember which one sends info to the ECU and which one is hooked to the gauge in the cluster though.
Image
User avatar
vvurdsmyth
E30 Guy
Posts: 58
Joined: Fri Jul 13, 2012 4:40 pm
AntiSpam: No
Location: Bronx, NY

Re: Temp gauge goes HOT- suggestions?

Postby vvurdsmyth » Sun Sep 02, 2012 11:31 am

Thank you Nsquared97 - just the kind of lead I need... figured there would be one other.. will check that out (~:
User avatar
Yoshi
Site Admin
Posts: 9093
Joined: Thu Feb 26, 2009 7:47 pm
AntiSpam: No
Location: North VA
Contact:

Re: Temp gauge goes HOT- suggestions?

Postby Yoshi » Sun Sep 02, 2012 1:47 pm

Oooooh I gotcha. Yea can't think of much other than what was already stated. There could be a break in the wiring.

The thermostat to the gauge cluster is one of the two sensors on the thermostat housing (not the one on the radiator). I'm assuming M20 here. Try unplugging one at a time and see if it makes a change. If it makes no change, I bet you have a break in the wiring. If it changes, I'd blame the sensor itself. Still, odd that a clutch job would do this.
Image
Status: HG repair. 488wtq though!
User avatar
vvurdsmyth
E30 Guy
Posts: 58
Joined: Fri Jul 13, 2012 4:40 pm
AntiSpam: No
Location: Bronx, NY

Re: Temp gauge goes HOT- suggestions?

Postby vvurdsmyth » Sun Sep 02, 2012 2:00 pm

Yoshi, I don't think the clutch job did it... I musta snagged a wire somewhere... sing with me- some-where over the guibo (~: and it must be the sensor sending to the CPU, bcuz when restarting hot, there is a bit of 'bucking' for a minute... before... likely the CPU figures it out and compensates, then it runs like nothing is wrong.
User avatar
Yoshi
Site Admin
Posts: 9093
Joined: Thu Feb 26, 2009 7:47 pm
AntiSpam: No
Location: North VA
Contact:

Re: Temp gauge goes HOT- suggestions?

Postby Yoshi » Sun Sep 02, 2012 2:23 pm

There's two sensors on the thermostat housing. One is for the ECU and the other is for the gauge. They don't cross talk. Unless you killed both wires at once, it shouldn't have made a difference in the ECU.
Image
Status: HG repair. 488wtq though!
User avatar
vvurdsmyth
E30 Guy
Posts: 58
Joined: Fri Jul 13, 2012 4:40 pm
AntiSpam: No
Location: Bronx, NY

Re: Temp gauge goes HOT- suggestions?

Postby vvurdsmyth » Mon Sep 03, 2012 4:30 am

OMG! Yoshi, there are five sensors on the thermostat housing; two more visible on the driver's side and three partly hidden by a hose on the passenger side of the thermostat.. it is going to be a busy Monday.
User avatar
Nsquared97
I <3 E30's
Posts: 2889
Joined: Mon Jul 25, 2011 7:08 pm
AntiSpam: No
Location: Grand Rapids, MI

Re: Temp gauge goes HOT- suggestions?

Postby Nsquared97 » Mon Sep 03, 2012 4:45 am

Whaaaat? Alright, which engine do you have? Just relized that being an '86 you won't have an M20B25 ('i') like I do. Do you have the 2.7L eta (M20B27) or the M10 (4 cyl)?
Image
User avatar
AustinR
I <3 E30's
Posts: 1184
Joined: Wed Dec 07, 2011 2:53 am
AntiSpam: No
Location: Grand Rapids, Michigan
Contact:

Re: Temp gauge goes HOT- suggestions?

Postby AustinR » Mon Sep 03, 2012 4:48 am

Jesus, there's 4 in this photo. I thought there were only 2. Why is this necessary? haha.
Image

Edit: Just saw Nick's post. What engine do you have dude?
Image
M20_fever wrote:Austin is right.
Nsquared97 wrote:You were right again Austin!
87e30 wrote:Austin is right yet again!

Build Thread
User avatar
vvurdsmyth
E30 Guy
Posts: 58
Joined: Fri Jul 13, 2012 4:40 pm
AntiSpam: No
Location: Bronx, NY

Re: Temp gauge goes HOT- suggestions?

Postby vvurdsmyth » Mon Sep 03, 2012 6:02 am

AustinR, I have the M20, 2.7 ltr (long stroke)... going to check out all the leads to those sensors Monday..
User avatar
AustinR
I <3 E30's
Posts: 1184
Joined: Wed Dec 07, 2011 2:53 am
AntiSpam: No
Location: Grand Rapids, Michigan
Contact:

Re: Temp gauge goes HOT- suggestions?

Postby AustinR » Mon Sep 03, 2012 10:59 am

Diagram looks like it's the same one I already posted. I'm gonna have to look at my car today. I could have swore there were only 2 sensors. Oh well!
Image
M20_fever wrote:Austin is right.
Nsquared97 wrote:You were right again Austin!
87e30 wrote:Austin is right yet again!

Build Thread
User avatar
Yoshi
Site Admin
Posts: 9093
Joined: Thu Feb 26, 2009 7:47 pm
AntiSpam: No
Location: North VA
Contact:

Re: Temp gauge goes HOT- suggestions?

Postby Yoshi » Mon Sep 03, 2012 11:46 am

<_< All the ones I've had were 2. wtf are the other ones for?!
Image
Status: HG repair. 488wtq though!
User avatar
vvurdsmyth
E30 Guy
Posts: 58
Joined: Fri Jul 13, 2012 4:40 pm
AntiSpam: No
Location: Bronx, NY

Re: Temp gauge goes HOT- suggestions?

Postby vvurdsmyth » Mon Sep 03, 2012 7:11 pm

AustinR U R right only four... the other is actually the fuel injector, very close, it looked like part of the cluster; I cleaned every connection and even took out the instrument panel to see if there was anything there... nada, put it back together and the problem is still there /~8

Return to “Electrical”

Who is online

Users browsing this forum: No registered users and 2 guests