Cooling Discuss all of the aspects of cooling that you can think of! Radiators, transmissions, electric fans, etc.

temp climbing right under red

Thread Tools
 
Search this Thread
 
Old 04-21-2010, 11:10 AM
  #1  
Junior Member
Thread Starter
 
WestCoastCamaro's Avatar
 
Join Date: May 2009
Location: Los Angeles, CA
Posts: 68
Likes: 0
Received 0 Likes on 0 Posts
Car: 1984 Z28
temp climbing right under red

Hey guys, i got an 86 iroc-z28 with 65K original miles. When i drive in the city with stop and go traffic the temp gauge climbs right up to underneath red and sometimes in the red. On the freeway doin 65 it doesnt do that. The previous owner said he changed the thermastat so I thought maybe since its an aftermarket one its giving problems so I went to a chevy dealer and bought a new original thermostat. Should this fix the problem and how hard is it to replace the thermostat on an iroc with that intake covering the block?
Old 04-21-2010, 12:56 PM
  #2  
Junior Member
 
Checkerbelly's Avatar
 
Join Date: May 2009
Posts: 50
Likes: 0
Received 0 Likes on 0 Posts
Re: temp climbing right under red

I would investigate the fan before tearing anything apart. Seems like if your temp is normal on the freeway, the coolant must be flowing through the radiator. If it's hot when you're standing still, the fan may not be pulling air through the radiator like it should.

Based on my own personal experience, I would almost change the temperature sender out before the thermostat. I found out mine was bad. It was giving me all kinds of weird temperature readings.
Old 04-21-2010, 01:46 PM
  #3  
Moderator

iTrader: (5)
 
JamesC's Avatar
 
Join Date: Aug 1999
Location: Lawrence, KS
Posts: 19,282
Received 93 Likes on 68 Posts
Car: Met. Silver 85 IROC/Sold
Engine: 350 HO Deluxe (350ci/330hp)
Transmission: T-5 (Non-WC)
Axle/Gears: Limited Slip 3.23's
Re: temp climbing right under red

Do you have a mechanical or electric fan? I assume it's the latter. Is it functioning as designed? Do you have the air dam in place?

JamesC
Old 04-22-2010, 12:44 AM
  #4  
Junior Member
Thread Starter
 
WestCoastCamaro's Avatar
 
Join Date: May 2009
Location: Los Angeles, CA
Posts: 68
Likes: 0
Received 0 Likes on 0 Posts
Car: 1984 Z28
Re: temp climbing right under red

ok, just noticed that the fan doesnt come in. At all. Temp goes down when im driving and goes up in stop and go traffic or stand still
Old 04-22-2010, 12:48 AM
  #5  
Member
 
Gregzz4's Avatar
 
Join Date: Jan 2010
Location: Burnaby, B.C.
Posts: 295
Likes: 0
Received 0 Likes on 0 Posts
Car: '78 GMC Sierra Heavy 1/2
Engine: GMPP ZZ4 Q-Jet
Transmission: 700R4 Stage 2 w/Race Internals
Axle/Gears: 10 Bolt 3:42 Eaton
Re: temp climbing right under red

Originally Posted by JamesC
Do you have a mechanical or electric fan? I assume it's the latter. Is it functioning as designed? Do you have the air dam in place?

JamesC
James, don't forget that with the airdam you gain airflow with higher speeds and he said he can do 65 MPH with no problems
You made some good points that I will address
Old 04-22-2010, 12:53 AM
  #6  
Member
 
Gregzz4's Avatar
 
Join Date: Jan 2010
Location: Burnaby, B.C.
Posts: 295
Likes: 0
Received 0 Likes on 0 Posts
Car: '78 GMC Sierra Heavy 1/2
Engine: GMPP ZZ4 Q-Jet
Transmission: 700R4 Stage 2 w/Race Internals
Axle/Gears: 10 Bolt 3:42 Eaton
Re: temp climbing right under red

Originally Posted by WestCoastCamaro
ok, just noticed that the fan doesnt come in. At all. Temp goes down when im driving and goes up in stop and go traffic or stand still

Well, you just found your problem

Lack of Airflow causes in City overheating
Lack of Coolant flow causes Highway overheating

Tell your friends
Old 04-22-2010, 12:57 AM
  #7  
Member
 
Gregzz4's Avatar
 
Join Date: Jan 2010
Location: Burnaby, B.C.
Posts: 295
Likes: 0
Received 0 Likes on 0 Posts
Car: '78 GMC Sierra Heavy 1/2
Engine: GMPP ZZ4 Q-Jet
Transmission: 700R4 Stage 2 w/Race Internals
Axle/Gears: 10 Bolt 3:42 Eaton
Re: temp climbing right under red

JamesC,
Sorry i didn't get a chance to explain myself when I wanted modify your ideas

I'm just trying to help all the members
Old 04-22-2010, 01:10 AM
  #8  
Member

iTrader: (1)
 
matts86cam's Avatar
 
Join Date: Jun 2009
Location: WI
Posts: 208
Likes: 0
Received 2 Likes on 1 Post
Car: 1986 chevy camaro z28 coupe
Engine: crate 355
Transmission: 700r
Axle/Gears: 3.42
Re: temp climbing right under red

Obviously the fan but just to throw something in there, I removed my thermostat and hooked up a new mechanical temp sender to help figure out the problem I had overheating.

With the thermostat out, if it still overheats then thats not your problem and a mechanical temp sender was a lot easier to install than messing with the one in the instrument cluster.
Old 04-22-2010, 01:18 AM
  #9  
Member
 
Gregzz4's Avatar
 
Join Date: Jan 2010
Location: Burnaby, B.C.
Posts: 295
Likes: 0
Received 0 Likes on 0 Posts
Car: '78 GMC Sierra Heavy 1/2
Engine: GMPP ZZ4 Q-Jet
Transmission: 700R4 Stage 2 w/Race Internals
Axle/Gears: 10 Bolt 3:42 Eaton
Re: temp climbing right under red

Originally Posted by matts86cam
Obviously the fan but just to throw something in there, I removed my thermostat and hooked up a new mechanical temp sender to help figure out the problem I had overheating.

With the thermostat out, if it still overheats then thats not your problem and a mechanical temp sender was a lot easier to install than messing with the one in the instrument cluster.

Yes Matts, you are right
We used to pull the T-Stat back in the day just to see how the system runs
Problem is that with newer systems, some need the stat installed so we stopped doing that test

But you are right. He could pull the stat to see how it runs.
When he has the stat pulled, what temps does he run @ ?
And now it won't go into the Loop, so fuel econ sucks
Best to put a new stock stat in

Last edited by Gregzz4; 04-24-2010 at 08:51 PM.
Old 04-22-2010, 09:29 AM
  #10  
Supreme Member

iTrader: (10)
 
86NiteRider's Avatar
 
Join Date: Dec 2000
Location: Somewhere around the South Side of Chicago just crusin' in one of the Niteriders
Posts: 3,242
Likes: 0
Received 3 Likes on 3 Posts
Car: 92RS 25th Anniv./88 IROC Z28 Vert
Engine: 305 TBI w/Tpi Air / 305 TPI
Transmission: 700r4/700r4
Axle/Gears: Posi
Re: temp climbing right under red

Originally Posted by Checkerbelly
I would investigate the fan before tearing anything apart. Seems like if your temp is normal on the freeway, the coolant must be flowing through the radiator. If it's hot when you're standing still, the fan may not be pulling air through the radiator like it should.

Based on my own personal experience, I would almost change the temperature sender out before the thermostat. I found out mine was bad. It was giving me all kinds of weird temperature readings.
Where is the temp sender located and how do you change it?

I am replacing my tstat today and possibly my guage tomorrow. Already changed the hoses and water pump. My fans are working but guage keeps reading in the red but car gives no symptoms of overheating except the guage. I have the airdam in place on my 72,000 IROC.
Old 04-22-2010, 12:35 PM
  #11  
Junior Member
 
Checkerbelly's Avatar
 
Join Date: May 2009
Posts: 50
Likes: 0
Received 0 Likes on 0 Posts
Re: temp climbing right under red

First off, I'm a newb, so take my advice with a grain of salt.

My car's sender is located on the driver's side of the engine, just behind the first cylinder, behind the spark plug. It looks like a little threaded brass plug with a metal tab coming out of it and a wire attached.

I drained most of my coolant out before I did mine, which I probalby didn't have to. Anyway, you unscrew the existing sender (if you dont drain coolant at least make sure the engine is cold and there's no pressure on the coolant). I used a crescent wrench because I didn't have a socket that would fit over the electrical connection on the sender.

If you don't drain coolant, unscrew the sender and pop the new one in and screw it in. Then reconnect the wire. My wire just snaps on and off. The sender is literally just a brass plug with a little metal rod that sticks into the coolant and an electrical connection tab on the other end.

I noticed that my existing sender had teflon tape on the threads. I was lazy and didn't put any new teflon tape on but nothing leaked.

That's it. I replaced mine with an aftermarket gauge, so it's easier to tell exactly what temperature I'm at. But it would be less work to just put in a new sender and see if the existing gauge reads it right.

I have a 195 degree thermostat right now and my old sender/gauge were reading something like 240. Put in the new sender/gauge and its reading 190 - 200.

Last edited by Checkerbelly; 04-22-2010 at 12:39 PM.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
cheesehomer
Power Adders
91
12-31-2015 08:48 AM
ULTM8Z
DIY PROM
12
10-02-2015 01:25 PM
SS-EXPRESS
Electronics
2
09-28-2015 09:14 AM
ironbmt
Tech / General Engine
0
09-27-2015 06:00 AM
Dragonsys
Engine/Drivetrain/Suspension Parts for Sale
2
09-25-2015 03:51 PM



Quick Reply: temp climbing right under red



All times are GMT -5. The time now is 01:18 PM.