Pennock's Fiero Forum
  Technical Discussion & Questions
  Why does my Fiero run so hot😡?

Post New Topic  Post A Reply
Email This Page to Someone! | Printable Version


next newest topic | next oldest topic
Why does my Fiero run so hot😡? by kevin
Started on: 06-10-2015 05:27 PM
Replies: 12 (456 views)
Last post by: rogergarrison on 06-13-2015 09:36 PM
kevin
Member
Posts: 2664
From: Elk Grove, CA USA
Registered: Jan 2000


Feedback score: N/A
Leave feedback

Rate this member

Report this Post06-10-2015 05:27 PM Click Here to See the Profile for kevinClick Here to Email kevinSend a Private Message to kevinEdit/Delete MessageReply w/QuoteDirect Link to This Post
Fellas,
I just completed getting my Fiero back on the road after seven years! 😀 My problem: (1) I bought a new thermostat
(2) I bought a new radiator
(3) I bought a new radiator cap
(4) I bought a new thermostat cap
(5) I bought a new temp switch
(6) I bought a new oxygen sensor (Bosch)
(7) I bought a '88 thermostat housing
(8h I bought a new sensor that plugs into that thermostat housing
With all that I drove maybe 1 mile and the engine gets HOT🔥 What didn't I buy? I added water, but maybe not enough? That's all I can think of ? Oh' I changed the oil and added all the anti-freeze to specs
Cordially,
kevin

[This message has been edited by kevin (edited 06-10-2015).]

IP: Logged
PFF
System Bot
Gall757
Member
Posts: 10651
From: Holland, MI
Registered: Jun 2010


Feedback score: N/A
Leave feedback





Total ratings: 88
Rate this member

Report this Post06-10-2015 05:40 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
What is hot in one mile? Feel the radiator and the coolant pipes to confirm coolant is moving. Air pockets in the cooling system are to be expected, and should work themselves out.

http://home.comcast.net/~fierocave/coolfill.htm

[This message has been edited by Gall757 (edited 06-10-2015).]

IP: Logged
phonedawgz
Member
Posts: 17011
From: Green Bay, WI USA
Registered: Dec 2009


Feedback score:    (23)
Leave feedback





Total ratings: 290
Rate this member

Report this Post06-10-2015 06:12 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
All car engines get hot after driving a mile.
IP: Logged
KMFDMFAN
Member
Posts: 157
From: Gulf Coast, MS USA
Registered: Sep 2013


Feedback score: (1)
Leave feedback

Rate this member

Report this Post06-10-2015 06:20 PM Click Here to See the Profile for KMFDMFANClick Here to Email KMFDMFANSend a Private Message to KMFDMFANEdit/Delete MessageReply w/QuoteDirect Link to This Post
Are your coolant tubes pinched or crushed? Most shops, even when Fiero's were new, didn't know how to properly lift the car. Check behind the front wheel wells and in front of the rear wheel wells.

After i fixed/repaired mine in three different spots it never gets above 215 deg with a stock thermostat and Rodneys low temp switch.

Like the exhaust system any restriction is not good.

[This message has been edited by KMFDMFAN (edited 06-10-2015).]

IP: Logged
steve308
Member
Posts: 3484
From: Stafford VA
Registered: Jan 2008


Feedback score: (2)
Leave feedback





Total ratings: 51
Rate this member

Report this Post06-10-2015 06:46 PM Click Here to See the Profile for steve308Send a Private Message to steve308Edit/Delete MessageReply w/QuoteDirect Link to This Post
Water pump was not on the list - If the car sat seven years I'd at least be worried about the impeller rusting away....... are you sure it's working?
IP: Logged
Patrick
Member
Posts: 30697
From: Vancouver, British Columbia, Canada
Registered: Apr 99


Feedback score: (1)
Leave feedback





Total ratings: 443
Rate this member

Report this Post06-10-2015 07:41 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by kevin:

I drove maybe 1 mile and the engine gets HOT 🔥


Define "hot".

The temp gauge in the dash is next to useless. Have you verified with a scanner how hot the engine is actually getting?

 
quote
Originally posted by kevin:

I added water, but maybe not enough?


I've used the following procedure with half a dozen different Fieros and never had an overheating issue...

 
quote
Originally posted by Patrick:

* Make sure rad cap is the proper one for Fiero use. The catalogs are wrong! You want a non-vented one,
* Check that the overflow tank and the small hose to the rad are both in good shape. Otherwise air gets sucked in.
* Ensure that coolant level in overflow tank is at the "Cold" level.
* Position rear end of Fiero higher than the front.
* Remove thermostat housing cap and thermostat... and then add coolant to thermostat housing with rad cap also removed until coolant runs out the top of the radiator.
* Re-install rad cap.

* Continue to add coolant until you see the level come up to where the thermostat normally sits.
* Put thermostat cap on and turn just barely enough to hold cap on.
* Start engine and run for about 30 seconds.
* Remove thermostat cap and check coolant level.
* Repeat last four steps until coolant level no longer drops.

* Re-install thermostat and thermostat housing cap.

As long as there are no blockages anywhere in the cooling system and the water pump is circulating coolant, you should be good to go.

[This message has been edited by Patrick (edited 06-10-2015).]

IP: Logged
kevin
Member
Posts: 2664
From: Elk Grove, CA USA
Registered: Jan 2000


Feedback score: N/A
Leave feedback

Rate this member

Report this Post06-10-2015 10:01 PM Click Here to See the Profile for kevinClick Here to Email kevinSend a Private Message to kevinEdit/Delete MessageReply w/QuoteDirect Link to This Post
Fellas,
I think it is remarkable how much knowledge the ''Fieronistas" have!! Truely outstanding. What I think is going on withe my Fiero is a lack of water/coolant. I have a new water pump (I forgot to mention that) and have no bent or cracked coolant tubes. I am going to add more water with the ass up in the air and the radiator cap off. I'll keep adding water at the Thermostat until it leaves out at the radiator cap. I believe that should cure my overheating issue. By the way, I ran the car for 17 minutes before the need rested on the red zone and the idiot light came.
I'll keep you all posted tomorrow morning. I have to drive it to a SMOG station tomorrow and I don't want to fail. It seems the pegged hot needle was my big issue. Thanks again for all your valuable insight.
Cordially,
Kevin
IP: Logged
tom10122
Member
Posts: 158
From: North Jersey
Registered: Jul 2014


Feedback score: N/A
Leave feedback

Rate this member

Report this Post06-11-2015 09:30 AM Click Here to See the Profile for tom10122Click Here to Email tom10122Send a Private Message to tom10122Edit/Delete MessageReply w/QuoteDirect Link to This Post
My thermostat went on my way for emissions so I pulled it and passed with the car in closed loop.

Btw You sure you aren't losing coolant? I had my waterpump loosen up some about 2k after it was installed
IP: Logged
QCMANAGER
Member
Posts: 166
From: Cedar Grove, NJ, USA
Registered: Jan 2015


Feedback score: (2)
Leave feedback

Rate this member

Report this Post06-11-2015 06:24 PM Click Here to See the Profile for QCMANAGERClick Here to Email QCMANAGERSend a Private Message to QCMANAGEREdit/Delete MessageReply w/QuoteDirect Link to This Post
While we are still on this subject let me interject my issue.

I have an 85 GT (haven't had it very long), 49k miles, superb condition. Today it was 90F in New Jersey and I got stuck in traffic going to work. As I was inching along in traffic I noticed the temp gauge was in the red zone. I pulled over and shut it off to let it cool down. Then I continued to finish my journey to work.

I watched it closely going home and it is at about 160 to 190F continuously as long as the car is traveling at 40 or more mph but when I have to slow down and sit in traffic it starts to creep up again. I have learned on this thread that there can be air pockets in the system and the coolant may be low and the thermostat may need to be changed and the water pump may need to be changed. Keeping in mind that the car only has 49k on it, which resolution do you think I should address first?

I am thinking of backing up onto my ramps and doing the back to front and front to back fill procedure, but if there were air pockets in the coolant system, would it run find at high speed?

Thanks for any help you can offer.

IP: Logged
Patrick
Member
Posts: 30697
From: Vancouver, British Columbia, Canada
Registered: Apr 99


Feedback score: (1)
Leave feedback





Total ratings: 443
Rate this member

Report this Post06-11-2015 06:33 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by QCMANAGER:

I watched it closely going home and it is at about 160 to 190F continuously as long as the car is traveling at 40 or more mph but when I have to slow down and sit in traffic it starts to creep up again.


You never mentioned whether or not your rad fan ever comes on.

 
quote
Originally posted by QCMANAGER:

...which resolution do you think I should address first?


It would probably take you less time to simply follow the steps I've outlined above than for us to discuss them individually.
IP: Logged
Csjag
Member
Posts: 3170
From: Ocklawaha,Fl, USA
Registered: Dec 2013


Feedback score: N/A
Leave feedback

Rate this member

Report this Post06-12-2015 05:36 PM Click Here to See the Profile for CsjagClick Here to Email CsjagSend a Private Message to CsjagEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by QCMANAGER:

While we are still on this subject let me interject my issue.

I have an 85 GT (haven't had it very long), 49k miles, superb condition. Today it was 90F in New Jersey and I got stuck in traffic going to work. As I was inching along in traffic I noticed the temp gauge was in the red zone. I pulled over and shut it off to let it cool down. Then I continued to finish my journey to work.

I watched it closely going home and it is at about 160 to 190F continuously as long as the car is traveling at 40 or more mph but when I have to slow down and sit in traffic it starts to creep up again. I have learned on this thread that there can be air pockets in the system and the coolant may be low and the thermostat may need to be changed and the water pump may need to be changed. Keeping in mind that the car only has 49k on it, which resolution do you think I should address first?

I am thinking of backing up onto my ramps and doing the back to front and front to back fill procedure, but if there were air pockets in the coolant system, would it run find at high speed?

Thanks for any help you can offer.


I also have an 85 GT that had sat for awhile before I got it. When I first started driving it after changing all fluids it would do what yours is doing. On my cat it turned out to be a bad water pump. When I took the old one off the impeller was all rusty and clogged.
IP: Logged
PFF
System Bot
GTMN
Member
Posts: 355
From: Iowa
Registered: Sep 2005


Feedback score:    (7)
Leave feedback

Rate this member

Report this Post06-13-2015 08:07 PM Click Here to See the Profile for GTMNClick Here to Email GTMNSend a Private Message to GTMNEdit/Delete MessageReply w/QuoteDirect Link to This Post
As a previous post asked, have you checked to see if you radiator fan comes on? If not it could be the temp switch at the engine block (which you say you have already replaced), the cooling fan relay (in front of the left headlight), or, less likely, the fan motor itself.
IP: Logged
rogergarrison
Member
Posts: 49593
From: A Western Caribbean Island/ Columbus, Ohio
Registered: Apr 99


Feedback score: N/A
Leave feedback





Total ratings: 552
Rate this member

Report this Post06-13-2015 09:36 PM Click Here to See the Profile for rogergarrisonClick Here to Email rogergarrisonSend a Private Message to rogergarrisonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Cool driving and overheating in traffic are 2 good signs the fans are not working. If I remember the fans are set on by the fan switch (sensor by the thermostat housing) to come on at 230* and shut back off around 190*. Rodneys switch drops that to like 185-210*. You need to verify the fans come on when the temp gets up to the red at minimum. They also come on when you turn the AC on at all temps.
IP: Logged

next newest topic | next oldest topic

All times are ET (US)

Post New Topic  Post A Reply
Hop to:

Contact Us | Back To Main Page

Advertizing on PFF | Fiero Parts Vendors
PFF Merchandise | Fiero Gallery | Ogre's Cave
Real-Time Chat | Fiero Related Auctions on eBay



Copyright (c) 1999, C. Pennock