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overheating by don850
Started on: 04-12-2015 06:06 PM
Replies: 19 (196 views)
Last post by: don850 on 04-13-2015 09:30 PM
don850
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Report this Post04-12-2015 06:06 PM Click Here to See the Profile for don850Click Here to Email don850Send a Private Message to don850Edit/Delete MessageReply w/QuoteDirect Link to This Post
Last week my 84 fiero needed a head gasket. It was dumping coolant ou t of the expansion tank. I finished the job yesterday and drove it home from my shop just fine (about a half hour). Today I decided to take it for a bit further ride (about an hour or so) to see how its holding up. Now when I did the head gasket I put a new thermostat in and the heat quickly rose over normal and I didn't like that so I kept the thermostat out. When I got to the last two miles today the car started acting like it was overheating so I pulled over and checked the gauge (it only works with the engine off and the key on but that's an issue for another day). The gauge read above normal but out of the red zone. I got it home and checked everything, no loss of coolant anywhere and nothing out of the normal. What else could be causing it to overheat.

I have already changed the radiator cap, thermostat but it isn't in, and the water pump. I also have a new temp sensor for it but haven't installed it. I also flushed the system after I did the head gasket.
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don850
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Report this Post04-12-2015 06:19 PM Click Here to See the Profile for don850Click Here to Email don850Send a Private Message to don850Edit/Delete MessageReply w/QuoteDirect Link to This Post
Also the fan works but only when the ac is "on"
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Scott2scott
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Report this Post04-12-2015 06:21 PM Click Here to See the Profile for Scott2scottClick Here to Email Scott2scottSend a Private Message to Scott2scottEdit/Delete MessageReply w/QuoteDirect Link to This Post
have u checked the radiator itself? could be blocked. causing low flow.
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Scott2scott
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Report this Post04-12-2015 06:23 PM Click Here to See the Profile for Scott2scottClick Here to Email Scott2scottSend a Private Message to Scott2scottEdit/Delete MessageReply w/QuoteDirect Link to This Post

Scott2scott

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or the coolant tube to rad. sometimes if u jack the car up wrong . u crush the tubes .
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Patrick
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Report this Post04-12-2015 07:06 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 don850:

Last week my 84 fiero needed a head gasket. It was dumping coolant out of the expansion tank.


What made you suspect the head gasket needed replacement? Coolant dumping out of the expansion tank can occur for several reasons, including air in the system and the wrong (vented) rad cap being used. It's possible the same problem is now still occurring.

 
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.

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don850
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Report this Post04-12-2015 08:27 PM Click Here to See the Profile for don850Click Here to Email don850Send a Private Message to don850Edit/Delete MessageReply w/QuoteDirect Link to This Post
I tried everything else that could cause fluid to come out of the expansion tank and nothing fixed it. Pulled the head after finding coolant in the oil. I'm not losing coolant anymore and I know for sure that its not pushing into the overflow tank. It is flowing through the rad and none of the lines are crushed.
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don850
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Report this Post04-12-2015 08:28 PM Click Here to See the Profile for don850Click Here to Email don850Send a Private Message to don850Edit/Delete MessageReply w/QuoteDirect Link to This Post

don850

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Also the car was running 2 years ago and nothing has been replaced since. I had this same issue with it and because of other projects put it on the back burner.
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Patrick
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Report this Post04-12-2015 08:30 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 don850:

Pulled the head after finding coolant in the oil.


Okay, that's not a good sign. The steps I posted above should solve your problem unless there's some other underlying issue.
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don850
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Report this Post04-12-2015 11:01 PM Click Here to See the Profile for don850Click Here to Email don850Send a Private Message to don850Edit/Delete MessageReply w/QuoteDirect Link to This Post
I've done those steps when I filled it and its still overheating. Not nearly as bad and the coolant level is staying the same. I'd say my gauge is just incorrect but for the last two miles it was acting as if it was overheating.
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Patrick
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Report this Post04-12-2015 11:16 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 don850:

I'd say my gauge is just incorrect but for the last two miles it was acting as if it was overheating.


It's hardly the depths of summer. There's no way your engine should be overheating, especially if your Fiero is moving though the air (as opposed to idling in one spot for a long time).

You need to get a scanner connected and find out what temp your ECM is actually seeing. I wouldn't trust the temp gauge in your instrument panel.
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fieromatty
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Report this Post04-13-2015 02:09 AM Click Here to See the Profile for fieromattyClick Here to Email fieromattySend a Private Message to fieromattyEdit/Delete MessageReply w/QuoteDirect Link to This Post
Check the coolent tubes on both sides of the car. They bend pretty easy in the rear behind the wheel wells.

http://steventsnyder.com/re...fiero-coolant-tubes/

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don850
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Report this Post04-13-2015 07:20 AM Click Here to See the Profile for don850Click Here to Email don850Send a Private Message to don850Edit/Delete MessageReply w/QuoteDirect Link to This Post
I drove the car to my shop today in 30 degree weather and wouldn't you know, it didn't overheat however it really didn't like the cold. It stalled at every stop sign and red light I came up to and I went through about half a tank on my 20 mile trip. I'm kind of at crunch time now since I need this car to be able to make it about 60 miles on Saturday morning. I'd say its the ecu temp sensor reading incorrectly except it runs fine when its warm out.
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Gall757
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Report this Post04-13-2015 10:09 AM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
It can run fine with the temp sensor malfunctioning. You will get lousy mileage and maybe damage the CAT.
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don850
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Report this Post04-13-2015 11:19 AM Click Here to See the Profile for don850Click Here to Email don850Send a Private Message to don850Edit/Delete MessageReply w/QuoteDirect Link to This Post
I was getting about 5 mpg this morning
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don850
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Report this Post04-13-2015 06:32 PM Click Here to See the Profile for don850Click Here to Email don850Send a Private Message to don850Edit/Delete MessageReply w/QuoteDirect Link to This Post
I think I figured out why its overheating. There's a blockage in one of the coolant pipes. I tried squeezing both rad hoses and all of them are hard. I'm not sure how the coolant is supposed to flow. Does it flow from the left of the rad to the right (super hose to lower hose) or right to left?
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don850
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Report this Post04-13-2015 06:34 PM Click Here to See the Profile for don850Click Here to Email don850Send a Private Message to don850Edit/Delete MessageReply w/QuoteDirect Link to This Post

don850

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I should have said all coolant hoses, not just the two rad hoses.
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Patrick
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Report this Post04-13-2015 06:37 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 don850:

I'm not sure how the coolant is supposed to flow.


I believe that hot coolant enters the top of the rad and exits at the bottom.
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don850
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Report this Post04-13-2015 06:45 PM Click Here to See the Profile for don850Click Here to Email don850Send a Private Message to don850Edit/Delete MessageReply w/QuoteDirect Link to This Post
Well now I'm really confused. If all the hoses are hardbwhere could the block be?
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Patrick
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Report this Post04-13-2015 07:06 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 don850:

If all the hoses are hard where could the block be?


Is the system hot and pressurized while you're squeezing hoses?
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don850
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Report this Post04-13-2015 09:30 PM Click Here to See the Profile for don850Click Here to Email don850Send a Private Message to don850Edit/Delete MessageReply w/QuoteDirect Link to This Post
Yes it is. I checked them after a half hour of driving. I know they're going to get hard from the pressure but this was abnormally hard. Also don't know if I posted that my issue this morning with dying all the time was due to a new plug wire that had melted and was grounding out on the exhaust manifold...oops.
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