Heater core replacement

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barnesjtsl
Posts: 203
Joined: Fri Apr 03, 2009 2:13 pm
Your car is a: 1979 Spider
Location: Hillsboro, OR

Heater core replacement

Post by barnesjtsl »

79 Spider 2000

I just replaced my heater core and hot water valve. They are both used.

After replacement I found no leaks. The heater seems to work fine. Warm air is comming out the defrost and the lower heat vents very well.

My question. The car seems to be running hot. Before replacing the core and valve I had them bypassed due to a valve going bad. The car ran at just above 190 degrees. Now after replacing the core and valve it is running at probably 210+ degrees and the fan does not seem to come on. Before when I got home from work (32 mile comute) when I shut the car off the fan would come on for a minute or so then shut off (the temperature would be just at 190). Now the temerature reads around 210+ and when I shut the car off the fan does not come on.

I didn't drive it to work today, and when I get home tonight I will check the fan to make sure it is still working properly. Also, can someone tell me how to check the fan thermostat to see if it has gone bad?

The fan and thermostat worked perfectly before installing the replacement core and valve. I can't imagine that one of these would have happened to go bad at the same time I did the repalcement, so I'm thinking there may be something going on with the core and valve themeselves.

Any thoughts?

barnesjtsl
jimincalif
Posts: 410
Joined: Sun Jan 25, 2009 12:43 am
Your car is a: 1980 FI Spider
Location: Lake Forest, CA

Re: Heater core replacement

Post by jimincalif »

Sounds like air in the cooling system, try "burping" it.
1980 FI Spider
htchevyii
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Your car is a: 1982 Spider hers 1972 Spider his
Location: Hydesville, CA (NorCal)

Re: Heater core replacement

Post by htchevyii »

I've heard of them running a little hotter with the heater valve closed, (reduced h2o flow to the head), but I haven't noticed any difference in my car. My guess would be air in the system. Do you have the flush tee in the heater hose?
Trey
Image
1982 SPIDER 2000, 1964 CHEVYII, 1969 Chevy Nova, 2005 DODGE RAM, 1988 Jeep Comanche
1972 Spider, 78 Spider rat racer 57 f-100,
barnesjtsl
Posts: 203
Joined: Fri Apr 03, 2009 2:13 pm
Your car is a: 1979 Spider
Location: Hillsboro, OR

Re: Heater core replacement

Post by barnesjtsl »

Thanks for the replys.

I probably don't have the "flush tee" in the heater hose being that I don't know what a flush tee is. Can you describe one to me and mention what it does?

Also, is running at 210 degrees too hot?

Thanks for the quick reply's, I appreciate all the help,

barnesjtsl
htchevyii
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Your car is a: 1982 Spider hers 1972 Spider his
Location: Hydesville, CA (NorCal)

Re: Heater core replacement

Post by htchevyii »

They are sold to hook up a garden hose to flush your cooling system, but also make a handy fill point. Available at your local parts store for $5-$7. 210d isn't too hot, but maybe hotter than "normal". Here's the tee:

Image
Image

O.k., maybe four bucks
http://shop.oreillyauto.com/productdeta ... yCode=3051
Trey
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1982 SPIDER 2000, 1964 CHEVYII, 1969 Chevy Nova, 2005 DODGE RAM, 1988 Jeep Comanche
1972 Spider, 78 Spider rat racer 57 f-100,
pope

Re: Heater core replacement

Post by pope »

The problem I see is that the fan is not turning on at that temp. The wiring for the radiator temp switch should be examined and cleaned
rlux4
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Your car is a: 1982 2000 Spider
Location: Granite Falls, Wa

Re: Heater core replacement

Post by rlux4 »

I think Pope has got it. Last week my fan wasn't working. Turned out the two wire connector from the temp sensor wasn't making a good connection.
Ron
Ron Luxmore
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'82 2000 Spider: after 26 years between Spiders.
nate302

Re: Heater core replacement

Post by nate302 »

Keep in mind as well, if the fan isn't turning on, some of the cars use an engine fan relay. If the connections are bad to this relay, or the relay itself is bad, fan wont work.
digitech
Posts: 336
Joined: Sun Jul 19, 2009 6:37 am
Your car is a: 1979 Fiat Spider

Re: Heater core replacement

Post by digitech »

If there is air in the system, the fan will never turn on with the thermo switch. Get the air out, verify fan works and install a safety switch to turn the fan on in an emergency "no fan" condition like you presently have. It's better than warping the head.
nate302

Re: Heater core replacement

Post by nate302 »

something else to consider, if your radiator is older, It is possible the radiator's core (the tubes which allow coolant to flow through) have corroded over time. This generally happens because people don't replace the coolant on a regular basis, and the Ph level goes off.
This causes the coolant to start eroding/eating away at not only the engine block, but heater core, and radiator. If this is the case, you can buy a cheap flush fluid to clear out the system, and refill with coolant (50/50ratio) Coolant with Distilled water. Tap water has minerals that will also wear down your cooling system.
To check if your radiator is plugging up (example near the thermo switch) run the car until it warms up. Put your hand on the radiator and feel downwards. It should go from warm/hot to cool/warm. (with fan engaged)

I drew this wiring diagram to also show how the Engine fan relay works (on 76 models and earlier) don't quote me exactly, but this gives a general idea.
Image

Edit:
on yours, there should be no relay. It should be a stright light blue wire directly from fuse i, to the fan, with a thermo switch in the ground. Check the thermo switch (the fan can only run when the key is turned) make sure it is getting a good connection, Use a DVOM (Digital Volt Ohms Meter) or a test light to verify you have current flowing from the Light blue wire, and also check your fuse. If those both check out, your thermo switch may have gone out or have a bad connection.
mdrburchette
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Joined: Wed Jan 25, 2006 5:49 am
Your car is a: 1972 Fiat 124 Sport
Location: Winston-Salem, NC

Re: Heater core replacement

Post by mdrburchette »

Nice diagram, Nate! I second the opinion that the system hasn't been completely purged of air. Installing a flush tee does make it more simple, even though I've never done it. You may also consider pressure testing the system to make sure there are no leaks. If water can get out, air can get in. :wink:
1972 124 Spider (Don)
1971 124 Spider (Juan)
1986 Bertone X19 (Blue)
1978 124 Spider Lemons racer
1974 X19 SCCA racer (Paul)
2012 500 Prima Edizione #19 (Mini Rossa)
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ga.spyder
Posts: 3478
Joined: Tue Nov 06, 2007 7:19 pm
Your car is a: 1982 Spider 2000
Location: Blairsville ,Ga.

Re: Heater core replacement

Post by ga.spyder »

The manuals all give a description of purging the system.It is a little different on the fi cars,but not at all difficult.Being that it was working fine before ,I say you definitely have some air in the system.I had the exact same symptoms on my 82.Purge it before you try anything more involved.Bet she will be running sweet and cool again!
Craig
Craig Nelson

1982 Spider 2000...pride and joy
1981 Fiat X1/9..gone but not forgotten
1976 124 Spider..the self-healer
2001 BMW 328ci daily driver and track car
Fling It Around Turns !
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