Moparchat - Home of MOPAR enthusiasts worldwide!



Go Back   Moparchat - Home of MOPAR enthusiasts worldwide! > Technical Forums > Performance Talk

Click here to search for Mopar cars and parts for sale.


Reply
 
Thread Tools Display Modes
  #1  
Old 01-06-2008, 12:20 PM
sthorvictor75duster sthorvictor75duster is offline
Inactive User
 
Join Date: Dec 2007
Location: Saskatoon
Posts: 197
rolleyes2 thermostat???

ok...i just put in a new heater core in my 75 duster, and im getting no heat when the car is at running temp...yet i have no leaks.. on top of that i dont think my thermostat is working right its a 180 degree and its spiking to 210 and not functioning right in the middle of winter!.. now does the thermostat control flow to the heater core as well as the rad??? can someone help me out??
thanks
Reply With Quote
  #2  
Old 01-06-2008, 12:31 PM
peg leg peg leg is offline
Inactive User
 
Join Date: Jan 2005
Location: Star, Idaho
Age: 88
Posts: 2,669
Default Hoses

Are the heater hoses connected to the correct places on the core? Disconnect one, and start the engine. Should have pressure. Disconnect the other, should have suction. Now check the core for indication of inlet side and outlet side. Hook them up accordingly, pressure to inlet.
My small block has different sized hoses for inlet/outlet. Do big blocks also?
Reply With Quote
  #3  
Old 01-06-2008, 01:00 PM
sthorvictor75duster sthorvictor75duster is offline
Inactive User
 
Join Date: Dec 2007
Location: Saskatoon
Posts: 197
Default

Quote:
Originally Posted by peg leg View Post
Are the heater hoses connected to the correct places on the core? Disconnect one, and start the engine. Should have pressure. Disconnect the other, should have suction. Now check the core for indication of inlet side and outlet side. Hook them up accordingly, pressure to inlet.
My small block has different sized hoses for inlet/outlet. Do big blocks also?
yes one hose is 5/8 and the other 1/2, they only go on one way..
Reply With Quote
  #4  
Old 01-06-2008, 02:16 PM
ehostler's Avatar
ehostler ehostler is offline
Registered User
 
Join Date: Jan 2000
Location: Annandale, VA
Age: 57
Posts: 15,212
Default

You could have crap blocking the passage in the block. Disconnect one hose, start the engine and make sure that you are getting flow. If you aren't, then there is a restriction in the block. It's also possible that you could have had crap in the passages and it ended up in the core and plugged it.

I would look at getting a new thermostat. Get one of the Mr. Gasket Hi-Flow designs. They work great.
Reply With Quote
  #5  
Old 01-06-2008, 02:46 PM
sthorvictor75duster sthorvictor75duster is offline
Inactive User
 
Join Date: Dec 2007
Location: Saskatoon
Posts: 197
Default

Quote:
Originally Posted by ehostler View Post
You could have crap blocking the passage in the block. Disconnect one hose, start the engine and make sure that you are getting flow. If you aren't, then there is a restriction in the block. It's also possible that you could have had crap in the plans and it ended up in the core and plugged it.

I would look at getting a new thermostat. Get one of the Mr. Gasket Hi-Flow designs. They work great.
what are the plans??? the cores bran new...and the hoses running to the core are cool not hot like normal... to unplug the core can i use compressed air?? lower the psi to 15-20 psi?? and how do oyu unplug the block??
Reply With Quote
  #6  
Old 01-06-2008, 03:15 PM
valiant64 valiant64 is offline
Inactive User
 
Join Date: May 2007
Location: Ridgecrest,Ca.
Posts: 885
Default

are you sure that the air doors are opening? That the blower fan is operating? Just some ideas...
Reply With Quote
  #7  
Old 01-06-2008, 03:37 PM
sthorvictor75duster sthorvictor75duster is offline
Inactive User
 
Join Date: Dec 2007
Location: Saskatoon
Posts: 197
Default

Quote:
Originally Posted by valiant64 View Post
are you sure that the air doors are opening? That the blower fan is operating? Just some ideas...
i know their working....i checked those first then put my hand in there to feel the core and it was cold... thanks though
Reply With Quote
  #8  
Old 01-06-2008, 05:00 PM
rumblefish360's Avatar
rumblefish360 rumblefish360 is offline
Moparchat Bronze member
 
Join Date: May 2000
Location: C
Age: 57
Posts: 11,120
Default

Do you have that, ummm, thing, do hickey, (DAMN IT!) valve on the heater hose?
Reply With Quote
  #9  
Old 01-06-2008, 05:11 PM
valiant64 valiant64 is offline
Inactive User
 
Join Date: May 2007
Location: Ridgecrest,Ca.
Posts: 885
Default

heater control valve. Some are vacuum contolled, some are cable. Easy to test either way. I forgot about that.Duh ha ha
Reply With Quote
  #10  
Old 01-06-2008, 05:43 PM
rumblefish360's Avatar
rumblefish360 rumblefish360 is offline
Moparchat Bronze member
 
Join Date: May 2000
Location: C
Age: 57
Posts: 11,120
Default

Yeaaa, thats the thingy, do-hickey etc.......
Reply With Quote
  #11  
Old 01-06-2008, 06:43 PM
sthorvictor75duster sthorvictor75duster is offline
Inactive User
 
Join Date: Dec 2007
Location: Saskatoon
Posts: 197
Default

no not that i know of...the hoses run straight from the block/pump to the core...
Reply With Quote
  #12  
Old 01-06-2008, 07:28 PM
valiant64 valiant64 is offline
Inactive User
 
Join Date: May 2007
Location: Ridgecrest,Ca.
Posts: 885
Default

are you sure that the waterpump is circulating the coolant? Also as far as the high temp prob, be sure youre using a rad cap that is the right pressure and is actually up to psi spec. Just more things to check...
Reply With Quote
  #13  
Old 01-06-2008, 07:32 PM
sthorvictor75duster sthorvictor75duster is offline
Inactive User
 
Join Date: Dec 2007
Location: Saskatoon
Posts: 197
Default

i thought a rad cap regulated when to let fluid into the over flow??? and i know i am having problems with the thermostat... but i wasnt shure if that affected the heater core at all
Reply With Quote
  #14  
Old 01-06-2008, 08:01 PM
valiant64 valiant64 is offline
Inactive User
 
Join Date: May 2007
Location: Ridgecrest,Ca.
Posts: 885
Default

I'd say that may have something to do with the high engine temps. Had the same problem. I changed the cap & added an overflow. No more heating issues & no more coolant on the driveway after shutoff. If you think the cap is suspect, it doesnt get any cheaper or easier to correct. Also, what size rad are you using? With the BB I'd use a 26" rad since the BB usually produces more heat than SB or slant 6's. Also, are you using a fan shroud? What type of fan drive? Electric? Clutch drive? Direct drive? Cap pressure needs to be around 16 psi.
Reply With Quote
  #15  
Old 01-06-2008, 10:28 PM
wilks3 wilks3 is offline
Inactive User
 
Join Date: Sep 2006
Location: Nashville,Illinois
Posts: 385
Default

Sounds to me like its airlocked. I always drill a 1/8" hole in the stat so the engine "burps" out the air when first filled up. If not air gets trapped in block,
and you think its full of coolant but its not. The heater not heating and water temps spiking are signs of being airlocked and low on water.
Reply With Quote
  #16  
Old 01-07-2008, 01:36 AM
dodger1 dodger1 is offline
Inactive User
 
Join Date: Feb 2004
Location: Princeton BC
Age: 85
Posts: 2,648
Default

Wilks3 has a point worth checking out. While you're doing that, stick a thermometer (anything that will go to 100 C - 212 F or more) into the rad filler neck and see what the temp gets to. Should be close to your t'stat rating. And, sure, blow out the core with low-pressure air as well. If none of that works, then you may have some internal crud blocking flow. Assuming of course you are sure the heater water valve either is non-existant and not just non-operative. (Mine won't open as a result of the vacuum controller switch being stuck, found that out after 100 miles in -5 temps)
Reply With Quote
  #17  
Old 01-07-2008, 01:53 AM
Dick's Avatar
Dick Dick is offline
Registered User
 
Join Date: Oct 2001
Location: Western NH
Age: 80
Posts: 8,880
Default

Quote:
Originally Posted by sthorvictor75duster View Post
no not that i know of...the hoses run straight from the block/pump to the core...
Somewhere, there has to be a heater control valve. Without it, you would have heat year 'round.

You mentioned new heater core. Sometimes, new products that have pipes, tubes or fittings, will have little cardboard or plastic caps that plug the openings to prevent dirt getting in prior to assembly. Pretty basic, but one may be jammed down in a tube or fitting.
Reply With Quote
  #18  
Old 01-07-2008, 01:58 AM
ehostler's Avatar
ehostler ehostler is offline
Registered User
 
Join Date: Jan 2000
Location: Annandale, VA
Age: 57
Posts: 15,212
Default

Many vehicles ran with the heater core getting coolant at all times. Even my '69 Coronet does not have a control valve. The air door determines if air flows across the core or not.

My '68 Charger has a flow valve and that is because it has A/C.
Reply With Quote
  #19  
Old 01-07-2008, 02:00 AM
Dick's Avatar
Dick Dick is offline
Registered User
 
Join Date: Oct 2001
Location: Western NH
Age: 80
Posts: 8,880
Default

Point taken. Added to files of continuing adult education.
Reply With Quote
  #20  
Old 01-07-2008, 08:27 PM
valiant64 valiant64 is offline
Inactive User
 
Join Date: May 2007
Location: Ridgecrest,Ca.
Posts: 885
Default

these are all good points & correct. back to square one, did the heater work BEFORE you changed the heater core? as mentioned above, maybe you overlooked the plastic plugs that sometimes are present on new core pipes? Drilling the 'stat to avoid air pockets is a great idea which I do myself to avoid much aggravation, however I forgot to mention that. glad someone elses brain was working at full capacity here!
Reply With Quote
  #21  
Old 01-08-2008, 01:17 AM
pishta's Avatar
pishta pishta is offline
Senior Member
 
Join Date: Aug 1999
Location: Tustin, CA
Age: 55
Posts: 3,987
Default

is your impeller still attached to your shaft? No circulation would cause an overheat and a cold (although pressurized) heater line.
Reply With Quote
  #22  
Old 01-08-2008, 01:20 AM
sthorvictor75duster sthorvictor75duster is offline
Inactive User
 
Join Date: Dec 2007
Location: Saskatoon
Posts: 197
Default

Quote:
Originally Posted by valiant64 View Post
I'd say that may have something to do with the high engine temps. Had the same problem. I changed the cap & added an overflow. No more heating issues & no more coolant on the driveway after shutoff. If you think the cap is suspect, it doesnt get any cheaper or easier to correct. Also, what size rad are you using? With the BB I'd use a 26" rad since the BB usually produces more heat than SB or slant 6's. Also, are you using a fan shroud? What type of fan drive? Electric? Clutch drive? Direct drive? Cap pressure needs to be around 16 psi.
ok i did change the cap to a 15 psi.. and she still does it..the rad is from the Newport that i pulled the engine from, and took it in and i think im running 4 cores if im not mistaken. using shroud and a flex fan, because there is no room for a viscous fan.....

ok as far as heater core caps i pulled the two rubber caps off before installation...

and my heat control is a door inside the heater box.. that directs flow through the core or by passes it, so i get fluid year round.. its a 69..
Reply With Quote
  #23  
Old 01-08-2008, 01:35 AM
Dick's Avatar
Dick Dick is offline
Registered User
 
Join Date: Oct 2001
Location: Western NH
Age: 80
Posts: 8,880
Default

Verify that you are getting hot water to the heater core. One of the hoses leading to the core should be damn hot and the other one pretty darn hot. If both hoses are cold, water is not circulating to the core.

Is your thermostat installed upside down, by chance? The "pill" goes toward the block. Sorry, it's a basic question, but sometimes simple things slip by us.
Reply With Quote
  #24  
Old 01-08-2008, 01:38 AM
sthorvictor75duster sthorvictor75duster is offline
Inactive User
 
Join Date: Dec 2007
Location: Saskatoon
Posts: 197
Default

ok the hoses are both cool while the rad hose burns a guys hand off...
and the thermostat was working but this summer i know i over heated the engine b accident when i blew out a belt under full throttle on the hiway..now giving eratic readings since....so im gonna replace it tommorow... but does that have anything to do with the heater core??
Reply With Quote
  #25  
Old 01-08-2008, 01:45 AM
Dick's Avatar
Dick Dick is offline
Registered User
 
Join Date: Oct 2001
Location: Western NH
Age: 80
Posts: 8,880
Default

If the T-stat is stuck closed, coolant will not circulate to the heater. A quick and dirty way to check that is pull the thermostat out and see if you get heat.

Your system may have an air pocket and need to be burped.

Did you have heat before the new core? If yes, you had to remove coolant to do the job. Did you get all the coolant back in?
Reply With Quote
  #26  
Old 01-08-2008, 01:49 AM
sthorvictor75duster sthorvictor75duster is offline
Inactive User
 
Join Date: Dec 2007
Location: Saskatoon
Posts: 197
Default

the answer to the last is no i think i added fluid but i dont know if it was enough...ill open her tomorrow then..how do i burp the system?? and there was heat in the ld core before she leaked...
Reply With Quote
  #27  
Old 01-08-2008, 01:55 AM
Dick's Avatar
Dick Dick is offline
Registered User
 
Join Date: Oct 2001
Location: Western NH
Age: 80
Posts: 8,880
Default

Burping can sometimes be done by idling the engine with the radiator cap off and the heater control on. When the thermostat opens, you can see coolant flowing in the radiator. Usually, the level will drop. Add coolant to keep the level in sight. Sometimes squeezing the hoses will help expel air. When the level doesn't drop anymore, the system is full.
Reply With Quote
  #28  
Old 01-08-2008, 11:18 AM
adodgemann's Avatar
adodgemann adodgemann is offline
Registered User
 
Join Date: Mar 2005
Location: Standish, Mi
Age: 63
Posts: 312
Default

Sounds like it air locked to me. I have had trouble getting the new heater core to fill with coolent. Pull off the hoses at the motor. You should be able to blow thru it with little effort, to make sure nothing is pluged up. If that checks out, put 1 hose back on. Hold the other up high, with a funnel fill the core up till it runs out the nipple on the motor. Hook up the hose back up and try it. Hold your thumbs over the end of the hose and nipple till just before ya shove it on, can be a little messy...Hope this helps ya
Reply With Quote
  #29  
Old 01-08-2008, 06:35 PM
sthorvictor75duster sthorvictor75duster is offline
Inactive User
 
Join Date: Dec 2007
Location: Saskatoon
Posts: 197
Default

Quote:
Originally Posted by adodgemann View Post
Sounds like it air locked to me. I have had trouble getting the new heater core to fill with coolent. Pull off the hoses at the motor. You should be able to blow thru it with little effort, to make sure nothing is pluged up. If that checks out, put 1 hose back on. Hold the other up high, with a funnel fill the core up till it runs out the nipple on the motor. Hook up the hose back up and try it. Hold your thumbs over the end of the hose and nipple till just before ya shove it on, can be a little messy...Hope this helps ya
alright thanks ill give that a shot too.... thanks allot guys for the info ill get this stuff done and tell you how it went...
talk to you later
Reply With Quote
  #30  
Old 01-16-2008, 12:06 AM
sthorvictor75duster sthorvictor75duster is offline
Inactive User
 
Join Date: Dec 2007
Location: Saskatoon
Posts: 197
Default

ok so i tried almost everything you guys mentioned...even tried a higher pressured cap.....and still no heat...i changed my thermostat to a new one which works great but no heat...any suggestions?? if it is still somehow air locked wont it correct itself eventually??
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
70s 360 thermostat gasket go above or below thermostat? 73_RoadRunner Performance Talk 13 12-10-2008 02:31 AM
thermostat 99 Dodge Ram Truck Chat 4 05-29-2001 06:40 PM
Thermostat GQMarinePilot Ram Truck Chat 4 05-20-2001 08:12 AM
Thermostat ? ehostler Performance Talk 3 05-06-2001 10:18 PM
Which 180 Thermostat is best? TruckBoy95 Ram Truck Chat 2 04-11-2001 07:19 PM




All times are GMT -4. The time now is 08:33 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
. . . . .