First few runs after engine rebuild and she over heats
I may have jinxed myself by saying cooling problem solved because I took the car for an hour ride and temp gauge climbed past the halfway point torwards about a little over 3/4s of the way. I started to smell antifreeze. The radiator just bought me more driving time before getting hot. My other choices now are to remove heads and check gasket and possible by 5 blade fan as you suggested.
Wow! I'm guessing that was probably in the 195-200 deg F range since 180 deg F is about in the middle of the gauge. What speeds were you driving at when the temps raised? Did you ever check to see if the head gaskets were installed correctly? Is this the first time you have smelled anti freeze? Since the smell have you seen any leaks? Out of curiosity, what were the outdoor temps? On a positive note, your old radiator was fairly dirty and only 2 rows. You had mentioned the temps were over half before the rebuild. So even without any other issues it would have been struggling to maintain temps. FYI, if coolant temps creep up turn on the heater with the fan on high. This will help cool the motor.

A couple of last ideas before condemning head gaskets. Ignition timing being too retarded will cause temps to rise. Make sure the mechanical and vacuum advance are working. An air fuel mixture being too lean will also cause temps to creep up.

Edit: Before I forget, did you get the fan shroud reinstalled? I know you had some fitment issues with the new radiator and I thought you initially left the fan shroud off. Did it have any other symptoms, pushing a more than normal amount of coolant out the overflow tube, temp gauge drifting up and down in large sweeps, intermittently running rough . . .? Did you ever have an opportunity to pressurize the cooling system, then disable the ignition system, crank the engine over with the spark plugs removed and look for coolant spray out of a spark plug hole? I think I mentioned that test in an earlier post.

Hi Mike,

So far I have fan shroud in (had to patch up broken pieces of it temporarily until i get a new one), 3 row radiator, vacuum advance is working and timing is good. Temperature settles around 195 (hose temperature). Gauge needle is between 3/4s and hot but stays there. I ran the car for an hour like this and she didn't steam and nothing out of radiator overflow. So new radiator definitely helped but still runs hot. I can sometimes hear pinging at the high temps but not before it.

We did pressurize the radiator and didn't see any coolant in combustion chamber. We also tested for radiator gases again with the test kit (blue liquid that turns yellow when mixed with gases) and the liquid remained blue. I'm still running the 4 blade fan but can't imagine a 5 blade lowering the temperature by that much.

We plan to pull the heads tomorrow to see if we installed the gaskets correctly. This is more of a last ditch effort as we did everything else. I have the new felpro gaskests. Should the side with the blue letter be facing up when installed? both sides of the gasket has front printed on it so want to make sure I install hem corretly.
So we removed the heads today and the gaskets were on backwards. They weren't fel-pro so there was no indication of front side. The back water jackets were covered by the gasket. We installed fel-pro with front side facing front as it is marked on the gasket. It looked a bit strange because only the back water jackets had holes as wide as the water jacket but the front ones had a small hole over the water jacket. I guess it is what it is.

I took it for a run and she hover about half way, maybe slightly passed half way so definitely and improvement than before. I'll want to drive her for about an hour or two to really feel comfortable though.
Well now you know.

Good to hear that you have found what should resolve your over heating issues.

Enjoy your ride.
Sorry I missed your post yesterday. Glad to hear you found the other head gaskets installed incorrectly. Learning something the hard way is never fun. We've all been there many times. On the positive side you tend to not forget those lessons.

With the Fel Pro gaskets just be certain the FRONT label is at the front of the motor. One side will look correct and the other will look upside down but they are okay. The coolant hole configuration you see with the Fel Pro gaskets is correct.

Since your temps are still hovering in the middle and slightly above I am also happy to see that radiator upgrade was worth while. Temps would have still been much higher with the old radiator.

Nice Work! Let us know what happens after a long drive.


Possibly Related Threads...
Thread Author Replies Views Last Post
  engine sputters when I punch it 784mula 2 551 09-11-2018, 03:09 PM
Last Post: Steven Harris
  Engine Won't Stop Running mason1958 8 7,667 06-16-2012, 10:07 AM
Last Post: 1969jimmach
Shocked Can't identify 2 wires after engine installation zekegood 5 5,549 08-10-2011, 11:26 AM
Last Post: 70427w

Forum Jump:

Users browsing this thread: 1 Guest(s)
Latest Threads
PCM keeps burning out have replaced for...
Last Post: Mustangbob
Yesterday 10:58 AM
» Replies: 8
» Views: 214
70 Boss 302 - Night Mission build blog
Last Post: JTS71 Mach1
12-07-2018 01:12 PM
» Replies: 109
» Views: 67858
Alternator Light Won't go off
Last Post: 1969_Mach1
12-05-2018 11:56 AM
» Replies: 10
» Views: 489
Last Post: Steven Harris
12-04-2018 02:36 PM
» Replies: 55
» Views: 8294
My newest 1970 Mustang Fastback 302
Last Post: BLACK JADE 69
12-04-2018 12:08 AM
» Replies: 24
» Views: 1816
351c wont start, help
Last Post: 1969_Mach1
12-03-2018 06:35 PM
» Replies: 62
» Views: 2078
New guy with a question.
Last Post: 1969_Mach1
12-03-2018 06:57 AM
» Replies: 25
» Views: 768
Dashboard lights REALLY dim, any fixes??
Last Post: Steven Harris
12-01-2018 12:04 PM
» Replies: 13
» Views: 13577
new member
Last Post: Steven Harris
12-01-2018 12:02 PM
» Replies: 4
» Views: 270
1971-73 "Clydesdales"
Last Post: Mister 4x4
11-29-2018 11:35 AM
» Replies: 26
» Views: 916
Installing Factory gauges in a '71-'73 M...
Last Post: Mister 4x4
11-28-2018 03:26 AM
» Replies: 4
» Views: 758
Pictures and some info from a new guy
Last Post: Mister 4x4
11-28-2018 03:02 AM
» Replies: 18
» Views: 1200
Been Awhile... '71 Rustang
Last Post: Mister 4x4
11-24-2018 01:49 PM
» Replies: 143
» Views: 92640
1965 Fairlane (Mustangmike)
Last Post: JTS71 Mach1
11-23-2018 02:56 PM
» Replies: 14
» Views: 770
Happy Thanks Giving!!!
Last Post: 1969_Mach1
11-23-2018 03:42 AM
» Replies: 2
» Views: 295
How not to Handle A DUI Checkpoint?!?!
Last Post: Vanbens91
11-14-2018 07:22 PM
» Replies: 1
» Views: 2134
Led lights not all that good.
Last Post: Mustangmike
11-14-2018 09:44 AM
» Replies: 20
» Views: 5642
1972 Mach1 rear fold down seat problems....
Last Post: John
11-13-2018 03:04 AM
» Replies: 10
» Views: 704
1972 Mach1 parts
Last Post: John
11-10-2018 10:31 AM
» Replies: 0
» Views: 234
Last Post: 1969_Mach1
11-08-2018 09:43 AM
» Replies: 5
» Views: 399