74 NovaMan’s … Novas

[74NovaMan]

Done some test driving. Trans is nice so far. Got a tire chirp going into 2nd gear. Runs through the gears nicely and the lockup is working. I tried running it with the radiator cap off as suggested by Randall. He was absolutely correct. It burps up alot of coolant and then the level drops. I must have been doing something wrong at this point because i really could not get much more coolant into the system. Next step was to drain the system. When I refilled it this time I removed the heater hose at the mainfold and filled it until it started coming out and reconnected the hose. The temp issue is a bit better so far but I cannot seem to get it to run under 190 and it bumps up over 200 at low speeds and at idle. It's 65 degrees out here now. What happens when I am down south in 98 degrees in a traffic jam? Will the air eventually work itself out? I'm seriously considering plan B, which is the wife's 2010 Ford Edge.

[TheSilverBuick]

Is it a 180*F thermostat? (as read on the bottom of the thermostat, not as told by the parts store guy). My 180*F runs consistently at 186*F according to my MegaSquirt sensor. Personally, if it's not pinging 190*F doesn't bother me at all. I run a 195*F in the Centurion because it's low compression, and I'd run a 195*F in the Skylark if I wasn't concerned about the higher compression (~10.6:1). How much over 200? Are we talking 205* or 225*? Are we talking steady and slow moving temperature changes now?

**Looking back a few posts, it looks like your fan doesn't go into your shroud. Am I mistaken? You'd like at least a 1/3rd of the fan inside the shroud (rules are fuzzy, 1/2", 1/2 the fan, etc. I'm just going for approximately a 1/3) for the shroud to be effective. How far in front of the car can you feel the air pull at idle? Holding up a sheet of newspaper might help you gauge it. I know on my Skylark I went from feeling the fan pull right at the grill to almost 3 feet in front of the car with a proper shroud on it. That's a lot of air! If it doesn't overlap, see if you can shim the fan out further, or if you happen to have a fan clutch set up, install it and see where it puts the fan. I wouldn't just go out and buy a fan an fan clutch for the test, but if you happen to have one might as well see.

***Also if you are close on temps, you can try using Water Wetter, I believe it does help in pulling heat out of the engine and getting it to the radiator.

[74NovaMan]

Randall - it's a 180. Used to run 185 consistently in the old body (same fan, radiator, motor - new t-stat, water pump). Going down the freeway at 70 mph on a shady 65 degree day it was about 200. It wants to creep up from there to about 220 when driving slower. Needle movement has been slower today as well. If it is still an air bubble, what are the chances it will work itself out?

Should I try running without a t-stat for a few minutes to try and purge the air?

This is killing me. The car runs great with the new Trans.

[74NovaMan]

One more question. How hot is too hot? I usually shut it down at 220.

[68scott385]

I hate to ask the obvious but are you opening the heater core to coolant while trying to fill the cooliing system? I haven't seen mention of it throughout the thread and just thought I'd throw my question in.

Regardless of brand or how much/little coolant was removed/evacuated from the system, I always turn the heat on while filling the radiator.

What type of gauge, electric or mechanical? Where is the sensor located?

[74NovaMan]

Scott - Ask away! I'm looking for any and all ideas. Heater core is open - there is no valve. I have an Auto-meter guage mounted in the passenger side head. The guage is older. There is a dummy light switch in the drivers head. The light has not come on yet. I have a spare guage I am going to try tomorrow.

[pintoboy77]

Before I put a new radiator and a eletric fan on last year I could'nt run the Pinto over 65 or it would get up to 230* on the highways,but if I slowed down to 55mph it would come down to 200* no matter what the temp outside was and in town it still ran about 190* on a 180* thermostat. When I had my new radiator made I added 21 more tubes to the radiator and made them 5/8" tubes instead of the normal 9/16" tubes made a world of difference now it runs 180* at any temp and any speed. So I feel your pain on over heating problems I have been there. One other thing I did when I was having the over heating issue was I ran a 70/30 anti-freeze mix it has a higher boil over temp. One other question what size radiator cap are you running if it calls for a 15psi cap that is what you need to run and do you run a puck bottle.

[74NovaMan]

I picked up a new 16 pound lever cap today. It has a factory "puke" bottle. Keep the ideas coming. Thanks.

[68scott385]

I've never seen a temp sensor in the passenger head, factory or aftermarket. All mine have either been in the driver's side head or in the intake port on the driver's side of the thermostat. Mechanical Stewart-Warner and later, electric AutoMeter.


from the redundancy department:

3*/lbs pressure

3 x 16 = 48

212 + 48 = 260* before oh spit moment

just for peace of mind..but i get antsy at 220* too

With 195* 'stat my dd runs up (gauge) to about 210ish before the settling to 175ish.

[pintoboy77]

Chris if it has a factory puck bottle on it you can't run a lever cap it is made for and open system not a closed system.

[Scott Liggett]

Time to take radiator in and have it checked out. If you have laser temp sensor, check the temp at different places around the cooling system.

I know. The radiator worked fine in the other car. Doesnt mean it go bad. Or its clogged. My Impala's 3 core worked perfectly fine for a decade, then it would overheat in traffic. It didnt work that great while driving. It would cool off 20-30 degrees if I shut the engine off for 15 min.

[TheSilverBuick]

Chris if it has a factory puck bottle on it you can't run a lever cap it is made for and open system not a closed system.

Sure you can, why couldn't you? I have for years on a variety of cars.

I start getting leary after 210*F because it usually means the cooling system is losing control of the heat management when you have a 180*F thermostat. Nothing is likely to get hurt on an engine up to around 240*F-250*F. I think you are on the right track being concerned at 220*F, but wouldn't shut it down unless it's climbing from there.

I prefer my temp sensors in the intake next to the thermostat, but I know Chevy has had the temp sender there forever.

I'm also thinking your bubble issue is mostly done with if oscillations of the temp are slow a bubble, if there, will likely work itself out at that point.

Your ignition timing set the same as it was in the other chassis? Same carburetor?



I highly don't recommend doing things like this, but when I had my old 231 V6 in the Skylark, I'd get that temp gauge pegged well above 250*F for an easy (or uneasy?) ten minutes running a long grade (outside Baker, CA going to Vegas for those that know the drive) in 100*F+ weather at 4,000+rpm. Soon as I would crest the summit the temp would drop back to normal, lol. Did that several times with the oil pressure around 10psi, lol. That engine never blew up, lol.

[pintoboy77]

The lever caps are designed for open systems not closed they won't let the fluid pass back into the radiator like it should as needed.

[Beagle]

I may have missed it - 190 doesn't bother me, 220 does... if you turn on the heater does it come down any? I'd consider that a radiator issue if it does.

Honda puts a purge valve on their old junk, maybe grab one of those from a wrecking yard? It'll look like the nut on the housing here:



they were really bad about trapping air bubbles. If any part of the fill opening is lower than the highest part of the cooling system, I'd put a vent screw in the highest location I could. I also sometimes forget to turn on the heater when filling them. I also sometimes forget to make sure the heater valve actually works like it is supposed to.

on an AT car, for the 150.00 or so a radiator costs, I wouldn't f* around much before I put a new radiator in it. Your tranny costs a lot more than 150... it may be wortwhile to get the original rodded but that may put you at the price of a new radiator too. (edit - maybe rebuilt and a core added)

Good luck with it, sorry if I repeated or said something you already answered.

[74NovaMan]

Thanks for the ideas guys. Here is where it stands now.


First start up details:

• Temps were good (nothing over 210 and running around 185 in town and on freeway) for about 200 miles.
• New water pump and thermostat
• New hoses (radiatior and heater)
• Old radiatior
• New chrome water neck (o-ring style)
• Same carb as previous setup.
• New MSD distributor - set at a very conservative advance.
• Heater core does not have a valve (open all the time)

When trouble started:

• Making no changes the temps started climbing to 220 in lower speed driving.
• Needle movements tended to be quick on the temp gauge up and down.

Stuff changed since then:

• New radiator
• New thermostat
• Drained and refilled coolant
• New radiator cap

Guage location: the intake port has a hose going right over it. I've always used the head locations.

I tested with a spare temp gauge this morning and it reads the same as the old one.

I pulled into the garage and the guage read 230. I opened the hood and pulled the release lever on the radiator cap and started the car back up. Temp was down to 190 immediately.
When I pulled the lever I could hear gurgling from the passenger side of the motor. Tells me I've got a bubble.

This should not be this difficult.

I'm going out to rotate the tires on plan B.