Truck is getting hot....

[64c20crewcab]

Here is whats going on:
Driving around during the day stock guage hits mid way if not hot. At night it does the same but takes a bit longer. On the freeway - forget about it. The needle get to just shy of being pegged to the right in the red. It may be the guage so I have guage from 66 cluster I'll try out later today. Also have a hand held laser thermometer that I'll use at the theromstat housing to get a better reading.

Here what I'm running:
1980's Goodwrench 350, TH350, Eaton rear w/t4.56 on 32" tall tires - we all know that is still tachs pretty high.

When I bought the truck it had a chrome , have round shroud/shied over the flex fan that mounted through the radiator. Flex fan was and still mounted to the pump on a 1.5" spacer.

Here is what I've replaced/done in recent past: full shroud, pump, rad & hoses, 160 thermostat, housing and temp sensor on the housing, flushed the system and added new coolant @ 50/50 mix, burped the system.

When I replaced the shroud with a repop for a 64-66, the flex fan now sits all the way inside the shroud. Is this correct? See pic below.

I've read info long ago that the fan should be sitting flush on the pully and not on the spacer. Possibly sitting 50/50 inside outside of the shroud. Did I read / understand this correctly?

Also have a new 19" fan and fan clutch sitting around that I thought I'd install. Will this help?

Can anyone here please confirm or advise here?

Thanks Guys!

[Chevy Fleetside]

if you changed the sensor to a new one it might not really work with your gauge. I had that problem and used a 32 ohm resister to get it almost right. I used to heat up the engine and when the water circulated I used a thermometer in the radiator and it only go up to about 200º, this is when the needle was pegged and the resister fixed that problem. I had replaced the sensor with a so called one for a 65 chevy truck from one of the suppliers.

Also. Look in through your radiator cap and see if the cooling tubes are clogged. That will do it also especially on the freeway.

[MacAttack]

You might also consider a radiator cap with a mechanical gauge built right in - just for back up reference.

[rss396]

My 61 has a very similar heating problem. Over the years I have been told the faster you go the hotter she gets the problem is the radiator is plugged or to small of a radiator. I inspected mine and sure enough the core is plugged. The fan and shroud has little to do with cooling at highway speed because there is plenty of air flow at highway speed. IMO you need to have the radiator rodded out.

[64c20crewcab]

Thanks for the replies.

Went out and hunted for a cap with a guage. No luck. Seen them before but forget where. Rad is less than 1yr old as is the rest of the cooling system. It looks fine no blockage. Laser temp reading showed no cold spots on the rad.

Since I've been out of work the past 3 mos, $$ has been a bit tight. I have a big interview tomorrow some 20 miles out. I needed this issue to be resolved yesterday. So to start with I decided to just go through the whole system and tighten all bolts and screws. The engine bay aint the nicest, but there is not much oil, dirt,etc. There was some build up around couple of spots below the water pump. Well it seems the lower pump bolt on p-side was able to take nearly a full turn! Tightend all up and then ran the motor without the cap for nearly 30 min to purge any air. Well all seem fine now.

Drove around for nearly an hour and all seems so much better as it should. Guage working but still not right. Laser reading at the thermostat housing read 178 and the needle was almost completely to the right. Will swap out the guage with another from a 66 this weekend. That should do until I find another for a 64.

Guess I need to get another truck just in case the beast goes down for awhile.

Thanks again!!

[joe231]

not to stray off the subject.....but good luck with the interview...i was off work for a month last summer when we moved back to Ok from Ak.....bout drove me nuckin' futs...you must be very patient with a decent savings account to make it 3 months

[64c20crewcab]

Hey Joe, Thanks! Just paid off all the bills on the last check prior to the AT&T layoff. Only had rent to handle and sold off much of the parts I had saved up for my truck: full OEM A/C system and other parts. Also rented out 2 rooms in my rented house to friends to make it through. Been lucky for the most part. Hope 8-8-08 is lucky day!

[MacAttack]

http://store.summitracing.com/partde...5&autoview=sku



Mac.

[joe231]

yeah i've been there....sold lots of stuff to make it, but you gotta do what you gotta do
let us know how it goes

[64c20crewcab]

Mac/Joe - Thanks!

Y'all,

Well guage is all over the place on thedrive back from interview. So I'll be swaping out here in just a few min. Lazer temp reading 175 at t-stat housing where the sending units is. Guage reads HOT.

Interview went very well. Its promising but they need a week to make a decision. Position is for Telecom Engineer/Design Coordinator with T/W Cable. Keepin my fingers crossed!

Now out to the garage to do some beer drinkin and truck wrenchin -
cause its 5 o'clock somewhere!

Thanks!

[slepysal]

you might want to check your lower hose too. Have some one step on the gas and see if the loewr hose sucks into it self ,that might be the problem Good luck

[Throwback]

it might be the water pump not circulating water enough water through. Possibly something clogged in it that is causing it to heat up

[Anthony Fremont]

Originally Posted by 64c20crewcab

Mac/Joe - Thanks!

Lazer temp reading 175 at t-stat housing where the sending units is. Guage reads HOT.

It's not hot, the gauge is lying. Just to be sure, take a reading off the ends of the heads (where the accessory holes are). If it's only 180ish, you're fine. Your sending unit is not matched to your gauge. Good luck on the job.

[64c20crewcab]

Originally Posted by Anthony Fremont

Your sending unit is not matched to your gauge. Good luck on the job.

I thougth that may be the case. Any suggestions on what i need to do here? Is it as simple as getting a s.u. for a 64 C20?

btw - I REALLY DIG THIS FORUM! So helpful and NO TUDES!

Thanks Guys!

[justcuz]

Norm you should be able to get it at any good auto supply. It may be the same as a Chevelle or passenger car of the same year. It has a connector on the top for a slip on spade connnector IIRC. Kind of looks like a little mushroom head.

[Bob66]

Keep an eye on your flex fan my friend, those things crack around the rivets after a while, I had one let go once and it swung out like a switch blade and sheared off my upper radiator water neck, chopped my bottom hose and tranny cooler lines. But that was a Ford, so it couldn't ever happen in a Chevy, right? Just a thought, does your radiator have a transmission cooler built into it? do you have an auxiliary tranny cooler?

[justcuz]

Norm, I would install the 19" fan and clutch too. I prefer them over flex fans for 3 reasons. 1. they are quieter 2. They work only when needed and freewheel when not. 3. The fans are more heavy duty than a flex fan (move more air).

[64c20crewcab]

Originally Posted by justcuz

Norm you should be able to get it at any good auto supply. It may be the same as a Chevelle or passenger car of the same year. It has a connector on the top for a slip on spade connnector IIRC. Kind of looks like a little mushroom head.

Cuz,
The s.u. I replaced last year was for the year of the motor - '85 and earlier. Looks as you describe but will go out and get another for a 64-66 truck - if possible.

Originally Posted by Bob66

Keep an eye on your flex fan my friend, those things crack around the rivets after a while, I had one let go once and it swung out like a switch blade and sheared off my upper radiator water neck, chopped my bottom hose and tranny cooler lines. But that was a Ford, so it couldn't ever happen in a Chevy, right? Just a thought, does your radiator have a transmission cooler built into it? do you have an auxiliary tranny cooler?

Bob, Will be swappin out the flex fan today for the fan & clutch. Will take a look at the flex fan too.

Did some reading up on 19" fan install yesterday. According to the info fan should be 2/3 inside the shroud and 1/3 outside. This answers my earlier question. Yes the new rad has a built in tranny cooler and no aux cooler.

Swapping out the rad support as well. Passenger side frame mount rotted out sometime before I bought the truck in 05! Recently found a decent replacement locally. I cleaned, prepped, and coated with POR-15 black and fogged with Rustolium flatback yesterday/lastnight. This will give it a duller finish and not the high gloss finish. Hides some of the brush strokes as well. Will have the other rad support repaired, blasted and powdercoated in the next few weeks.

THANKS GUYS!!

[Anthony Fremont]

You might want to consider an electric fan. I put a 14" pusher in front of my radiator. I don't actually drive my truck yet, but I've let it idle/run in the driveway for extended periods (30 minutes or more) while tinkering. This is in houston on a typical 95F day. The engine never got to 185F with a 180F thermostat. My fan cycled on and off running way less than 50% of the time. It uses a sensor in the intake next to the water neck, my temp gauge uses a sensor in the head. I was lucky enough for the factory to include a 3 core radiator though. It really cleans up the engine compartment IMO. I still gotta take that fan extension off and put in shorter bolts, but I've been waiting till I can swap the pulley out for one that is polished aluminum.

[64c20crewcab]

Anthony, thanks for the info and pics of your setup. Yes it does clean up the engin bay!

Because I'm not working yet, I'm trying to resolve this on a pennies and dust budget. Gonna install the fan & fan clutch today.

Went out to find a proper sending for the 283 that orignally was in my rig. Noting in stock yesterday. Another local shop should have one in stock today. This hopefully should take care of the false guage readings.

Rad had some residue in it so I spent most of yesterday flushing the cooling system. Rad does have a small weaping leak around the trans cooler bung on lower passenger side. I'd take it back but the shop is 80 miles away in near San Diego. I'll do a cold weld repair (j-b-weld) on this in just a few min. Thanks guys!

[VDOG]

My 69 keep showing the idiot light as being hot, but my truck was not.
I purchased a temp gauge from Kragen installed it, now I see my true temp.
For now, I would get an aftermarket gauge, then later on in your build you can get the correct parts for your dash temp gauge. Just a thought.