Serpentine cooling Issues..HELP

[trev1]

I am in need of some guidance...

I have an early model 350 block, bored .040 over, 193 heads,202grind cam,flat top pistons,edelbrock intake and edelbrock carb. I put a serpentine setup on it from a 97 350 out of a silverado. I replaced the water pump with a new reverse rotation water pump. Did not want to skimp on it. . Looking at the engine the water pump pulley is rotating counter clockwise. It's turning the proper direction. Cooling is a reg radiator, with pusher fan. I am having overheating problems.

Here is what it is doing..
engine starts and idles fine, but shortly the engine temp guage climbs steadily to 200 plus. The thermostat opens and the temp climbs to 220 plus. The cooling fans come on around 195. The engine overheats.

I did notice that the bottom rad hose is hotter than the top rad hose. The heater hoses are both hot, the heater blows hot. I know I have a circ problem. But can't find it. The rad is not plugged it flows freely.

Here are some pics of what I have. Any help will be appreciated. Tomorrow I am going to pull the thermostat and hook everythingup, and see if its flowing backwards. Don't think it is but anything is possible.

[HavinSomeFun]

I'm not sure the 97 is a reverse flow deal...

[Lee H]

How did you determine the engine is overheating?
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[wzuke]

Cooling system may have an air lock. I bled the air out of mine by loosening the temp gauge sending unit in the intake and let the air out -- I could actually hear the air coming out. You might also drill a 1/8" hole in the thermostat.

[screamin_c10]

Where are you measuring your temp? If in the head then you will read higher than the intake. I also bleed the air out at the intake.

[Longhorn Man]

the head is where he is supposed to be getting a temperature reading.
I suspect you have the wrong pump. Did you go to the parts store asking for a reverse rotation pump for a small block... or did you say I have an old motor with a serp conversion added?
Don't give the (typical) parts guy more info than he needs. You need a pump for a '97 5.7? That's what you ask for.
A pusher fan is not ideal. While I doubt it is your problem, if you are able to mount it on the back side and have it work properly, it'll work better. Better yet, a quality fan clutch on a mechanical fan will last you a long time and work better.

[trev1]

When i went to Orielys I asked for a water pump for a 97 Silverado with a 5.7l. Thats where I found out it was a reverse rotation pump. I am using a Equos temp guage that is mounts in the intake beside the water neck. The serpentine belt is routed correctly, it causes the water pump pulley to turn to the left wnen you are looking at the engine. I am going to get a different thermostat today, and see if that is it.

After a couple of hours of web surfing, I believe that I can have four or five problems.

1. Wrong water pump
2. Head gaskets installed wrong
3. Faulty thermostat
4. Blown head gasket
5. Air locked engine

Too address these I plan on doing the following.....

Im going to get a new thermostat installed today.

Im going to bleed the system at the Temp sending unit.

Dont think the head gaskets are faulty. No steam or vapor out the exhaust, Im not losing coolant anywhere.

The water pump will be the last resort. I will double check the # I was given if I can locate the reciept, If not when Im at Orileys I'll have them look it up. It a warranty Item. I didnt skimp on it. WAY WAY WAY too much tied up in this engine.

I found the reciept for the pump. MWP 58-147. Going to look it up on the web in a min.... Heck I even paid a core. LMAO

[cdowns]

first thing to do with overheating issues is to verify accuracy of the gauge you are using

i take a known good thermometer and take the actual temp of the coolant// some guys use the new school way with the infrared thingys

i've seen plenty of guys spend many a hurndreds chasing an overheating issue when a good check of actual temp would have saved that money for better tthings

[trev1]

I agree Cdowns... Ill get the wifes thermometer from the kitchen..shes goin to kill me for that one..haha...
I looked up the water pump, it was the first one I bought. I returned that one and then got the one for the 97. As i remember. I'm still diggin through all the reciepts to find the exchange one. It's there somewhere.

When the thermostat does open it boils over. I honestly think the thermostat I got is a POS...And its compounded by being air locked...

[midniteblues]

I know once a buddie had the same problem and when i looked into it i found he put the thermastat in upside down.ha ha b4 i fixed the problem i confonted him on it (theres no way i did that!) had to show him to beleive it

[trev1]

OK WE FIGURED IT OUT!!!!

Went to Oreillys and bought 180* bypass thermostat, and new gasket. Took the old one out. It WAS installed correctly. Took temp sending unit out of intake, and heater hose from the water pump off. Filled with coolant and when it ran out of the holes and hoses put them back on.

Fired it up and it ran up to 180 and the thermostat opened, we then had to add another 3/4 gal of coolant. We then let the motor warm up and let the thermostat open up a couple of times. Shut it off and walked away. Came back when cooled off topped the coolant off and it ran for a long time and never offered to go over 185*.

Long story short... The engine was terribly air locked and might have had a bad thermostat. I'm taking the POS back to Oreillys tomorrow to get my money back.

[litew8]

I installed a fail-safe thermostat.
Upon system failure, FAIL-SAFE locks in the open position. Coolant flow freely. Helps protect the engine in the event of over heating

[screamin_c10]

Originally Posted by Longhorn Man

the head is where he is supposed to be getting a temperature reading....

I am well aware of that... My worry was that he may have had an intake mounted sensor previously and then he swapped it to the head, where it would look like (on the gauge) that he was running hotter.

Glad to see it was only in need of a good burping...

[trev1]

Ok, I dont know how to get the quote to show up. But... I have never heard of measuring the temp from the head. Don't even know where to mount the temp sending unit in the head. If someone has a pic it would be helpfull. As far as the failsafe thermostat it never dawned on me to get one. It seems tobe the "smart" thing to do. With as much time and money I have invested in the engine, it would probally be worth it.


As far as the "Good burping", it was much more like a belch after the bottom part of a 6 pac!

Thanks for all the suggestions. Keep them comming. PLEASE

[domeier]

My 350 is guaranteed to air lock whenever the cooling system gets messed with. I go through all the motions, thermostat, gauge, flow, and it always turns out to be air.

[litew8]

For a temp sensor in the head, check my build thread. I've got pics.

Originally Posted by trev1

Ok, I dont know how to get the quote to show up. But... I have never heard of measuring the temp from the head. Don't even know where to mount the temp sending unit in the head. If someone has a pic it would be helpfull. As far as the failsafe thermostat it never dawned on me to get one. It seems tobe the "smart" thing to do. With as much time and money I have invested in the engine, it would probally be worth it.


As far as the "Good burping", it was much more like a belch after the bottom part of a 6 pac!

Thanks for all the suggestions. Keep them comming. PLEASE

[rpmgroup]

primary temp should come from the head location rather than the top of the intake manifold and never from the the thermostat housing, as the sender work immersed in liquid and not in air or steam.

[litew8]

Since I've got an electric fan, a temp sensor (for it) is located in the head. The sensor for the dash gauge is located in the intake manifold.

[stsalvage]

I have a question.In the 1997 engine Are you using a Carb or the fuel injected If you put a carburetor on a fuel injected motor you need to change the Cam the Fuel injected cam is different then the the carburetor Cam different cam lobs

[Andy4639]

I have the 305 HO out of a 96 Camaro you can barely see the senor connection between the #1 and #3 spark plugs. The blue connector.

[trev1]

I am using a Edelbrock 2104 intake a Edelbrock 500 carb. The Cam is an Erson 110044 292* 480* 108* duration. It is not for an Fuel Injected engine. I am going to look at my heads to see if I can see where the temp guage could go. But it will be this weekend the truck is up at the father-in-laws garage. The temp guage iscurrently located in the front part of the intake. Not in the thermostat housing. Just used it as a reference point for location for everyone.

Can anyone give me the reasoning for the temp guage in the head and not the intake.

[BIGKEV]

Originally Posted by stsalvage

I have a question.In the 1997 engine Are you using a Carb or the fuel injected If you put a carburetor on a fuel injected motor you need to change the Cam the Fuel injected cam is different then the the carburetor Cam different cam lobs

Are you referring to the 97 being a roller cam or the fact that it has wider lobe separation? Either way there is no need to change the cam unless there is more to be desired!

[sleepertruck72]

Can anyone give me the reasoning for the temp guage in the head and not the intake.[/QUOTE]

The best idea I can give you is to think of it as the human body. When a nurse takes your temperature, they prefer the rectum which can be thought of as the cylinder head. Thats where the combustion takes place and where the coolant would be the hottest as well as our body temp. If they take the temp. reading off the surface of our skin , or the intake manifold, the temperature would be cooler because it had a chance to dissipate some heat while circulating away from the combustion chamber... I think that makes sense

I have the same set-up on my engine, I have the same water pump pictured. The smooth pulley would indicate it is reverse rotation. Grooved pulleys would usually be regular rotation. I was lucky enough to have no problems with the cooling system but I used the AirLift system that pulls a vacuum on the cooling system and then refills it without any air pockets. It works awesome but you must have a good air compressor for it to work... I think I drank too much tonight

[Meatman]

Oreillys thermostats are total junk. And they fail safe ones are a joke. Only thermostat I buy is a Stant.

[litew8]

I agree, most mainstream things are junk nowadays. Stant may be better, I don't know, but their website is a joke. It doesn't align in 2 diff browsers.

Originally Posted by Meatman

Oreillys thermostats are total junk. And they fail safe ones are a joke. Only thermostat I buy is a Stant.