overheating....help!

[67cst]

hey guys, got the new motor fired up today, she purrs like a kitten but its getting really hot, like HOT. wtf.....antifreeze is topped off, (mixed 50/50), new thermostat etc..i cant figure it out, anyone have any ideas?

thanks, DEREK

[RACINJASON22]

Timing ?? Maybe ?? more info

[watahyahknow]

waterpump maybe if you got one for a serpentine belt it might run the wrong way

[67cst]

its an edelbrock water pump, regular short sbc pump, hmmmm..dont mind my stupid questions guys im by no means a mechanic, but what would timing have to do with overheating? im wondering if maybe my gauge is or wiring could be the problem....

[bucket]

i had similar problem during my break-in. squeezed the upper hose while running to "burp" the air out of system. was then good to go.

[timcos]

I would first take the hose off the heater core that comes from the intake manifold....see if water is flowing...hang it over the front of the truck...while csomeone cranks it over...for a second or two.

Good water flow?

Then...make sure the thermostat is in the correct way so it opens..

I would start there...make sure the water is flowing.

[GMCMAX]

I did that not paying attention and put the intake gaskets on the wrong sides and blocked the water ports. pulled the stat and could see the blocked port on the one side.

[FarmTruk]

I do not claim to know a lot either, but excessive ignition advance is a possible cause of overheating. Also, too lean of a air/fuel mixture will lead to overheating.

Not all new thermostats work properly. The operation of the TS can be checked by placing it into a pan of water, heating to boil, and checking for opening.

I'm sure others here can add/expand on this...

[ThatOneBlue67]

Does your temp gauge's wire touch the driver side header or anything? That would set it off I should imagine. I believe the temp gauge plugs in somewhere near the driver side exhaust manifold. Or at the top of your intake manifold if it is aftermarket. Either way, excess wire could always find its way to the header.

[67cst]

thanks for the ideas guys, the temp sensor is on the intake and the wire is inside a sheath i guess you could call it. the top hose is one of those stainless flex hoses so i cant really burp it, ill try the heater hose idea next. thanks guys, DEREK

[cooters]

actually if you do not enough timing, this will cause extra high cylinder temps. What kind of temps are you talking are you having? New motors tend to run hotter at first

[dmec]

have you checked the radiator cap? if radiator is not pressurised it will boil over.

[67cst]

the rad cap is new, its 16 psi cap. the needle on the stock gauge is basically pinned after about 5 minutes at idle

[trkklr77]

the gauge reads hot but how does it acttualy feel? can you comfortably hold your hand on the rad or upper hose?

can you smell burning antifreeze?

if you pop the cap off is it exploding all over to get out or just quick brust and thats it?

[hvychve]

verify the gauge isnt lying to you, I use to have another temp gauge before I got an infrared tester, I use to use another gauge, just screw into water jacket and hang on fender or where ever, if its pegging in five minutes, the thermostat should be changed regardless of it working or not, once its gotten hot , you distort the stat, dont take a chance on it, I would guess you have probably already tried another stat, if not, that would be the cheapest and easiest, next, yes , excessive timing will cause overheating issues, but first verify the actual temperature with another gauge or infrared tester, New motor, doesnt have excessive compression with too big of a bore? big bores cut away the material used to keep cylinders cool along with high cmpression, I would assume at this point you are stock . What about the radiator plugged, you dont have issues with air flow blocking the fins in the front? what about the cores inside the radiator, anytime I install a new engine, I always have radiator rodded out . you should be able to see when the thermostat opens with radiator cap off and engine running, you would look down the neck of rad. and eventually see the flow begin. this indicates stat. opening. You say it idles and runs good, this would indicate to me its not overly lean, yes an overly lean condition will also cause it to run hot.
first you need to verify gauge is in fact true, if so , start eliminating. good luck

[hvychve]

forgot to mention , but what about the belt that drives the water pump, its not slipping and you have the right direction of spin on the water pump, do you have a clutch fan, and is able to pull air into engine. should be able to put hand in the area of the fan and see if any air is being pushed across engine.....

[67cst]

hvychve, thanks for all the great info, ill get another gauge and start there.

Derek

[67cst]

well it looks like everything mechanical is fine, turns out it is the stock gauge acting up, or so it looks. i bought a cheapo mechanical gauge and installed it with the sensor it came with and it reads about 190* degrees once its warmed up. looks like ill be replacing some gauges here, i was thinking about maybe going with one of those dash pads with the gauge pods, that way i wont have to mess with my original cluster and wiring. ill have to do a search or perhaps start a new thread on those dash pads b/c i dont know where you can even get one, anyways thanks for the help everyone

[67cst]

i picked up a cheapo gauge and hooked it up, this is what it reads... is this a normal temp when the truck is idleing?

[RACINJASON22]

looks good Imo what degree themastat do you have.

[[ol'Blue]]

what thermostat you running?
and what Pressure rating is your radiator cap?

[[ol'Blue]]

RACINJASON22 barely beat me! at that question

[67cst]

160 degree, its just a summer cruiser and the guy at the parts store recommended that stat..sound right?

[RACINJASON22]

The 160 stat will be fine for you summer cruiser that way it will stay open for better cooling the higher stat standard 180 is to keep heat in the engine for heater purposes.

[RACINJASON22]

BTW as stated before timing will effect temp. both ways adv. and retard. Also to get the best performance out of you engine I suggest proper timing adjustment. Just my .02