overheating help

So I just finished the rebuild but the dang truck overheated (well almost, I didnt let it go all the way up) again right away. I never did take the head in the be checked b/c the previous owner had just done it (it still looked all shiny and what not) but he had overheating issues too. So I already did the radiator. I put in a new thermostat (with the bleed hole at the top). I did not check the heater core but I will check that. Anything else anyone can think of? I could hear water bubbling in the intake manifold area when was heating up.

forgot to say i'm obviously going to pull the head back off and send it in this time, but can a clogged heater core do this? timing was right, i checked...

so i took it out for a drive and it has a thermostat but it took a good while for it to get hot. i noticed that even while it's cold outside, if i let it it coast in neutral down the highway, it does not get any cooler at all. wondering if the water is not flowing. so i'll get the radiator checked and the heater core too.

any ideas welcome here guys, i'm starting to feel like im in isolation on this thread... :l

are you sure the water pump is circulating??...sometimes the cheap plastic impeller ones crap out and don't cycle the water

i cant really tell... i didnt put a new water pump on but i did take off, inspect and reinstall the old one. but it was fine, didnt even look worn at all, and it didnt bleed out of the bleed hole. the radiator and heater core are the only things that would really make sense but i've never had either go wrong on a car before...

if your curious if the heater core being stopped up then just get a piece of hose and bypass it. then watch the temp gauge to see if it happens the same way or if it doesnt. take the radiator cap off to see if its circulating. also leave the cap off to keep the pressure off and if it doesnt overheat then there could very well be a crack somewhere. ofcourse do all these steps one at a time so you get a proper diagnosis






-justin

try a quick check of the radiator...pull the upper and lower hoses and jam a garden hose in the top inlet...see how long it takes for the water to come out of the bottom...if it takes a little bit it's due for a good cleanout..any decent radiator repair shop can clean it properly pretty cheap...also! just thought of it...double check your timing...if you are running way advanced it can run engine temps alot higher in turn making it over heat...

btw...double check your temp switch to make sure it isn't going bad..just unplug it when the truck is up to temp and have someone ground it against the block to make sure it isn't a bad switch

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