liquidpower

so my car keeps over heating on the high way if I drive for more then 45 mins. last year i put a new 4 core radiator, new water pump, i have the heater core bypassed going straight back to the water pump, a high flow 180 degree t satat. new fan clutch too.

I dont see any smoke out the back. going to get a leek down tester ( is there a better way to test this) and check and see if the head gasket is gone. I have herd that the higher rpm on the high way can cause the exhaust to get in the the anti freeze, or can this be a cracked head?

Thanks,

442Harv

Give it a compresson and leak down test.

Texas Jim

...and check on the oil dipstick f/ any sign of moisture, as w/ slight leaks, the moisture is very evident on the dipstick just after normal operation @ normal operating temperature. (ie; come from work, stop in the driveway, pop the hood and check the dipstick.) Any steam from the exhaust?

Rickman48

Start it cold with the radiator cap off and watch for bubbles throughout the warm-up cycle - a steady stream would indicate a head gasket/cracked head probem.
Olds motors are notorious for cracking exhaust seats between 3-5 or 2-4, as they're together almost.
If nothing, try premium fuel on the highway - if that stops it, you may have worn springs on the centrifigual advance in the distributor, creating a lean condition, thus overheating.
Or the carb is jetted too lean - initial timing too advanced.

liquidpower

on the way back home today ill check for the moisture on the dipstick i don't ever see any steam from the exhaust except in the cold mornings.

and rickman i run premium fuel and have a new distributor but i'm running with full vac on the distributor. i haven't changed any settings on the carb

arodenhiser

I did a real dumb thing once when I still had my manual fan. Bolted it on backwards. It pulled air from the engine an pushed it into the rad. Ran out at slow speeds, overheated on the highway. Have a look.

Adam

Boldsmobile

Define overheating. Gauge or light comes on? Or, it comes out at cap.

If the later also try a pressure test on the cooling system.

64Rocket

I have seen the stamp tin impeller blades in the pump break off.

Gene

liquidpower

Boldsmobile the as for the over heating it only happens when im on the high way. i installed a water temp gauge because the light was turning on. it looks like when i get on the high way the temp will be at 180(new t-stat correct opening) and then they just start to climb slowly. yesterday i drove about 6 mi going 65 and by the time i got off the highway it was at 200.

if i drive for longer it just keeps climbing. once i got off the high way though it calmed down and after about 5 mins in stop and go it went back to 180.

The fans on right and looks good, the radiator is missing one side shroud.

im going out today to by a compression tester

Rickman48

I'd try a radiator pressure tester, first.
Hook it up, put pressure in it, and if it doesn't leak, wire it down at get on the x-way.
When it gets to 200 - stop and check it again!! That shoud tell you for sure!
If you're not loosing coolant, and the cap is good, ????????
Are you sure about the fan???
Compression tester may not tell you anything, unless the engine is hot, and then it's a REAL pain in th a$$!!

liquidpower

I did the compression test with a hot engine and got the readings of 205 on all, except 3 and 4 got 190. the fan is good I have double checked it. I haven't lost any coolant, ill do the radiator pressure next.

also when pulling the plugs all of them had a good light brown color nothing weird about them.

Thanks guys

liquidpower

so hear are my findings after the radiator pressure test.

with engine cool i pump 16 psi in to and it holds for over 3 mins.

then i release the pressure let engine get to 180 psi now at 8ish then i pump full to 16 it loses psi at about .5 psi per 45sec.

IM GOING CRAZY. what dose all of this mean.

could there be a supper small leek in 3 and 4?

i cant take the radiator pressure tester on the high way because the hood wont close all the way with in on.

any thing else, OH i did hear from some guy at the store that his lower hoses one time had a collapsed spring that at high rpm would get sucked in and block some water flow. IDK about that one but im about to try any thing

liquidpower

so i guess the compression test and radiator pressure test where ok. the last thing that im seeing that i have not said is if i have the heater off once the tstat opens at 180 it will climb up to 210 and then back down to 180. if if the car is heating up to 180 with the heater on and i close it the temp will drop down 20 or 30 degrease. this is not normal right could the blocks coolant passages be clogged maybe.

Rickman48

Since you're in Florida, not using the heat much, get a 160 thermostat, and see what happens!
I've seen brand-new defective thermostats - they stick before opening!!
You can check that lower hose just by squeezing it - if it collapses by hand - the spring is gone!

matt69olds

Make sure the spring is in the lower hose. The water pump can suck the hose shut, causing overheating at high speeds.

liquidpower

ok so squeezing the lower hose and if i can close it then its the lower hose. ill try that next. the thermostat is opening right at 180 but if i have the heater turn on it will stay at 180 but if i have the heater turn off then right when it gets the 180 it will jump up quick to like 210 and then go back down quickly. but if i have the heater on and then right be for it gets to 180 i turn it off the temp gauge will jump down too 160 and then climb back up.

thanks guys i think it might be the lower hose

liquidpower

so the car is still over heating and it has always done this wared thing.
http://www.youtube.com/watch?v=B7aBJ...er_profilepage

when the heater valve is off the temp will jump around till the engine is all the way heated up. if the heater valve is closed it will go up steady till the t-stat opens.

also its over heating if it idles way to long and if its on the high way still

I cant squeeze the hose if the engine is hot but when its cold i can close the lower hose. i bought a new one whit a spring in it and that one i cant squeeze at all but have not put in yet. after a drive on the high way it looks like my radator over flow tube is wet maybe the cap is not holding 16 psi it gets up to 205 on the high way before i start to pull over.

today was 93 in Orlando

radiator is a 4 core less then 2 years old same with water pump and the tsata is a 180 high flow.

Rickman48

Today it's 45 in Chicago - NOTHING OVERHEATS!!
Put that lower hose on, and it should be fine!
Sounds like the thermostat is on its way out, too!

1968Cutlassfallbrook

Well from what I have spoken to my radiator guy he says that some 350s can get up to 215 and it's normal as they tend to run hot. I don't know if you have an overflow tank installed. i know when I put one in that it helped lowering the temp in my cutlass. Also run a 160 thermostat.

liquidpower

any idea about the weird worm up with heater on and off

Rickman48

In re-reading this thread, reminded me when I set an engine timing by ear, but there was mid-range gas in it.
With regular gas, it'd run much hotter, and no 'pinging'.
Try backing-off the timing 2 degrees - could be the vacuum advance at cruise speeds is a touch high!?!?!

liquidpower

well the new lower hose with the spring in it did not fix it. my car has had mid range in it ill fill up today will premium and drive for half a tank if that dose not fix it ill take the full vac off and see what that dose.

i thought that with the 4 core radiator it would be damn near impossible to make it over heat. guess i was wrong.

ill let you know what happens.

455man

Install an overflow tank. I got a cheap one for $15. Have you checked your air fuel mixture? If it's too lean it will get hot. So it's getting hot on the highway and at an idle? Fixing the fan shroud would help at an idle but not the highway. I'm assuming you have checked for a proper ratio of antifreeze and water? No milky look in the oil?

liquidpower

ya the antifreez to water is 50 / 50 just changed that all out and when i flushed it was not dirty and the oil is good too.

the air fuel is i think set ok i have the idle screws 3 turns out.

Shizzy

how do you have the heater core bypassed?

do you have a fan shroud on the car?

By "overheat" what temp are we talking? is it steaming and puking coolant or is it just running a little on the warm side?

64Rocket

Have you checked the vane in the water pump? Is it a stamp tin or cast impeller?

Gene

greenslade

you may have air in the cooling system.were you doing service to the cooling system before this problem occured?

liquidpower

i took the full vac off the distributor and drove on the high way for 20 min stayed right around 190 and never got hot at idle. im going to put it back on ported vac and then maybe full back but turn the timing down some.

Shizzy

do you have the vac advance on ported or manifold vac? It's supposed to be on ported vac.

liquidpower

i had the vac advance on manifold. right now its not running any vac advance

Shizzy

try it with ported vac and see how that works.

liquidpower

Hey guys so the dizy is now on ported vac now and its still over heating in the city same with no vac adv. i will test it on the high way with ported adv tonight and let you know(with out adv it was fine on high way). iv posted some pics of the fan shroud theres a small gap at the bottom of the radiator and theres no side flaps that cover the gap from the condenser and radiator. is this the source of all my head aches.

today the car got up to 210"


Thanks

liquidpower

possible 1 am brake threw!

i get on the high way temps clime super slow after like 20 mins its at 188 (tstat 180)
the temps all most at 190 when i put the car in neutral at 55 mph and rev the car up to 4k the temps drop fast to 180. making me think that the water pump moved more water, and then cooled the car down. the fan should have no effect at this speed 55mph wind is doing the work not the fan right?

i think when i put the new water pump in 2 years ago it was a tin impeller.

so it sounds like this is my best bet right? god i hope so

455man

Fan shroud will only affect the heat at low speeds. That side piece will have a small affect on the highway. looks like the bottom just needs tightened up.

Could be water pump but really 188 on a 180 thermostat is not that high. Placement of the temperature sensor and accuracy of the gauge makes a difference. When it gets over 200 then it's a problem. What was the temp outside when you were driving?

liquidpower

last night it was about 70 or so. i mean it wasn't staying at 188 it was climbing slowly. when i got off the high way for the 3 mile drive home it got back up to about 199 i have a good temp gauge and its in the standard temp spot.

but with all of this happing and a 4 core radiator something has to be wrong. right?(or am i just thinking that the 4 core can do too much) i mean i'm not towing any thing or giving it WOT all the time.

i mean a small gap in the fan shroud shouldn't let it get up to 210(and it will keep climing i always shut it down) in the city with a high flow 180 tstat.

455man

Yeah I agree. Something is wrong. Running out of ideas though...

liquidpower

I squeezed the uper hose and didnt feel any water flowing through. Im going to try and make clear tube in the uper hose and see if I can see the water flowing

greenslade

does the top rad hose heat up?is there presser in the system,check rad cap.

liquidpower

yep top hose gets hot there is presser in the system too

liquidpower

http://www.youtube.com/watch?v=6YReJyjB-yQ turn down the sound. i took out the tstat and then bumped up the idle and theres a good amount of water not flowing threw the cores it looks like

what do you guys think