vipershark11

iTrader: (6)

i just put in a used 350 in my firebird a couple weeks back. it has a comp xe268 cam, procomp aluminum heads, ported tpi and such, 160* thermostat brand new, dual fans, headers, brand new water pump, arap bin(modded), etc. the car heats up slowly but when just idling or going at low speeds the car just heats up and the guage keeps going past 220 when before the motor it only went 1/4 way on the gauge. last night it hit 3/4 way mark and i shut it off and the fenders were burning. however if i drive on the highway it doesnt overheat. what could be causing this? my fan turns on at 159* and it works i checked. thermostat works and is brand new. water pump is brand new delco. i dont get it my 305 i had before never overheated.

mawinc

If it heats up sitting still check to make sure you have the correct rotation water pump. The fans may not pull enough air if it overheats at slow speeds or at idle.

jamon8

iTrader: (3)

defector shield

doc221978

Correct water pump? Radiator flushed? Stock y-pipe/cats/muffler? Stock fan?

I had put in a aluminum radiator and twin fan.... my firebird still overheated until i completely replaced the exhaust. It is so restrictive it actually heats up the engine a lot, but mine would even get hot doing 70 down the road. It sounds like you just need a better fan setup.

impaled

make sure that the water pump is correct rotation, the rotation was changed in 87 or 88, i dont remember for sure, but that could definietly cause issues.

i would wire your fans to an on/off switch that you can control. it is relatively simple.

is it the stock gauge? i wouldnt put much faith in the stock gauge on any third gen.

BASSETT IROC 85

iTrader: (2)

Intake gaskets upside down?

vipershark11

iTrader: (6)

my air deflector is in perfect shape. i used this water pump on the 305 for about 50 miles and it always cooled the motor. intake gaskets were installed right both sides were open anyways and it was closed on the intake manifold in back. radiator was emptied a month ago and the antifreeze was clean. i used a datalogger to tell the water temp. the dual fans are stock but only 1 turns on because i dont know how to tune for the second fan in $6E so maybe thats it. the exhaust was all replaced, has headers, 2.5" y pipe, gutted cat, 2.5" mandrel catback, spintech muffler and dual 2.5" tips.

i actually have a hunch that the lower hose is being crushed and restricting flow so ill check that this week cause i remember it was a tight fit. btw the 1 of 2 fans was run on the 305 that was also modded and that kept the temp around 160 like it should be.

impaled

what i was suggesting was that GM changed the direction of rotation of the waterpump at some point in like 87 or 88, so if one engine was pre 87 and the other was after, that might cause issues.

vipershark11

iTrader: (6)

o crap, then you might be on to something. because i believe its 88 or older and my waterpump is 89 and newer. damn.... ill look into it thanks.

black89ws6

The rotation of the pump was changed in 88. It was changed when they went to serpentine accessory drive.

V-Belt drive = pump runs off the inside edge of vbelt, rotates same direction as engine.

Serpenting belt drive = pump runs of the back side of the serpentine belt, thus rotates in the opposite direction as the engine.

I ran the wrong pump for my application for a few years. The car would get warm standing still, or under high load (120sec standing burnout), but during normal driving, never indicated a problem.