OVERHEATING

[tassie wombat]

--------------------------------------------------------------------------------

just fitted a 350 into my 88 gq and im having trouble keeping it cool on the road,it will sit at idle all day long and wont get past half way on the gauge.radiators been serviced(tanks off etc) running engine driven fan with shroud.has anyone else had this problem and cured it? any help would be graetly appreciated,thanks

[its aford not a nissan]

either the radiator is too small
the thermostat is stuffed
thermostat too cold causing the water to flow too fast
guage isnt accurat and the water temp is actually fine

heaps of possibilities

[tassie wombat]

thermostat is new(have checked it in hot water,its opening ok) im pretty sure the gauge is ok because when it gets up near the "h" mark the engine will "ping"(it wont do this when at normal opperating temp)

[its aford not a nissan]

thermostat is new(have checked it in hot water,its opening ok) im pretty sure the gauge is ok because when it gets up near the "h" mark the engine will "ping"(it wont do this when at normal opperating temp)

this ping could be an indication of the timing too far advanced which can cause overheating , it may even be running too lean , but that normally results in backfiring through the carby

try backing the timing off a little and see what happens
and check the guage for accuracy

[tassie wombat]

timings spot on,mechanic set it using a vacume gauge,its about 9' advanced on the light.
spoke to pwr who reconed the std radiator should be ok.also spoke to aussie desert coolers who said the std one is not large enough(they make a 4 row one that bolts straight in)? im running out of ideas!

[SilverBulletBM]

Most of the overheating problems ive seen where the car is fine standing still but overheats when driven is from air blocks in the cooling system, are you sure its bleed up right? The easiest way ive found is to get a bottle that just fits in the radiator opening (1L coolant bottle fit well), rap some electrical tape round the thread on the neck, cut the bottom off and stick it in the radiator opening. This raises the coolant lever higher then the engine making it the highest point, and forces the air out.

[Rhysta]

Whats in front of the radiator?

Anything that could prevent decent airflow?

[tassie wombat]

Most of the overheating problems ive seen where the car is fine standing still but overheats when driven is from air blocks in the cooling system, are you sure its bleed up right? The easiest way ive found is to get a bottle that just fits in the radiator opening (1L coolant bottle fit well), rap some electrical tape round the thread on the neck, cut the bottom off and stick it in the radiator opening. This raises the coolant lever higher then the engine making it the highest point, and forces the air out.

tried that! and its got the air con' condenser in front of the radiator,arb highmount winch bar(with low mount winch fitted,and a pair of 7'' driving lights.

[bogged]

Spoke to aussie desert coolers who said the std one is not large enough

then why are you looking elsewhere? get a bigger radiator.

[jessie928]

--------------------------------------------------------------------------------

just fitted a 350 into my 88 gq and im having trouble keeping it cool on the road,it will sit at idle all day long and wont get past half way on the gauge.radiators been serviced(tanks off etc) running engine driven fan with shroud.has anyone else had this problem and cured it? any help would be graetly appreciated,thanks

the GQ radiator is plenty enough to cool a standard to mild 350 on the road.
is the engine driven fan fixed or does it have a fluid coupling attached?
if it has the clutch, it could be buggered.

whats your pulley size on the engine, has it got a good water pump?
are you running 50/50 coolant?

do you have any obstructions in front of the radiator?
what about your radiator cap is it keeping pressure at highway speeds?

Jes

[ANDREWGQ 351]

I had exactly the same problem with my reco 351, i switched in a worn out cool running 302 from my XY and the same problem occured.
The 351 went into my XY and had no problems at all.
I eliminated the air con, added a reverse bonnett scoup, removed the inner wheel arch rubber bits, used water wetter and fixed the viscous fan solid.
played with mixtures, timming and when it overheated it would ping.
for a few days i ran with no grill or highmoung bar with only minimal improvement. i even ran with no bonnet, things didnt change.

My conclusion was the new 3 core radiator i was using did not have the cooling capacity to cope with the extra heat created at highway speeds or under high load.
As i was runnig straight LPG i used the fuel tank to hold water and then used fog sprinkler nozzels behind the grill to mist the radiator, these turned on when the temp hit 97 deg.
On a 38 deg day i used more water to keep it cool than fuel to drive

[tassie wombat]

Spoke to aussie desert coolers who said the std one is not large enough

then why are you looking elsewhere? get a bigger radiator.

im looking elsewhere because i want to make sure that the radiator size is the problem,half of the people ive spoken to say the std radiator should be large enough,i dont want to spend $750 to find that the radiator isnt the problem!

[tassie wombat]

--------------------------------------------------------------------------------

just fitted a 350 into my 88 gq and im having trouble keeping it cool on the road,it will sit at idle all day long and wont get past half way on the gauge.radiators been serviced(tanks off etc) running engine driven fan with shroud.has anyone else had this problem and cured it? any help would be graetly appreciated,thanks

the GQ radiator is plenty enough to cool a standard to mild 350 on the road.
is the engine driven fan fixed or does it have a fluid coupling attached?
if it has the clutch, it could be buggered.

whats your pulley size on the engine, has it got a good water pump?
are you running 50/50 coolant?

do you have any obstructions in front of the radiator?
what about your radiator cap is it keeping pressure at highway speeds?

Jes

ive tried the fluid coupling as well as a fixed flexi fan,i think both crank and water pump pulleys are roughly the same size(as it is on my k20 ute) water pump is brand new,im running about 30% coolant.there are a few obstructions,ive got the air con' condensor,arb highmount winch bar and a couple of driving lights.

[tassie wombat]

might have found the problem,had the engine running tonight after re fitting the std radiator(had it modified to make it a tripple flow) and i noticed the bottom radiator hose sucking in when the engine is revved! go to repco tommorow and get some new hoses.

[cooki_monsta]

fix that problem by putting a hose in with a spring never collapse again

[tassie wombat]

well the spring stoped the hose sucking in,but it didnt fix the overheating problem,back to square 1!!!

[stool]

Its not a reverse flow water pump is it

[tassie wombat]

Its not a reverse flow water pump is it

nah,that was one of the first things i checked.looks like the larger radiator might be my last option!

[stool]

Ford EL thermo fans will sort you out

[tassie wombat]

might have found the problem,pulled off the arb high mount bar and put the old low mount winch bar back on and it didnt even get past half on the guage!

[vcharter]

it all to do with air flow i run a 351 windsor with 40 over bore and found that 3core and el fans work well as fords dont like being bored over 30 as this makes them thin in the bores and run hot but this combo works even on a 40 degree day off road ,and all like i said air flow on gq,s no d,lights or no.plates or high mounts in the way of air flow.

[Renton]

have you had the radiator unblocked/cleaned out? if its fine at idle but getting hot on the highway thats where i'd be looking first. i don't think thermo fans will help on the highway but more at lower speeds where you don't have the airflow.

[tassie wombat]

the radiators been flushed,i think i might have to re locate the aircon condensor(not sure where??),even with the differant bar temp still crept up this arvo going up a big hill.also still think i might move the radiator closer towards the engine and fit a pair of thermos on the outside pushing air through?

[Renton]

flushed or rodded? you can put radiator flush thru it till the cows come home but if its blocked the flush aint going to do much. best way is to take it to a radiator shop and have it rodded. from my experiance that is the first thing you should be doing

[tassie wombat]

flushed or rodded? you can put radiator flush thru it till the cows come home but if its blocked the flush aint going to do much. best way is to take it to a radiator shop and have it rodded. from my experiance that is the first thing you should be doing

tanks were removed and each tube was cleaned(done by radiator repair shop)

[tassie wombat]

fitted twin thermos off el falcon(inside face of radiator,drawing through),fitted a new vdo temp gauge,got to 95'c on the gauge tonight.

[msjc38]

Sound like you have a water restriction problem. Find out what size hoses chevs run modify the radiator to the same sizes. If you get i done modify the tank to suit the bigger outlet. Alot of places will solder a bigger outlet on over the old outlet. Buy putting the spring in the hose has helpt but not solved the problem. These motors are in alot of differant vehicals & they didnt over heat. Mr Chev spent millions to make sure this didnt happen so go & have a look at a chev in a holden or an old imparla. You have put an engine in to a vehical that came out with a six cylinder. You need to make the rest of the car fit the v8. Keep it simple & good luck

[purplebus]

I FEEL YOUR PAIN. i had a gq with a 350 on straight lpg and it was the best thing ever. standard radiator and chev fan and it would never heat up. towing a van up the beach at high tide it got to 90 in a qld summer.
never got hot.
rolled it and now have a gq4.2td (gu pump and turbo set for daily driving)that heats up if you have 4 people in it.
3 diff rads now runs a 4 core triple flow aluminium desert cooler .
4 diff thermostats gen
4 different fan and hub assblys
bar/winch on - off
new amkt water pump
new hoses
dynoed 4-5 times now
nothing will fix it.
ordered a gen water pump to try that.
rad shop and mechanics cant work it out. uses no water, cool on idle but heats up under load.

make sure with the radiator to check the "fin count". measure 2" across and 3 rows down and count the fins. i had one rad that had half the amount of fins as the gen one. some imports and aftermarket rads are like this.
good luck and if anyone has any ideas on mine i would love to hear it.

[Quadcamshorty]

purplebus,

Does the A/C make a massive difference to your temps?
I have a turbo petrol and it heats up as soon as the ac is on.

When you measure the 2 inches across and three rows down, how many fins should you have? Mine is a brand new job from natrad so it would be good to check.

cheers

[purplebus]

my desert cooler has 16 tops of fins in a 2" wide span. top of the " A " so to speak starting at a top point. the rows are 12mm high so 4 rows in 2'' down means 4rows multiplied by 16 fins/row equals 64 fins/ 2'' square. the import one i had was 8 fins across in the same area so only 32fin/2"square

the rad shop guy told me to check this as fin count = cooling ability.
half the fins the rad works half as well.

mine heats up only a tiny bit more with the ac on. if yours heats up heaps maybe check if the a/c compressor bearing is on the way out.
seems common for the gq to go either way. my mate runs huge boost and diesel gas 330rwhp and the thing takes ages to heat up and never gets over half temp even when racing with a stock rad.