1989 C3500 4x4 454 always runs hot
mle...@key.net
Clutch, Radiator or Thermostat, yet this 454 with throttle body
injection always runs hot when towing. 240-270 It can get to the red
line and beyond when pulling a steep hill on a hot day. The power is
not good on those days and I don't run with the throttle mashed down.
It runs hot on hot days when not towing also. I'm considering an oil
cooler and would like to do it the right way if I do. I'm looking for
links, advice, other peoples experiences with their projects.
I'm my own mechanic and body man not afraid to tackle a major
change
to the engine or body. Though I'd like to keep this truck fairly
stock
on the outside.
The engine runs very well, though it seems to lack power for a big
block. I will consider an engine overhaul with performance
enhancements if someone can turn me on to the right combination of
ingredients.
Augustus
<mle...@key.net> wrote in message
news:a4f27bfa-98b5-4e27...@c18g2000prh.googlegroups.com...
On a 20 year old unit, other than the obvious things you've likely checked
like the fan clutch, thermostat function, ECM timing set etc, you have to
consider the possibility that the rad is corroded and deposits are causing
the issues. I would remove and repair/replace the rad if everything else
checks out OK.
mle...@key.net
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2 years ago i put a new core in the radiator that included and extra
layer making the radiator a custom 5 core version. It may have helped
a little. The fan clutch is extra heavy duty making the engine howl.
Though noisier it is somewhat reassuring as the engine does not heat
up on mild days unless towing. I've been told cooling was an issue on
this model year and this is the main reason no 4 or five speed version
was offered in 1989. I'd really like to talk with someone who has
modified something ie, engine oil cooler, electric fans or some
combination of changes to the engine that will make this engine run
strong and cool.
Desertphile
--
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Desertphile's Desert Soliloquy. WARNING: view with plenty of water
"Why aren't resurrections from the dead noteworthy?" -- Jim Rutz
Steve W.
When was the last time the fuel filter was changed and the fuel system
cleaned? Lack of power and running hot could be caused by an engine
running leaner than it should.
What rear gearing does it have? Higher gearing will make the engine work
harder and hotter.
What exhaust system does it have? A partially blocked converter or
muffler could also cause it to be low an power and run hot.
You already have a larger radiator. Is the fan shroud in place?
Running that hot I would install a heavy duty trans cooler and run
synthetic fluids as well. You could install a rear facing hood scoop to
release the heat from the engine bay. Something like the Z28 style from
the 60's.
Good luck and report back what you find.
--
Steve W.
Bill
Paper, or foam?
Elbert
Can we assume all the mechanical parts are there and in full working
order... to include the fan shroud and thermostat. I would not run it
past 220F.
Do you have the right fan and fan clutch combination. No-one's
swapped some aftermarket parts in there?
I don't anyone makes a better fan clutch than GM, for a GM vehicle. On
a heavy tow rig....I would not use electric fans as the primary
cooling.
Does the truck have 4.10 gears and are you pulling loads within your
rated range.
Don't know if you get off in the mud but make sure your radiator and
condensor are not full of mud, or crap between the condensor and
radiator blocking the air flow.
No check engine light is on I assume, no reason to expect a head
gasket issue?
What temp does the truck run at unloaded in the summer now?
Have you checked the temp that the computer see's by using a scan tool
to verify that the gauge temp is correct? and that you don't have a
faulty sending unit.
On a tow truck like that...I would want the biggest 4 core radiator
that fits, OEM fan and OEM HD fan clutch, correct thermostat, and
proper gearing at the differentials.
I do think some of those older trucks were known to run fairly hot.
My 01 2500 suburban with 496 runs about 195F unloaded...its rather
new to me, and so far I've not pulled any heavy stuff with it. With
A/C on , idling or running, it never gets over 195 or maybe close to
200. What's your truck doing in present weather conditions..unloaded?
When the truck is warmed up and ambient temp is 80+F outside I assume
you can hear the fan clutch cycle on and off under load? Also when
engine warm and you open the hood you have a nice air flow across
the radiator?
-----------
Elbert
a...@me.com
mle...@key.net
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If Someone has a line on a functional rear facing soop or a tidy way
to vent the hood I'd like to try that. I'm not oppose to modifying the
hood or replacing it with one that is alredy modified.
mle...@key.net
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First i think I'll put a test tube in place of the cat converter to
see if ther is any good to come from that.
Martin Riddle
<mle...@key.net> wrote in message
news:274600d9-748f-44e9...@s1g2000prd.googlegroups.com...
What I had done is make a small plate with a hose barb thru it and mount
that in place of the EGR valve. (gasket too)
Block off the EGR vacuum, and connect the barb to a pressure guage. ( I
have a old Vacuum/Fuel pressure gauge)
Run at different RPMs and check the pressure. A blocked Cat will show
pressure readings, where a clear cat will show next to nothing.
If you have dual Cats then this approach may not work.
Cheers
Lynn
Ever check the water pump? I've seen the wrong water pump installed
on
small blocks that caused overheating. Some pumps rotate in the
opposite direction depending on how the belt wraps the pulley. Big
blocks may have different pumps as well.
William R. Walsh
> 2 years ago i put a new core in the radiator that included and extra
> layer making the radiator a custom 5 core version.
I'm reasonably sure that can't have harmed anything. You don't want to cool
the engine too much, but the thermostat should regulate things pretty well
if it's working properly.
I know that somewhat later models (mid 90s) of these trucks often got an
"extra" grille underneath the main grille because it wasn't enough to keep
them cool. You've probably seen some with it--there is the main grille and
then underneath it is a piece of plastic running the length of the grille
with smaller slits in it. This was done to solve an overheating problem. I
don't know how succesful it was, but I'm surprised nobody has mentioned it.
> I'd really like to talk with someone who has modified something ie,
> engine oil cooler, electric fans
You really don't want electric fans--they cannot and will not move the air
that an engine driven fan will. Things will suffer--anything that's being
cooled won't be cooled as well, and your alternator will run hotter and
closer to its limits from the added load.
A transmission cooler is always a good idea. Mount it as close to the front
of the truck as is possible, in front of the other radiators. This will give
it the ability to do the most good.
William
mle...@key.net
Hey I've had this twelve years now and I've been through at least four
different thermostats with the same results. Now I finally removed the
thermostat and this engine runs cool. Is it possible that none of the
thermostats can pass the water well enoguh to not cause restriction?
Can I buy one that is not a restriction?
klutz
<mle...@key.net> wrote in message
news:712ba5c1-e55a-4921...@x3g2000yqa.googlegroups.com...
Have you tried a 160 degree thermostat? The engine will probably run a lot
cooler, but it might be too low of an operating temp to pass a smog test.
If that's the case, swap out the thermostat before you get a smog check.
mle...@key.net
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We don't have smog tests here in Walla Walla. I will check into
getting a high flow thermostat. I have a 160 I just took out. It may
have opened sooner but I'm quite sure it does not open enough. I'm
trying to get some old equipment to make hay today but once that's in
the barn I'll get into the thermostat thing again. Mike