On my bare-bones factory ’93 P/U with a 22R, it seems that when I turn
on the heater on it causes the engine temp. gauge to red-line SUDDENLY.
When I turn it off the heater, and the needle swings back to normal, but
will
have an erratic, quick movements between normal and red-line.
Turning the engine and the heater off, then restarting USUALLY resets
the problem.
If the heater switch is kept off, the temp gauge works properly.
The truck is not overheating and the thermostat is working.
Would a sensor fail with these characteristics?
Anyone know the relation between the sensor and the heater switch?
TIA
ROn
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Ron Domino wrote:
> On my bare-bones factory ’93 P/U with a 22R, it seems that when I turn
> on the heater on it causes the engine temp. gauge to red-line SUDDENLY.
> When I turn it off the heater, and the needle swings back to normal, but
> will
> have an erratic, quick movements between normal and red-line.
> Turning the engine and the heater off, then restarting USUALLY resets
> the problem.
> If the heater switch is kept off, the temp gauge works properly.
> The truck is not overheating and the thermostat is working.
> Would a sensor fail with these characteristics?
> Anyone know the relation between the sensor and the heater switch?
A common problem and an easy fix:
http://4crawler.cruiserpages.com/4×4/CheapTricks/index.shtml#Thermostat
There is a TSB for this problem, too.
Ron Domino wrote:
> On my bare-bones factory ’93 P/U with a 22R, it seems that when I turn
> on the heater on it causes the engine temp. gauge to red-line SUDDENLY…
Is this when you turn on the fan, or move the temp slider from cold to hot?
If the fan, then it is most likely the engine ground strap. Locate it,
remove it, clean and burnish it, and reinstall. Will probably fix that
problem, as well as other intermittent gauge flutters you may have seen.
If the slider, then it is happening when you’re opening/closing the coolant
path to the heater core, and then see Roger Brown’s response re: tstat.
>Turning the engine and the heater off, then restarting USUALLY resets
t>he problem.
Saying that turning the engine and off resetting it (i.e. the engine hasn’t
cooled down) leads me to beleive that it is electrical, and thus the ground
strap. Common 22RE problem. I’ve done it several times in Celicas and
trucks.
good luck!
GTr
gregory trimper wrote:
> Ron Domino wrote:
> > On my bare-bones factory ’93 P/U with a 22R, it seems that when I turn
> > on the heater on it causes the engine temp. gauge to red-line SUDDENLY…
> Is this when you turn on the fan, or move the temp slider from cold to hot?
> If the fan, then it is most likely the engine ground strap. Locate it,
> remove it, clean and burnish it, and reinstall. Will probably fix that
> problem, as well as other intermittent gauge flutters you may have seen.
Well, that seems to be the solution!!!
If the problem arises again, I’ll proceed w/ Mr. Brown’s suggestion.
Many thanks gentlemen!
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> If the slider, then it is happening when you’re opening/closing the coolant
> path to the heater core, and then see Roger Brown’s response re: tstat.
> >Turning the engine and the heater off, then restarting USUALLY resets
> t>he problem.
> Saying that turning the engine and off resetting it (i.e. the engine hasn’t
> cooled down) leads me to beleive that it is electrical, and thus the ground
> strap. Common 22RE problem. I’ve done it several times in Celicas and
> trucks.
> good luck!
> GTr