lucarvette

Highway , march in Maryland, pretty cold weather. Cruising 50-60mph , engine temperature around 140f. In traffic temperature climbs up, 180f and above, fan starts working.

C409

..... Sounds pretty normal to me if the gauge sender is in a cylinder head , though I'm not positive as to where the gauge sender is located on LT1's ... If I recall the ECT sender is in the water pump ... remember , the whole design idea behind the LT1 motor is the reverse flow cooling where the cooled water from the radiator enters the cyl heads first then on to the block ...........

desertmike1

The Lt1 use's an 180° thermostat from the factory. It sounds like your Tstat is partially stuck open, this happened to me, and it turned out to be a piece of (plastic) stuck under the valve.

don hall

No mention if using analog or digital gage to determine temp.

lucarvette

I checked the digital gauge. On the highway the engine temperature barely went over 130F. It was a pretty cold day, 40F.

lucarvette

where is the thermostat located in a 1992, c4 model?

antfarmer2

Top of the water pump follow the hose two bolts on the housing do not let the opti get wet!!!!!!!

c4cruiser

If the temp readings are accurate, I would think there is no thermostat installed. The 130 and 140 readings are just not right for an LT1. The digital displayed coolant temp will be more accurate than the analog gauge.

Normal operating temps should be 180-195 when cruising, even up to 200. It's not uncommon to see 200-ish temps in city traffic even when the air temp is in the 40's.

don hall

My guess is the temp gage is faulty.

RollaMo-LT4

Also possible.

OP, set your heat to high and see how hot it gets.
If the temps your listing are accurate, the temp coming out of the heat vents will be luke warm at best.

lucarvette

Thanks for helping. Why would the thermostat be not installed?

chadk

probably not the gauge but sender. I thought I read the LT1 has two temperature sending units. One for the computer and one for the gauge. If fans are kicking on I would think the temperature is getting hot enough to activate the fans. My guess is the sender unit for the gauge is in accurate. I like the idea of feeling how hot the heater is getting. This should be a good first step to troubleshooting.

Other possibility; you have a air in the coolant system causing cavitation of the pump. The coolant in the head is hot, telling computer to activate the fans, the sending unit near thermostat is cooler because of lack of fluid flow or stuck closed thermostat.

antfarmer2

Some yahoo took it out

antfarmer2

If it had air in the system you would get a low coolant light there are two bleeders for this and if it was stuck closed he would be over heating

aDigitalPhantom

Both senders? For some reason I doubt that. I would look at the thermostat first, and then look at replacing one or both temp senders.

antfarmer2

Christi@n

Sure t stat stucked open, or without t stat, steady cold coolant flow from radiator to the engine, there's no closed circuit in the engine only that can permits to it to warm up, a part when you are in trafic

Had same issue on my 1995 ( i was without t stat)

Christi@n

Yes top of the water pump, need to remove the TB intake IMO , to work properly on it, if is it an lt1?

lucarvette

It is an LT1. The former owner told me that he replaced the intake manifold.

Christi@n

Its okay

I've just said to remove it to get acces to the t stat housing, then re-put it on Throttle body and air cleaner house, after t stat replacing

P.S. (As Throttle body intake i meant rubber hose from air clenar to Throttle body) hope its correct therm, intake manifold is another thing, it is immediately after throttle body,

Wait for someone that confirm this therms

Intak