lancesmith1

Hi. I just test drove a 96 LT4. The car seems to have been taken care of and ran smoothly. During the test drive I noticed that the oil and water temperature gauges stayed buried on the cold side. Also, the digital readout posted in the low 100 degree range. The car was driven plenty long enough to have been up to normal operating temps. Any ideas on what is going on? I could see one or the other being off due to a bad sending unit or the like. Why would both be off and reading minimum temps at the same time?

desertmike1

3 out of 3 say cold...this sounds like a thermostat issue.

lancesmith1

Ok on the H2o temp with the thermostat but why the oil?

desertmike1

Oil temperature is affected by Block & Head temperature, as well as outside air temperature.

Duntov85

Plug in a OBDII scanner and look at the data. If it has been running that cold, look in the valvecover for massive sludge.

lancesmith1

The car is about 100 miles south of me. I believe that I will ask him to take the car to a qualified mechanic and have this checked out. He offered to take the car to a Chevy dealer yesterday but we were not very near any dealerships.

NMsharkracer

My '92 does the same thing. Changed sending units, cleaned grounds, no change. I was told by someone knowledgable that it most likely is in the gauge cluster. I use the digital and that seems to be reliable. Someday, when I want to spend the money, I'll have the gauge cluster checked out.

lancesmith1

Also - the heater was blowing very hot air. It was about 30 degrees outside. Could it just be the gauges?

lancesmith1

Thanks Sharkracer. I suspect that is the issue here as well. However the digital was showing under 120 for both as well. I sent him an email and asked him to take the car to the shop and have it checked.

The car is really slick 53k miles, paint is very nice and the top looks brand new. This guy is the second owner.

MK 82

Sounds to me like it does not have a thermostat in it. Or the wrong one. LTX thermostats are different from your typical SBC.

94vettelover2

It could be bad thermostat,sensors(coincidence both are bad),gauge cluster,computer,or wiring.You could use computer resistors to check to see if gauges are the problem or see what computer is seeing with scantool.If engine is running that cool it is not good for engine(sludge build-up,always running rich,etc).Keep us updated

lancesmith1

The owner had it replaced and it's working fine. I bought the car. These LT4s are nasty quick. It seems quicker than my 01 LS1 that I had. I have not had it out on the open road yet but just driving around local it seems more nimble. Thanks for all the replies.

lt4obsesses

Congrats on the LT4! I agree with the comarison to the LS1. I came over to LT4 from a 98 Camaro Z28. You will hear much about the LT4 being under rated, perhaps it's true, prehaps it's not. But I do know that the LT4 could run circles around the Z28. Maybe power, maybe gearing, maybe weight or all three. It's alotta fun though. check out www.grandsportregistry.com when you get a chance. Some good stuff on there about your engine. Google "LT4" to find other good stuff too.

onedef92

I remember in the book "All Corvettes Are Red" one of the factory managers made a similar comment, saying he felt the LT4 was faster off the line than the '97 LS1. The GM engineering brass denied it, though.

lancesmith1

I drove for about a half hour yesterday with the temps in the low 60's. The H2O stayed in the 190's and the oil temp was right at 200 the whole time. Does this sound about right? I checked the radiator and it looks clean with no debris.

lt4obsesses

That's about right. You will find that the LTx motors run a little hotter than what you might be used to. In stop and go traffic you will see your H20 go up to 230. Your primary fan comes on at 228 and your secondary at 230. At that point you will see the temp fall again. It's normal to see that so don't worry. There are a ton of threads about this topic.