update on engine operating temperature issue

**Raise** · 09-23-2005, 06:38 AM

i changed out the thermostat and coolant temp sensor. apparently the problem wasnt with either of these. but anyway, heres what the guage is doing. ill start the car. it will take its usual few minutes for the needle to hit 160. once it does, i start driving. i cruised for maybe 10-15 minutes. the needle never got above 175-180 while cruising. now, if i stop at a light, the needle will slowly start climbing til it hits operating temperature. then when i start driving, the needle goes back down to around 175-180. my other ls1 cars always stayed at around 200-210....whether i was stopped at a light or cruising. i thought 200-210 was operating temperature, and my other cars always got there within 10-15 minutes. can someone give me a lil help here??

**Street Lethal** · 09-23-2005, 06:07 PM

Originally Posted by Raise

i changed out the thermostat and coolant temp sensor. apparently the problem wasnt with either of these.

Has you're RPM lowered any during idle?

Originally Posted by Raise

it will take its usual few minutes for the needle to hit 160. once it does, i start driving. i cruised for maybe 10-15 minutes. the needle never got above 175-180 while cruising. now, if i stop at a light, the needle will slowly start climbing til it hits operating temperature. then when i start driving, the needle goes back down to around 175-180.

This is perfectly normal....

Originally Posted by Raise

my other ls1 cars always stayed at around 200-210....whether i was stopped at a light or cruising.

You're other LS1 had the problem then.... cuz it's normal for the temp to hit 180 when cruising, as cold air is purposely directed there from down underneath you're rad. Take a peek.

Originally Posted by Raise

i thought 200-210 was operating temperature, and my other cars always got there within 10-15 minutes. can someone give me a lil help here??

I wouldn't consider it "operating temperature", but it is set up from the factory that way. There are programs that purposely kick the fans on earlier, maybe the owner before you went that route....

**Raise** · 09-23-2005, 07:47 PM

i dont think my other ls1 cars had a problem, but i think the newer guages are wrong. they stay at 210 all the time after being warmed up. i noticed this on all 3 of my other ls1 cars. but this one seems to have very accurate guages. i guess i dont have a problem. this rocks!!!! time to start moddin

**SeVeReDiStOrTiOn** · 09-23-2005, 10:25 PM

mines around 200...but it does flucuate here and there enough to where i know it's reading tempature and not just a dummy gauge. 175 seems pretty cold...can you even go into closed loop at that temp?

**Redphoenix1998** · 09-24-2005, 12:20 AM

figure out the oil prob yet?

BlackHawk T/A · 09-24-2005, 12:24 AM

1998 if I remember correctly was the only year with an accurate coolant temp guage...after that they installed idiot gauges in all the cars.

Mine sits at 210 all the time (as if I didn't realize what was going on).

**GatorSS** · 09-24-2005, 12:56 AM

Yep, that stock temp gauge from '99-'02 is irritating.

What did GM save, $10 a guage?

They could have just passed that extra cost on to us, even adding a profit margin. Say they charged $20 or so more for a fully functional temperature gauge. I would have gladly paid it rather than get the lame one that's there now.

**Street Lethal** · 09-24-2005, 04:00 AM

Originally Posted by Raise

i dont think my other ls1 cars had a problem, but i think the newer guages are wrong. they stay at 210 all the time after being warmed up. i noticed this on all 3 of my other ls1 cars. but this one seems to have very accurate guages. i guess i dont have a problem. this rocks!!!! time to start moddin.

I'm a little more concerned about the oil pressure, is it still as low as it once was? Also, you mentioned the idle being a tad high.... tell us where it is now (during idle, in both park, and in gear).

As for the temperature, when I'm on the highway, the gauge stays steady at around 180-185, but when I come to a red light and stop for a few minutes myself, it gradually makes its way back up to 210-220. Perfectly normal.

Believe me, when you're at the track, you'll want that gauge to stay at 185 at all times... as our engines run their best at this temperature....

**Raise** · 09-24-2005, 04:55 AM

idle speed is always the same. the only time the oil pressure looks like it goes low is when i am sitting at a light and the eng temp goes up towards 210. then the oil pressure guage drops down to around 20-25. the rest of the time the oil pressure is fine. it stays around 30-35 at warm idle. why would the pressure drop when the eng temp is rising at a stoplight??

**Street Lethal** · 09-24-2005, 06:37 AM

Originally Posted by Raise

the only time the oil pressure looks like it goes low is when i am sitting at a light and the eng temp goes up towards 210.

This is normal, because pressure is based on RPM... the higher the RPM, the higher the vacuum pressure, the lower the RPM, the lower the vacuum pressure. Engine temp has much to do with pressure as well, as when the temp is cold, the pressure is high, when the temp gets hot, the pressure gets low....

Originally Posted by Raise

then the oil pressure guage drops down to around 20-25. the rest of the time the oil pressure is fine. it stays around 30-35 at warm idle. why would the pressure drop when the eng temp is rising at a stoplight??

Don't forget that oil, like coolant, get's extremely hot (especially in the summer).... and hot oil is much harder to pump (it get's thicker), than cold oil.

**Raise** · 09-25-2005, 08:06 AM

thanks street lethal...youve been more than a big help

ive learned quite a few things just from u responding to my post. i appreciate it man....hope to see ya someday

6speeder · 09-26-2005, 10:13 AM

Lethal: You've got it backwards on the oil. As it gets hotter it gets thinner and easier to pump. Cold oil is thick. That'w why we ues a multiviscosity oil like 10w-30, when it's cold outside the oil acts like a 10 weight, so it'll flow. Then after warmup it's like a 30 weight and still protects, not thinned out.