981uz

Hey everyone! I keep getting turned away from every shop telling me that this is normal, so I'm just not going to worry about it. Shop measured the temp a month ago with a scanner and the engine at full load was at 190 degrees, Today I had a different shop measure the temperature with a different temperature gun as well has a scan tool. The scan tool picked up 192 degrees and the gun measured 195 degrees. Thermostat and coolant has been changed recently but the gauge keeps creeping up. Is my gauge possibly not working? I'm going to have them change the timing belt and water pump while its in the shop aswell maybe that will result in a lower temp with a fresh water pump.

P.S Thermostat is OEM 180 degree.

djamps

Does it move at all? Like drop down any amount when coasting at higher speeds or go higher when idling with the AC on? I'd say that if it's planted firmly in that place once warmed up it's probably the gauge or the sensor feeding the gauge (I don't think it's the same sensor the ECU is using). That said, mine stays planted just under half no matter what the car is doing even on hot days.

timmy0tool

iTrader: (7)

try this before anything else; the next time you see the needle go beyond 50%, blast the heater. if the temp returns to normal (under 50%), then you have air bubbles in your coolant system.
this is most likely due to the recent tstat and coolant change. lots of indy shops lack the full knowledge to bleed the LS400 engine. I say bring it back for a proper bleed!

djamps

This is wierd because when I did a water pump, radiator and tstat all at once along with block drained I just filled the darn thing up and topped it off once...no issues. But I used a vacuum filler so maybe that's the trick.

981uz

It used to go to the half mark but over time it started getting higher and higher, I'm beginning to think its a sensor.

981uz

it always goes above the half mark, When I first bought the car it would stop at the half mark but it just recently started creeping up. Last month it started going a little above the half mark this when I got the coolant flushed and thermostat changed and I was told there was no leaks of any kind going on. Last week it started touching the next bar up. I cant think of anything else other than the receiver on the cluster or something. Also last week the gas gauge has started reading off about half a tank, I don't know if this is related or not.

Superfast1

It should be rock solid just a ted above the middle once warmed up. If the needle moves up & down, especially during stop & go traffic then you have air in your coolant system. You can purge it yourself by opening the coolant reservoir's cap once car's is warmed up but be extremely careful as it's under-pressure so place a thick towel over the cap & open it slowly. Do this a few times. Since you're going to have a shop changes the timing belt & water pump, once they re-filled & purged the system, this issue should go away, assuming they're doing it correctly. It's a simple procedure so you'll be fine.

Fro98686

Maybe your temp is normal but the gauge is not. I know mine reads at the mark below the halfway point and is the same whether winter or summer. I was told my car had a weak fan clutch, but still temperature gauge reading or temperature not a problem at all. I would try a new temperature sending unit if not too expensive.

mjeds

I was going to suggest the same thing, sounds like air in the sealed system..

GeenIdee

Mine is sitting like between 1/3th and half way. Is that normal? I'm used to those gauges sitting nicely halfway.

Losiracer2

It's not normal. Should be just below half, ALL the time. This is coming from someone who lived in AZ and drove in 115+ temps.That happened to me when I had air trapped in the system or my system was under filled. These cars are a bit more difficult to bleed the air out since the rad cap isn't directly above the radiator and on a reservoir, so most people don't do it correctly.

981uz

I completely understand, I have had the system bled already, when the car goes in for the timing belt/water pump job I will tell them to do that as well as replace the ECT sensor. Also if there is air trapped in the system wont the gauge fluctuate? Which it does not under any circumstances. By the way my cluster does have sticky needles as well as the gas gauge is off to.

Losiracer2

good that you're getting the ECT sensor done. I did that very early on mainly because everyone said to and netted about 2mpg better hwy, so i'm doing about 27hwy now with some SC430 18s and wider tires so I can't complain.

It could be your Thermostat too if that's old and tired. make sure to replace the cam/crank seals when you have the belt job done. I had to do mine 40k early due to a blown crank seal gushing out oil all over my tbelt.

981uz

I really appreciate your help, The thermostat is actuality new I got it done a month ago when I got the coolant flushed. They measured the temp and the internal sensor is measuring 192F, the thermo gun measured 195F. This is what is leading me to believe the sensor or the cluster is off. Its also a OEM 180 degree thermostat as well. I would think if the car started reaching up to the 200's it would cause the gauge to read at the temp mine is at.

YODAONE

A scan tool.that can read coolant temperature input might provide insight..

Another thing...

Many of us still.have original radiators...

After 20+ years there is going to be a fair amount of crud in the radiator fins that are reducing it's efficiency....removal, inspectionl and cleaning (or replacement DENSO.95+ are inexpensivet) are in order.

Also expired is the foam sealing strips with pressure sensitive adhesive that are used between radiator and shroud...which reduces efficiency.

Anyone source a durable replacement?