Another Coolant Temp Question
Thread Starter
Melting Slicks
Joined: Feb 2006
Posts: 2,938
Likes: 62
From: Columbia SC
Another Coolant Temp Question
Let me start off by saying I know 215 - 220 Coolant Temp is normal, so with that said here is my question. I just recently changed my water pump (due to weep hole seepage) along with upper and lower rad hoses. Prior to the change the temp on the digital guage would read 189 - 196 in traffic and would, like it is designed to do at a stop run up to 228 and the fan would come on and bring it back down to 205, even in 100 degree weather. Now temps stay at 210 - 219 even while driving in 40 degree weather. I have burped the system, but the FSM speaks of two bleed screws, one on thermostat housing (which I have found) and one on the the Throtle Body, I can not find this one. My car is currently in the garage cooling down with the front in the air hoping the air will work its way to the thermostat bleed screw and I will burp the system again. Am I missing something?
One other note, I did put a new Coolant Temp sensor in the Water pump as the old one had broken from the plastic and I kept having to push it back in. Could my old CTS have been sending false reading in the first place which led me to believe I was running cooler that I actually was? I know 210 - 219 is normal so I am not overly worried, just looking for some feedback. Thanks
One other note, I did put a new Coolant Temp sensor in the Water pump as the old one had broken from the plastic and I kept having to push it back in. Could my old CTS have been sending false reading in the first place which led me to believe I was running cooler that I actually was? I know 210 - 219 is normal so I am not overly worried, just looking for some feedback. Thanks
Melting Slicks
Joined: Dec 2004
Posts: 2,137
Likes: 5
From: Howard PA
Your 96 only has one bleed screw on the t-stat housing. Should have drilled one tiny hole in the t-stat before you installed it and your air worries would have been history. Now we'll hear the bandwagon jerks spout off about a hole cooling too much, or whatever, one tiny hole won't change jack as far as the characteristics of the t-stat are concerned.
I haven't had to bleed my system at all using a small hole in the flange.
BTW, yes I think your old CTS if we must call it that, the manual calls it a ECT sensor, was probably reading low. I'm fearing this is going to become a normal thing as time goes on. Yet we'll see the bandwagon jumpers again tell all the LT1 owners how normal it is to melt down sitting in your car. There is a age issue happening here and spouting off that everything is normal without all the facts if counterproductive to our hobby.
I haven't had to bleed my system at all using a small hole in the flange.
BTW, yes I think your old CTS if we must call it that, the manual calls it a ECT sensor, was probably reading low. I'm fearing this is going to become a normal thing as time goes on. Yet we'll see the bandwagon jumpers again tell all the LT1 owners how normal it is to melt down sitting in your car. There is a age issue happening here and spouting off that everything is normal without all the facts if counterproductive to our hobby.
Last edited by ALLT4; Feb 6, 2007 at 08:33 PM.
Thread Starter
Melting Slicks
Joined: Feb 2006
Posts: 2,938
Likes: 62
From: Columbia SC
I fished the old ECT from the out of the shed and did an Ohlm test and for the current temp in my garage it had a correct resistance. I guess I will have to burp the system again till I get all of the air out as I have read that any air in the closed system will cause the temp to be higher, is this true?
Safety Car
Joined: Aug 2002
Posts: 3,842
Likes: 230
From: SANTA CRUZ CA
Your higher temp problem is more likely linked to the new temp sensor rather than trapped air. Air will eventually bleed itself into the higher positioned reservoir, so I would not be concerned with trying to bleed air. You only replaced two items: pump and sensor. Obviously, the pump is working, and the temps with the new sensor are more within the operating range when compared to the old sensor.
If your fans are activating at the programmed temps, and the coolant loses heat with the added air flow, all seems normal.
Make sure the coolant level in the overflow bottle is higher when hot when compared to the level when cold. This proves that the system is operating as a closed system: expanded coolant is forced into the overflow bottle when heated, and siphoned back into the cooling system during cool-down.
If you haven't read this link before, it contains some good info:http://www.theherd.com/articles/lt1_cool.html
If your fans are activating at the programmed temps, and the coolant loses heat with the added air flow, all seems normal.
Make sure the coolant level in the overflow bottle is higher when hot when compared to the level when cold. This proves that the system is operating as a closed system: expanded coolant is forced into the overflow bottle when heated, and siphoned back into the cooling system during cool-down.
If you haven't read this link before, it contains some good info:http://www.theherd.com/articles/lt1_cool.html
Thread Starter
Melting Slicks
Joined: Feb 2006
Posts: 2,938
Likes: 62
From: Columbia SC
OK, yes the primary fan are comming on at 228 and the temp drops to about 210 - 213 fairly quickly. Yes the overflow level is higher when running and just after shut off and goes back to normal cold level after everything cools down.
I know the normal operating temps are in the 205 - 220 range and I am not overly concerned about that, I just was not sure at to why the temp change difference now vs than.
My old ECT sensor was broken at the plactic colar on the sensor itself and that is whay I changes it, that may account for the temp difference now as the old ECT may have been good but with the plactic colar broken may have caused it to read lower that it realy was.
No major problems the highest I have seen since the change is 230. My fan came on at 228 (also checked with a Actron Scan tool) and temp went to 230 and than slid down to 213 with fan on. Thanks for responses
After reading that link and seeing that most new cars come with a 195 stat I think I will check my stat to make sure it is not a 195.
I know the normal operating temps are in the 205 - 220 range and I am not overly concerned about that, I just was not sure at to why the temp change difference now vs than.
My old ECT sensor was broken at the plactic colar on the sensor itself and that is whay I changes it, that may account for the temp difference now as the old ECT may have been good but with the plactic colar broken may have caused it to read lower that it realy was.
No major problems the highest I have seen since the change is 230. My fan came on at 228 (also checked with a Actron Scan tool) and temp went to 230 and than slid down to 213 with fan on. Thanks for responses
After reading that link and seeing that most new cars come with a 195 stat I think I will check my stat to make sure it is not a 195.
Last edited by Fast Cop; Feb 6, 2007 at 10:02 PM.
Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
Wow, dejavue (or however you say it). Just saw a very similiar post in the general section. Same advise, get it to op temp (t/stat open and coolant circulating) and bleed it again.
ps--I am going to the parts 4sale section next, do you have a post on this over there too?
ps--I am going to the parts 4sale section next, do you have a post on this over there too?
Safety Car
Joined: Aug 2002
Posts: 3,842
Likes: 230
From: SANTA CRUZ CA
The tstat, whether it be 160, 180, 195 does not enter into the cooling equation once it is open. If the temp is running in the low 200s, and the tstat is of a lower degree, it is essentially just an open pipe in the system.
Last edited by don hall; Feb 6, 2007 at 10:18 PM.
Racer
Joined: Sep 2005
Posts: 271
Likes: 0
From: New Freedom PA
Cooling System Info
Your higher temp problem is more likely linked to the new temp sensor rather than trapped air. Air will eventually bleed itself into the higher positioned reservoir, so I would not be concerned with trying to bleed air. You only replaced two items: pump and sensor. Obviously, the pump is working, and the temps with the new sensor are more within the operating range when compared to the old sensor.
If your fans are activating at the programmed temps, and the coolant loses heat with the added air flow, all seems normal.
Make sure the coolant level in the overflow bottle is higher when hot when compared to the level when cold. This proves that the system is operating as a closed system: expanded coolant is forced into the overflow bottle when heated, and siphoned back into the cooling system during cool-down.
If you haven't read this link before, it contains some good info:http://www.theherd.com/articles/lt1_cool.html
If your fans are activating at the programmed temps, and the coolant loses heat with the added air flow, all seems normal.
Make sure the coolant level in the overflow bottle is higher when hot when compared to the level when cold. This proves that the system is operating as a closed system: expanded coolant is forced into the overflow bottle when heated, and siphoned back into the cooling system during cool-down.
If you haven't read this link before, it contains some good info:http://www.theherd.com/articles/lt1_cool.html
Good Job
Desert
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