95 LT1 Engine Cooling Question
Thread Starter
Intermediate
Joined: Jan 2014
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Hello Everyone,
Sorry for the delayed update...I was in the middle of resealing the intake manifold due to a leak and then replaced the injectors due to a leaky injector. Now that I buttoned everything up, the only thing I have left is the cooling issue. So I bought a new coolant temp sensor and plugged it in. Amazingly, this fixes one code and it also fixes the issue of a hard warm start...however, only the primary fan comes on at 228. Any ideas if this is normal and if/when the secondary fan should come on?
Thanks
Jerome
Sorry for the delayed update...I was in the middle of resealing the intake manifold due to a leak and then replaced the injectors due to a leaky injector. Now that I buttoned everything up, the only thing I have left is the cooling issue. So I bought a new coolant temp sensor and plugged it in. Amazingly, this fixes one code and it also fixes the issue of a hard warm start...however, only the primary fan comes on at 228. Any ideas if this is normal and if/when the secondary fan should come on?
Thanks
Jerome
Safety Car
Joined: Aug 2010
Posts: 3,601
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From: F'burg VA
St. Jude Donor '13 thru '20,'22,'24 thru '26
Does your vehicle have 2 fan relays or 3 fan relays. If it's the 2relay setup then only one fan will run, the other is triggered by the A/C. If 3relay setup, then temp should trigger both fans running at low speed .
You should have a the 3 relay setup. One fan running is most likely due to your previous post
You should have a the 3 relay setup. One fan running is most likely due to your previous post
I did check the fan relay harness and it does look modified because there are two wires grounded together and lots of electrical tape
Last edited by Snake.Oiler; Feb 18, 2014 at 12:11 AM.
Pro
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Team Owner
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Melting Slicks
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From: Palmdale CA
95 functions differently.. try not to get him confused. OP needs to get into his FSM for a complete and detailed explanation on how his system functions.. I can tell you right now the 95 system runs both fans together in stock form.
Pro
Joined: Mar 2013
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From: Indiana
My 96' and I believe your 95' will start both fans at 228 on low speed. Once you reach a higher temp they will go into high speed. They will also come on with the A/C. In the summer I always use the A/C and my car never overheats. Turn off the A/C in traffic and your asking for trouble. These cars (LT-1) are reverse flow cooling and run at higher temps normally so don't panic unless you see really high temps like 260 degrees. Then shut it down and pull over, your antifreeze will boil under pressure at that temp. You need to fix the three relay wiring so this thing works correctly. You came a good way by getting that sensor fixed and now you just have a little wiring to straighten out and your good to go. Has the temp sensor made the car run better? It should now go into closed loop and run smoother with better gas mileage.
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Thread Starter
Intermediate
Joined: Jan 2014
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My 96' and I believe your 95' will start both fans at 228 on low speed. Once you reach a higher temp they will go into high speed. They will also come on with the A/C. In the summer I always use the A/C and my car never overheats. Turn off the A/C in traffic and your asking for trouble. These cars (LT-1) are reverse flow cooling and run at higher temps normally so don't panic unless you see really high temps like 260 degrees. Then shut it down and pull over, your antifreeze will boil under pressure at that temp. You need to fix the three relay wiring so this thing works correctly. You came a good way by getting that sensor fixed and now you just have a little wiring to straighten out and your good to go. Has the temp sensor made the car run better? It should now go into closed loop and run smoother with better gas mileage.
Thanks for the reply, I'm hoping to iron out the wiring this weekend...I have the FSM, so hopefully that will help. As for the car running better, absolutely! Also, it used to sound like a flooded carb during a warm restart and I also got rid of the service engine light. I still can't believe this mod was a mechanics answer to higher running temps.
Thanks,
Jerome
Safety Car
Joined: Aug 2010
Posts: 3,601
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From: F'burg VA
St. Jude Donor '13 thru '20,'22,'24 thru '26
Are you positive only the one fan came on when temp hit 228*? Was this one fan the driver side fan? It should have been.
Last edited by Snake.Oiler; Feb 18, 2014 at 10:14 PM.
Thread Starter
Intermediate
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I'm sure they have with all the electrical tape work and the double ground. Yes, I'm sure the driver side fan was the only one to come on at 228. I monitored it as it came on, then turned off at around 210-215. I have the car on jack stands and was monitoring the fans. Is this double ground stock?
Safety Car
Joined: Aug 2010
Posts: 3,601
Likes: 118
From: F'burg VA
St. Jude Donor '13 thru '20,'22,'24 thru '26
Yes, that should be a stock ground. One ground wire from each fan motor. When you tested and the one fan came on, did you have the A/C on or in defrost mode?
Safety Car
Joined: Aug 2010
Posts: 3,601
Likes: 118
From: F'burg VA
St. Jude Donor '13 thru '20,'22,'24 thru '26
Two things you can try:
1) swap the relay 1 and relay2 and check to see if fan still comes on at 228*
2) try grounding relay2 in order to energize it - this should kick on the passenger side fan. Do this with key in run position(engine off). In order to ground it, I would use a multimeter and back probe the dark blue wire, using the multi meter to check for continuity thus signaling a good ground
1) swap the relay 1 and relay2 and check to see if fan still comes on at 228*
2) try grounding relay2 in order to energize it - this should kick on the passenger side fan. Do this with key in run position(engine off). In order to ground it, I would use a multimeter and back probe the dark blue wire, using the multi meter to check for continuity thus signaling a good ground
Pro
Joined: Mar 2013
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From: Indiana
The amazing thing is some guys go through all of these half azzd mods thinking they have a problem when in actuality these cars run hot. Heck the fans don't even come on till 228 degrees and that's low speed. I think the next level is in the high 230's. As I stated before the biggest problem is the radiator getting covered with debris sucked up off the road. Guys even come to this site and ask about temperature and we tell them its ok and they still mod them thinking their doing the right thing. The LT1 is designed to run at these temps and you can actually do damage by running them to cool but they argue and do it anyway. If you have smog testing you definitely need the heat to pass. One other thing you need to know is the little black plastic spoiler on the front has got to be maintained and functional. You can buy an entire new replacement for like $80.00, takes about a half hour to put it on. The fans don't run when you are moving at speed and these spoilers are the only thing forcing air up into the engine compartment. Without the center spoiler piece they will overheat. Change it every few years or when damaged, even a little, its that important.
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Le Mans Master
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From: H-Town Texas
I'm sure they have with all the electrical tape work and the double ground. Yes, I'm sure the driver side fan was the only one to come on at 228. I monitored it as it came on, then turned off at around 210-215. I have the car on jack stands and was monitoring the fans. Is this double ground stock?
Don't know why anyone would disconnect the temp sensor, but I think the ecm would run the fans constant if it were getting no reading as a precaution.
Make sure you change that oil a few times within the next couple of hundred miles. In fact, I would change it, run the car for about 30 min, change again, and then at about 200 after that. That much gas in the crank case has broken that oil down tremendously and taken much of the coating off the the bearings and internals.
Thread Starter
Intermediate
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All,
Thanks again for your all of your advice... I tried swapping relays and it didn't change anything, however i did straightened out some wiring and both fans now come on at low speed at 228, then shutoff at 215. So I guess it works as it should?!?! At what point should the fans run at high speed? BTW, I went ahead and ran the AC but the fans don't activate when the AC is on... Is this an issue that I should look into? They do turn on at 228 regardless of the AC tho. Also, does anyone recommend changing out the thermostat to a 180 degree setting? Idk, it's just really uneasy watching that analog gauge get close to the danger zone...
Thanks!
Jerome
Thanks again for your all of your advice... I tried swapping relays and it didn't change anything, however i did straightened out some wiring and both fans now come on at low speed at 228, then shutoff at 215. So I guess it works as it should?!?! At what point should the fans run at high speed? BTW, I went ahead and ran the AC but the fans don't activate when the AC is on... Is this an issue that I should look into? They do turn on at 228 regardless of the AC tho. Also, does anyone recommend changing out the thermostat to a 180 degree setting? Idk, it's just really uneasy watching that analog gauge get close to the danger zone...
Thanks!
Jerome
Drifting
Joined: Mar 2012
Posts: 1,492
Likes: 61
From: New Jersey
Some mistakenly believe the standard thermostat is a 195 degree thermostat. Wrong. The standard thermostat is an 180 degree thermostat. If you change it make sure you get the correct style of thermostat made specifically for the LT1.
