Overheating
Thread Starter
Intermediate
Joined: Jun 2012
Posts: 26
Likes: 0
From: North Texas
Overheating
Just took my '95 coupe outta 12 month storage. Got it to pass inspection, so I'm road legal. Good news.
Bad news. The A/C wasn't working. (Not good in North Texas summer). Took it to A/C shop and found the high pressure switch was bad. R/R and off we go with good cold A/C.
Also bad news. The cooling system is getting a little hot. Even without A/C on, the temps are reading around 230F when sitting at a red light. Once moving they drop to around 205F. I'm thinking I need to investigate the reasons. From reading on the C4 forum, I believe I can start to eliminate some of the culprits. A list follows.
1) Flush cooling system.
2) Replace coolant.
3) Replace thermostat (which one I'm not sure 160F vs 185F)?
4) Drill hole in thermostat? Do new ones come with pre-drilled hole?
5) Replace cooling system pressure cap.
These are the easy ones. Now they get more difficult (time issue)
6) Check primary and secondary cooling fan operation. (How to do this?)
7) If bad replace cooling fans or cooling fan relays?
8) Remove radiator and clean cooling fins. Other posts have a good description of this.
9) Replace radiator with a DeWitts or Champion.
This is a list of possibilities. Does anyone have any other ideas or perhaps a different way to approach the overheating problem?
Thanks.
Bad news. The A/C wasn't working. (Not good in North Texas summer). Took it to A/C shop and found the high pressure switch was bad. R/R and off we go with good cold A/C.
Also bad news. The cooling system is getting a little hot. Even without A/C on, the temps are reading around 230F when sitting at a red light. Once moving they drop to around 205F. I'm thinking I need to investigate the reasons. From reading on the C4 forum, I believe I can start to eliminate some of the culprits. A list follows.
1) Flush cooling system.
2) Replace coolant.
3) Replace thermostat (which one I'm not sure 160F vs 185F)?
4) Drill hole in thermostat? Do new ones come with pre-drilled hole?
5) Replace cooling system pressure cap.
These are the easy ones. Now they get more difficult (time issue)
6) Check primary and secondary cooling fan operation. (How to do this?)
7) If bad replace cooling fans or cooling fan relays?
8) Remove radiator and clean cooling fins. Other posts have a good description of this.
9) Replace radiator with a DeWitts or Champion.
This is a list of possibilities. Does anyone have any other ideas or perhaps a different way to approach the overheating problem?
Thanks.
Melting Slicks
Joined: May 2007
Posts: 2,075
Likes: 109
From: Longmont Co
Just took my '95 coupe outta 12 month storage. Got it to pass inspection, so I'm road legal. Good news.
Bad news. The A/C wasn't working. (Not good in North Texas summer). Took it to A/C shop and found the high pressure switch was bad. R/R and off we go with good cold A/C.
Also bad news. The cooling system is getting a little hot. Even without A/C on, the temps are reading around 230F when sitting at a red light. Once moving they drop to around 205F. I'm thinking I need to investigate the reasons. From reading on the C4 forum, I believe I can start to eliminate some of the culprits. A list follows.
1) Flush cooling system.
2) Replace coolant.
3) Replace thermostat (which one I'm not sure 160F vs 185F)?
4) Drill hole in thermostat? Do new ones come with pre-drilled hole?
5) Replace cooling system pressure cap.
These are the easy ones. Now they get more difficult (time issue)
6) Check primary and secondary cooling fan operation. (How to do this?)
7) If bad replace cooling fans or cooling fan relays?
8) Remove radiator and clean cooling fins. Other posts have a good description of this.
9) Replace radiator with a DeWitts or Champion.
This is a list of possibilities. Does anyone have any other ideas or perhaps a different way to approach the overheating problem?
Thanks.
Bad news. The A/C wasn't working. (Not good in North Texas summer). Took it to A/C shop and found the high pressure switch was bad. R/R and off we go with good cold A/C.
Also bad news. The cooling system is getting a little hot. Even without A/C on, the temps are reading around 230F when sitting at a red light. Once moving they drop to around 205F. I'm thinking I need to investigate the reasons. From reading on the C4 forum, I believe I can start to eliminate some of the culprits. A list follows.
1) Flush cooling system.
2) Replace coolant.
3) Replace thermostat (which one I'm not sure 160F vs 185F)?
4) Drill hole in thermostat? Do new ones come with pre-drilled hole?
5) Replace cooling system pressure cap.
These are the easy ones. Now they get more difficult (time issue)
6) Check primary and secondary cooling fan operation. (How to do this?)
7) If bad replace cooling fans or cooling fan relays?
8) Remove radiator and clean cooling fins. Other posts have a good description of this.
9) Replace radiator with a DeWitts or Champion.
This is a list of possibilities. Does anyone have any other ideas or perhaps a different way to approach the overheating problem?
Thanks.
Le Mans Master
Joined: Jul 2004
Posts: 6,227
Likes: 697
From: Clifton Park, NY ............Clearwater, FL ... 85 Original Owner
Just took my '95 coupe outta 12 month storage. Got it to pass inspection, so I'm road legal. Good news.
Bad news. The A/C wasn't working. (Not good in North Texas summer). Took it to A/C shop and found the high pressure switch was bad. R/R and off we go with good cold A/C.
Also bad news. The cooling system is getting a little hot. Even without A/C on, the temps are reading around 230F when sitting at a red light. Once moving they drop to around 205F. I'm thinking I need to investigate the reasons. From reading on the C4 forum, I believe I can start to eliminate some of the culprits. A list follows.
1) Flush cooling system.
2) Replace coolant.
3) Replace thermostat (which one I'm not sure 160F vs 185F)?
4) Drill hole in thermostat? Do new ones come with pre-drilled hole?
5) Replace cooling system pressure cap.
These are the easy ones. Now they get more difficult (time issue)
6) Check primary and secondary cooling fan operation. (How to do this?)
7) If bad replace cooling fans or cooling fan relays?
8) Remove radiator and clean cooling fins. Other posts have a good description of this.
9) Replace radiator with a DeWitts or Champion.
This is a list of possibilities. Does anyone have any other ideas or perhaps a different way to approach the overheating problem?
Thanks.
Bad news. The A/C wasn't working. (Not good in North Texas summer). Took it to A/C shop and found the high pressure switch was bad. R/R and off we go with good cold A/C.
Also bad news. The cooling system is getting a little hot. Even without A/C on, the temps are reading around 230F when sitting at a red light. Once moving they drop to around 205F. I'm thinking I need to investigate the reasons. From reading on the C4 forum, I believe I can start to eliminate some of the culprits. A list follows.
1) Flush cooling system.
2) Replace coolant.
3) Replace thermostat (which one I'm not sure 160F vs 185F)?
4) Drill hole in thermostat? Do new ones come with pre-drilled hole?
5) Replace cooling system pressure cap.
These are the easy ones. Now they get more difficult (time issue)
6) Check primary and secondary cooling fan operation. (How to do this?)
7) If bad replace cooling fans or cooling fan relays?
8) Remove radiator and clean cooling fins. Other posts have a good description of this.
9) Replace radiator with a DeWitts or Champion.
This is a list of possibilities. Does anyone have any other ideas or perhaps a different way to approach the overheating problem?
Thanks.
Le Mans Master
Joined: Oct 2004
Posts: 7,706
Likes: 485
From: Everett WA
C4 of Year Finalist (appearance mods) 2019
I drive a 95 and what you are describing is normal. Your dual fans come on at low speed at 228 and turn off after a 5 degree drop. Both fans come on at high speed at 237 and drop to low speed after a 5 degree drop. Turning on the AC will put both fan on high speed by default.
On your list #8 has the most significant impact .... really.
On your list #8 has the most significant impact .... really.
Instructor
Joined: Mar 2019
Posts: 163
Likes: 25
Like others have said, it's normal for the system to run at 230* while sitting on a hot day. If you're still concerned, try turning the A/C on and see what the system runs at since with the A/C on, both radiator fans should be running always. A lot of people when they tune their ECUs will set the radiators to come on sooner. I have my first come on at 195* and second at 210* I think.
Safety Car
Joined: Aug 2002
Posts: 3,842
Likes: 230
From: SANTA CRUZ CA
With reference to replacing the rad cap: Usually, it is not the cap that causes air to enter the
'closed system', but a deformed cap gasket causes the trouble. I know the cap is not an
expensive item, but you can cut a new gasket for pennies.
'closed system', but a deformed cap gasket causes the trouble. I know the cap is not an
expensive item, but you can cut a new gasket for pennies.
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