replaced head gasket, still overheating!
Super Moderator
Joined: May 2006
Posts: 18,398
From: Wisconsin
Sorry I wasn't on here for a couple days...
NO.
When you jumper the wire for the fan switch, you're simulating a HOT condition, so the fans are supposed to run. If they don't then there's a problem somewhere in the fan control circuit. In that case, you still have to chase down what the problem is, like a bad relay or broken wire.
Most of the time, this test WILL make the fans run, which means that everything except the switch is OK. By process of elimination that means it's a bad switch.
When you jumper the wire for the fan switch, you're simulating a HOT condition, so the fans are supposed to run. If they don't then there's a problem somewhere in the fan control circuit. In that case, you still have to chase down what the problem is, like a bad relay or broken wire.
Most of the time, this test WILL make the fans run, which means that everything except the switch is OK. By process of elimination that means it's a bad switch.
Thread Starter
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Junior Member
Joined: Jan 2009
Posts: 73
Sorry I wasn't on here for a couple days...
NO.
When you jumper the wire for the fan switch, you're simulating a HOT condition, so the fans are supposed to run. If they don't then there's a problem somewhere in the fan control circuit. In that case, you still have to chase down what the problem is, like a bad relay or broken wire.
Most of the time, this test WILL make the fans run, which means that everything except the switch is OK. By process of elimination that means it's a bad switch.
NO.
When you jumper the wire for the fan switch, you're simulating a HOT condition, so the fans are supposed to run. If they don't then there's a problem somewhere in the fan control circuit. In that case, you still have to chase down what the problem is, like a bad relay or broken wire.
Most of the time, this test WILL make the fans run, which means that everything except the switch is OK. By process of elimination that means it's a bad switch.
according to my mechanic, the switch is working fine,(i intend to verify on my own), but we are still overheating...boiling up through the overflow tank.
i will make another thread regarding this...any ideas?
Super Moderator
Joined: May 2006
Posts: 18,398
From: Wisconsin
Radiator = new
rad.Cap = new
T-stat = new
right??
(confusing...)
You say waterpump is "OK" but maybe that only means it isn't leaking & the bearings turn smoothly. It's unusual, but not impossible, for the impeller to be corroded so it doesn't pump well.
Or maybe scale & crud buildup inside the water passageways to obstruct the proper flow of coolant??
(I'm only guessing at things for you to check out)
rad.Cap = new
T-stat = new
right??
(confusing...)
You say waterpump is "OK" but maybe that only means it isn't leaking & the bearings turn smoothly. It's unusual, but not impossible, for the impeller to be corroded so it doesn't pump well.
Or maybe scale & crud buildup inside the water passageways to obstruct the proper flow of coolant??
(I'm only guessing at things for you to check out)
Thread Starter
|
Junior Member
Joined: Jan 2009
Posts: 73
Radiator = new
rad.Cap = new
T-stat = new
right??
(confusing...)
You say waterpump is "OK" but maybe that only means it isn't leaking & the bearings turn smoothly. It's unusual, but not impossible, for the impeller to be corroded so it doesn't pump well.
Or maybe scale & crud buildup inside the water passageways to obstruct the proper flow of coolant??
(I'm only guessing at things for you to check out)
rad.Cap = new
T-stat = new
right??
(confusing...)
You say waterpump is "OK" but maybe that only means it isn't leaking & the bearings turn smoothly. It's unusual, but not impossible, for the impeller to be corroded so it doesn't pump well.
Or maybe scale & crud buildup inside the water passageways to obstruct the proper flow of coolant??
(I'm only guessing at things for you to check out)
yes, all new.
it was determined that the waterpump didnt need replacing, when the HG was replaced.
i am starting to think that there is still a HG problem...or worse; cracked block or something?
i will check coolant flow.
thanks
Joined: Feb 2009
Posts: 6
This is an interesting troubleshooting thread.
1. Car runs OK with AC on
2. Car overheats with AC off
3. Thermostat tested OK
4. Fans switch tests OK
According to all this, it must be a faulty temperature sensor (I don't know the specifics as I am not a mechanic) or relay that activates the fans. Something tells the fans when to turn on.... that something is bad.
And by the way, a cooler thermostat is not good for your engine, once the troubleshooting and repair is done the OEM thermostat should be installed.
1. Car runs OK with AC on
2. Car overheats with AC off
3. Thermostat tested OK
4. Fans switch tests OK
According to all this, it must be a faulty temperature sensor (I don't know the specifics as I am not a mechanic) or relay that activates the fans. Something tells the fans when to turn on.... that something is bad.
And by the way, a cooler thermostat is not good for your engine, once the troubleshooting and repair is done the OEM thermostat should be installed.
Thread Starter
|
Junior Member
Joined: Jan 2009
Posts: 73
This is an interesting troubleshooting thread.
1. Car runs OK with AC on
2. Car overheats with AC off
3. Thermostat tested OK
4. Fans switch tests OK
According to all this, it must be a faulty temperature sensor (I don't know the specifics as I am not a mechanic) or relay that activates the fans. Something tells the fans when to turn on.... that something is bad.
And by the way, a cooler thermostat is not good for your engine, once the troubleshooting and repair is done the OEM thermostat should be installed.
1. Car runs OK with AC on
2. Car overheats with AC off
3. Thermostat tested OK
4. Fans switch tests OK
According to all this, it must be a faulty temperature sensor (I don't know the specifics as I am not a mechanic) or relay that activates the fans. Something tells the fans when to turn on.... that something is bad.
And by the way, a cooler thermostat is not good for your engine, once the troubleshooting and repair is done the OEM thermostat should be installed.
i sure hope it is something that simple.
the fact that the coolant is boiling in the overflow even when the AC is on and the gauge is reading normal, distresses me tremendously...
Joined: Feb 2009
Posts: 6
I'd look at other things at this point. Clogged radiator, bad waterpump, mechanical blockage of air flow, leaks.
Unregistered
Posts: n/a
I had a similar problem on my 91 Acc EX about 4 years ago. If I remember correctly, it was one of the fans that was bad.
The radiator fan comes on as soon as the engine reaches normal operating temp, then it cycles on and off periodically. The condenser fan ( passenger side i believe but not sure) comes on as soon as you switch on the A/C or when the radiator overtemps.
Under normal conditions and with the A/C off only the radiator fan should be coming on.
Hope that helps.
New here, by the way.
The radiator fan comes on as soon as the engine reaches normal operating temp, then it cycles on and off periodically. The condenser fan ( passenger side i believe but not sure) comes on as soon as you switch on the A/C or when the radiator overtemps.
Under normal conditions and with the A/C off only the radiator fan should be coming on.
Hope that helps.
New here, by the way.