Overtemp, with a difference?

[V10 ACR]

Hi All,
I have been having the car show normal temp when on the highway, driving 50-80. As soon as I get off the higway and onto surface streets the fun starts. If I am stopped at a light the temp gauge will start to rise. If I am there for more than a min it is up 15 degrees. Today it went just shy of the red mark! As soon as I start driving, even if it is a slow 35-45 mph, the gauge drops within a min or two. I have checked coolant and all looks fine. I have tried burping and that does not seem to be a problem. Any suggestions? Water pump? Fan? Relays? Sensor? Guage? Thanks.

Kurt

 

[Silver Snake]

If you tried burping it and there is no air in the system it seems like your fans may not be coming on. When you are sitting in traffic can you hear the fan come on? Stick your arm out the window, can you feel the hot air coming out of the side gills?

I would start there.

Mark

 

[Russ M]

Explain what you mean by hot?

-\||/- picture this being your temp guage.

It is not unusual for viper to run between / and -.

If that makes sense.

2000? You may have the faulty water pump.

 

[V10 ACR]

It is a 2000 GTS ACR (Jan 2000 build/April 2000 Inservice date). For the last two years the needle on the temp guage has always been straight up to slightly right. -\||/- So I would say always between ||. The last few months it has been moving more towards / and today it was between /- when stopped at a light. No dash lights have come on. I have a Roe fan switch on the car and that will activate a few min after I am parked and stay on for about five min. So I know the fan motor is working. I drive the car 2-3 times a week and have put 8,000 miles on it in the last year. Any way to check the sensor, or is it cheap enough to replace? Thanks.

 

[95Viper]

What is the coolant level in the surrogate tank (the one with that radiator cap) and the facia tank(in front of pass front wheel)?

 

[V10 ACR]

Both tanks are full. On my way back from lunch today it just about hit the red mark when I was in traffic for 4 or 5 min. When I pulled into the parking lot it was nearly at the red as well. I waited and the Roe fan relay did not trigger the fan to come on. So I'm guessing it's the sensor, relay, or fan motor?

 

[Kiaser]

My guess is the fan not coming on or the water pump (isn't there a common problem with the water pumps on certain years). I was having the same problem a few weeks ago. I knew my fan worked because it would come on when I turned the car off (roe timer). It ended up being the sensor that takes temp readings to kick the fan on (after 207 degrees I believe). This is a different sensor than my roe used.

If you know for sure it runs cool when air is flowing through the radiator (highway speeds), then you can rule out a lot of things. I'll try to find my paperwork on what exactly fixed my issue and reply again.

 

[V10 ACR]

I know for sure it runs cool at highway speeds. Since it does, does this rule out the water pump and leave us with the fan or the sensor?
Thanks

 

[Silver Snake]

I know for sure it runs cool at highway speeds. Since it does, does this rule out the water pump and leave us with the fan or the sensor?
Thanks

That's my story and I'm stickin' to it.

You did say that your fan has not come on, right?

Mark

 

[smfettig]

I have a 94 Viper and my temp runs up to 215 or so (just shy of the orange shaded area) in heavy traffic and then the fan kicks on. Of course this only happens in traffic. On the freeway the needle points straight up.

 

[REDSLED]

I know for sure it runs cool at highway speeds. Since it does, does this rule out the water pump and leave us with the fan or the sensor?
Thanks

It runs cool at highway speeds because you are getting a greater volume of constant air to the radiator. Impeller could be going bad, causing cavitation? The fans may not be turning on. Do you keep high RPMs when driving on the street? I used to do inadvertantly so I could her the exhaust burp and crackle on decell. This would cause the temps to rise. Just a thought.

 

[95Viper]

V10ACR, Both tanks shouldn't be full. The surrogate tank should be but the facia tank should be between the marks. At night, shine light through rubber donut in facia and really see the marks. Then, open the radiator cap and really see if it is full.

 

[Catwood]

Kurt,

Check out the fan relays. There are three relays, two fan and one headlight (I think) I had trouble with mine before and the fans were coming on....

I had the same issue on a GM product.

Carl

 

[BruceW]

The Roe fan controller has it's own relay and circuit. If it isn't working then either its relay or the snap-thermostat switch isn't working.

 

[V10 ACR]

Carl, There is one fan and two headlight relays. Does anyone know if these are interchangable? If so, I'll just swap them around and see what happens. Bruce, it looks like the fan in not coming on at all, either through the Roe switch or the normal mechanism. I had the car running in the garage last night and I turned on the AC and the fan never came on. The temp guage was up to the red line in about 10 min. and still no fan came on. I scheduled a vist to the dealer (Yuk!) for the week of the 22nd since I'll be away for work next week. Any last ideas before I let them beat on it? Thanks.

 

[BruceW]

The heavy gauge wire running from the Roe relay that's tapped into the harness is the +12V line to the fan. Apply 12V to that. If the fan goes on then it's your stock fan relay and either the Roe relay or the Roe switch that's bad. If not, it probably has to be the fan motor.

 

[Catwood]

Carl, There is one fan and two headlight relays. Does anyone know if these are interchangable? If so, I'll just swap them around and see what happens. Bruce, it looks like the fan in not coming on at all, either through the Roe switch or the normal mechanism. I had the car running in the garage last night and I turned on the AC and the fan never came on. The temp guage was up to the red line in about 10 min. and still no fan came on. I scheduled a vist to the dealer (Yuk!) for the week of the 22nd since I'll be away for work next week. Any last ideas before I let them beat on it? Thanks.

Ok...I had it backwards. Mine had the same part number on the outside so I moved them around for testing. You should double check yours before moving them.

Carl