Need help with heat/throttle issue - LONG

[cornfish]

Hey Guys, I have a problem that I really need help with. I have been fighting a few issues with the car and now I am so pissy that I don't know what to do anymore. I just need help. Here are the issues:

The first one is that recently I changed out my O2 sensors to try and fix the bog I get when the car is cold. I went and purchased BOSCH O2 sensors for the car and when I went to put them in, I noticed that the original O2 sensor wires were extended because of the relocation of them due to the SVS headers I have on the car. Ok, well off to the store to get wire. I extended the wire with 18 gauge threaded wire and put them in the car. I took the car out and now when it gets really hot, the car idles occasionally at 1800 RPMs. Obviously heat is getting in to the wire so I went back and took the original wire off of the old O2 sensors and soldered them on, replacing the wire I purchased. I assumed that since the old O2 sensor wire SVS used was good because I never had this issue before so I just used that. I then wrapped the wire with 2000 degree heat shielding just to further make sure I don't have any heat issues. Well, tested the car again and they were perfect for about 45 minutes of driving but then when the car got extremely hot again, the super high idle came back with a vengence. What do I do here? Do I call up SVS and try to get them to send me new O2 sensors that are already wired by them (hopefully they would do this for me.) Did I screw the O2 sensors up with the first wire I put in? WTH??

The second issue is a heat issue. About a year ago I blew my original radiator. Well, I purchased a PWR radiator and then called up JonB and got a new '99+ fan shroud. I put both of them in and ran for a while. I have a new radiator, a triple pass one at that, and my car is running hotter than before. After a short period of time, I blew that radiator (pin holes in the welding) and this time purchased a Ron Davis radiator from JonB. Put that one in and it is still running hotter. I took the car to a radiator place here in town and they flushed the coolant and put some new stuff in. They ran tests and said that the car was fine. Well, it wasn't super hot outside so it seemed fine. Now that it is hot outside, the car was running at the far notch to the right (notch before the redline) and my car now does that crazy idle thing that I mentioned before. That hot with a Ron Davis radiation - overflow tank has the correct amount of coolant/water/water wetter and it still runs that hot? Of course when it is that hot, the AC doesn't work and I look like I just ran a 10k run when I get out of the car. I swear that I could smell burning flesh in the car

Any advice would help and if someone wanted to come and help me out, I would be the happiest person in the planet. I would take it to a Viper Tech if WE HAD ONE here in Bend. I think the closest place is Portland and I don't want to drive it there like this.

I will note that when the car isn't super hot, it runs very good. Good power, no stuttering and it feels like I have every bit of power that I should have minus the altitude here in Bend. The car only has 17k miles on it now and didn't have a single issue with the car until I put in the new radiatior. I have tried to burp the thing like 1000 times. I shave my head but seriously, if I had any hair I would have pulled it out by now.

Thanks in advance.

- Ron (cornfish)

 

[EllowViper]

My $.02c on a Monday AM...water pump impeller spinning on the shaft and a tempermental IAC valve.

 

[dave6666]

Problem #1 - Never modify the wires on an O2 sensor. Only the chassis wiring can be modified. You have to either buy extenders, buy sensors with the correct extended wire built in, or modify the wire on the car to reach. My understanding is the sensor wire itself is not copper but a steel alloy. Tinkering with it is a no-no. My Monday 0.02 is you just wasted 2 sensors. No rewind button on what you did to them.

Problem #2 - Your cooling system. A 1998 car is not the year known for spinning impellers. That was 2001, not that any water pump could not also fail however.

I have used both Ron Davis and now a Roe triple pass (in 105 - 110 degree ) and neither are a miracle for cooling. They help, but the factory radiator ain't that bad.

A quick note on radiator specs... So they make the core 50% thicker on the aluminum aftermarket ones. But they use a metal not nearly as capable of heat transfer. Depending on the exact alloy of each, copper can shed twice as much heat as aluminum. So, um...

What about your thermostat? Could it be sticking? What temp is it?

Your radiator cap... Is it good for sure? Have you pressure tested it? Bad ones run hotter. And your blows radiators...?

The gauges are infamous for being off. Or did your car used to run cool and now it doesn't? And all this is according to the gauge right? My gauge in my '01 is off by about 10 degrees or so.

Sending units also can go bad and are easy to swap.

 

[Paul S Lacey]

Also water not filled correctly or car not burped, if air is in the system and it seems likely then water level is not correct and you really need to ensure that the system is emptied again with both block drains out, the engine started and the car refilled while running, then burp the system refill drive burp refill etc, or thats what I had to do when changing the water in the GT2.

Extra high temps do cause 'idle hange' search for it the most effective tip I seem to rember was to change the size of the hole in the idle sensor.

Hope this helps, water changing a Viper can be a PITA.

 

[cornfish]

Problem #1 - Never modify the wires on an O2 sensor. Only the chassis wiring can be modified. You have to either buy extenders, buy sensors with the correct extended wire built in, or modify the wire on the car to reach. My understanding is the sensor wire itself is not copper but a steel alloy. Tinkering with it is a no-no. My Monday 0.02 is you just wasted 2 sensors. No rewind button on what you did to them.

So you think I should go get steel wire and extend the connections from the car? I can do that rather quickly since I am now a solder genius with my solder iron. I assumed I destroyed my O2 sensors when I first got the throttle issue. I have never had that issue before and it happened day one when I put in the new sensors. Keep in mind that it was 90 degrees outside so it was perfect for testing them. I would have never seen these issues if the car didn't get so hot.

What about your thermostat? Could it be sticking? What temp is it?

Your radiator cap... Is it good for sure? Have you pressure tested it? Bad ones run hotter. And your blows radiators...?

.....Sending units also can go bad and are easy to swap.

My buddy and I think the thermostat is opening. All the way? --> Not sure. What I know is not normal is the car was staying at the mark before the redline for an extended period of time. I had the AC on to try and get the fan running as quick as possible but ended up flipping it off when the temp was so high. I did buy a new cap by the way. I put it in when I filled the overflow tank. When I checked the tank, it was almost empty (to the point where I couldn't tell if it had any in it looking at the slit in the wheel well.) It has the perfect amount in there now - based off of your post in the illustrated upgrades. Good stuff there.

I just want the car to run good again. There is only one more Gen 2 here in town and I haven't seen him in a while. So you can imagine the buzz the car generates.

Thanks for the quick reply guys!

 

[dave6666]

The O2 sensors cannot be modified. Repeat... Cannot be modified. If you modded the set you just bought, throw them away and get another set with either extenders or the extension built in. DC performance has the ones with the extension built in, Viper Tony knows where to get the extension cables. I lengthened the wire on the car when I did mine. The "legal" thing to do for the soldering buff.

The hash mark before the final red zone at 250 is where my car will run with the AC on in traffic. That mark is not too high.

When you start the engine cold watch it warm up and you should be able to see the stat open on the gauge. Mine opens right past the first center mark and then if I haven't been hammering on it during this warm up will briefly drop about 5 degrees to the other side of the mark, when the cold fluid in the radiator replaces the hot in the engine. Watch to see if that happens. Just let it warm up gradually - no romping on it.

Also, if you don't have a big air bubble problem it will eventually work it's way out. You should see the level in your fascia bottle drop a bit as air is replaced with fluid.

 

[cornfish]

I have a call into DC Performance. Hopefully they will get back to me soon. After I get the new O2's in, I will see what we can do with the heat issue. You know, I took it into a place here in town to get the coolant replaced last summer and they said that the thermostat was opening fine. The viper is a different beast tho and will try to get some more info when I get it back up and running with the non tampered with O2s.

 

[SingleMalt]

Just curious -- do you have after-market throttle bodies?

Mike

 

[cornfish]

Just curious -- do you have after-market throttle bodies?

Mike

Yeah. I have the SVS throttle bodies.

 

[SingleMalt]

I know there were issues with the BBK units; there were not enough cavities built into the aluminum housing to allow for expansion and the throttle plates were getting stuck partly open when the cars came to temperature. You may be able to observe the phenomena if it happens to you; get it to misbehave and pull the intake tubes and try to open and close the plates by hand as you watch the clearances between the flap and housing.

Good luck -- hope you get it figured out soon.

Mike

 

[SingleMalt]

Also, I have spliced O2 sensor wiring on my car with no ill effects. Is the key to be mindful of the heat transferred to the sensor body?

Here's a writeup from Bosch regarding proper procedure for performing the splice; they state a minimum distance of 5" from the sensor body for any splice joints. Notice they don't make any mention of a solder joint? I don't know how to interpret that. Heat? But then again, it's right up against your exhaust system... This one's out of my league.

http://www.boschautoparts.com/NR/rd...3-9098-727C01AF4B7D/0/OxygenSensorInstall.pdf

Mike

 

[dave6666]

That is an interesting article. They obviously use a special mechanical wire joint connector. I wonder if this "universal" O2 sensor would be applicable to every application, especially more specialized ones like a high performance car? Or if it's more of a Taurus/Intrepid/Corvette kind of part?


Anyway, any of our resident expert parts and tuning suppliers I've talking to about modding sensor wires say don't do it. Just repeating after them.

 

[ViperTony]

Anyway, any of our resident expert parts and tuning suppliers I've talking to about modding sensor wires say don't do it. Just repeating after them.

Interesting, my quick fire O2's from DC came modified, extended an extra 3 inches. I didn't notice it until last week.

 

[cornfish]

Interesting, my quick fire O2's from DC came modified, extended an extra 3 inches. I didn't notice it until last week.

Mine came modded from SVS as well. Well, I decided to go the expensive route and purchased new O2's from DC performance and O2 extensions from American Racing Headers. The only reason I purchased the extensions is because the longer wire O2's from DC were still too short. After next day from DC and next day from ARH, it wasn't cheap. Hopefully the car will be doing good tomorrow after I get off of work. Shouldn't be more than a 15 minute job now since I am so used to taking off the sills and routing the sensor wires now. If I get that throttle issue again after this, I am shooting someone.

 

[dave6666]

Next Day Air 2x?

Track event or just plain old jones'n?

 

[dave6666]

Interesting, my quick fire O2's from DC came modified, extended an extra 3 inches. I didn't notice it until last week.

Obviously per the Bosch link above, and your specimens too, there is an acceptable way to do it. But if the wire is indeed some type of steel alloy or whatever, who has that in their toolbox of home improvement electrical aisle? And also per the Bosch link, if good old toolbox solder works why do they have that fancy screw type connector? Why not crimps? Or does solder not work? Or...?

So I just keep repeating what I've heard many times from many of our reputable site supporters - don't mess with the sensor wires. But have your way with the copper chassis wires if you can solder and heat shrink.

 

[cornfish]

Next Day Air 2x?

Track event or just plain old jones'n?

Hahaha.. I like to waste money. No, I just really want to drive it and the weather here has been so nice. Did you see my latest post?

Since the O2 sensors were too short, I had one on my coffee table and one in the garage. I came home tonight to my dog chewing on the one that was placed on the coffee table. Man, this *****..