Need help, Viper overheats.

[Bo knows]

Ok, here's what's going on. Never had an overheating problem. I installed a Roe supercharger. Installed headers, had cylinder heads ported also. Changed thermostat to a 180 degree stat. and had stock radiator recored to a three core. Car started and ran fine for 2 weeks, didn't overheat at all. All of a sudden one day I look at the temp gauge and it reads around 230 and is climbing. I stab the gas hard and the temp gauge quickly returns to normal. In the next few days this happens a few times but always cools off after I get on it. Then it overheats again & won't go down even after getting on it. I pull over & coolant boils out overflow. I let it cool and drive home stopping several times to let it cool off before it boils over again. I replace the water pump figuring it's 16 years old and must have went bad. Car overheats before I can get it out of the garage. Now I'm thinking I must have gotten a bad thermostat. Off comes the supercharger and in goes another new NAPA superstat PN 613080 180 degree thermostat. Car ran all day long without overheating. After sitting for 4 hours I went for another ride and it overheated again but cooled off quickly after I got on it. Anybody ever experience anything like this before? Anybody got any ideas ?? Bo don't know.

 

[AZTVR]

First thing is to check the overflow bottle in the front fascia and see if it is empty. Then. is the expansion tank full? Then, is the radiator fan running? From what you've done, you sound like you probably have looked into those things, though. Other than that, I got nothing.

 

[Bo knows]

Overflow tank full, expansion tank full, fans come on but don't help. Thanks for responding AZTVR .

 

[speedracervr4]

Are you sure the fan is coming on in low and high speed mode? Checked the relays under the hood?

I just read on VA of a guy having an issue with a newly installed water pump failing within 3 months. Do you get heat out of the vents when the heater is turned on?

I know it's a far fetch, but you might want to make sure it's not a head gasket issue by testing the coolant. They have a tester at your local auto parts store (block tester).

 

[Bo knows]

More info if anybody is following this thread. When car is started cold and is idling during warm up I get plenty of heat out of the heater. The radiator stays cold. As it warms up the temp gauge climbs. When it reached 230 still had plenty of heat from the heater and a cold radiator. I reved the engine and quickly the temp gauge dropped to normal and the radiator got hot.

 

[AZTVR]

I'm afraid that all the smart people may have left the building. (or enjoying a weekend off.) If you hadn't changed it already, I'd point at the thermostat. Remotely possible is two bad thermostats if they came from the same batch. If you decide on doing a third, I would put it or the one coming out in a *** of water, heat it, and see when it opens. Realistically, how could that be it. It has been a couple of years since I changed mine Is it possible the thermostat is installed upside down? I don't remember if that is possible but might explain why 2 do the same thing. So, then we think , how might it be due to something related to your new supercharger install? This is a stab in the dark. I'm not familiar with the supercharger belt setup. Does the same belt now drive everything? Lets consider the issue people have had where the crankshaft dampener bolt comes loose a bit and allows the dampener and pulley to spin at a slower rate than the crankshaft. That would run the water pump slower. Seems like there would be noticeable noise, though. That's all I got for ya. Good luck.

 

[Hostile]

Bo knows
Watter pump impeller slipping on the shaft.

Skeeter

 

[mtmclaughlin]

Maybe there's air in the cooling system. You may also check the radiator cap since it's an easy check and these have a limited lifespan.

AZTVR has an interesting point about your supercharger belt. If the supercharger belt runs the rest of the accessories, could it be possible that you have the belt routed incorrectly so that it's trying to spin the pump backwards?

 

[speedracervr4]

Seems like a water pump/flow issue. I don't think it would matter, but did you install the proper idler pulley for the 10lb pulley?

 

[Fatboy 18]

Sounds like you may have air in the system? Is the overflow bottle in front of the passenger wheel at the correct level?

When did you last change the coolant?

Another thing that can happen is the plastic impeller that is attached to the water pump shaft can spin on the shaft so you do not get the correct flow through the system. 'Life is Good' posted some pictures of his worn water pump somewhere?

Not saying it is this as to be honest you would have to remove the water pump to check! Not a 5min job

 

[CajunMojo]

Dumb question from a new owner: How the hell do I access the overflow bottle in the front fascia? I can see it through the fog light access, but haven't really figured out how to get to it.

 

[cfiiman]

I was thinking air in the system as well, although the water pump suggestion could also be a cause.

 

[speedracervr4]

Dumb question from a new owner: How the hell do I access the overflow bottle in the front fascia? I can see it through the fog light access, but haven't really figured out how to get to it.

If you want to remove it then the fascia has to come off. If you need to add water then disconnect the small hose on the pressure tank (right below cap) and add fluid with a small funnel.

 

[CajunMojo]

Thx speedracer.

 

[SEASNAKE]

There should be threads about burping the air from the coolant system on this site somewhere. If you drive regularly and let the car go through normal heat cycles, then check the overflow tank after each drive. You can get all the air out pretty quickly. I have air bleeders in the hoses on my car. Roe used to sell some pretty good ones. I assume he still does.

 

[Turbolag]

Quick question. When you say overeat, do you mean the temperature gauge just goes to the hot side ?

I had a 96 camaro Z28 that did the same thing. I had installed off road headers on it, and the heat these headers made was enough to cook meat on. It really bothered me one day when I was sitting in traffic and I looked at the needle and it was almost pegged. I thought to myself "wow, this needs to cool down or its gonna warp the heads".

I brought it to the radiator shop, and turns out the temp sensor was giving a faulty reading ! The car wasn't overheating, it was fine.

Have you checked your temp sensor ? What might be happening is there is more heat inside the motor at idle and the temp sensor is picking it up.

That's why when you start moving it will cool down because the heat is blown off from the air rushing through.

Once I got out of stop and go traffic the gauge would go back to normal.

Just a thought for you.

 

[past ohio]

Two things I can think of, "burp IT" may have air in the system, and racers use a product called "water wetter" in their solution...brings it down 4-5 degrees...hope any/all suggestions can help you good luck !

 

[Leslie]

I clean my radiator frequently, run 70% distilled water, 30% coolant and 2 bottles of water wetter and 170 t stat.
If it's 80 degrees or hotter outside, I hit 230 temps after 15 min.run at track and usually pit out.

On the street I am at 160, unless I am idling, then it's 190. Not bad! Used to be higher

 

[speedracervr4]

Skip the Water Wetter, no need for it on a street car with a properly operating cooling system. It sounds like an overheating issue as opposed to a sensor issue due to it pushing coolant to the overflow bottle. I like burping the system with a Lisle filter with multiple heat cycles with the heater on. Let us know when you figure it out.

 

[Bo knows]

I got this all apart again and I can't find anything wrong. If anybody has anything, any ideas at all, I don't care how ridiculous it may sound, just throw it out there. I'm going to put in a different brand of thermostat although I don't see anything wrong with the two I took out. Thanks

 

[speedracervr4]

Since you have it apart I would pull the radiator and have it flushed/checked out.

 

[Bo knows]

Speedracer, thanks for your reply. I have a brand new 3 core radiator in it. It runs perfectly cool for a while then the temp shoots up, after I get on the gas hard the temp will quickly drop back down.

 

[AZTVR]

Speedracer, thanks for your reply. I have a brand new 3 core radiator in it. It runs perfectly cool for a while then the temp shoots up, after I get on the gas hard the temp will quickly drop back down.

Well, at this point it might be time to take it to Chuck Tator. (or at least solicit his advice. )

 

[Viper Specialty]

Water pump. Water pump. Water pump.

99 times out of 100 this particular issue can be traced back to a pump issue.

 

[CEJ]

Bo, what year is your Viper?

 

[7TH_SIGN]

What is the stock coolant? Or is there a better option?

 

[7TH_SIGN]

I clean my radiator frequently, run 70% distilled water, 30% coolant and 2 bottles of water wetter and 170 t stat.
If it's 80 degrees or hotter outside, I hit 230 temps after 15 min.run at track and usually pit out.

On the street I am at 160, unless I am idling, then it's 190. Not bad! Used to be higher

Is that OEM spec?

 

[Bo knows]

Ok, once again thanks for your replies. I put a new water pump in. Couldn't find anything wrong with the old one. The new one didn't make any difference. Talked to Chuck Tator, he had a few ideas that I tried and made no difference. My Viper is a 1997 with 37,000 miles on it. If anyone is interested you could go back & read my first post, it sums up what I've done so far. Please keep the ideas coming !!

 

[speedracervr4]

Did you try a new radiator cap? Cheap thing to try. I don't think that's your issue, but worth a shot. How was the coolant when you changed the water pump? Clean/dirty?

 

[Viper Specialty]

Check crank damper- is bolt loose?

These cooling systems are very simple, nothing magical by any stretch.

Any signs of coolant in oil? Coolant system pressure test results?