Clarifications on burping my 97 GTS and fixing my overheating issue

[97GTSDave]

I'm having some issues with my '97 GTS overheating. I spoke with JonB from PartsRack about it (who was kind enough to walk me through the burping process), but I'm still having some issues and don't want to bother him too much. Maybe you guys can help, as I think I'm maybe not burping the right way.

As I understand, if you can squeeze the upper radiator hose (even when the car is cold), that's essentially an indicator that there is air in the system?

Here are the notes that I took for burping so you can see the process I am using:


You know it needs to be burp if the top driver's side radiator hose can be squeezed really easily while the car is cold
Make sure heater is on full blast inside the car
Keep towel around the pressure/surge tank on the passenger side to make sure it doesn't bubble up everywhere
Pour distilled water until the tank is about 2/3 full
With 2 people, have one person squeeze the upper radiator hose slowly with two hands and the other person see/hear if it bubbles up in the tank
As you let go slowly, the other person will pour distilled water down in the pressure tank
Keep repeating that process, could be 20 or 30 times until hose is no longer soft/squeezable and no more bubbling up. This gets the air out of the motor.
Ideally, the overflow tank in front of the passenger wheel well should be half full at the end, can take light on cell phone with video to see the level
Fill water to brim on the pressure/surge tank, close and try running car



I attempted to do this and went through over a gallon of distilled water without any change. There is no sign of leakage or anything, so I don't know how the coolant could have gotten so low, unless it's another issue? Another odd thing is that when I add water to the surge tank, I can fill it to the top, and by itself, the water will start to go down. I took a video, skip to around 42 seconds and you'll see what I mean: https://photos.app.goo.gl/mHgC8hPEERCUY3m6A

I reached out to a local shop I use for oil changes, he was saying that the upper radiator hose being squeezable cold is normal...so I just wanted to get clarity around this. When the car is cold, should you be able to squeeze the upper rad hose?

My thought is hopefully it's just air in the system and nothing else. Assuming I can conclude that and get it resolved, my next step is a coolant flush. I have the 3 year green Mopar stuff in there now, and it sounds like I should be changing to the orange 5-year. I plan on having a shop do the flush (I'm going to show them this thread (https://www.viperclub.org/vca/threads/coolant-change.550922/) for guidance), any idea on what they should charge for that?

Any help would be appreciated!

[Fatboy 18]

No1 Where the hell is your Antifreeze? The coolant should be Green in colour if you are using the correct brand?

No2 Hard to tell from the Video but is the engine running?

Until the Thermostat opens you will likely have air in the system, there is a small bleed screw on the thermostat housing.

Yes you can squeeze the hoses when cold.

[97GTSDave]

No1 Where the hell is your Antifreeze? The coolant should be Green in colour if you are using the correct brand?

The pressure tank was empty when I started to overheat, and with JonB's advice for the burping procedure, I used distilled water to refill it. That's why it's clear. I have not turned the car on since adding it. The coolant that is in the system is the green 3-year Mopar from a flush I did a few years ago (I'm overdue on time, not many miles have been added).


No2 Hard to tell from the Video but is the engine running?

No, it's cold.


Yes you can squeeze the hoses when cold.

Ok, so that sort of changes everything on my end as I was doing the burping process without the engine running. Is that wrong? Is there a defacto guide on burping properly, I feel like I'm missing some stuff...

[Fatboy 18]

So you fill up the header tank and squeeze the odd hoses until you get to the top of the filler neck.

Heater fully on direct heat to the defrost windshield.


Put the cap back on the car header tank, start engine, Watch Temp Gauge!
At first you will be able to go back around to the filler header tank and you should see (with the cap removed the level going down....Add more coolant, Replace cap.

(Ideally you should be premixing coolant to maintain correct consistency then adding it to existing coolant)

Check Engine Temp..... thermostat may not yet have opened so Engine may get hot.... Check Temp gauge and if the needle is pushing past the 2pm position switch of engine and wait for a bit before restarting.
Is Hot air heating the windshield? If not this means there is likely a blockage or thermostat had not yet opened

Check top and bottom rad hoses to see if one is hotter than the other, that will tell you if the thermostat has opened.

With engine off and car cooled down a bit Carefully remove cap on filler tank and again check level.
Basicly the full level of the header tank should be where the horizontal tank seam is, at the back of the tank there is a level marker.

If you go over this, No problem as any excess coolant will disperse into the tank in the front nose of the car.

[71firebird400]

Or just use a vacuum bleeder and save yourself all of these headaches and home remedies. It is well worth the $125 in my opinion.

[JonB ~ PartsRack]

Final note was to run the car! You gotta get the water pumping.

[01sapphirebob]

Or just use a vacuum bleeder and save yourself all of these headaches and home remedies. It is well worth the $125 in my opinion.

This. OR get Lisle spill free funnels. I used one on my ‘01 to refill the coolant. Worked like a charm. Its less then $40 too!

[97GTSDave]

Final note was to run the car! You gotta get the water pumping.

How long do you run the car? Do you repeat the process until the levels stay at a specific level in the pressure tank? Basically, I'm asking, what do you do when you start the car, and what do you do after?

[dave6666]

I've done a lot of Gen 2 complete drain and refills on the cooling system. I've never had to burp one. Ever. Because the system is designed by the factory to be self purging of air.

If you have to burp your car to get the air out of your cooling system you should fix the problems with your cooling system. It is that simple.

[BK99GTS]

This. OR get Lisle spill free funnels. I used one on my ‘01 to refill the coolant. Worked like a charm. Its less then $40 too!

I love the Lisle funnel. Turns what is normally a complete mess into a clean and easy job. Has lots of different fittings to accommodate all sorts of setups. I have used on '85 chevy, square body truck, '83 Jeep CJ7, '95 LT1 Corvette, '99 Viper and works like a charm. Since I use it all of the time out of habit, I automatically used it on the Viper.

[TP_ GTS]

This. OR get Lisle spill free funnels. I used one on my ‘01 to refill the coolant. Worked like a charm. Its less then $40 too!

Agreed....assuming you don't have any underlying issues or leaks, this is the way to go.

[TP_ GTS]

https://driveviper.com/forums/threads/7517-Coolant-Drain-and-Fill-s?highlight=Coolant+drain


Hopefully this thread will help.

[97GTSDave]

Agreed....assuming you don't have any underlying issues or leaks, this is the way to go.


This. OR get Lisle spill free funnels. I used one on my ‘01 to refill the coolant. Worked like a charm. Its less then $40 too!


I love the Lisle funnel. Turns what is normally a complete mess into a clean and easy job. Has lots of different fittings to accommodate all sorts of setups. I have used on '85 chevy, square body truck, '83 Jeep CJ7, '95 LT1 Corvette, '99 Viper and works like a charm. Since I use it all of the time out of habit, I automatically used it on the Viper.

Those of you that mentioned doing the Lisle funnel...I just want to be sure I understand completely.

If I use the funnel, this will essentially burp the system, so there would be no need to go through the process I mentioned originally (squeezing the upper radiator hose), is that correct?

Do I just put the funnel on the pressure tank, or where do I do that?

[BK99GTS]

Lots on youtube, but here is one that should give you the idea. Make sure you pre-mix yourself or buy pre-mixed unlike what is described.
https://www.youtube.com/watch?v=xYkKW0OyeUc

[97GTSDave]

Lots on youtube, but here is one that should give you the idea. Make sure you pre-mix yourself or buy pre-mixed unlike what is described.
https://www.youtube.com/watch?v=xYkKW0OyeUc

Does it go in the pressure tank?

[mdpalmer]

Those of you that mentioned doing the Lisle funnel...I just want to be sure I understand completely.

If I use the funnel, this will essentially burp the system, so there would be no need to go through the process I mentioned originally (squeezing the upper radiator hose), is that correct?

Do I just put the funnel on the pressure tank, or where do I do that?

I second (third, fourth?) using the Lisle funnel. Yes it goes on the pressure tank. I've used it twice and the engine only ran a little hot (until fan came on) the first half-dozen or so drives. The point of the funnel is to minimize introduction of air into the system as you fill. Make sure you use the appropriate fitting on the flange of the pressure tank (should not leak at all while filling). As was mentioned, air works itself out of the system as you heat cycle the engine, assuming there is no additional air coming in. Make sure your fascia recovery tank is filled per the linked post above.

https://driveviper.com/forums/threads/7517-Coolant-Drain-and-Fill-s?p=115091&viewfull=1#post115091

Check the level in the recovery tank when the engine is cool.

All this business about squeezing the radiator hose, blah blah blah.. I never did any of that.

[aakviper]

Why not use Genuine Mopar Fluid 50 50 Pre Diluted Antifreeze Coolant 1 Gallon Bottle No mixing required! That is what I use, a pre mix in all my cars! Simple and no chemistry involved.


38646

[97GTSDave]

Thanks all for the advice. So it turns out, I actually do have a leak from the radiator:

38647

So it looks like I have two options, looking for advice as to what you would recommend.

- There's a local shop that can re-core it. They would convert it to a 3-row. It's about $1,500 all said and done (re-core, remove/install, new rad hoses, and having the car towed there).
- Getting an aftermarket radiator and having it installed locally. It looks like they range from about $600-800 or so. I think the all-in cost would be pretty similar.

If prices are about the same, which route would you go?

[98RedGTS]

Thanks all for the advice. So it turns out, I actually do have a leak from the radiator:

38647

So it looks like I have two options, looking for advice as to what you would recommend.

- There's a local shop that can re-core it. They would convert it to a 3-row. It's about $1,500 all said and done (re-core, remove/install, new rad hoses, and having the car towed there).
- Getting an aftermarket radiator and having it installed locally. It looks like they range from about $600-800 or so. I think the all-in cost would be pretty similar.

If prices are about the same, which route would you go?

How much to re-core it without them doing all the labor to remove? If that is $400-$500 I'd go that route. I have the HOWE in mine. While I like it I haven't really noticed much, if any, change in cooling. At this point I would have gone re-core if I could find a shot to do it locally.

Just a FYI that the lower hose is NLA and dang near impossible to find. Took me a couple of months until I found a member willing to sell me one. Silicone hoses are readily available though.

P.S. - Changing the radiator out of the Viper is STUPID easy. If you have even basic mechanical skills I would do it myself way before paying someone to do it.

[97GTSDave]

How much to re-core it without them doing all the labor to remove? If that is $400-$500 I'd go that route. I have the HOWE in mine. While I like it I haven't really noticed much, if any, change in cooling. At this point I would have gone re-core if I could find a shot to do it locally.

Just a FYI that the lower hose is NLA and dang near impossible to find. Took me a couple of months until I found a member willing to sell me one. Silicone hoses are readily available though.

P.S. - Changing the radiator out of the Viper is STUPID easy. If you have even basic mechanical skills I would do it myself way before paying someone to do it.


That's a great question, I'll have to find out. I think I can handle taking out the radiator if I had to, but I am changing the coolant to a different color, so it really needs to be flushed well...I'm not super comfortable dealing with the drain plugs on the block and would rather pay somebody than take the risk of f'ing something up (plus, it looks like it needs some custom tool to remove them).

Regarding the hoses, I ended up getting the silicone Mishimoto ones (https://www.mishimoto.com/dodge-viper-silicone-hose-kit-96-02.html) with new clamps.

[71firebird400]

I removed my block drain plugs for the first time this past winter and it was about the simplest thing in the world. Zero reason to be weary of it, just a 5/16" pipe plug socket is needed.

[Fatboy 18]

Thanks all for the advice. So it turns out, I actually do have a leak from the radiator:

38647

So it looks like I have two options, looking for advice as to what you would recommend.

- There's a local shop that can re-core it. They would convert it to a 3-row. It's about $1,500 all said and done (re-core, remove/install, new rad hoses, and having the car towed there).
- Getting an aftermarket radiator and having it installed locally. It looks like they range from about $600-800 or so. I think the all-in cost would be pretty similar.

If prices are about the same, which route would you go?

I would get your original one re-cored, far less hassle. :)

[Lemay88]

Had mine re-core here in town for 350$.
Kept it 2 row because Canada eh!!!
I’m a amateur shade tree mechanic and did the job myself,(with the hood on)...scary but surprisingly easy job.
Mishimoto top and bottom hoses. Used the funnel technique and followed instruction from Steve and Dave666.
Viper is running fine

[97GTSDave]

So I ended up getting it re-cored (they also converted it to a 3-row). The old radiator was pretty bad, he said it was probably around 35% flow at best. It's still at the shop now, but I wanted to see if you guys had any idea about the following two things that came up:

1) It seems to run just above the 190 marker on the temperature gauge. I believe that's how it was before, but the new radiator should be much more efficient. Should I be alarmed, or is that all good?
2) Separate topic, but the guy noticed that no hot air comes out the vents, even though the hoses get hot. Any idea what could be going on there?

Thanks again all for the tips and advice.

[71firebird400]

So I ended up getting it re-cored (they also converted it to a 3-row). The old radiator was pretty bad, he said it was probably around 35% flow at best. It's still at the shop now, but I wanted to see if you guys had any idea about the following two things that came up:

1) It seems to run just above the 190 marker on the temperature gauge. I believe that's how it was before, but the new radiator should be much more efficient. Should I be alarmed, or is that all good?
2) Separate topic, but the guy noticed that no hot air comes out the vents, even though the hoses get hot. Any idea what could be going on there?

Thanks again all for the tips and advice.

1. Operating temp is determined by the thermostat, not the radiator.
2. Heat will only come out of the footwell vents and defrost; A/C will only come out of the dash vents. Have him change the vent selection. Viper quirk.

[97GTSDave]

1. Operating temp is determined by the thermostat, not the radiator.
2. Heat will only come out of the footwell vents and defrost; A/C will only come out of the dash vents. Have him change the vent selection. Viper quirk.

1. Right, but if the radiator is more efficient, won't the operating temperature be reduced?
2. I should have mentioned that, he said he didn't feel heat coming out of any of the vents, including the defrost and footwell.

[Fatboy 18]

When he says no hot air comes out of the Vents, Which Vents is he referring to?

The 3 vents in the middle of the car above the radio do not blow Hot Air, they are fresh air vents only.

Heat should come out of the windscreen vents and using the diverter knob come out of the footwell vents.

If no hot air comes out of any vent then its one of two things, Airlock OR on the passenger side of the car under the hood where the "heater" radiator is is a small black round cylinder with a lever on the top, its common for the sprung clip to come off and when you turn the heater knob the plunger should move up and down.

Take a look at this pic, you can see that small black round cylinder (with two silver screws) looking into the hood gap
https://live.staticflickr.com/8702/16758602385_55cbcc65af_b.jpg (https://flic.kr/p/rwUdCr)20141123_173357 (https://flic.kr/p/rwUdCr) by Fatboy 18 (https://www.flickr.com/photos/90582394@N02/), on Flickr

[Fatboy 18]

Who's doing the work on this car? You or a qualified mechanic? Some of the questions here seem strange, this is basic stuff for a mechanic!

[71firebird400]

1. Right, but if the radiator is more efficient, won't the operating temperature be reduced?
2. I should have mentioned that, he said he didn't feel heat coming out of any of the vents, including the defrost and footwell.

1. No. The thermostat won't open as far if the radiator is dumping heat more quickly.
2. Is it airlocked? Is the valve opening? Did the heat work before?

[pokeyl]

After reading all this, there is an old racer trick. Drill a 1/32 (small hole) hole in the thermostat. Vents the air and makes it easy to bleed. I have not done it to the viper but I will next time I have it apart.