Need Info/Help GEN IV Cooling System Drain/Refill

[A1998]

I'm thinking this is about 1-2 hour job at the most. Removed the radiator cap from the coolant recovery bottle. Removed the bottom radiator hose from the radiator. Then removed the starter so I could remove the plug above it and the one on the other side. Replaced plugs and starter. (Disconnected battery before removing the starter). No problems everything OK at this point.

Service manual says to open bleed screw on thermostat (check) attached clear hose to it. Fill coolant recovery bottle slowly until fluid comes out of the screw. OK after 1-1/2 hours ( this is how slow it drains) I have managed to get 3-1/2 gals (50/50 mix) poured into it and I don't think it will take anymore. Nothing coming out of the bleeder screw (still open). So I decide to start the car to see if this will help. Air comes out of screw for short time then stops. I'm checking my tempature gauge when I notice on my dash below the brake light there is a red flashing light. Turns out to be the throttle control relay or something like that. Manual says if it's flashing stop the car and service.

So now I'm stuck here wondering what to do next?? Never had these problem on my Gen 2. But this is the first for me on a Gen IV.

A1998

 

[Viper Specialty]

Let me preface this by saying;

DO NOT go through the hassle of removing the block plugs on the Gen-3+ cars. The Coolant used in this generation is not of a degrading type with respect to time. That last little bit of coolant will serve no purpose in replacement. I have yet to see a Gen-3 with "dirty coolant" that was not due to contamination of some sort. That said, Gen-3/4 also have a radiator drain petcock. Do not remove radiator hoses. Gen-3/4 cars should not be treated like Gen-1/2 cars, as they do not have the same components or problems in general with regard to service work.

For a Gen-3/4, simply remove the cap, and open the petcock until it stops draining. Close the petcock, open the bleeder, and fill with Mopar Orange [5-year] coolant. When it stops taking coolant, cap the bottle, and squeeze the top hose until coolant comes out of the bleeder screw. Close the bleeder while holding the hose, and then release and top off the bottle, cap, and start engine. Make sure the engine warms up, and watch the needle to confirm the thermostat opens; should see it raise to thermostat temp, then fall back slightly, while radiator gets warmer to the touch. Let run for a few minutes, revving occasionally to push any air to the top of the system- you can also crack bleeder slightly to help speed this up. Turn off, allow to cool completely, and top off coolant. Done.

Note: DO NOT attempt this while car is slanted towards passenger side, or slanted forwards- bleeder should be lower than coolant bottle cap.
Note: SOME cars may have slight air pockets, simply squeeze the upper radiator hose in rapid succession until they break down and coolant level starts to drop again as it displaces the air- this is obvious if you cannot get coolant out of the bleeder or add coolant to the bottle, at a time when you are nowhere near being full.
Note: SOME cars may have clogged bleeders- make sure it isn't, and if so remove the bleeder and clean it out. This can cause the above as well.

 

[A1998]

Dan: Well better late than never! Appreciate the advise. Will use it next time. BUT ! What about the flashing light for the Electronic Throttle Control?? Do I need to be concerned about this or will this go away once the thermostat opens and coolant starts flowing?

 

[SSGViper]

Let me preface this by saying;


For a Gen-3/4, simply remove the cap, and open the petcock until it stops draining. Close the petcock, open the bleeder, and fill with Mopar Orange [5-year] coolant. When it stops taking coolant, cap the bottle, and squeeze the top hose until coolant comes out of the bleeder screw. Close the bleeder while holding the hose, and then release and top off the bottle, cap, and start engine. Make sure the engine warms up, and watch the needle to confirm the thermostat opens; should see it raise to thermostat temp, then fall back slightly, while radiator gets warmer to the touch. Let run for a few minutes, revving occasionally to push any air to the top of the system- you can also crack bleeder slightly to help speed this up. Turn off, allow to cool completely, and top off coolant. Done.

Bleeder Screw? Where is that and can someone take a pic if the bleeder screw? I've been changing mine on my 08 and was not aware of any bleeder screw. I simply open petcock on the lower radiator, let it drain, replace petcock, remomve any remaining from reservoir, fill reservoir until it fills radiator and will not take any more, start up and let idle till all air is out, and squeeze upper rad hose to help purge air. Add more to reservoir until it no longer goes down. Amount added should equal amount drained. Keep an eye on the temp gauge through idle/purge process. Mine never goes above normal op temp. And turn on the heater to full hot high during this process.

This bleeder screw is new though. Please provide details.

 

[Steve-Indy]

Flashing lightning bolt may mean battery was disconnected...as I recall.

 

[Steve M]

Driver's side of the engine near the throttle body. That's the bleeder screw.

 

[SSGViper]

Mine goes off after a few mins. May need to turn off engine and restart. I did get this light after a drain and refill but it went off.

 

[SSGViper]

Ok thanks. This must not be necessary as my drain and refills are fine without using the bleeder screw. Good to know though.

 

[A1998]

I simply open petcock on the lower radiator, let it drain, replace petcock, remove any remaining from reservoir, " fill reservoir until it fills radiator and will not take any more," start up and let idle till all air is out, and squeeze upper rad hose to help purge air. So at that point, do you put the radiator cap back on the surge tank or leave it off???

 

[SSGViper]

I simply open petcock on the lower radiator, let it drain, replace petcock, remove any remaining from reservoir, " fill reservoir until it fills radiator and will not take any more," start up and let idle till all air is out, and squeeze upper rad hose to help purge air. So at that point, do you put the radiator cap back on the surge tank or leave it off???

I let it run with the cap off for a while until the level stabilizes in the surge tank. Then I put the cap back on and bring it up to operating temp. Refil the surge tank to the proper level as needed.

 

[Viper Specialty]

Dan: Well better late than never! Appreciate the advise. Will use it next time. BUT ! What about the flashing light for the Electronic Throttle Control?? Do I need to be concerned about this or will this go away once the thermostat opens and coolant starts flowing?

As posted above, this may simply be an indicator that you have disconnected the battery and the DBW system needs to error check itself. If it continues to flash, scan it for a CEL.

 

[A1998]

Dan:

Have ingested 3-1/2 gallons of Anti-freeze into the system. Doesn't seem like it wants to take anymore. At this point, the top radiator hose is still empty. I'm thinking at this point to start the car and let it warm up enough to open the thermostat. I would think the 3-1/2 gallons couldn't hurt anything. Your thoughts???

 

[Viper Specialty]

Dan:

Have ingested 3-1/2 gallons of Anti-freeze into the system. Doesn't seem like it wants to take anymore. At this point, the top radiator hose is still empty. I'm thinking at this point to start the car and let it warm up enough to open the thermostat. I would think the 3-1/2 gallons couldn't hurt anything. Your thoughts???

The thermostat needs to open in order to fill the top hose- it is an air-tight blockage against it filling. The "bleeding" procedure is just to get coolant up to the thermostat so that it actually opens. Once it does, the system will self-bleed through the return hose from the thermostat to the bottle, hence the "revving while the t-stat is open" and then topping off once cooled back down.

You are fine, just confirm that the system is pumping and the stat opens up. The oil cooler will get warm very quickly indicating that the system is pumping coolant, and then thermostat opening will cause the radiator to warm up.

 

[A1998]

Dan: (And others)

Went and let the car warm up enough to open the thermostat. Fluid flowed and the surge tank beagn dropping. Put about another quart in it. Shut it down for about 15 minutes then went for a short drive. Came back and had to add about 1/2 qt. The Electronic Throttle (Lightning Bolts) did not come back on when I started it up. But I did get a check engine light which indicated thermostat tempature not high enough??, reset it with my meter and everything is fine now. Hopefully this thread will help other GEN IV owners. There is a lot of info about this on the Gen 2's but not on the Gen IV. What surprised me the most was how long it took to refill. The service manual never gave you an indication it would about 2 hours!! I saw where Dave 666 posted about the Lisle Radiator funnel and I think this would be a great tool to have. Thanks again for all you help!
A1998

 

[Viper Specialty]

Dan: (And others)

Went and let the car warm up enough to open the thermostat. Fluid flowed and the surge tank beagn dropping. Put about another quart in it. Shut it down for about 15 minutes then went for a short drive. Came back and had to add about 1/2 qt. The Electronic Throttle (Lightning Bolts) did not come back on when I started it up. But I did get a check engine light which indicated thermostat tempature not high enough??, reset it with my meter and everything is fine now. Hopefully this thread will help other GEN IV owners. There is a lot of info about this on the Gen 2's but not on the Gen IV. What surprised me the most was how long it took to refill. The service manual never gave you an indication it would about 2 hours!! I saw where Dave 666 posted about the Lisle Radiator funnel and I think this would be a great tool to have. Thanks again for all you help!
A1998

Tstat CEL was probably an air-bubble that registered as a temp drop/jump... no big deal.