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2000 Dodge Ram still overheats


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Christian9653
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Apr 26, 2010, 8:15 AM

Post #1 of 17 (3537 views)
2000 Dodge Ram still overheats Sign In

I have a 2000 Dodge Ram 1500 4WD, 5.9L with 146k miles. Radiator cracked and started to overheat for less than 2 min. (long enough to get it off the interstate. So I replaced radiator, water pump, hoses, (except heater hoses), thermostat. Changed oil, new plugs, distributor cap. (wires next).

Still overheats.

Water is running out of overflow when running. Heater only gets warm when you step on gas. Also, you can hear water sucking sound under dashboard. When I turn the heater on the AC runs too now. No obvious leaks except from overflow. Thought I had something but then saw it was condensation from the AC (which was supposed to be off)


nickwarner
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Apr 26, 2010, 8:53 AM

Post #2 of 17 (3534 views)
Re: 2000 Dodge Ram still overheats Sign In

likely you have an air pocket in the cooling system still. The last of heat in the cab is a big indicator. I use a Lisle Spill-Free funnel that most any parts house can sell you for pretty cheap. Comes with adapters for many types of caps. It allows room for the coolant to surge up without making a big mess. Run the engine through a few cycles of thermostat opening and closing with the funnel on in place of the cap. This way the system doesn't pressurize. Keep the heater control on hot the whole time. You'll see the air pockets working out in the funnel, and be able to feel how much heat you're getting in the cab. As to the AC issue, check for power at the AC clutch. If present you have a separate electrical short that can be taken care of for now by pulling the fuse for the AC. If the AC continues to run without electrical power, you have a locked up clutch and it shouldn't be driven until replaced as it will build up a tremendous overload of pressure when it isn't able to cycle off and will cause you such costly damage that the repair bill will make a wrecker bill look like a deal of a lifetime. Post back and let us know what you find.


Christian9653
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Apr 26, 2010, 9:40 AM

Post #3 of 17 (3533 views)
Re: 2000 Dodge Ram still overheats Sign In

So what I have done so far today is get some flush and am flushing out the system. I figured it couldn't hurt and maybe I had some blockage. I'll fill it back up and let you guys know. Thanks a bunch. So far so good.


Christian9653
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Apr 26, 2010, 10:20 AM

Post #4 of 17 (3530 views)
Re: 2000 Dodge Ram still overheats Sign In

Using just straight water I have attempted to refill the coolant system. After about 2.5 gallons it's bubbling and overflowing. When it goes down I add more water. It should be a 5 gallon capacity. I have let overflow and attempted to place 7 gallons of water. Bubbles keep coming up like someone is blowing with a straw in the water. No engine smoke, no water in the oil,(AC shut off BTW ok). Idles a tiny bit rough but runs very smooth. Is this my head gasket?


Christian9653
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Apr 26, 2010, 11:23 AM

Post #5 of 17 (3528 views)
Re: 2000 Dodge Ram still overheats Sign In

Well drove it ,around the block and the temperature varies quite a bit. Water is blowing out of the overflow. Idle is rougher and the engine light came on with a po300,po301, and po302 reported on the ODB. All the results are pointing to a head gasket. Next question...

I know their are additives to try and seal the gasket. Should I even try that? Or am I just putting on the wrong band aid which will cause me more problems?


alienshadow
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Apr 26, 2010, 11:41 AM

Post #6 of 17 (3527 views)
Re: 2000 Dodge Ram still overheats Sign In

I am no mechanic and my comment may get deleted.. But are you sure the T-Stat isnt a bad one? I know on my chevy I had over heat issues when all was said and done it was a bad brand new T-Stat.. Guy told me 1 in 5 are bad.. Just trying to help hope you get it fixed and I sure hope its not the head gasket..




If you cant fix it then dont mess with it...
Unsure


Christian9653
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Apr 26, 2010, 2:40 PM

Post #7 of 17 (3521 views)
Re: 2000 Dodge Ram still overheats Sign In

New Development! Water on the floorboard on the passenger side. That means Heat core(coil) has gone bad I believe. At least I know what to try and fix.


Tom Greenleaf
Ultimate Carjunky / Moderator
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Apr 27, 2010, 3:22 AM

Post #8 of 17 (3515 views)
Re: 2000 Dodge Ram still overheats Sign In

That couple extra miles on the Interstate was pretty costly IMO. System needs be filled. Run a few minutes till level drops when thermostat opens if it will and level will drop when air is let out to radiator. Next fill it should become more stable but will still have air to purge out over a few warm up/ cool down cycles.

Seems it got so hot it probably did blow head/intake gaskets and now you are getting combustion gasses in cooling system. A/C staying on AND making condensate if so when heat and only heat requested isn't right. Are you sure it isn't set to "mix" of heat and defrost? If it was A/C would cycle but not stay on. That's now a separate problem.


Water on floor. Yes - that suggests a heater core leaking or necks are broken/cracked where hoses go thru firewall. Necks or the core itself would still need the core but I doubt that will be the fix for this.

That overheat probably caused wild damage along with tossing parts at it that shouldn't have had a thing to do with a crack in radiator tank to begin with.

Pressure test the system. Check for combustion gasses in radiator and or recovery tank. I think it's going to need head and intake gaskets, the heater core probably is leaking.

It's an open book now. In refilling the thermostat if normal would lock air in the engine side until warm (not piping hot) enough to open. Upper hose would feel warmth as an indication (caution as it could be VERY hot) then shut it down. Fill as needed when COOL and repeat. Constant or if bubbles seen right away the gaskets are high on the list.

Got a lot of work and testing to do,

T



Christian9653
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Apr 29, 2010, 5:10 PM

Post #9 of 17 (3496 views)
Re: 2000 Dodge Ram still overheats Sign In

Updates and issues:

Hard to start. Once it did a little blue smoke. Exhaust "feels" moist but it's hard to tell. Still idles rough.

Put a radiator pressure gauge on it and got a 17lbs. reading. While idling it started to run warm. Shut it off pressure dropped slowly down to 14lbs.

The top hose was cold. Lower hose had pressure and was warm.

Pulled the #1,#2,#4,#6 spark plugs. All had a white residue. No moisture.

Next I am going to put a 2nd new thermostat in it tomorrow and run a compression test on each cylinder.


Tom Greenleaf
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Apr 29, 2010, 6:42 PM

Post #10 of 17 (3491 views)
Re: 2000 Dodge Ram still overheats Sign In

You do a pressure test with engine off as with certain head gasket and or intake gasket failures you would blow radiator and heater cores with too much pressure if allowed.

Your new plugs already show flaws so I'd proceed to check for blown head gasket(s) and hope that's all that's damaged,

T



Christian9653
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May 4, 2010, 6:53 PM

Post #11 of 17 (3477 views)
Re: 2000 Dodge Ram still overheats Sign In

OK, took out the thermostat. Checked it and it was sticking. Put in another one. By-passed the heater core, flushed the system again and the temp is now fine. New plug wires. No codes. Did another pressure test on the radiator cap. While running pressure got up to 28lbs. at idle. As I released the pressure you could smell fresh gas coming through the cap. So, in the morning I am going to do a compression check on the cylinders. I believe at this point the intake manifold gasket is leaking. Will know more tomorrow. I have all the gaskets so this weekend I am planning on changing the Head gaskets and manifold gaskets. Hopefully the compression test will tell me more. Still no water in the oil or oil in the water. No smoke. Just bubbles in the overflow of the radiator.


Tom Greenleaf
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May 4, 2010, 8:27 PM

Post #12 of 17 (3469 views)
Re: 2000 Dodge Ram still overheats Sign In

How in the heck are you using a pressure tester? You would pump one up to see if it would hold or where it would leak not exceeding the systems rating which is probably about 16 psi. You DON'T leave it on with engine running and wait for pressure to built up or allow it over the limit.

If testing with engine running and a pressure tester you would be ready to quit and release pressure if it built up from zero with engine running right away instead of slow heat expansion. If fast that way it's near sure combustion gasses are entering the cooling system.


If head gasket(s) are determined bad do send out the heads to a machine shop for inspection and or service as they may be warped beyond machine work limits or cracked,

T



(This post was edited by Tom Greenleaf on May 4, 2010, 8:29 PM)


Christian9653
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May 5, 2010, 10:00 AM

Post #13 of 17 (3459 views)
Re: 2000 Dodge Ram still overheats Sign In

Here are the results (and they are not good)

Right bank #1=110, #3=100, #5=125, #7=95

Left bank #2=120, #4=135, #6= 115, #8=105

These numbers are all over the place. I don't know what they should be, but I do know that isn't right. I would think that each bank would be the same and that both banks should be within 10.

I did a pressure test on the radiator when the engine was cold and could not find any leakage, sounds of leakage or signs of fluids anywhere. That's why I tried it with the engine at idle.

I am a novice at this fellows. That said, I am doing what I can to get the diagnostics the best I can. I do have some help to pull the top part of the engine off. Also, I have found a machine shop to check the heads when I do.

I have to try and fix this myself. I just don't have the funds at this time to pay a shop to do it all.

I want to thank everyone, especially Tom for all the great advice and help.

Any input is greatly appreciated. Please comment on these numbers and what they might mean. Any tips on pulling this thing apart and putting it back together will also be taken in.

I will check other threads as well.

The saga continues,

Thanks again,

Chris


Tom Greenleaf
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May 5, 2010, 12:45 PM

Post #14 of 17 (3454 views)
Re: 2000 Dodge Ram still overheats Sign In

Yes - those #s are all over the place. Do you recall what plugs on the three lowest looked like in comparison to the highest since they are all new? Test is generally done with warm engine when possible, all plugs out, throttle held at least part open, written observations which you did, and again with just a squirt of oil to see if and how much different that makes. With (just a small squirt) pressures would all go up. You count the fourth compression stroke # not the first - if memory (go easy now) serves me.

You would like to see all within about 10% of each other which that isn't. For now it's inconclusive to me as the engine runs and those #s are low enough to cause combustion problems.

Back: When pressure testing cooling system you mentioned you could smell gas (gasoline - right?) when you relieved the pressure. Can't say exactly what style pressure testers do to relieve pressure but it radiator was full, and pressure cap is on radiator it would have gushed just liquid out or there was abundant gaseous (non liquid) in the cooling system. It could hold even the 28lbs (never allow that high on a cooling system again please) as that's diddle low pressure compared to combustion pressures of a running engine. Some head gasket failures will not leak out to ground or burn coolant or mess up the oil but can put combustion pressure into cooling system which behaves like plain air for cooling purposes and the pressure cap would constantly be venting off any pressure over its rating.

Side notes: Heat rises and so does air/vapor in a liquid. Air doesn't cool a "water cooled" engine nor throws heat in a heater which is really just a mini radiator. It's "caloric" value (air) isn't much compared to coolant/water. DON'T TRY THIS BUT NOTICE THAT A HOT SHOWER FOR EXAMPLE CAN BE 110F DEGREES. 110F AIR IS HOT BUT YOU CAN RUN THRU IT. AN OVEN CAN BE WAY UP THERE WHEN YOU REACH IN 200-300 OR MORE AND YOU DON'T GET BURNED IF QUICK. WATER AT 140F FEELS AND CAN BE SCALDING NEVER MIND ENGINE COOLANT TEMPS NORMALLY NEAR 200ISH! This is about the caloric ability of heat exchange. Vapor is slight and liquid greater.

What I mean to express is that the heads are high on engine and would be hotter than the oil pan for instance. The combustion is glowing hot - rough guess 6-8 hundred degrees! More perhaps. I really don't know what Chrysler did for heads on this but many started using alloys like aluminum which has a lower caloric value than cast iron and expansion and contraction rates are different which is a stress for gaskets in normal conditions and a real problem with overheats.

All this adds up to high likelihood of failed head gasket(s) but you do want to be sure as it's a big job. Heads or even block (less likely but possible) can crack or warp which is why we suggest sending heads out and you still would inspect block as best you can. Ask machine shop for their ideas on verifying block trueness and lack of cracks.

~~~~~~~~~~~~~~~~~~~~~~~~

You can get test strips or a kit to test for combustion gasses in the vapor of cooling system. Ask a real parts store what they have available. Again - it would stink to be wrong with the diagnosis so use all means to verify it before digging in. This is mostly labor intensive but with new oil, coolant, some hoses maybe or all, it can add up parts too.

Check, check, check and get pro advice if needed would be $ well spent. You really can't know exact condition of heads till off but know as much as possible while intact. Don't know my Mopars that well so intake manifold could be and should be checked too if you determine this is going to get the full gasket job,

T



Sidom
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May 5, 2010, 7:44 PM

Post #15 of 17 (3445 views)
Re: 2000 Dodge Ram still overheats Sign In

Just skimmed thru this thread and is sounds like you're on the right track.....

I'll just add one quick suggestion. If it was mentioned & I missed it, I apologize....

When running a compression test the throttle needs to be held wide open, compression is very dependent on air volume. Also it would be a good idea to pull the fuel pump relay, start the engine and let it die. This way the cyl walls aren't getting washed out with gas. Holding the pedal @ wide open should clearflood it & kill the injectors but this way you know for sure, also have all the plugs out at the same time.

(ok that was 3 but I never claimed I could count)


Christian9653
Novice
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May 6, 2010, 12:09 PM

Post #16 of 17 (3437 views)
Re: 2000 Dodge Ram still overheats Sign In

I went ahead and did another compression test with the good advice I have been given and the numbers came out a little better but not what I would like.

Right bank #1=135, #3=115, #5=135, #7=115

Left bank #2=100, #4=145, #6=130, #8=125

I did get misfire codes 302 and 306 this time. Also after idle, turn off and starting back up was a hard start. (This baby has always started at a quick turn of the key)

Radiator overflow still bubbles steady. But the truck runs smooth and does not over heat. I went to 2 different auto parts stores and they did not have any test strips. So I'll keep looking.

Sounds like with all the testing it's time for intake and head gaskets. I'm going to start on tearing it down Friday.

Any tips and opinions welcome.


Tom Greenleaf
Ultimate Carjunky / Moderator
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May 6, 2010, 1:15 PM

Post #17 of 17 (3432 views)
Re: 2000 Dodge Ram still overheats Sign In

My fingers just refuse to type that I'm sure of anything but the constant bubbles in radiator especially if right away is a damning clue for the gaskets.

Advice. Work as clean as you can. # your parts to go to the same spot they came from - use a cardboard box with holes or whatever. Don't let junk get where it doesn't belong! Paper towels can prevent losing a bolt or washer down the wrong hole!

Be gentle but clean gasket surfaces well. Be VERY careful of alloys as a good sharp gasket scraper can dig into that metal. Use the solvents for gasket removal can help but not a total solution if you have a nasty one - they can still be work.

Short of torches and you can't use those on everything I find PB (Power Blaster) as good of a penetrating oil as there is for sticky or corroded parts. Let it sit and try not to break any studs or bolts. Rushing doesn't pay off,

T







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