Temp Issue
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Joined: Sep 2008
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From: Simpsonville, SC
Temp Issue
Okay guys I need a little help. I did a search and have read multiple thread on temp issues. I just want to see if I understand what's going on.
1st its a 2000 4.7 4x4 w/ 145k miles on it. Now for the story. My idler pulley went bad this weekend. I replaced it and the belt. I let it idol in the drive way for about half an hour with no problems. Temp was fine. I hopped on the hwy & at about 70 mph the temp crept up past the halfway mark on the temp gauge. It never did overheat, but was way warmer than normal. A side note, this was our first warm day we've had it quite a while, 75 degrees. I took it back home, while driving through town, the temp dropped back down to a closer to normal range. I check the belt to make sure everything was okay. It was but the fan appear the be turning slow. I drove it to town later that night with no problems. This morning I drove to work, about 45 degrees outside, with no issues @ 70mph. My initial thought was the fan clutch was bad, but after reading this morning I see that has little to do with hwy temp.
I'm going to start by pressure washing the radiator & AC coil. Then I'll move on to the thermostat if I still have issues. I'm going to check the fan clutch to make sure its not bad.
What else should I check or replace if these steps don't fix my problem? Thanks in advance for the help guys.
1st its a 2000 4.7 4x4 w/ 145k miles on it. Now for the story. My idler pulley went bad this weekend. I replaced it and the belt. I let it idol in the drive way for about half an hour with no problems. Temp was fine. I hopped on the hwy & at about 70 mph the temp crept up past the halfway mark on the temp gauge. It never did overheat, but was way warmer than normal. A side note, this was our first warm day we've had it quite a while, 75 degrees. I took it back home, while driving through town, the temp dropped back down to a closer to normal range. I check the belt to make sure everything was okay. It was but the fan appear the be turning slow. I drove it to town later that night with no problems. This morning I drove to work, about 45 degrees outside, with no issues @ 70mph. My initial thought was the fan clutch was bad, but after reading this morning I see that has little to do with hwy temp.
I'm going to start by pressure washing the radiator & AC coil. Then I'll move on to the thermostat if I still have issues. I'm going to check the fan clutch to make sure its not bad.
What else should I check or replace if these steps don't fix my problem? Thanks in advance for the help guys.
It may be possible one or both your main radiator hoses may be collapsing causing a crimp in antifreeze flow. This is the only other possibility other than thermostat as you only overheat if driving on the hwy. Another possibility, you may have air in the system and may need to purge it out.
Otherwise, usually if you have a water pump or radiator clog issues, it would start to overheat no matter if you are idle, intown/hwy driving conditions.
Also, some additional FYI,
When your Durango reaches the halfway mark on temp, let's say 210 and up, the PCM will put your 4.7 into limp mode. No power, etc. This is by design to prevent the engine from being overworked when it is starting to overheat. So be gentle and exercise caution for your durango when your temp hits this mark.
Otherwise, usually if you have a water pump or radiator clog issues, it would start to overheat no matter if you are idle, intown/hwy driving conditions.
Also, some additional FYI,
When your Durango reaches the halfway mark on temp, let's say 210 and up, the PCM will put your 4.7 into limp mode. No power, etc. This is by design to prevent the engine from being overworked when it is starting to overheat. So be gentle and exercise caution for your durango when your temp hits this mark.
Last edited by Kensai; Feb 9, 2009 at 10:16 AM.
Thread Starter
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Registered User
Joined: Sep 2008
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From: Simpsonville, SC
It may be possible one or both your main radiator hoses may be collapsing causing a crimp in antifreeze flow. This is the only other possibility other than thermostat as you only overheat if driving on the hwy. Another possibility, you may have air in the system and may need to purge it out.
Otherwise, usually if you have a water pump or radiator clog issues, it would start to overheat no matter if you are idle, intown/hwy driving conditions.
Also, some additional FYI,
When your Durango reaches the halfway mark on temp, let's say 210 and up, the PCM will put your 4.7 into limp mode. No power, etc. This is by design to prevent the engine from being overworked when it is starting to overheat. So be gentle and exercise caution for your durango when your temp hits this mark.
Otherwise, usually if you have a water pump or radiator clog issues, it would start to overheat no matter if you are idle, intown/hwy driving conditions.
Also, some additional FYI,
When your Durango reaches the halfway mark on temp, let's say 210 and up, the PCM will put your 4.7 into limp mode. No power, etc. This is by design to prevent the engine from being overworked when it is starting to overheat. So be gentle and exercise caution for your durango when your temp hits this mark.
In April of last year my upper hose body seperated while on vacation at Disney World... The shop on site at Disney replaced the hose and pressure tested my system. No problems were found. I'll check the hoses. What's interesting is the "limp mode". I didn't notice any power difference or any difference at all while driving it back home. Thanks for the info. I'll take care to watch the temp.
I used 210 as a starting reference. This is the magic setting for our 5.9's and when my fan clutch went out a while back, and the temp was slightly above 210, my 5.9 was running like crap. No acceleration or power persay.
The temp setting may be set a little higher for the 4.7's? Dunno, but in case you feel a power loss on the 4.7 due to the temperature being a little high, your pcm will reduce the power on your engine to preserve it from overheating and lockup.
The temp setting may be set a little higher for the 4.7's? Dunno, but in case you feel a power loss on the 4.7 due to the temperature being a little high, your pcm will reduce the power on your engine to preserve it from overheating and lockup.
Champion
Joined: Jun 2006
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From: Indiana
If you added coolant, or had the system open to the air, the 4.7s need to be "burbed." Otherwise, overheating issues are sometimes common. Also, use only a stocker stat. Aftermarket stats forget or have incorrect 'weep' holes.
IndyDurango
IndyDurango
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From: Simpsonville, SC
Alright guys...
Time for me to feel a little stupid, which is not a unusual occurrence.
After driving for several days to and from work, which is almost no stop and go traffic, I have realized that I do not have temp issues on the hwy. I have temp issues in town. The temp must have been up before I got on the hwy & I just didn't notice. This actually makes much more sense because my fan clutch is bad. I will replace it on Friday, and post back with the results.
Also, Does a strap wrench really work to hold the fan assembly during removal? & do I have to remove the upper shroud to get the fan assembly out?
Time for me to feel a little stupid, which is not a unusual occurrence.
After driving for several days to and from work, which is almost no stop and go traffic, I have realized that I do not have temp issues on the hwy. I have temp issues in town. The temp must have been up before I got on the hwy & I just didn't notice. This actually makes much more sense because my fan clutch is bad. I will replace it on Friday, and post back with the results.
Also, Does a strap wrench really work to hold the fan assembly during removal? & do I have to remove the upper shroud to get the fan assembly out?
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Captain
Joined: Apr 2008
Posts: 579
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From: Dallas, Tx
Some say hek yeah I personally found it easier to use a large vise grip to lock on the pulley,Note do not grip on the surface the belt sits on lock it on to the face of the pulley and the outer rim closest to the water pump.