No power after rest stop. Couldn't get to highway speed on onramp.

Russ Chung

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I've followed this thread since its inception; a sudden, unexpected power loss should be a concern for all of us. I've had my JLURD for 11 months and driven over 29,000 miles often pulling my 1,500 lb camping trailer. Fortunately, I've never encountered a power loss but I've been aware of my engine temps on hot days and now I'm aware of the possibility of unexpected power loss.

I believe that we have two different problem situations with different causes and different remedies.

1. High engine compartment temperature after stopping at a highway rest stop. This was the problem that started this discussion. I believe that the cause of this problem is the heat soaking of the entire engine compartment. Some threads hypothesize that the excess heat causes high air inlet temps and possibly poor intercooler performance which triggers "limp mode". I believe some remedies include letting the engine idle for a few minutes, waiting until the engine has had a chance to cool down before restarting, and opening the hood while stopped.

2. High engine oil temperature while slowly climbing hills. I believe that this is the problem that Casey250 noted in his YouTube video and the problem noted in this recent post by diezselsmk:
…I have had the limp mode affect me twice on slow crawl trails on hot days and once waiting in traffic setting there idle for some time. I have found that if you are rolling you can put the trans in neutral and pump the pedal and then put it back in drive. This only works if you are rolling but it does reset the limp mode that is being enforced on the throttle control sensor.

The heat build up in the small turbo and the undersized intercooler is triggering the Turbo variable vane sensor and forcing a limp mode scenario. the EGTs seem to build quickly when the the turbo is not spinning more then 10psi . A larger intercooler would help this issue out but I haven't seen to many offerings on this yet.
So we have evidence of a problem while accelerating from a rest stop and a problem when slow crawling. Strangely, no one has reported a power loss once they have reached highway speed In hot conditions. A few days ago, I was towing my trailer across the Mojave on I-40. The outside air temp was 105F. I was traveling at the 70mph speed limit climbing the grade west of Needles. My engine oil temp hit 260F just before the top of the hill. I did not encounter any loss of power, but I immediately slowed down to about 50 mph to let the engine oil cool down. It seemed to take forever but it was about 15 seconds before the engine oil temp began to come down. Has anyone encountered a power loss while cruising at the speed limit under those conditions?
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diezselsmk

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I've followed this thread since its inception; a sudden, unexpected power loss should be a concern for all of us. I've had my JLURD for 11 months and driven over 29,000 miles often pulling my 1,500 lb camping trailer. Fortunately, I've never encountered a power loss but I've been aware of my engine temps on hot days and now I'm aware of the possibility of unexpected power loss.

I believe that we have two different problem situations with different causes and different remedies.

1. High engine compartment temperature after stopping at a highway rest stop. This was the problem that started this discussion. I believe that the cause of this problem is the heat soaking of the entire engine compartment. Some threads hypothesize that the excess heat causes high air inlet temps and possibly poor intercooler performance which triggers "limp mode". I believe some remedies include letting the engine idle for a few minutes, waiting until the engine has had a chance to cool down before restarting, and opening the hood while stopped.

2. High engine oil temperature while slowly climbing hills. I believe that this is the problem that Casey250 noted in his YouTube video and the problem noted in this recent post by diezselsmk:


So we have evidence of a problem while accelerating from a rest stop and a problem when slow crawling. Strangely, no one has reported a power loss once they have reached highway speed In hot conditions. A few days ago, I was towing my trailer across the Mojave on I-40. The outside air temp was 105F. I was traveling at the 70mph speed limit climbing the grade west of Needles. My engine oil temp hit 260F just before the top of the hill. I did not encounter any loss of power, but I immediately slowed down to about 50 mph to let the engine oil cool down. It seemed to take forever but it was about 15 seconds before the engine oil temp began to come down. Has anyone encountered a power loss while cruising at the speed limit under those conditions?


It sounds like your EGTs were high causing the oil to heat passing through the turbo. MOST likely you were in the middle of a DPF burn cycle that caused the elevated temps in the exhaust and the high inlet temps did not help. If you tow allot invest in the Banks gauge. it plugs directly to the OBD and can read your EGTS among a ton of other parameters including letting you know when you are in a DPF burn cycle.
 
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Gorilla57

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It sounds like your EGTs were high causing the oil to heat passing through the turbo. MOST likely you were in the middle of a DEF burn cycle that caused the elevated temps in the exhaust and the high inlet temps did not help. If you tow allot invest in the Banks gauge. it plugs directly to the OBD and can read your EGTS among a ton of other parameters including letting you know when you are in a DEF burn cycle.
Hey, you need to edit this post. It's DPF regen/burn cycle, not DEF.
 

Harrybeerbelly

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Lol keep coloring inside the lines if it makes you feel better. Leave it idling, take your fob and lock it. When you’re done unlock it, hop back in and go. My F250 diesel never shuts off on road trips or when towing. Leave it idling and locked up. Never had an issue or had anyone even attempt to steal it

Looks like I did something good without even knowing. I used my Jeep on several road trips. Really the reason I purchased a diesel. I never shut it off while fueling or any stops. As mentioned I left it run and locked it up. Never had a problem in 15k miles worth of road trips.
 
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