The Chrysler Minivan Fan Club Forums banner
21 - 40 of 41 Posts

·
Registered
Joined
·
1,239 Posts
3500 shouldn't do it in, but running the engine at a higher RPM constantly or for an extended period of time can hurt it and prematurely wear it

these are not aircraft engines, they were not built to hold 90% throttle for 8 hours
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #23 ·
Back in 2015 I had a similar occurrence. Engine would sometimes cutout - tach needle would drop - and die at higway speeds. Sometimes it would continue running after the cutout while still at highway speeds with cruise control active.

Mine is a high mileage 3.3 3rd Gen but the systems are similar.

In my case it turned out to be a worn out timing chain. As engine load varied the "slop" was great enough at highway speeds to cause the cam and crank sensor to be temporarily out of phase. The engine would die as a result. It took a while to diagnose that one.

It is pretty simple to rotate the crank back and forth with a 15mm to feel if there is any "slop".

I changed the timing chain and the issue was resolved.

The worn timing chain. Previous owner did not change oil regularly.

That seems very likely. What does that job consist of, or cost to do?
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #24 ·
Back in 2015 I had a similar occurrence. Engine would sometimes cutout - tach needle would drop - and die at higway speeds. Sometimes it would continue running after the cutout while still at highway speeds with cruise control active.

Mine is a high mileage 3.3 3rd Gen but the systems are similar.

In my case it turned out to be a worn out timing chain. As engine load varied the "slop" was great enough at highway speeds to cause the cam and crank sensor to be temporarily out of phase. The engine would die as a result. It took a while to diagnose that one.

It is pretty simple to rotate the crank back and forth with a 15mm to feel if there is any "slop".

I changed the timing chain and the issue was resolved.

The worn timing chain. Previous owner did not change oil regularly.

Is that costly ?
 

·
--UNKNOWN MEMBER--
Joined
·
15,159 Posts
Back in 2015 I had a similar occurrence......In my case it turned out to be a worn out timing chain. As engine load varied the "slop" was great enough at highway speeds to cause the cam and crank sensor to be temporarily out of phase. The engine would die as a result. It took a while to diagnose that one.

It is pretty simple to rotate the crank back and forth with a 15mm to feel if there is any "slop".

I changed the timing chain and the issue was resolved.

The worn timing chain. Previous owner did not change oil regularly.

Engine can run with cam sensor disconnected, so it had to be something else.
 

·
Registered
Joined
·
91 Posts
To me this is a matter of common sense.
We do not drive 75mph in 3rd gear even while pulling a trailer.
You want to drive that speed put it in gear. I personally would not want to drive 75 mph with a heavy trailer behind me. Without a proper tow vehicle & I am not convinced a FWD van is the correct tow vehicle for a heavy load.

My opinion is, the car died. I would be happy it died. I assume the 3rd gear at 75mph hauling a heavy load. The computer saw a error and shut it down.
I think the computer in your case saved your vehicle from serious damage.
I would think towing a trailer in 3rd gear at 60-65 mph would be a good idea ... 75 in 3rd gear you lucky the trans still works.
 

·
Registered
2013 Dodge Grand Caravan
Joined
·
3,293 Posts
(moderator edited to removed reference to deleted posts)

And I completely agree that 3rd gear at 75 mph is unreasonable for any long distances in anything but a 3-speed. Is it the cause of the shut off? Possible, but I don't think so, at least not directly. A sudden non-catastrophic transmission failure could only stop the engine during torque converter lockup, otherwise the converter would slip and allow the engine to continue turning. He was likely baking the helI out of his solenoids and sensors in the trans, but that did nothing but dump more heat into the radiator as far as the engine was concerned.

I think the issue is either the fuel pump or electrical gremlins that were discussed on page 1. Related to the whole 3rd gear thing, the fuel pump would have been running at a medium to high duty cycle during that which would have made it heat up, especially if the tank was low. The pump could have briefly seized and that may have stalled the engine.
 

·
Registered
2005 Dodge Grand Caravan C/V
Joined
·
620 Posts
I think the issue is either the fuel pump or electrical gremlins that were discussed on page 1.
That would be my guess as well. If it shuts down again, I'd see if the fuel pump is running and go from there.

If the pump strands you somewhere, sometimes you can bang on the bottom of the tank and it will work for a little while, hopefully at least long enough to get you home. I had to do that in a Mustang once.
 

·
3rd gen > all others
Joined
·
3,750 Posts
"He was likely baking the helI out of his solenoids and sensors in the trans..."

This right here. There is a transmission temperature sensor in the NGC system 2004+, so what would happen if transmission was run too hot? Would the computer force an upshift?

I agree with the common sense not to run the engine at those speeds, with that little of load on it. Going uphill temporarily yeah, but not on flat freeway for a length of time. This forum gave him bad advice. That's why I actually tried that speed in that gear on my van, instead of guessing "it should be okay". Thank goodness he has the 3.8, because the revs would have been even higher with a 3.3.
 

·
Registered
2005 Dodge Grand Caravan C/V
Joined
·
620 Posts
If the TCC was locked, the trans shouldn't have had a reason to be running hot in third, regardless of speed.

As I mentioned before, the transmission actually downshifts to third when it is trying to protect itself from overheating. I did read that on this forum though, so who knows, that might actually be total BS.:cool:

I guess someone will have to install a trans temp gauge and actually try it.
 

·
3rd gen > all others
Joined
·
3,750 Posts
I think the issue is either the fuel pump or electrical gremlins that were discussed on page 1. Related to the whole 3rd gear thing, the fuel pump would have been running at a medium to high duty cycle during that which would have made it heat up, especially if the tank was low. The pump could have briefly seized and that may have stalled the engine.
Why would the pump run hot, when it is designed/located inside it's own "reservoir" filled with fuel for cooling it? When pumps die, they die and don't come back to normal function. You might keep it running by banging on the bottom of the tank, but once you turn it off it likely won't come back. Mine died on me while driving 55mph, just like that started sputtering. I stopped and parked, got out and kicked the bottom of the tank and it spurred back to life for 10 seconds, then started sputtering again. If I could have kept kicking the tank while driving, I could have made it to the next town. Turned out to be arcing/burnt electrical contacts on the spade connectors of wire to pump motor.

Only other time something has died while driving was a bad crank sensor, and a bad igniter for an ignition coil. Unplugging the cam sensor WILL result in killing the engine in 2004 and earlier. For some reason 2005 and newer got new programming to only need either a cam or crank sensor to keep running. I would suspect underhood heat soak, but the van restarted rather soon after, right? Ah, intermittent failures suck!
 

·
Registered
2005 Dodge Grand Caravan C/V
Joined
·
620 Posts
When the fuel pump failed in the Rustang, I had just pulled out of a mall parking lot, and the car shut off. I kept cycling the key, and the pump was silent. I banged on the bottom of the tank with a drill that was in the back, hit the key, the pump ran, and the car started. I drove it the ~40 miles back home without a problem. I didn't dare shut it off when I had to stop, though.

I had a fuel pump fail in the driveway in a Chevy S10 Blazer. The water pump took a crap right before my mom got to the house the day before. I put water in it and went to drive it to work where I was going to put a new WP in it, and found the fuel pump was dead. Mom took my car to work, so I had to call my boss with the rollback to get to work.:rolleyes:
 

·
Registered
Joined
·
113 Posts
75mph highway speed in 3rd gear might be your problem. If it was flat, even when towing, it would be okay to use overdrive. Transmission fluid could have gotten too hot, and computer sensed it and shut it down to protect itself. Just a theory, but torque converter lock-up is to help keep the transmission fluid cooler.
My opinion is, the car died. I would be happy it died. I assume the 3rd gear at 75mph hauling a heavy load. The computer saw a error and shut it down.
I think the computer in your case saved your vehicle from serious damage.
I think this might be a good time to dispel the myth that the computer will intentionally shut off the engine without warning or notification under conditions such as transmission or engine overheating. The PCM is NOT programmed to do that. It never has been and never will be. No vehicle manufacturer would ever program a PCM to do that. The potential liabilities would be ridiculous.
 

·
--UNKNOWN MEMBER--
Joined
·
15,159 Posts
I think the issue is either the fuel pump or electrical gremlins that were discussed on page 1. Related to the whole 3rd gear thing, the fuel pump would have been running at a medium to high duty cycle during that which would have made it heat up, especially if the tank was low. The pump could have briefly seized and that may have stalled the engine.
No such thing as medium/high duty cycle. Electric fuel pumps work at the same capacity once system reachs normal working pressure, which only takes a couple of seconds.
 

·
--UNKNOWN MEMBER--
Joined
·
15,159 Posts
I think this might be a good time to dispel the myth that the computer will intentionally shut off the engine without warning or notification under conditions such as transmission or engine overheating. The PCM is NOT programmed to do that. It never has been and never will be. No vehicle manufacturer would ever program a PCM to do that. The potential liabilities would be ridiculous.
Proof?

When engine overheats, you can keep driving until it explodes. Why a PCM would protect the transmission but not the engine?
 

·
Registered
2013 Dodge Grand Caravan
Joined
·
3,293 Posts
A PCM will go into limp mode to try to protect the powertrain, but it is not made to shut off going down the road. In no way would that ever be a feature.

Ever look at your FP_Duty% PID, Levy? It fluctuates with RPM.
 

·
--UNKNOWN MEMBER--
Joined
·
15,159 Posts
A PCM will go into limp mode to try to protect the powertrain, but it is not made to shut off going down the road. In no way would that ever be a feature.

Ever look at your FP_Duty% PID, Levy? It fluctuates with RPM.
Fuel pump is designed to provide a certain volume and PSI of pressure. Pressure is not regulated by the fuel pump itself.

Fuel regulator (either in tank or in engine compartment) will release any extra fuel to keep the internal pressure to whatever pressure is need for that particular vehicle (around 50 psi on most F.I.vehicles). That means your fuel pump is always working on a little bit higher pressure, regardless of engine RPM's.

Let's suppose the fuel pump is failing and not pumping enough volume to keep up with the fuel regulator, on that case the fuel pump wil be working at lower pressure, meaning it is working at lighter cycle (as you call it), not at "higher duty" cycle as you suggested. Less pressure means fuel pump is working lighter, not harder (you can use an amp meter to test it).
I'm not a ASE Certified technician, but I'm ASME cerified, which is a little different certification. 😁
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #39 ·
To me this is a matter of common sense.
We do not drive 75mph in 3rd gear even while pulling a trailer.
You want to drive that speed put it in gear. I personally would not want to drive 75 mph with a heavy trailer behind me. Without a proper tow vehicle & I am not convinced a FWD van is the correct tow vehicle for a heavy load.

My opinion is, the car died. I would be happy it died. I assume the 3rd gear at 75mph hauling a heavy load. The computer saw a error and shut it down.
I think the computer in your case saved your vehicle from serious damage.
I would think towing a trailer in 3rd gear at 60-65 mph would be a good idea ... 75 in 3rd gear you lucky the trans still works.
It wasn’t a heavy load. I have a Chevy dually for that. This was some music equipment and honestly the van did great . I kept it under 75. About 2500 miles.
 

·
Registered
Joined
·
1 Posts
This past week I did a 2400 mile trip. 2005 3.8. With six people, towing a trailer. In 3rd gear, entire trip. The van did great. Except for one time, out of nowhere, at highway speed (approx 75 mph) the engine just cut off. No warning, no nothing just cut off. Coasted to the shoulder of the road, and checked all I could think to check, found nothing wrong. I started it back up, and was fine. That was about mid trip. Never did it again. Any ideas on that ?
 
21 - 40 of 41 Posts
Top