[kmdExe]

New-to-me 2013 Grand Caravan RT with 119,000 miles. After the van has been driven around 20 minutes it will start stalling inconsistently at stops, prior to this it runs great before warmed up. Just prior to stalling the RPMs bounce around 500, and if shifted into neutral quickly the van will not stall and I can idle fine at the stop, but when shifting back into drive it will stall unless gassing it quick. Also when it dies, it will start again fine in neutral or park, but when shifting to drive it will want to die again. There are no check engine lights on. Sometimes it will do it every stop, and sometimes 1/10 stops. In order to fix this the previous owner had the transmission, torque converter, solenoid block, and TIPM replaced recently which did not change anything. I have a new MAP sensor on the way. What else could be causing this problem? Thank you so much for any advice.

 

[Sienile]

Torque converter is locking up when it shouldn't. You can try changing the solenoid for it, but it may be the converter itself which means the trans has to come off.

 

[ggoose]

If I read this correctly, replacing the transmission and torque converter did not resolve the issue? This points away from the transmission as I would not expect 2 transmissions and torque converters to have the same issue.

There may be diagnostic codes active or stored that do not light the check engine lamp. You would need a high end scanner to pull these codes.

One area that comes to mind is the IAC (Idle Air Control). It is responsible to adjust the engine speed when the throttle is not open. If it is sticking it would not be able to adjust the incoming air quick enough to prevent stalling. For example, when you shift into drive, the IAC will open to allow more air in to increase the engine rpm to compensate for the added load from the transmission. When you come to a stop, the throttle is closed completely and the IAC would open to add air and keep the engine rpms up. That it seems to occur after 20 minutes of driving indicates it may be affected by the heat in the engine compartment.

 

[Drunken Elvis]

When stopped in drive, does it feel like the vehicle is trying to lurch/pull forward more than usual. If it does, then yes, probably torque converter related.
When stopped, warmed up, in neutral, at idle, no brakes applied, does applying the brakes cause the engine to stumble? Release the brakes and wait, reapply the brakes, stumble?
If the brakes appear to be related to this stumble, the brake booster and/or the idle control, or throttle body may be the cause.
Possible a small air leak?
edit: I don't believe this engine has an Idle air control valve.

 

[kmdExe]

Thanks for the input everyone. Transmission, torque converter, and solenoid replaced less than 2,000 miles ago which didn't help. Previous owner did have dealer working up problem last month, here are their notes - seems as if they were unsure though they replaced TIPM with no effect. I was under the impression that the 5th gens did not have the IAC valves anymore? It does not want to pull forward more than usual when stopped in drive. I'm not sure about the brakes actually, I will try that today and see although there are typically no symptoms at all when in neutral.

 

[johncampanale]

It could be a dirty throttle body as well. Take off the tubing and look inside, and open the butterfly and see the inside as well. Mine was like that and was having issues similar to that.

 

[kmdExe]

I removed the throttle body today and it was somewhat dirty, cleaned it but it’s still running the same - didn’t actually get it to stall but it gets very close. Doesn’t seem to be affected by pumping the brakes. I’ll check for air leaks tomorrow.

 

[Vandad123]

I hope someone can provide an answer to this issue as I have a 2018 SXT with 66,000 miles and it does almost the exact same thing. After warm up, sitting at idle in Drive, engine is rough, has not actually stalled yet but close. Transmission fluid is in good condition and good level, I am going to do an AT fluid/filter change very soon as well.

No other driveability problems exist-no lurching at idle, no hesitation, trans shifts fine, no codes, etc. Fuel economy is normal as well, average around 21 mpg in mostly city driving(80% city/20% HW)
I cleaned my throttle body and it didn't help.
I ran Techron through a couple tank fill ups-didn't help.
Changed PCV valve-didn't help

 

[shuswap]

I hope someone can provide an answer to this issue as I have a 2018 SXT with 66,000 miles and it does almost the exact same thing. After warm up, sitting at idle in Drive, engine is rough, has not actually stalled yet but close. Transmission fluid is in good condition and good level, I am going to do an AT fluid/filter change very soon as well.

No other driveability problems exist-no lurching at idle, no hesitation, trans shifts fine, no codes, etc. Fuel economy is normal as well, average around 21 mpg in mostly city driving(80% city/20% HW)
I cleaned my throttle body and it didn't help.
I ran Techron through a couple tank fill ups-didn't help.
Changed PCV valve-didn't help

I'd suggest identifying if a particular cylinder is the issue when it is running rough. This can be caused by a failed/failing rocker or a number of other issues, but first id the cylinder or eliminate that a single cylinder is the culprit. Too low an idle can also result in a rough engine.

 

[Vandad123]

I was looking into this issue and the original post had attached dealer paper work alluding to a voltage problem, so they replaced the TIPM to no effect.

I know that the 2017-18 GC's had 2 separate recalls for bad voltage regulators in the PCM, specifically for stalling.

This could be a route to check for the stalling issues.

 

[kmdExe]

After replacing MAP sensor and PCV valve, I gave up and took the van to the dealership (different dealer than previous owner took it) for diagnosis who concluded "verify stalling concerns, no DTC in vehicle system, happens hot only, verify trans not free wheeling, converter not releasing. Fault is coming from torque converter or from transmission assembly internally." With everything already rebuilt less than 1,800 miles ago, I'm about to sell this and take the loss.

 

[Sienile]

Rebuilder didn't have a warranty? That soon after most places would cover it. Some places might even if they didn't have a warranty on it just to keep the customer happy and their reputation untarnished, since the issues were almost immediate. Sure worth a shot.

 

[AeroZ]

Isn’t one of those sensors’ functionality to keep the car from stalling? Maybe it’s faulty?

Sent from my iPhone using Tapatalk

 

[Sienile]

Sensors can only sense. Solenoids are what control the fluid circuits. The TCC solenoid is a possibility.

 

[Vandad123]

I find it really hard to believe that a new torque converter, rebuilt trans, and new valve body are the cause of this issue as it existed prior to to those pieces being replaced.

It has to be solenoid or PCM issue.

 

[Sienile]

Agreed, it doesn't seem likely that a new transmission would have the same issue as the old if the problem is in the trans. PCM and/or wiring are the most likely causes.

If this were a GM product, all that goes out the window though. Their transmissions can eat themselves in days if not correctly programmed. Went through 3 reman trans in a month on a G8. First one lasted a weekend and had as much shavings in the pan as the one we took out, second one had shavings in the pan from pre-shipment testing so we rejected it before install, 3rd one finally worked, but took many attempts over 3 days to program it right.