After the engine kicks in, continues to run for no reason

I just got my 2018 Outlander PHEV about 6 weeks ago and I've noticed that when I climb hills or hit the accelerator a bit too hard that the engine kicks in, as it should, but after I've finished climbing the hill or no longer need the extra power the engine will continue to run intermittently for 2-3 minutes afterwards when it's not needed.

The behaviour once triggered isn't totally consistent, sometimes it will just come on whenever I touch the accelerator, and other times it just turn on and off intermittently every few seconds for no reason at all. It will alternate on and off every few seconds while I'm coasting or even completely stopped at a red light. After about 2-3 minutes, it goes back to normal operation. This happens even with a full battery, with the AC and heat both off. I tried hitting the EV mode button but that does nothing, I just have to wait for it to clear itself.

I took it to the dealer today to get it checked and they took it out and said not to worry about it, that there weren't any errors coming up and my fuel economy is good so that it was normal. But the behaviour doesn't make sense to me and frankly it's a waste of gas for no reason. I have two big hills on my way to work and I can climb them without triggering the engine if I'm super careful. But it seems dumb that triggering the engine for a mere moment causes the engine to run for 3 minutes.

Does this happen to other people?

Same, I think its a case of when its started its worth it ( from a heat/energy/reliability pov?)

starting the engine for 5 seconds every now and then is probably quite rough on it so run it for a couple of min just in case?

It is normal and was actually the subject of a recall for the earlier cars. The engine would not run long enough and eventually the spark plugs could foul. This was fixed by changing the plugs and updating the software to make the engine run longer.

When I first experienced/noticed this behavior I thought it could be trying to warm itself up or lubricate the engine before shutting down again, sort of like you're suggesting. But if it were that it seems weird that it would turn the engine on and off for 3 minutes rather than run for a specific duration and shut down. It can also go through this cycle more than once during the same 20-30 minute trip. The two hills I climb are about 5-10 mins apart at about 50km/h so you would think the engine would still be warm by the time I hit the second hill and skip this process the second time.

The engine does NOT turn of and on during the warm up fase. Although the dash suggests it does, when looking at RPM via proper OBD tools (like PHEV WatchDog or EvBVatNMon) you will see it does not. I think it is the dash's way of telling you the engine is warming up.

That's possible as I can't hear or feel the engine running when it appears to go on and off on its own, I just assumed it was operating at low RPM and couldn't feel it switching.

But then why in some cases does the same scenario cause the engine to rev up when I touch the accelerator? In those cases I can definitely hear and feel the vibration of the engine rev up whenever I touch the pedal and then it goes silent when I let it go. But then after a few minutes of driving it goes back to normal. Is there another mode it goes into that causes this different behavior?

Maybe I will have to move someplace flat to make my car happy? :lol:

I guess you have to distinguish two scenario's:

Engine started because of low SOC

The engine will take some time to warm up before providing power to the battery. Don't forget: you have some buffer so there is no need to rush. But at higher speed, the buffer is depleted faster so there is a little bit more urgency. This explains why at higher speed the engine starts at a higher SOC (approx. 30%) than at lower speed (as low as 25.5%).

Engine started because of high power demand

In this scenario power is needed right there right then. No time for a proper warm-u fase. Also, once the engine is started (because of for high power demand), the car will try to source all power from the engine and use the battery only as back up when the engine cannot provide enough power This may explain the high revving.

anko said:

Engine started because of high power demand
In this scenario power is needed right there right then. No time for a proper warm-up fase....

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This is why I sometimes press "Charge" when driving behind a slower vehicle and waiting for an oppportunity to overtake.
Not enough for a proper warm up of the ICE, but at least oil on the relevant parts before using the engine under heavy load.

Harald said:

This is why I sometimes press "Charge" when driving behind a slower vehicle and waiting for an oppportunity to overtake.
Not enough for a proper warm up of the ICE, but at least oil on the relevant parts before using the engine under heavy load.

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Although Mitsu claims the engine is specially treated for this (special coating on crankshaft bearings and such), I guess this does make sense. Also, it takes care of some 'startup latency' and helps you overtake faster.

There is one thing that makes me wonder: the oil pressure light. It comes on at startup and extinguishes after a second, just like an ICE starting up - when it doesn't start. Does this car have an electric oil pump? That would make sense, as it would eliminate the objections against frequent cold starts.

Good question. But it makes me wonder, how effective would an electric oil pump be if the engine was not turning over?

You know the big discussion about Artificial Intelligence taking over from humans? Well, this car is at the forefront. Absolutely no human mind has any idea what this car is up to.

I must admit that I put the car onto Charge if I know I'm going to be needing the ICE. Overtaking is one scenario, and another is joining a dual carriageway. It saves the extra second for the ICE to kick-in as well as warming it up a bit...

anko said:

Good question. But it makes me wonder, how effective would an electric oil pump be if the engine was not turning over?

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The main problem of a cold engine start is the oil dripping back into the sump when turned off warm and being slow to recoat the surfaces when starting up again. I can imagine that maintaining a certain oil circulation with the engine not running might go a long way to mitigate this effect.