X5 Hesitation

[mharper76]

2015 xdrive35, having the light throttle hesitation issue I’ve read all over the internet.
See guys changing parts but not clear results.

72k miles, just put in new plugs and 2 tanks with seafoam. Cleaned the map sensor with map sensor spray. Run 93 octane only.

The problem only happens once the engine is completely warmed up.
Very light throttle, feels like someone is bumping into me.
Feels worse as slower speeds - 20-30 mph.

Give it 25%+ throttle, no issue.
Does not happen all the time.. some drives, no issue at all (on the same tank of gas) No CEL.

Did the pedal reset, no change.
Reset all adaptations, no change.

Don’t hear any vacuum leaks. There is a little oil on the underpan -haven’t spotted a leak yet (suspect the dealer just had sloppy techs), and oil level is full with 2k miles since last change.

New air filter.

Dealer flashed latest ecu and tcu software.

Any suggestions? Plan to clean map again along with maf.

I don’t want to just change parts - there has to be a systematic method to finding the cause.

[Clifton]

What did the old spark plugs look like? Color might help point to possible source.

Other items:
Battery voltage
Coils
Fuel Injectors

[Tomcat_F15_STL]

Transfer case fluid change and TC Adaptation Reset. Transmission filter with fluid drain & fill.

[mharper76]

All plugs were identical - light brown, some wear but no damage.

[Edwardsc1]

Originally Posted by Tomcat_F15_STL

Transfer case fluid change and TC Adaptation Reset. Transmission filter with fluid drain & fill.

This right here is likely the problem. Had the same issue on my 50i, and a TC flush and reset solved it.

[F15_SGM]

Change the coil pack with sparkplugs. Your old coils are shortening out the plugs.

[tlow98]

Yeah, it's such a pain to do plugs on these always do coils with them.

It's either the coils or the transfer case fluid and calibration.

Both are cheap, but the coils take more time due to the dismantling involved.

Unlikely to be the injectors, but not impossible.

[mharper76]

Update - new coils today, no change.
Trans fluid up next. Really thinking it’s trans related.. at temperature it should be locking/unlocking the converter, which would take place at off/on throttle.

[mharper76]

Transmission fluid/filter changed - will see if any improvement this week.

One thing I noticed - the trans seems noisy to me. While idling it sounds like a heat shield type rattle. Do these transmissions normally make noise, or am I driving a time bomb?

[Chilled]

Originally Posted by mharper76

Transmission fluid/filter changed - will see if any improvement this week.

One thing I noticed - the trans seems noisy to me. While idling it sounds like a heat shield type rattle. Do these transmissions normally make noise, or am I driving a time bomb?

When i did mine, I don't particular remember anything that stuck out.

Did you do the full proper fill procedure, making sure the TQ gets fluid, getting up to correct temp, etc.

Did you end up doing the Transfer Case?

[tlow98]

Originally Posted by mharper76

Update - new coils today, no change.
Trans fluid up next. Really thinking it’s trans related.. at temperature it should be locking/unlocking the converter, which would take place at off/on throttle.

I was referring to the transfer case. That’s normally the one that causes the issue you’re describing.

[yupetc]

- Battery voltage
- Ignition Coils
- Injector Leak
- VANOS
- Valvetronic sensor and motor

These are the common issues if you've already ruled out air leaks, MAP/MAF, and spark plugs.

[skoold2003]

Originally Posted by tlow98

I was referring to the transfer case. That’s normally the one that causes the issue you’re describing.

Originally Posted by Tomcat_F15_STL

Transfer case fluid change and TC Adaptation Reset. Transmission filter with fluid drain & fill.

When I was having the hesitation issues due to TC it was just on acceleration.

[Florida-X3]

Our hesitation was the transfer case too under acceleration, it was more like a hiccup or slight jolt type hesitation. It was still under CPO warranty and first thing the dealership replaced plugs and coils, that didn't help. Then they disconnected the TC and it went away (I believe there is an electronic plug somewhere you can disconnect). They replaced TC case parts (about $7K worth if memory serves) and good as new.

[mharper76]

Transfer case done… a few miles down the road and much better! Will keep an eye on it and report after some miles…

Thanks all