5.7 Hemi, 2011 MAP Sensor Question

[AlaRama]

Is the MAP sensor supposed to wobble after it is fully engaged in bore after the 1/4 turn?

I've been chasing a no CEL RPM fluctuation and it appears to be associated with the MAP sensor. I cleaned it and put some grease around the Oring and it ran like a champ for about 100 miles, then started its crap again. Got a new sensor on order. Just need to know if it's supposed to wobble when installed correctly. TIA.

 

[rzr6-4]

Depends what you mean by "wobble" but since its a plastic sensor in a plastic housing I would expect it to have some play.

 

[AlaRama]

Depends what you mean by "wobble" but since its a plastic sensor in a plastic housing I would expect it to have some play.

Yes, that makes sense. It moves around about 1/4 inch with little force. More than I think the oring can handle. I think it's pulling air in around the oring during high vacuum. I added some grease to the oring and my theory is that it stopped surging until all the grease disbursed from heat and vac.

 

[Atcer2018]

Yes, that makes sense. It moves around about 1/4 inch with little force. More than I think the oring can handle. I think it's pulling air in around the oring during high vacuum. I added some grease to the oring and my theory is that it stopped surging until all the grease disbursed from heat and vac.

Is it an OEM sensor? I ask because aftermarket isn’t always up to spec. Recently replaced my daughter’s Hyundai PCV valve with an aftermarket Amazon part and it was a mm or two smaller in diameter on the threaded portion than the OEM sensor. Sent it back and forked over the $30 bucks for an OEM and it fit snug.

 

[AlaRama]

Is it an OEM sensor? I ask because aftermarket isn’t always up to spec. Recently replaced my daughter’s Hyundai PCV valve with an aftermarket Amazon part and it was a mm or two smaller in diameter on the threaded portion than the OEM sensor. Sent it back and forked over the $30 bucks for an OEM and it fit snug.

Yes, it's OEM but has been superseded by Mopar. I ordered the new PN off EBay. Maybe it wont wobble. I checked the area of the bore with a bright light and mirror and saw no damage. Im hoping this will fix it, been going on for a while. Have to stay in the gears to climb a hill, using lots of gas. Everytime i mess with the sensor, its okay for a few trips to town and then falls on its face.

 

[Atcer2018]

Yes, it's OEM but has been superseded by Mopar. I ordered the new PN off EBay. Maybe it wont wobble. I checked the area of the bore with a bright light and mirror and saw no damage. Im hoping this will fix it, been going on for a while. Have to stay in the gears to climb a hill, using lots of gas. Everytime i mess with the sensor, its okay for a few trips to town and then falls on its face.

As a last resort if the new part wobbles maybe try plumbing teflon thread and wrap the threads a few times to snug it up. Good luck!

 

[AlaRama]

I installed the new OEM MAP sensor and it doesn’t wobble as bad, however it exacerbated the problem.

Wide swings (300) in RPMs between 1300 and 2000 under light load. I suppose it’s more sensitive to the vacuum fluctuations. So I loosened and sequentially re-torqued the intake bolts to 110 in/lb. Now the RPM flux is at a slightly higher range but the swings aren’t as wide (150)

I’m thinking it’s time to reseal the intake unless someone has a better idea? TIA

 

[AlaRama]

UPDATE: It had too much transmission fluid in it. Yes, I feel stupid, like the KISS guy. still trying to determine if the transmission is damaged. Surges are minimal at low RPMs, but much better shifting and more power.

 

[AlaRama]

Just wanted to update this post for anyone who happens to find it. The symptoms were sluggishness, rough idle, wouldn’t climb a hill unless I pulled it down into lower gears, wild shift patterns, no down shifting, NO CEL. It was doing all of this since I bought it and as I said previously, I changed the MAP sensor and adjusted the transmission fluid level, those helped but the problem persisted. It finally threw a P0019 and P000b after an oil change. I shot the parts cannon at it, changed cam and crank sensors and the oil control valve. When I removed the intake, oh boy. Two bad intake gaskets. One was like 2/3 there. The oil control valve had a busted screen, but no trash accumulation. So I cleaned everything up changed the valve, new gasket set, new injector seals, new TB seals.

It’s like driving a different truck. Win win. For now.