Fuel mileage loss, fix = clean the Map Sensor again.

84673 Views 110 Replies 36 Participants Last post by MP81, 2 mo ago

Cruz15

Discussion Starter · Dec 27, 2016

Fuel mileage loss, fix = clean the Map Sensor again.
I might just buy a couple of them and replace it every 12 months while cleaning every six months.
I have never had to do such a thing to any other vehicle I have owned. I have never owned a boosted car before.
Cheers.

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theonlypheonix

· #61 · Mar 13, 2017 (Edited)

diesel said:
One of the things I set out to do on this car from the beginning was to do as little as possible , so that I could observe how long it takes things to get gummed up.

:blush::not_worthy::signs015:

No offense, but is this also like not changing the oil to see how far you can go before things get gummed up?? Personally I follow a PM PLAN, especially after owning several different diesels over extended miles and years. There is nothing like cranking it up and just going rather then rrra...rrra...rrra, O shXt I should have...??

diesel

· #62 · Mar 13, 2017

theonlypheonix said:
:blush::not_worthy::signs015:

No offense, but is this also like not changing the oil to see how far you can go before things get gummed up?? Personally I follow a PM PLAN, especially after owning several different diesels over extended miles and years. There is nothing like cranking it up and just going rather then rrra...rrra...rrra, O shXt I should have...??

Not at all. I change oil, fluids, filters, etc per a strategy appropriate for my driving. I am talking specifically about not doing things like removing sensors to clean them, removing the intake to burn out the carbon, removing and blasting the cylinder head valves with walnut shells, etc. I don't think any of that remotely falls into PM. And so far, for 202K miles, my strategy has worked just fine.

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Rivergoer

· #63 · Jun 22, 2017

Well, Now I'm Screwed

diesel said:
Not at all. I change oil, fluids, filters, etc per a strategy appropriate for my driving. I am talking specifically about not doing things like removing sensors to clean them, removing the intake to burn out the carbon, removing and blasting the cylinder head valves with walnut shells, etc. I don't think any of that remotely falls into PM. And so far, for 202K miles, my strategy has worked just fine.

I should have listened to Diesel. If it ain't broke, don't fix it.

67K on the odometer, not original owner...read this thread and decided to check the MAP sensor today. Now my perfectly fine CTD is disabled because the bottom 1/2 o-ring end of the sensor is busted off in the bore.

Auto part Engine

Technology Electronic device Finger

Scratching my head as to how best to remove the broken end. Will keep u posted...ugh!

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2

Aranarth

· #64 · Jun 22, 2017

Rivergoer said:
I should have listened to Diesel. If it ain't broke, don't fix it.

Scratching my head as to how best to remove the broken end. Will keep u posted...ugh!

I bet a dental pick or a large needle bent to a short fish hook will work quite well...

Reactions: 2

beaurrr

· #65 · Jun 22, 2017

Rivergoer said:
I should have listened to Diesel. If it ain't broke, don't fix it.

67K on the odometer, not original owner...read this thread and decided to check the MAP sensor today. Now my perfectly fine CTD is disabled because the bottom 1/2 o-ring end of the sensor is busted off in the bore.

View attachment 233866 View attachment 233874

Scratching my head as to how best to remove the broken end. Will keep u posted...ugh!

I agree; most of this 'cleaning' business is overrated. Just because a sensor appear dirty doesn't mean it's not working as intended.

Reactions: 2

theonlypheonix

· #66 · Jun 22, 2017 (Edited)

beaurrr said:
I agree; most of this 'cleaning' business is overrated. Just because a sensor appear dirty doesn't mean it's not working as intended.

I believe lack of maintenance cleaning is the cause of this problem, totally carbon fouled. I removed and cleaned mine at 50K miles, no problems what so ever. Note the o-ring can harden and be the source of the problem if its still in the bore. I had a similar issue on my 6.0L diesel with the ERG valve removal and cleaning. Had to remove the retaining bolts, spray cleaner into the seam, and very gingerly rock and twist until it started to loosen, then repeat a little more cleaner until it was moving so it could be removed. Always use care when things are seized up especially plastic parts and cleaners which are approved for rubber seals, plastics and sensors! This type of fouling can be anticipated anywhere in a diesel exhaust system.

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theonlypheonix

· #67 · Jun 22, 2017 (Edited)

Aranarth said:
I bet a dental pick or a large needle bent to a short fish hook will work quite well...

agree with using a angled pick and maybe a little approved cleaner to loosen up ... also have a shop vac spout right near the port to suck up the loosened pieces. Afterwards you can open the vac to make sure you have all the pieces of the sensor. Viewing the photo in post #52 you can see what is still stuck inside the port. As previous suggested you might be able to hook and pull out if a hardened o-ring isn't the cause of it being stuck.

Reactions: 1

Cruz15

Discussion Starter · #68 · Jun 22, 2017

Rivergoer said:
I should have listened to Diesel. If it ain't broke, don't fix it.

67K on the odometer, not original owner...read this thread and decided to check the MAP sensor today. Now my perfectly fine CTD is disabled because the bottom 1/2 o-ring end of the sensor is busted off in the bore.

View attachment 233866 View attachment 233874

Scratching my head as to how best to remove the broken end. Will keep u posted...ugh!

Ouch. If I was closer I would help out. Sorry that happened to you.

Reactions: 1

Cruz15

Discussion Starter · #69 · Jun 22, 2017

beaurrr said:
I agree; most of this 'cleaning' business is overrated. Just because a sensor appear dirty doesn't mean it's not working as intended.

My car gets much better fuel mileage and drives much better when its clean. Its definitely not overrated on my car.
People that drive like they have an Indy car (Heavy Foot) will most likely not notice much difference with anything they do to improve mileage.

Reactions: 3

Rivergoer

· #70 · Jun 22, 2017

Before the replies I had all the same thoughts. The 45 degree angled pick tool worked. O-ring came out 1st then the broken plastic body reluctantly exited with a lot of coaxing and patience. Unfortunately it fell off the tool and down the back side of the motor, lost in no man's land.

Luckily Chevy had one (ONLY one) in stock, $47. Might want to call ahead and ensure your local dealer has one in stock in case it breaks like mine did.

Topped with Diesel and 65 miles into hopefully another 1,000 mile tank (wink). All good no CEL.

Thanks again everyone!

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Cruz15

Discussion Starter · #71 · Jun 22, 2017

Im glad you got it out and were able to get one right away.
Cheers.

Reactions: 1

smkn600ctd

· #72 · Jun 25, 2017

Went to clean mine today and it broke off in the manifold. I was able to get the o-ring out, but the plastic body fell into the intake.

I took a shop vac to the throttle body and to the MAP port to try and suck it out, but no luck.

Hopefully the valves smash it to pieces and then the fire burns it up and sends it out the exhaust.

Got a new one Delco part coming from Amazon for $26.

Reactions: 1

Rivergoer

· #73 · Jun 25, 2017

smkn600ctd said:
I was able to get the o-ring out, but the plastic body fell into the intake... Hopefully the valves smash it to pieces and then the fire burns it up and sends it out the exhaust.

Got a new one Delco part coming from Amazon for $26.

Dang, that's two of us with the same issue. I'm sure like you I thought I was being as gentle as possible when mine broke off. That MAP sensor must get brittle from the heat and soot build-up over the years.

The o-ring came out first for me too. The remaining plastic body fell down into the bore but I was able to "stab" it with a straight prong tool. I pinned it to the bottom of the manifold and got the tool to penetrate the plastic enough to hold it as I guided it back up through the bore.

As mentioned previously, I can't emphasize enough how important it is to make sure your dealer has the part in stock before you work on the MAP sensor or have one on hand from Amazon or eBay before starting work. AC/Delco Part from GM is #55568175.

smkn600ctd, I hope you're right about chewin' up and spittin' out that broken piece. Crossing fingers. :hope:

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IndyDiesel

· #74 · Jun 26, 2017

I kinda think cleaning this sensor is way more potential risk and trouble vs the benefit. I will leave my alone. I change the oil and the filters, if it needs something else I will take to a dealer. The idea of a plastic anything sitting inside a cylinder bore is a [email protected] nightmare on my mind.

Reactions: 1

Cruz15

Discussion Starter · #75 · Jun 27, 2017

IndyDiesel said:
I kinda think cleaning this sensor is way more potential risk and trouble vs the benefit. I will leave my alone. I change the oil and the filters, if it needs something else I will take to a dealer. The idea of a plastic anything sitting inside a cylinder bore is a [email protected] nightmare on my mind.

I would have to agree after two ended catastrophically. Just leave it for the dealer Peoples. If it needs cleaning or replacement to the dealer it should go.

Reactions: 1

IndyDiesel

· #76 · Jun 27, 2017

Cruz15 said:
I would have to agree after two ended catastrophically. Just leave it for the dealer Peoples. If it needs cleaning or replacement to the dealer it should go.

I haven't really researched this topic in detail, but I can safely say if I had plastic sitting on a piston, I would probably remove the intake manifold and remove the plastic prior to starting it again. Then would inspect the intake and possibly clean that while off the car. I just don't want to open that can of worms unless necessary. I think I will do some more wide open throttle more often.

Reactions: 1

Diesel Dan

· #77 · Jul 7, 2017

Well after a reoccurring P0133 that kept resetting I found this thread. Pulled the O2 and MAP sensors of which both were heavily sooted up. With 56k miles I'd rather work on it than a dealer if possible.

Cleaned both with MAF sensor cleaner and compressed air. Been a few days and no SES light.

The MAP is a little sensitive getting out and I can see how it will break the tip off. You need to pry it up from two sides which can be tricky. If you just pry from the mounting flange it bends the sensor which can break it.

While I don't have any hard data to back up this maintenance I'd recommend it. Don't feel like getting any PCM reflash at this point.

Reactions: 1

MRO1791

· #78 · Jul 7, 2017

Diesel Dan said:
Well after a reoccurring P0133 that kept resetting I found this thread. Pulled the O2 and MAP sensors of which both were heavily sooted up. With 56k miles I'd rather work on it than a dealer if possible.

Cleaned both with MAF sensor cleaner and compressed air. Been a few days and no SES light.

The MAP is a little sensitive getting out and I can see how it will break the tip off. You need to pry it up from two sides which can be tricky. If you just pry from the mounting flange it bends the sensor which can break it.

While I don't have any hard data to back up this maintenance I'd recommend it. Don't feel like getting any PCM reflash at this point.

Thanks, I just had the latest recall flash on one of my cars.. so far no issues.. waiting to verify all is well before I do the other. I actually had the bad recall that was suspended done on both, but I was fortunate, no problems with either car.

Sent from my Moto G (4) using Tapatalk

Cruz15

Discussion Starter · #79 · Jul 8, 2017

Diesel Dan said:
Well after a reoccurring P0133 that kept resetting I found this thread. Pulled the O2 and MAP sensors of which both were heavily sooted up. With 56k miles I'd rather work on it than a dealer if possible.

Cleaned both with MAF sensor cleaner and compressed air. Been a few days and no SES light.

The MAP is a little sensitive getting out and I can see how it will break the tip off. You need to pry it up from two sides which can be tricky. If you just pry from the mounting flange it bends the sensor which can break it.

While I don't have any hard data to back up this maintenance I'd recommend it. Don't feel like getting any PCM reflash at this point.

What size is the O2 sensor? Have to pick up a crows foot today. Is there a spec for the torque on it?
Thank you.

Diesel Dan

· #80 · Jul 11, 2017

Cruz15 said:
What size is the O2 sensor? Have to pick up a crows foot today. Is there a spec for the torque on it?
Thank you.

Sorry for the delay, no internet at the house.

I do believe it is 7/8 or equivalent metric. Had to use crows foot since my standard O2 socket was not deep enough. Just snugged it down, did not use a torque spec.

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