Boost Pressure Sensor

BlackLibertyCRD · **Posted:** Wed Dec 27, 2006 10:25 pm

I started getting a MIL intermitting last night that went out till morning. It came back on on the way to work and was out when I left from work. I came back on the way home and went into limp mode and would go only 25 mph till I pulled over and shut off and restarted the engine. Then the MIL stays on solid as soon as the engine is started. :evil:

I took the chance and drove it to the dealership and has the codes pulled. Wouldn't you know it, the TPM light came on in the dash and stays on also. :evil:

The mechanic didn't tell me the code but told me that it was the turbocharger boost pressure sensor error. He also thinks it might be related to the flow control and EGR valve. He also checked all the tire pressure and told me that the spare was a few pounds low but the light is still on the dash and warning on overhead console. First chance they can get me in with loaner car is 01-08-07.

Has anyone have similar problem with boost sensor and TPM?

RFCRD · **Posted:** Wed Dec 27, 2006 10:43 pm

BlackLibertyCRD wrote:

I started getting a MIL intermitting last night that went out till morning. It came back on on the way to work and was out when I left from work. I came back on the way home and went into limp mode and would go only 25 mph till I pulled over and shut off and restarted the engine. Then the MIL stays on solid as soon as the engine is started. :evil:

I took the chance and drove it to the dealership and has the codes pulled. Wouldn't you know it, the TPM light came on in the dash and stays on also. :evil:

The mechanic didn't tell me the code but told me that it was the turbocharger boost pressure sensor error. He also thinks it might be related to the flow control and EGR valve. He also checked all the tire pressure and told me that the spare was a few pounds low but the light is still on the dash and warning on overhead console. First chance they can get me in with loaner car is 01-08-07.

Has anyone have similar problem with boost sensor and TPM?

Just wondering if you have a Provent or EHM hose? This problem has been posted a few times before. The sensor is located in the intake manifold, down-wind of both the airflow control valve and the EGR port. The sensor becomes covered/fouled with the oil & soot crud. This is a sign of things to come once the carbon & oil begin building-up in the intake.

BlackLibertyCRD · **Posted:** Wed Dec 27, 2006 10:46 pm

Thanks for the reply, can the sensor be cleaned or does it has to be replaced??

RFCRD · **Posted:** Wed Dec 27, 2006 10:57 pm

BlackLibertyCRD wrote:

Thanks for the reply, can the sensor be cleaned or does it has to be replaced??

I think it can be cleaned. It's located under the black engine cover (driver's side) next to the common fuel rail pressure sensor. Look through some recent threads. There was insructions for removal & cleaning (not difficult). I was going to pull mine to inspect for build-up but I figured it would just raise my blood pressure so I didn't do it yet. It will trash you fuel mileage if it's fouled.

BlackLibertyCRD · **Posted:** Thu Dec 28, 2006 7:17 pm

It kept going into limp mode every few traffic lights so I had roadside assistance tow it in on roll back. The mechanic at the dealership said something about cleaning or replacing it yesterday but have to run a lot of test before hand. I don't have the crankcase mod and trying to hold off on it.

RFCRD · **Posted:** Thu Dec 28, 2006 7:28 pm

BlackLibertyCRD wrote:

It kept going into limp mode every few traffic lights so I had roadside assistance tow it in on roll back. The mechanic at the dealership said something about cleaning or replacing it yesterday but have to run a lot of test before hand. I don't have the crankcase mod and trying to hold off on it.

The oily intake is the #1 complaint on my short list. I should clarify that a CCV mod or Provent won't guarantee an oil-free intake. It will help but it's not perfect on this engine as the turbo seals still pass oil under certian circumstances. Oil + Soot + Heat = Big problems in the intake manifold.

BlackLibertyCRD · **Posted:** Fri Dec 29, 2006 7:28 pm

I talked to the mechanic at the dealership and he said that he replaced the flow control for the EGR first because it was sticking. He had to order the boost sensor and it should be in Tuesday. He believes that the sticking flow control cause more soot and oil to clog the sensor. Sounds to me that he is on top of the problem.

Ranger1 · **Joined:** Mon Oct 17, 2005 7:40 pm **Posts:** 1137

Quote:

I think it can be cleaned.

It can. Look under the failing egr thread for several who have just inspected them, found the sensor clogged solid to the point where the sensor could not function at all. One clogged in 11K. Intake cleaner works well on them, engine runs much smoother, mileage appears to be increase at least on the EVIC. Looks like a major design fault - sensor can't make it 15K due to soot level in the intake.

RFCRD · **Posted:** Sun Dec 31, 2006 11:38 pm

Ranger1 wrote:

Quote:

I think it can be cleaned.

It can. Look under the failing egr thread for several who have just inspected them, found the sensor clogged solid to the point where the sensor could not function at all. One clogged in 11K. Intake cleaner works well on them, engine runs much smoother, mileage appears to be increase at least on the EVIC. Looks like a major design fault - sensor can't make it 15K due to soot level in the intake.

It got pulled today, was completely packed with soot. Easily cleaned and reinstalled.

BlackLibertyCRD · **Posted:** Sun Dec 31, 2006 11:39 pm

Ranger1 wrote:

Quote:

I think it can be cleaned.

It can. Look under the failing egr thread for several who have just inspected them, found the sensor clogged solid to the point where the sensor could not function at all. One clogged in 11K. Intake cleaner works well on them, engine runs much smoother, mileage appears to be increase at least on the EVIC. Looks like a major design fault - sensor can't make it 15K due to soot level in the intake.

I have 13,700 miles on her now. If what you say is true its due for cleaning. I remember the next time it gets clogged.

Ranger1 · **Joined:** Mon Oct 17, 2005 7:40 pm **Posts:** 1137

Quote:

I have 13,700 miles on her now. If what you say is true its due for cleaning. I remember the next time it gets clogged.

If the tech just replaced the boost sensor, it should be good for another few thousand miles before a cleaning is needed. Might be worth pulling it at 3K miles just to see how the soot level is on it. I'll be pulling mine at the next 1K miles since I just cleaned it - but just to see how much soot is there now that ULSD is here.

The more I think about the soot level shown clogging the boost sensor, I'm now wondering why those of us who cleaned them didn't get a CEL? How could the boost sensor be providing any rational readings to the pcm with that level of clogging?

Goglio704 · **Posted:** Mon Jan 01, 2007 4:00 pm

Ranger1 wrote:

Quote:

I have 13,700 miles on her now. If what you say is true its due for cleaning. I remember the next time it gets clogged.

If the tech just replaced the boost sensor, it should be good for another few thousand miles before a cleaning is needed. Might be worth pulling it at 3K miles just to see how the soot level is on it. I'll be pulling mine at the next 1K miles since I just cleaned it - but just to see how much soot is there now that ULSD is here.

The more I think about the soot level shown clogging the boost sensor, I'm now wondering why those of us who cleaned them didn't get a CEL? How could the boost sensor be providing any rational readings to the pcm with that level of clogging?

I'd like to know those answers myself.

litton · **Posted:** Mon Jan 01, 2007 6:44 pm

Got some interesting info to pass along.

I pulled and cleaned the boost sensor this afternoon. At 8250 miles it was modestly crapped up with soot and cleaned easily with CRC electrical cleaner. First observation is that it appears to be a displacement type flow sensor. That little wand that is supported by the plastic bar probably measures total air flow. I suspect that there is a static pressure transducer as well as a temp sensor in there as well. I didn't check for sure but I'll bet there are four wires....common, temp, flow, and pressure. The soot would cause flow and temp to under-report but pressure is probably not affected by the deposits.

After cleaning, I drove into town and refueled....about 25 miles each way. On the way home, I saw the best fuel economy ever on the EVIC.....30.1 instead of the ~26 I would normally see. This is only one data point but it's very significant. Of great interest to me is if this has an impact on my EVIC error.....I should know in a week or so when I refuel again.

MACKJ · **Posted:** Mon Jan 01, 2007 10:06 pm

RFCRD wrote:

BlackLibertyCRD wrote:

Thanks for the reply, can the sensor be cleaned or does it has to be replaced??

I think it can be cleaned. It's located under the black engine cover (driver's side) next to the common fuel rail pressure sensor. Look through some recent threads. There was insructions for removal & cleaning (not difficult)...

That was me in late November...sorry, I've been on holiday and haven't logged on for some time.

Here is the text from my previous threads;

I have recently cleaned the boost pressure/Intake temp sensor. It was completely covered with a sticky mix of oil and carbon, in other words, beautifully insulated. After cleaning I have noticed smoother operation and possible improved torque as the rig holds fifth gear much longer when going up an incline. Idle smoothness has also improved, although not to my satisfaction yet.
The question is, does the ECM re-learn parameters after a sensor clean or replacement?
Or does it have to be reset?

Where is this sensor located?

It's just behind the fuel rail pressure sensor and hidden by the wiring loom that goes across the engine.
Pull that loom up out of the way and undo the heater hose bracket to the left of the oil filler (this is a section of hex that forms one of the front supports for the engine cover).
Also disconnect both the boost sensor plug and the one for the fuel rail pressure sensor to give you a bit more freedom with the wiring loom. You need a 3mm allen key for the one bolt on the boost/intake temp sensor. Make sure you pick up the washer under this bolt so you don't drop it down the hole when removing the sensor! Gently pull upwards on the sensor, there is only a recessed O ring on the unit so it comes out very easily.
Clean the sensor head carefully with a good quality carby cleaner...

After disconnecting and reconnecting the battery after about twenty minutes, I now have my old rig back.
It is a completely different drive...smooth idle (for a diesel), crisp acceleration and smooth gear changes. Just like it was a year ago. I just can't believe that I asked Jeep to look at the boost/ intake air temp sensor about nine months ago. Of course they said everything was performing per the manufacturers specs...they obviously didn't even look...

DarbyWalters · **Posted:** Mon Jan 01, 2007 11:47 pm

Go to this website and then click on PDF Instructions...some great pics of Fuel Pressure Sensor and Boost Sensor:

http://painlessperformance.com/InfoSear ... ield=64075

Joe Romas · **Posted:** Tue Jan 02, 2007 3:30 pm

At 4600 miles I pulled the sensor out to have a look. Mine was covered with soot but no "crud". I installed my provent at 600 miles and in 4000 miles the oil level did not drop any at all. So maybe the provent kept oil from getting to it causing the "crud" I've seen in my X 99.5 tdi manifold. I used spray carb cleaner. Boy those round clips were a B@#$H

DnA Diesel · **Posted:** Tue Jan 02, 2007 4:42 pm

Joe Romas wrote:

At 4600 miles I pulled the sensor out to have a look. Mine was covered with soot but no "crud". I installed my provent at 600 miles and in 4000 miles the oil level did not drop any at all. So maybe the provent kept oil from getting to it causing the "crud" I've seen in my X 99.5 tdi manifold. I used spray carb cleaner. Boy those round clips were a B@#$H

LOL....yup!

Has anyone had any issues with the dealers and the Provent?

Cheers,
Duey

midwest · **Joined:** Tue Apr 25, 2006 12:03 am **Posts:** 173

Just checked mine at 14500 miles. It was crudded up but not as bad as others that posted pics. I agree this is going to be a regular maintenance item. Thank God it is at a easy to get at location. By the way, all stock CRD here.

Joe Romas · **Posted:** Tue Jan 02, 2007 5:37 pm

DnA Diesel wrote:

Joe Romas wrote:

At 4600 miles I pulled the sensor out to have a look. Mine was covered with soot but no "crud". I installed my provent at 600 miles and in 4000 miles the oil level did not drop any at all. So maybe the provent kept oil from getting to it causing the "crud" I've seen in my X 99.5 tdi manifold. I used spray carb cleaner. Boy those round clips were a B@#$H

LOL....yup!

Has anyone had any issues with the dealers and the Provent?

What provent :lol:

Mine will be in my garage when I get LBJ and F31 done. I've mounted it with tye-wraps for easy removal

Cheers,
Duey

BlackLibertyCRD · **Posted:** Tue Jan 02, 2007 6:25 pm

Got the Jeep back from the dealer today. New Flow Control Valve and Boost Sensor. All is well and I will remember to clean boost sensor with every oil change. I don't think I needed the Flow Control Valve yet. It was changed because the mechanic believe it caused the problem. Was no codes for the control valve or EGR. Hopefully ULSD will keep it going.

Boost Pressure Sensor

Who is online