C7 Turbo Questions on 102-07 Code

[LPD218]

Hello folks,

On our way back from three months parked in Arizona I had a Check Engine Light and Stop Engine Light occur only when I was rapidly accelerating. As soon as I released foot pressure the lights went out. This occurred several times until no more lights after the second day home and all was well from then on. I did change my single fuel filter but the lights persisted on rapid acceleration the rest of the first day.

My scan gauge showed 102-07 code which I used the internet to find it listed as Boost Pressure Sensor Not Responding. That was the only code.

On the second day of our leg I set my scan gauge to read boost pressure and received a boost pressure reading of 29 once after first leaving the campground. The boost remained at or under 25 the remaining of our trip after that and no lights occurred with acceleration.

Can a turbo waste gate stick and unstick? Is there a lube location on the turbo for the waste gate?

Is the pressure sensor needing replacement?

Any ideas?

Many thanks.

[Skip426]

I'd say check the connector on the boost sensor , for tightness and any corrosion . Then follow the harness to the main connector from the engine harness to the chassis and do the same .

[Bigd9]

I'm having the very same problem with the Cat C7 engine in my coach. The lights and loud buzzer only seem to sound when she is in 5th gear and wide open throttle, they last for 5 seconds and then go away for maybe days before coming back.

So far I have replaced both fuel filters, lubricated the Waste gate mechanism ($0.00) and made sure it was working, replaced the Boost Sensor ($250+-) and I just replaced the IAP Sensor ($163+-). I'm still having the problem. I have also checked the wiring as Skip426 mentioned. I have even checked out the inside of the HEUI Pump and found it was as clean as a whistle with no metal shavings at all.

Next I'm going to check out the CAC and its inlet/outlet pipes. I have read where another Cat owner found pin holes inside the metal cooling sleeve, and he indicted you couldn't see the holes until he slid the sleeve away from the area.

I'm running out of options if that doesn't produce results.

[LPD218]

Bigd9,

Sorry to hear you are having the same issue with no known resolution yet. Are you getting codes?

I posted in the Diesel RV Club and will post if I get any more responses.

[Bigd9]

I don't have any good way to see codes as they happen. But one shop I took it to so they could read the engine codes indicated they were all referring to boost pressure problems.

If you search the iRV2 forum, you will see many owners Cat C7 owners posting about this same problem.

Thanks for any information you can come up with.

[discovery39s]

Pete,
What is your boost pressure under full acceleration when the bells and whistles go off?
My silver leaf tells me 25 psi solid and then descends proportionally as I reduce the peddle. You may also want to check the hoses right where the clamps retain it to the cac. I had one last week that had a 3" cut all the way through. The clamp read "made in china" and had a very sharp edge that caused the cut from vibration. It was hard to see until I tugged on the hose. Max boost was 13 psi until I replaced the clamp and hose. After, 24 under full acceleration. Ran like a champ.
Good luck,
George

[Bigd9]

Thanks George. I don't have Silver Leaf so I don't know what the pressure is. However, I am going to check out the hoses.

I still need to write up a description on the HEUI Pump inspection. I just need some mental time to do it.

Thanks again George.

[discovery39s]

Pete,
We are leaving for a three week trip on Wednesday. If you don't find anything by then let me know and I'll send you my silver leaf tablet and cable to use to diagnose. I'ts plug and play. The ECM connector is right under the dash below the steering column. You can set on the dash and see live data as you test drive. Pretty hard to diagnose unless you have data to go by.

Glad to hear your HEUI inspection went well.

Good luck and hope you "Discover" something.

[discovery39s]

Pete,
One more thing to look for on the hoses. The inlet/outlet ports of the CAC have a formed knob on the ports. I have seen the clamps to close to the knob and when tightened down can severe the hose. Be sure the hose clamps are closer to the CAC rather the end of the port where the knob is. Just FYI.

[Bigd9]

Thanks I will check that out. Thanks for the offer of the Silver Leaf. That is very nice of you. Hopefully in two weeks we will be out and about maybe up towards Montana direction or possible down in North Carolina direction. That boss hasn't told me which way to steer yet!

We were near your home town the last trip out.....well maybe not real near but at least in your state! We spend several days hiking in and around Hocking Hills State Park.

[discovery39s]

I received my steering directions. LOL "Go South Young Man"
My reply, "Whatever you say my Dear"

Safe Travels my friend, email or call when you get back around.
George

[FIRE UP]

Hey Gang,
I have a factory installed boost pressure gauge in our coach. The max it's ever seen is 27 psi. It normally hovers in or around 25-26 psi at full throttle.
Scott

[desertdd]

I have had low boost on my C7 for about 2 years. Maximum boost is a 20 lbs now. I have checked and double checked all of the hoses etc. I talked to a service manager at a Cat dealer and he told me a C7 will run with a wide variance of boost from 15 lbs to 90 lbs and told me not to worry about it. I have never had an error code and it seems to run well. All filters including the air filter are all new. But it still bugs me thinking there might be something wrong with the wastegate, maybe I worry to much,

[cbeierl]

Just fyi, here are the factory Dyno results for my Late-2004 350HP C7. Turbo tested at 28.8 psi, spec was 28.3 psi.