Turbo underboost condition after turbo replacement

Not really a Ford tech but I've done a lot of Mercedes diesel repairs. Trust the computer, you left something loose. It's under boosting. The computers are real smart and although you may think it's ok, it's not you that matters. It's the computer. So if you do not have a high pressure smoke tester, I suggest you borrow one. Remember...... I'm not a Ford tech so you may want to see what a…

I am not a big fan of the smoke machines on heavy duty diesels. Not enough pressure IMHO. We have cuff seals on the Navistar MaxxForce DT's that don't leak until there is 15 to 20 or more psi against them. We use our Charge Air Cooler (CAC) test set up. Connect at the turbo output and manifold inlet. Put 25 to 30 psi in thru a regulator. You will likely hear it. If not soapy water in a spray…

Really? 43 psi isn't enough? aeswave​.​com/smart-pressure…

Marlin, this is the first I have seen this. We were force fed a Red Line machine as an essential tool about 5 years ago. For more than twice the money. I was very unimpressed. This at first glance looks to be much better. Lack of pressure was the problem with the Red Line. At least I have a nice set of adapters! The air pressure set up has worked OK for us on medium and heavy duty. I have also…

Lisle makes a block off kit that allows you to pressurize the cac piping so you can find leaks. If you do any turbo vehicle repairs, get one.

I just ordered the light duty kit for that. I had the HD one already, but most of the adapters are too big. I got taken by the local Matco guy on that. He insisted the HD kit was the one I needed. Once I tried to sue it and found out it wasn't, he refused to take it back. Useless tools is starting to become a theme with Matco. It's leaving a bad taste in my mouth.

You've stated you replaced the air filter. This TSB might give you a clue about what's going on with this Ford: 16-0004. Try this TSB while you're at it: 19-2143. The factory service manual, step KA2, has a whole bunch of inspection points to look over on these before hitting them with the smoke tester. After the initial steps, then, like the others posted...bring on the smoke.

You need to pull the map sensor on the top on the intake and make sure it's not plugged. Send a picture of it and I can tell you. All I work on is powerstroke. I would start there first

I found a leak at the CAC pipe fitting at the throttle body. Had to replace the whole pipe. Ran the KOER test and now I have a P1249. when we did the turbo we also replaced the upper intake with a Dorman. It had a new MAP sensor in it. I’m seriously wondering if it’s not working correctly. Is there a way to check it other than substituting a known good?

Why did you replace the manifold? Dorman means that is most likely is not working correctly. Why not just test it with a vacuum pump and gauge? The PID and the gauge need to match within a couple in/Hg.

Manifold was replaced due to having to break it to remove bolts. I don't agree with the blanket statement about Dorman although some of their stuff is problematic.

Interesting. Were the bolts seized due to rust, and the hex not enough to loosen them? Did you test the sensor?

Yes, the bolts were seized due to rust (Ohio road salt). The rust had actually split the plastic where they went through. Testing the sensor as you suggested was a good idea, however, I tried substituting a different sensor(see my revision above). thanks for your involvement.

Can you share the FF data and or any data you collected when the vehicle enters this mode? Your question about the EGR pid is probably normal and reporting atmospheric pressure. There are a ton of resources like this and more at the Motorcraft website.

Scott, Thanks for the information. I couldn't find any information in Alldata, Pro Demand or Identifix as to what it took to run and pass the turbo monitor. Also could not find any sensor values. What you sent was enlightening. I didn't save the freeze frame data before I cleared the P0299 code so I don't have that to show. I wish I would have since I haven't been able to get the code to…

Remember if you're roughly at sea level 1 atmosphere is about 14.5psi. So any sensors that measure air pressure should read around this if they are absolute pressure sensors with koeo (gauge pressure sensors read zero at 1 atmosphere). So this applies to the MAP sensor as well as the exhaust backpressure sensor.

This still points to unexpected MAP signal. Did you check over the small vacuum hoses? Did you ensure that the MAP sensor hole isn't faulty?

Yes, I removed the map sensor and inspected it. The hole in the intake is open. If it wasn’t working I would think I would have other codes. I have a actuated the wastegate solenoid with a scan tool and a vacuum gauge teed in and I get 15 inches of vacuum at 100% duty cycle. Thanks for working with me on this.

I think that one has a vacuum operated valve at the EGR cooler also. Did you go over all of the vacuum hoses?

I didn’t check vacuum there.

Hey Lamont. Just my opinion. I would say that the p0299 caused the PCM to never run the monitor for the P1249. The P1249 has probably been there for awhile but didnt set till you fixed p0299. The MAP is used for determining the actual boost pressure. If there was a problem with the MAP it would not pass P0299. In fact the MAP was doing its job because it set P0299 and you found a leak to prove…

The wastegate moves when I command it with the scan tool. When I checked it I had a vacuum gauge teed in and I had 15 inches of vacuum @ 100% duty cycle. I have not watched it while the KOER test is running. This was a new Garrett turbo. I assume they are properly adjusted when you get them. There was a paint mark on the adjust rod so we didn’t move it before installing it. If the truck comes…

Awesome good deal.

Thanks for your help.

Good find. I am surprised they use vacuum. The diesel I work with use the boost from the turbo itself to run the wastegate pod. They use pressure, not vacuum.