Turbo Issues/No boost

[Kapster55]

No I get it, more frustrated that the dealer ship has had it twice in past 6 months and as soon as put your foot into it trips the underboost code and goes in to low power mode.

I know there going to try weasel out of covering anything because I out the intercooler on it.

How about back precure? I have a set of valvetronics mufflers with there opeaning and closing flap I keep it closed and was closed when it tripped the code.

 

[TMac]

If you can't DIY a boost leak, I don't know how anyone can help you.

The only way it could be back pressure is if you had some significant mechanical failure of the mufflers, so bad that they are nearly completely choked off. Don't take this wrong, but you don't strike me as someone who has anywhere near the mechanical ability to deal with this. I've given you the very first thing to look for. After that it could be anything- none of them good. Best advice, take it back to the shop that did those mods and have them check it out.

 

[TMac]

Hey @l1tech anything you can contribute to @Kapster55 ? Start reading at post #15

 

[DaveG ST]

On my ST with similar issue the dealer replaced the throttle body at about 20K miles. At 50K miles now and all has been fine since.

 

[l1tech]

Boost leaks can be a PIA to find especially if they don't develop until higher boost pressures are reached. As TMac stated the 1st step would be in checking all of the connections to make sure that they are TIGHT and that the clamps are in the right place. If that is ok I have a machine that can pressurize turbo piping up to 30 psi with smoke so leaks become very easy to find. I have found some leaks that aren't leaks until 15 psi of boost is acheived, these are the ones that can cause you to pull your hair out. Not all shops have a machine for this but I would suspect that a dealership should. If no leaks are found than it is time to data log the desired and actual boost pressure to make sure that you are actually losing boost (this is actually the 1st step). Clogged cats can cause low boost issues but it is usually accompanied with rich codes. Clogged cats almost always wipe out the turbo also. If everything checks out then you may just have a bad turbo....I've replaced more than my fair share of them on Fords.

 

[Kapster55]

Boost leaks can be a PIA to find especially if they don't develop until higher boost pressures are reached. As TMac stated the 1st step would be in checking all of the connections to make sure that they are TIGHT and that the clamps are in the right place. If that is ok I have a machine that can pressurize turbo piping up to 30 psi with smoke so leaks become very easy to find. I have found some leaks that aren't leaks until 15 psi of boost is acheived, these are the ones that can cause you to pull your hair out. Not all shops have a machine for this but I would suspect that a dealership should. If no leaks are found than it is time to data log the desired and actual boost pressure to make sure that you are actually losing boost (this is actually the 1st step). Clogged cats can cause low boost issues but it is usually accompanied with rich codes. Clogged cats almost always wipe out the turbo also. If everything checks out then you may just have a bad turbo....I've replaced more than my fair share of them on Fords.

Thank you, I'll be pulling the front off the car in next two weekends to check the connections to the intercooler as thats really been the only thing thats been messed with. This does only happen when your getting your foot into it and its under heavy load. I'll check with dealer to see if they have a way to test for leaks ..

 

[Kapster55]

Hey @l1tech anything you can contribute to @Kapster55 ? Start reading at post #15

Thank you TMac

 

[Stone17]

Did you find the problem with your ST?

My neighbor 2020 ST (Stock, 41k Miles) is having low boost problem. Only making 8 to 9 PSI at WOT.
No check engine light. Tranny feel slow to shift in Sport mode.