Determining if/where a boost leak is

[AMontgomery]

I'm trying to determine if I've got a boost leak and if so which connection is leaking.

I've got 1150 miles on my FiST. I've noticed a bit of a mileage drop from around 37mpg to around 31mpg. The car also seems to pull less. I still get torque steer in first and second gears, but my launches burn out less and first and second gear don't seem as strong when not at WOT.

I've gotten to most if not all of the intercooler piping clamps with a 7mm socket except the ones closest to the turbo outlet.

I'm getting a Cobb AP, RMM, and filter this week and I half want to wait until I can log pressures to make sure I'm not just going crazy.

But I can't shake the feeling I've got a leak.

Where are the most common connections that leak on our cars? And what is definitive proof that a leak is present?

 

[AMontgomery]

Bit of clarification. I also don't notice the problem as much when driving at night (70 F air temp). Could it just be intercooler heat soak on the stocker?

 

[dyn085]

The only way to tell will be to do a boost leak check. Google 'boost leak check' for an idea of the parts you'll need to acquire (they're cheap and readily available) and general testing procedure. Make sure you remove your oil cap and start with 5 psi before working up in pressure.

 

[AMontgomery]

http://http://www.turboboostleaktesters.com/servlet/the-HOW-TO-BOOST-LEAK-TEST-101/Categories

I found this guide for anyone else having the same issue.

The plan at the moment is to tighten the remaining clamps when I have the car in the air for the RMM. I'll then install the AP an get a reading of what my operating pressure is. If it's in the normal range all is well. If it's not I'll get a boost pressure tester as displayed on the site above

 

[westcoaST]

Anyone know the turbo inlet diameter?

 

[dyn085]

Honestly, you'll probably want to connect somewhere further upstream due to the turbo being so far back and down in the car.

 

[BlueBomber]

I'm trying to determine if I've got a boost leak and if so which connection is leaking.

I've got 1150 miles on my FiST. I've noticed a bit of a mileage drop from around 37mpg to around 31mpg. The car also seems to pull less. I still get torque steer in first and second gears, but my launches burn out less and first and second gear don't seem as strong when not at WOT.

I've gotten to most if not all of the intercooler piping clamps with a 7mm socket except the ones closest to the turbo outlet.

I'm getting a Cobb AP, RMM, and filter this week and I half want to wait until I can log pressures to make sure I'm not just going crazy.

But I can't shake the feeling I've got a leak.

Where are the most common connections that leak on our cars? And what is definitive proof that a leak is present?

There are a total of 10x 7mm clamps securing the entire path of your charged intake system. Tighten them all. Don't overtighten though.

All are EASILY accessible without removing the bumper or any components. Use a 7mm and a stubby ratchet for an easier time.

Tighten these and that should help but it could also just be carbon build up starting to form.

 

[dyn085]

There are a total of 10x 7mm clamps securing the entire path of your charged intake system. Tighten them all. Don't overtighten though.

All are EASILY accessible without removing the bumper or any components. Use a 7mm and a stubby ratchet for an easier time.

Tighten these and that should help but it could also just be carbon build up starting to form.

That much carbon buildup at 1150 miles? Have other FiST's shown to have that much buildup that early (or at all, for that matter)?

Boost leaks don't only occur at boost clamps. If they did then no one would do a boost leak check, they would simply tighten clamps.

 

[BlueBomber]

That much carbon buildup at 1150 miles? Have other FiST's shown to have that much buildup that early (or at all, for that matter)?

Boost leaks don't only occur at boost clamps. If they did then no one would do a boost leak check, they would simply tighten clamps.

Right, they're not the only place leaks occur, but the established issue - which is documented here on this forum- is that most of our cars came off the line with loose boost hose clamps, several of mine were quite loose. Others I am sure can vouch for the same, and this was one of the first things I did to the car.
Guy thinks he has a boost leak. Let's start with eliminating the clamps, which are known to be loose from the factory, as a possible source of leakage.

Onto carbon.

Carbon buildup SHOULDN'T be significant YET but I don't think our cars have a injector upstream - let me explain.

so we've got direct injection cars right?
Direct injection relocates the injector inside the cylinder. OK, great, but what's that have to do with carbon?

So, with traditional port fuel injection, there's a constant stream of gasoline being sprayed, cleaning the intake valves and intake (ahead of the compression chamber) - with direct injection this is no longer present and the intake valves and valve inlets This means that carbon can accumulate freely because it is dry up there and nothing cleans it.

BMW N54 and N55 engines (without an oil catch can) accumulate carbon so rapidly that it's recommended by BMW to have the intake valves walnut media blasted EVERY 30K MILES (not covered under normal service either)! That's a really short interval, and consider - we are also turbocharged, and also direct injected, why wouldn't the same issue afflict us?

This is why I am in a hurry to put together an oil catch can setup.

 

[dyn085]

Right but the established issue is that most of our cars came off the line with loose hose clamps, several of mine were quite loose.

Carbon buildup SHOULDN'T be significant but I don't think our cars have a injector upstream - so we've got direct injection cars right? Direct injection relocates the injector inside the cylinder. OK, great, but what's that have to do with carbon?
So with traditional port fuel injection there's a constant stream of gasoline cleaning the intake valves and intake (ahead of the compression chamber) - with direct injection this is no longer present. This means that carbon can accumulate freely because it is dry up there and nothing cleans it.

BMW N54 and N55 engines (without an oil catch can) accumulate carbon so rapidly that it's recommended to have the intake valves walnut media blasted EVERY 30K MILES! That's a really short interval, and consider - we are also turbocharged, and also direct injected, why wouldn't the same issue afflict us?

Thanks for the class, but this is my fourth DI vehicle so there's little you could teach me.

I never said this couldn't eventually become an issue, but we're talking about a car with 1150 miles. Having knowledge is great, but if you can't apply it correctly to the application or conversation... There's also no Ford-approved method for cleaning any of the Ecoboost engines yet. Also, catch-cans don't catch vaporized oil, which is what actually sticks to the valves.

So anyways, back on-topic.

It never hurts to try and tighten clamps like you had already done, but if you really want to know if you have a leak then there's really only one way to find out. Make the tester once and you can use it pretty much forever.

Edit: You should eventually stop editing your post.

 

[AMontgomery]

Tightening the clamps seems to have done the trick. I think temp changes may have something to do with this as well

 

[dyn085]

Tightening the clamps seems to have done the trick. I think temp changes may have something to do with this as well

Awesome. Also keep in mind that fuel stations have the option to swap to winter blend fuels in mid-September, and that generally takes a toll on mileage and power. It shouldn't be that drastic of a change, but it could play into it.

 

[Kip2MyLou]

Tightening the clamps seems to have done the trick. I think temp changes may have something to do with this as well

I should have had mine tighten when I got all my parts on this weekend. I didn't notice any performance differences but I guess it wouldn't hurt to check anyway. Glad it worked for you!

 

[BlueBomber]

Tightening the clamps seems to have done the trick. I think temp changes may have something to do with this as well

Sometimes the answer is the obvious one. I recommend checking the boost hose clamps for all new ST owners.

Good to hear it resolved the issue.

Check your connections first, then if all looks good move on to using a tester.

 

[AMontgomery]

So, I flashed the stage 1 V200 91oct map and kept the AP connected for a little ride tonight. (First second and third have really picked up a good bit) I noticed my boost pressure hitting 18psi in 2nd and hitting 19.5-20psi in third. Outside air temp was 82*F and I was running 92oct gasoline. Seems pretty par for the course for the conditions.

 

[AMontgomery]

Though admittedly, it could have been higher in second. I just didn't have the time to watch it!

 

[Kip2MyLou]

Good info. I'm definitely getting mine tighten here shortly and see if I noticed any difference.

 

[dyn085]

Though admittedly, it could have been higher in second. I just didn't have the time to watch it!

You don't have to watch it, it will list your low/high directly below the current readout.

 

[AMontgomery]

That's a nice feature. I was guessing that was what those were listing. I'll check that this morning.

 

[AMontgomery]

Here's my results from this morning