Hey guys....recently upgraded my intercoolers and I am noticing a smooth running car that does not build boost. I thought these cars were MAF and if there is a leak present that I would at least get a check engine light. Is it possible to have a boost leak and have a smooth running car with zero check engine lights?

 

dealer worked on it...so need to take it back. Was just wondering how come no check engine light. I would imagine a failure to build boost should be something caught by the ECU/DME.

 

Nope, unfortunately you can have lots of leaks and you will get no CEL.

I've had a blown off hose on a dirverter valve (showed up as lower boost than I was expecting given the conditions, also showed as a larger-than-normal delta in the logs between actual & desired boost at WOT.)

Also had the Y-pipe come lose from the TB, which would manifest itself as fine during normal driving but a giant whooshing sound at around >5psi of boost.

All these with no CEL.

THe Y-pipe issue occured after a dealer visit.. I fixed it myself rather than subject the car to more dealer "punishment" .LOL

I have a set of Boost Leak testers from Markski that I use to track down these things.. they def. come in handy..

 

I found the boost leak testers on Markski's website - do you have any info about how to actually install/use them? How do you typically do it?

https://www.markskituning.com/produc...t-leak-tester/

For $115, it would probably make sense to have these around to ensure things are working perfectly every now and then.

 

I made my own for 10 bucks out of pvc and some pvc glue

 

You also need an air compressor, fittings, and a gauge, right?

I don't have a large tank compressor...is that a requisite?

 

Yep, which is why I ended up buying mine..

..althoguh inflation must be in effect as I only paid $75 for my pair less then 2 years ago..

You dont need a large compressor, I would imagine you could use a small pancake one.. they are pretty cheap..

Using it is easy.. Put car on lift (if you have one, makes access soo much easier) & disconnect the hose at the turbo outlet -> intercooler on both sides of the car..

Put one of the "caps" on the rubber hose on one side and the other "cap with the air fitting" on the other..

Tighten the hose clamps tight.

Now using your compressor, slowly put air in, about 5 psi at a time.. check the pressure using a small dial gauge (tire gauge works) ..

Listen for leaks, hissing sounds. If all is well it will be quiet.. Add 5 more psi, going all the way up to 20 psi (some go higher if they are running higher boost)

Listen for leaks..

when done, bleed out air thru fitting and remove caps and reconnect hoses.