losing boost..

SharkDiver

Member
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Speed3
So heres the story.I took my car to mazda for the motor mount recall and my car was fine.I got the car back 9 days later..Thats right 9 days...In the mean time my TXS race pipe came in.So I get my car back and I took it right home and installed the race pipe.When I took it out for a drive my boost would only go to about 15psi,It use to spike to 18 then hold 15psi.Now 4 days later my car will only go to about 13psi with no spiking to 15psi at all.I do not want to take it back to the dealer again unless I have too.I checked the vac. lines by the blow off valve and also put zip ties on the hose for the boost gauge but that is the only vac lines I looked at.I dont know what other ones to check out.
Could this for some reason be caused by the race pipe?What other vac lines should I check?
Any ideas on what I should do or check.This really sucks because my car has no balls any more and my dealer isnt the greatest at finding problems that are not coding.

Shark
 
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Also I did check the hoses that connect to the IC and they seem fine.I didnt check for cracks tho if thats possible.

Update:
Well Im at work so i dont have any tools but I did go and have a look at the car.when checking for a boost leak I only need to worry about the hoses after the turbo and not the intake and pcv lines,Is that right?And Im guessing I should check the turbo gaskets even tho Im not sure how I would do that.

Thanks
 
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dude that sucks with that pipe and no tune you should be spikeing even higher not less....., hope you figure iit out did you have to mess with anything that connected to the turbo? maybe you loosend something and are getting a leak
 
I didnt mess with anything that goes to the turbo,But the dealer may have.Im going to make a boost leak tester and see what happens.
 
man your situation sucks cuase from your story its probaly something the dealer mess with but if you take it in they go ohhh you installed this......that reeeeeeeeelly sucks!!!!!!!!!!!!!!!!! hope its a simple no truoble procees bro
 
you prob just have a boost leak you havent found yet. good luck. i doubt your dealer did anything to make the boost go lower then lower again but id wouldnt rule it out completely those *****. i changed my oil and tranny fluid today and my oil filter had the original gaskets on it plus the filter wasnt swapped so i got changed 45 for half an oil change last time which prob costs like....15 bucks....booooo. but like i said....prob a boost leak somewhere stupid.
 
correction i changed ur oil and tranny fluid Mr Webb... in any case i dont trust the dealership and im not going to put the blame on them but i could be.. im suppose to have the TSB done on my clutch, full replacement but i dont trust them so it may not happen.
 
Did you take off your battery cable to reset the ecu after the mods. The car has to relearn how things are going to be. If its still screwey after an ecu reset I would put the cat back on being that its easy as heck. Then if its still screwed up find another dealer to help you out.
 
Did you take off your battery cable to reset the ecu after the mods. The car has to relearn how things are going to be. If its still screwey after an ecu reset I would put the cat back on being that its easy as heck. Then if its still screwed up find another dealer to help you out.

Yes I did reset the ecu 2 times.Im going to check for a boost leak and then if there isnt any Im going to have to switch it all back and take it in again...This suxs......
 
Yes I did reset the ecu 2 times.Im going to check for a boost leak and then if there isnt any Im going to have to switch it all back and take it in again...This suxs......

You keep saying check for boost leaks. How? you can't plug off the valves into the engine. You can take stuff apart and seal ends but that will not tell you much more than that the intercooler is tight to the air filter.
 
You can take the hose off of the throttle body and put a end cap on it then I can take the hose off the turbo and put the boost tester on there.From what Ive read it should work good enough to hear any leaks.
 
You can take the hose off of the throttle body and put a end cap on it then I can take the hose off the turbo and put the boost tester on there.From what Ive read it should work good enough to hear any leaks.

OK but your not testing any items on the intake manifold and you dont know if the control solenoid is normally open or closed.
 
I never done this before and Im only going by what Ive read..Please tell me how I can do it the right way.

Ok well diag'ing a car is best done in person. From your sig you have a test pipe, an intake, and a boost gauge. You say it feels slow as s*** so I'll assume your boost gauge is correct and you don't have full boost. Do you have vacuume at idle? Do a few full boost full throttle runs on the highway maybe you can trip a check engine light. Basically try to do full pulls from 2k to redline in 3rd and 4th. That will at least give you a direction to look in. Go to autozone and ask them to check for pending codes, but don't buy anything they try to sell you. I didn't catch if you had a bov before I started typing this. If you have one put on your stocker and recheck. If you wanted to check for boost leaks I will assume that you have a hand pump mighty vac that can generate low pressures. Use that to test the bov. If nothing happens then the test pipe is 4 bolts and most likely you couldn't screw up a boost source from under the car. I say remove that and recheck. From there on the dealer saw the intake so just bring it back. The car has a warranty for a reason, so you don't have to do this s***. Good luck make sure to post it up here if you figure it out (or need more help)
 
Ok well diag'ing a car is best done in person. From your sig you have a test pipe, an intake, and a boost gauge. You say it feels slow as s*** so I'll assume your boost gauge is correct and you don't have full boost. Do you have vacuume at idle? Do a few full boost full throttle runs on the highway maybe you can trip a check engine light. Basically try to do full pulls from 2k to redline in 3rd and 4th. That will at least give you a direction to look in. Go to autozone and ask them to check for pending codes, but don't buy anything they try to sell you. I didn't catch if you had a bov before I started typing this. If you have one put on your stocker and recheck. If you wanted to check for boost leaks I will assume that you have a hand pump mighty vac that can generate low pressures. Use that to test the bov. If nothing happens then the test pipe is 4 bolts and most likely you couldn't screw up a boost source from under the car. I say remove that and recheck. From there on the dealer saw the intake so just bring it back. The car has a warranty for a reason, so you don't have to do this s***. Good luck make sure to post it up here if you figure it out (or need more help)

I do have about 20-21 InHg vac at idle so that seems to be right.Ive done boost runs till redline and never had a cel.I still have the stock BOV.How can I check to see if the BOV is holding boost?Ive heard about leaks in the stock BOV on the 6 forums.
 
Update:Well I went thru and zip tied all those small vac lines and my boost gauge lines.I also found that the screw clamps on the IC and turbo hoses were pretty loose,1 of them was not even tight at all.Now Im back to spiking to 18psi and a steady 15.....(breakn)

Thanks for the replys and help guys and girls...Shark
 
Glad you found your problem!

I've never experienced boost leaks before but from what I understand is that if you are leaking, the car will run extremely rich causing it to stutter and backfire. Since metered air is leaking, the ecu is matching the proper fuel even though not all the air is making its way to the chamber. I guess its just not as bad if its a small enough leak.

In anycase, I'm sure it feels nice to have your car back to normal again. :)
 
Update:Well I went thru and zip tied all those small vac lines and my boost gauge lines.I also found that the screw clamps on the IC and turbo hoses were pretty loose,1 of them was not even tight at all.Now Im back to spiking to 18psi and a steady 15.....(breakn)

Thanks for the replys and help guys and girls...Shark


I typed below before I saw you found the problem, left it incase it might happen to someone else... Good you fixed it!



I didnt read through all the post but I had a similar problem and what happen was when my engine dropped it pinched my vac line leaving a little hole, so my gauge was reading incorrectly. The dealer didnt notice it or seemed anything else when my mount broke, the only reason I knew is because I was a few psi off, I would really go over the vac lines or anywhere it may have gotten pinched and look for a tiny hole. Hope this helps..
 

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