Lost w/ (assumed) vacuum leak

[Bc-386]

I dont know what to do next. I have owned the car for a month and it ran great for the first week. Ever since then i have been chasing down a supposed vacuum leak. The car runs/idles best when it is cold and warming up. Once it is warm, it becomes very hard to idle and my vacuum pressure is between 0 and 5hg. When it is warming up i can tap the gas and get the vacuum pressure to stick between 10-12hg. Once the car is warm, ill test drive it, and it runs good until i put it in neutral to brake. Then it dies.... I have researched sooo much online looking for an answer but i feel like i am running out of ideas and patience, lol.

What i have done so far; replaced EGR, replaced wastegate, cleaned iac valve, replaced pcv valve, tightened all couplers on the piping, checked all of the vacuum lines (i think)...

I have a CEL on, but i dont feel very comfortable driving it to autozone to see what the codes are because the car dies almost every time i come to a stop.


ANY IDEAS or recommendations would be GREATLY appreciated.

 

[duren03msp]

drive to autozone with a different car, give them your drivers license and they let you take the scanner home with you. check codes.

or seafoam through the brake booster to intake mani line and watch for smoke come from the leak.

 

[hornsfan10609]

It has to be a huge vacuum leak, either from the intake or exhaust mani/gaskets or possibly the charge piping.

 

[Bc-386]

I will check on that. Thank you for the responses. I was worried it was a head gasket. I just noticed there was some white residue on the oil cap when I replaced the valve cover gasket.

I was thinking about the code reader from harbor freight... Do they work well enough?

 

[duren03msp]

not great quality but should work. just may not be very specific as to the codes that pop up. white residue on inside of oil cap is usually just gunk buildup from moisture or sometimes a bad PCV valve. as long as their is no oil in the coolant or coolant in the oil your head gasket is more than likely fine. you could run a simple compression test to be sure. if the comp results are around 7 or more psi off from any of the other cylinders then try a wet comp test to check rings. if that helps the results then you know your compression ring is on its way out, if the differences between cylinders stays the same after wet test then do a leakdown test and that will tell you if and where anything is bad. eg : head gasket. etc...

 

[thuzil]

Classic Vac leak symptoms. Easy test is to remove some intake piping as close to the air filter as possible. Get a coupler of some sort depending on your intake set up and feed an air compressor fitting in. I have round intake piping (aftermarket) so I just use a coupler with an ABS pipe cap with a hole drilled in it and an air compressor fitting. Once this is on air tight, just use the compressor to charge your whole system to around 5 psi (if you go too high you will start to blow out seals). Wait until your compressor shuts off and listen for the hissing of leaks. If everything is sealed up correctly there should be none. You may get some small hisses around the throttle body but these should all be minor. To nail it down even more, get some soapy water and spray it on the areas where you think the leaks are. The nice think about this method is that you can tighten couplers on the fly and listen for the hissing to stop.

 

[Bc-386]

Would no air filter cause this? I bought the car with out one mounted. I have bought an air filter for it but haven't installed it because I didn't think it would have an affect on the solution of the problem.

 

[duren03msp]

I wouldn't think that would cause your problems. even though you SHOULD always have one installed.

 

[hornsfan10609]

Don't drive the car without an air filter.

 

[Bc-386]

ok, i finally had time to work on the car. I pulled the intake manifold. I thought i found my problem with a vacuum tube underneath the manifold (dry rotted hose). I replaced the hose, im gasket, plenum gasket, and the tb mounting gasket. Installed the air filter. Guess what, nothing changed... Car still runs like crap, aka monster vacuum leak. I am lucky to pull 5hg of vacuum pressure.

I got the balls up to drive the car to autozone. Error code, P0031. Which o2 sensor is this code referring to? On the way home, the car cut out and completely quit boosting. I was not driving hard by any means. After it cut out, i tried to make the car boost and it wont even push the boost gauge into the positive. I looked under the hood to find a couple blew off the charge piping. I reattached it, but still unable to create positive boost.

Any thoughts?

 

[hornsfan10609]

Check all the rest of the charge piping and the exhaust manifold hardware

 

[Bc-386]

Replaced the o2 sensor. I have checked all the couplers. And they seem tight. There were a couple bolts loose on the exhaust manifold. I loosened all of them and re-torqued them. I still am unable to create boost and there is a minimal amount of vacuum pressure.

 

[hornsfan10609]

Is there oil in the hot pipe coming off the turbo? The turbo seals may be shot, a vac/boost leak this large should be easy to spot.

 

[Bc-386]

You would think it would be. But I feel like I have checked everything. Sprayed a couple cans worth of carb cleaning (slowly of course). Bought and rigged up a fog machine.

Waiting on the two truck now. Taking her to the shop. Damn it.... I haven't even driven the car 40 miles since I bought it in mid November.

 

[hornsfan10609]

It takes someone that knows these cars well to look them over and find any issues and ensure they are getting a clean car before you buy.

 

[Bc-386]

Replaced the blow off valve at the shop. And re routed some lines. They didn't know much about mazdas. The car runs better. But still not right. I question what he said, is "the excess air coming out the bov supposed to be recirculated back Intake pipe before the turbo". He said it sounded like my car has cams in it. Because it has cams it has low amount of vacuum pressure. In the end I got to drive the car home. It idles super low still especially after tapping the throttle.

I stopped by autozone and pulled these error codes.

P0102
P0103
P0106
P0171
Bad battery

I have replaced the battery. Now minimal difference, but I still have the cel

 

[hornsfan10609]

Is it a stock bypass valve or aftermarket blow off valve? You can setup and aftermarket BOV to vent the air to atmosphere or recirculate it back into the intake, venting requires relocating the MAF sensor after the BOV.
Have you checked the WGA by blowing into the vac line? Primary O2 sensor can cause P0171 but it is usually a vac leak or exhaust leak before the O2. P0102 and P0103 are MAF codes, does the car have a piggyback ECU? Check the harness at the ECU to see if it has been hacked up, otherwise the MAF may be bad. P0106 is MAP sensor but it may be throwing that code due other issues.

You likely have a vac leak or other problem that is causing the other codes so consider that before you throw new parts at it.

Pull the valve cover and see what the cams are marked as.

 

[Bc-386]

I had a turboXS blow off valve. We pulled it out bc it wasn't opening. I was having a lot of turbo surge if you hit the throttle. My Maf has been relocated. It is just before the throttle body after the bov. I have already replaced the wastegate actuator, egr valve, and cleaned the iac valve. The car has stock tuning to my knowledge.

I drove the car yesterday it ran Ok ish. Today I started it up and it sounded like crap. Like it is running on two cylinders or something. I took it to orielly's, the car was wicked slow but I had consistent vac pressure and the car still created boost (not as much as normal). The car idled better and more consistent than it has in a long time (kinda wierd)The guy said I only had one code p0171.

I pulled the spark plugs and the Maf sensor when I got home. I posted a picture of the plugs below, and they are in order as if they were in the car. The Maf sensor was dirty. Question, does the Maf on these cars have two wires inside the Maf sensor housing? I only see one...

 

[hornsfan10609]

The #2 plugs looks clean like it hasn't been firing. See if the car still has stock cams or not. The BOV requires vacuum to open, if the motor is leaking vacuum like yours is the BOV won't open. You may be replacing unnecessary parts instead of fixing the actual problem.

 

[Bc-386]

Cam shaft says

FSH9
IN