nillviod

Well this is just great... The engine has about 3500 miles on it and I think it might be blown. I'm not really sure what to expect from a blown motor - so I'll explain the symptomes.


I didn't want to drive the car today because I haven't had a good chance to look through it after it was leaking something under the engine.. However - my mom forced me to drive it to school because she said she couldn't give me a ride and wouldn't let me be late by taking the ride-on bus.

Anyways, I'm driving a long and wait for it to get adequately warmed up before I give it any boost at all. Going about 30 in 2nd I give the car about half throttle and noticed that there was absolutely no torque... The engine made a really mild hissing sort of sound that wasn't the normal deep hum that comes from my engine when I spool up the RPMs. The sound was barely audible but it was there... The sound immediately went away as something seemed to "catch" in the engine. Anyways, I drove around for a little and even gave it full boost in 2nd and got almost no torque. The boost was fine, never went past 12 (which I hit under 2/3 throttle). Blown motor? The prior owner installed the new engine and I'm at school so I can't check the warranty, if there is one. He bought it from M____ Mazda or something... its a reman. No mods have been installed since the installation of the engine, and the only thing done to the car has been two oil changes. Will I get any type of warranty on this thing or what?

Anyways, I have absolutely no idea what to do. I'm at school so I can't look at the car's records or anything... I'm really worried and just feel like **** ...

The car was feeling fine until I started it up today...

nillviod

I've only driven the car in the way it's supposed to be driven... The proper break in procedures were followed and the engine check up at 500 miles said everything was okay.

paw140

It doesn't sound like a blown engine at all. What is your vacuum at idle?

nillviod

-20psi - I have a DP/intake/catback

nillviod

sometimes it's around -22, goes to about -25-7 when I downshift... Boost is fine. At neutral under WOT i peak to 4-5psi at around 6-6.5k, and though I get a pattern of about 12-8-12, its due mostly to my mods and the cold weather.

911GT2

Well it definitely doesn't sound like a blown engine. More than likely its some other issue, though I can't say what.

My first suggestion would be to get some sort of boost controller to keep boost down to 10psi, cus 12 just isn't safe on the stock ECU.

Then I'd say start checking the normal stuff, plugs, wires, vacuum hoses, check exhaust for clogged parts, fuel filter, etc.

nillviod

Alright... Well as long as it isn't a blown motor I'm happy hehe... Also I"m not sure if this is normal, but when I start the car up the fuel pressure deal reads 120... instead of like the 30-60 it goes down to when I'm idle after the car is warmed up.

felix_is_alive

that doesnt sound like blown engine at all
whats youre idle
check for any loose vacuum hoses under the intake manifold

nillviod

Is it possible that my engine might be damaged? I guess I'd have to get the compression checked.. Might as well go do that today.

nillviod

also the car idles at 1200, almost always... sometimes when its really warmed up it'll drop down to like 8.5-9k after sitting at 1200 for a few mins

nillviod

I'm actually excited to go home pop open the hood and find my damn problem... as long as its not a blown motor

nillviod

Okay, I know this is a dumb question but after searching for a while I need an answer... Where can I get my engine compression checked? Like what kind of place will do it and does anyone know the approximate cost? Finally - what numbers should I see on the compression test. I plan on going to get this done as soon as I find an answer ^_^ - thanks

dubulup

$65 for a test...don't think you need one. Sounds like you have a boost leak somewhere. But I can't see how you can have a transistion if you're leaking enough boost to feel no power. Check your lower and upper IC hoses for splits. They are hard to see, since they have those rubber rings around them, so squeeze the hoses. Check for cracks in the plastic cross over tube and the rubber couplers. On a healthy engine set-up seq. you should be able to build 4psi of boost in neutral while reving. Rev the engine with the hood open from the throttle body and listen for that "hissing" noise...most likely leaking boosted air.

hope some of this helps...don't waste money on a compression test. Buy a new fuel filter with that money and get fuel in your eyes and the satisfaction of tackling that beast like the rest of us.

dubulup

and adjust your idle air bleed off screw in the front of the TB. Philips screw pointing straight up with a nut on the bottom. loosen the nut and back out the screw until the idle is around 725-775 with no load (A/C, lights, etc)

RollnDrty

Although it doesnt appear to be the case this time, it is possible to blow a motor at 12psi with those mods. Especially in cold weather (Maryland). Get a boost controller.

nillviod

The thing is Dubulup i get 4-5psi in neutral when revving... so how could it be a boost leak if I get perfect boost in all gears?

dubulup

Clogged cat???

nillviod

also, when i started the car to drive home from school it held at about 3500RPMS at -10 PSI!! Freaked me out i had to mush the pedal a little bit to get the rpms to go down to my normal idle... like i really dont think this is a boost problem because im gettin perfect boost. .. ill go check the hoses but any other ideas please? im really strugglin here :\

dubulup

when not in boost its called vacuum (sp)

vac is measured in in-hg not psi.

Thats called the accelerated warm up system...it happens on a cold start, hahaha! That's normal, just start the car with the shifter in 1st gear...but take out of gear before releasing the clutch.

You got a lot to learn kiddo keep reading.

nillviod

yeah I know i do :-\

been trying to learn as much as I can ..

again - the thing is - this isn't normal for me - my car hasn't done that before to that extreme of a measure, and I've started it on way colder days. The engine had been driven on just 2 hours before i started i up also!!

how would I go about checking for an exhaust clog?

paw140

If you are pulling 20 to 25 in Hg (not -psi) of vacuum during idle, you don't have blown motor. Also, you should not be running 12 psi on a stock ECU unless you do want to blow your motor.

I don't see how it could be boost leak if you are getting 12 psi. I really don't know what to suggest, though. So, it runs perfectly fine at idle, and boosts perfectly, but doesn't have any power? Sounds like either you are either lacking spark or fuel.

By the way, your cold start going to 3000 rpm is normal. I'm surprised you haven't encountered it before.

nillviod

thats a picture of my engine :p although I wish I could just spend 30 hours right now and learn about all the parts you guys are talking about - I cant...

can someone tell me where exactly on this picture I'd be wanting to check for leaks? or in what vicinity at least hehe

dubulup

Mine does the same...only some times it will go striaght to 3k. But I've by-passed the coolant in the TB (which tells the AWS to activate or not) so, mine always shoots to 3k and then settles in a few seconds, I think it's kind-of cool...but whatever... like I said it only happens in Neutral.

checking for a clogged cat...have you friend hold his hand infront of the exhaust tip, slight reving should blow air out. That's the only thing I can think of...unless you unbolt it and take it somewhere. If it's clogged a hi flow cat will be cheaper to replace than the stocker...just an idea.

nillviod

i doubt the fuel filter has been changed in a LOOOOONG time... is this an easy thing for a first install - or would you recommend I take it somewhere to get it done? im willing to spend as much time as needed to get it right - i dont have to drive to school/job/etc.. so if the process takes a week, i wont drive it for a week

dubulup

don't think you have leaks...

do you know where the IC is? Fawk it...look at all the larger diameter black hoses.

The TB is the part that connects to the silver pipe (elbow) on the right. That's where you can adjust your high idle...you'll see the screw if you look where I said too earlier...

another thing you can do is spend $100 and get an aluminum AST...the little tank that is bolted to the IC...it has a pressure cap on it.