Cowzzz

Ok so a couple of days ago i was just driving normal and i went to pass some people and did so. the next stop light i got too my car was acting real real weird. it had a stedy idle but yet not stedy. it sounds like the exhaust is coming out in clumps like brap brap brap brap. and befour it was just a smoth stedy idle. but its still ideling at 850. i also noticed my vacum went to about -8. so i got home and i was expecting just a blown off vacum hose, nope nothing.

So i got it up on the hoist today still hoping it was a lose vacum line and i couldnt see anything. i started the car and stood by the turbo and i could hear what sounds like an exhaust leak. it was coming from the exhaust side, and my engine was shaking kind of bad but not too bad. befour there was no shake at all.

I also pulled the plugs to check them. all of them were black except one. it was leading 1, it was kind of brown/tan'ish. weird color and ive never seen it befour.

So im totaly lost on what to do. i know none of this makes any sense but if anyone has any ideas on what could be wrong it would be great.

Mods: 88 turbo II
Full exhaust (gutted main cat)
intake
FCD
Gauges
no ac,acv,air pump,egr
act clutch
and some others......

boosted1205

iTrader: (9)

If you still have the AFM to turbo duct, check that. Finding a vacuum leak is troublesome. Use a carb cleaner and spray around the turbo duct and vacuum hoses. If the idle changes, that's where it is. By the look of your mods, I hope you have either upgraded the fuel pump or installed larger injectors. An FCD with full exhaust and stock fuel system will cause lean conditions. I've been there and done that. Do you know how to do a compression check? Inspecting the plugs right after says very little. Let's hope the numbers are good.

Cowzzz

ya i forgot to add that i have a walbro 255 and holding at 10 psi. but what throws me off is that sound of an exhaust leak by the turbo and egr block of plate, i have a gasket around it. also the movement of my engine is making me wonder too.

Cowzzz

Its shaking real bad now. is there any like seals or anything in the turbo that would break and cause a leak and lose of vacum??? or any vacum lines that you know of that would make my car act like this??

apreludem

if the engine is shaking does this mean he has a broken motor mount?

Bob_The_Normal

Haha yeah I'd check the motor mounts man... get under there while it's cold and take a look at the mounts on each side of the engine.

Specifically check the mount on the header side, (passenger side) because that would let the engine dip enough to make stuff leak too.

--Gary

boosted1205

iTrader: (9)

A broken motor mount won't shake the engine that bad. It's noticable when you rev it . Do a compression check which will tell you the condition of the motor.
A large vacuum leak will cause what looks like a blown motor. So, do the above I mentioned. If your boost/vacuum gauge bounces all over the place that would be a bad indication.

Cowzzz

I have mazda speed harden motor mounts and they are not broken. thats what im wondering what the hell the shaking could be becuase it usually never shakes.

SureShot

Like boosted1205 said, Is it idle vacuum steady or is it bouncing with RPMs?

If so, it's time to do the compression test.

SureShot

D/P.

Cowzzz

when i get off the gas my car like wants to die. it will drop to about 200 then shot up to about 800. where can i get a compresson tester and how does it work??? and what kind of numbers should i be seeing for a good motor and whats concidered blown?

rs_1101

sounds vacuumy.. thats why it almost stalls out. if it was a blown motor, i dont think it would recover from 200rpm

boosted1205

iTrader: (9)

It's kinda late here (2am) to post a how to fora compression check but you could search the forum.
If you want , you could pull the plugs and EGI fuse and have someone crank the engine. You should hear even pulses (ch-ch-ch) without a break in rhythm.
Do that for both housings in the meantime.

Cowzzz

Ok i just pulled my intake off and was wiggling the turbo wheel around and wow. there is movement. when i was moving it i could hear the exhaust side hit the housing. does this mean the turbo is blown. btw i just turned 100k and turbo is stock.

VietFC

wow... lots of play... sounds liek it's in need of a rebuild.

Cowzzz

how much is a re-build and where can i get it done at. is there ways to make it beter when it gets re-built?

igottafc

iTrader: (6)

try some local diesel service companies if there are any, alot of them rebuild their own turbos and can do yours as well. I got a quote from one in my area for $70.

VietFC

look for any place that works on semi's... they are like masters at doing turbos.

boosted1205

iTrader: (9)

Thats' very odd and a blown turbo would not cause the motor to idle that bad. You said it idled rough at idle right? If the turbo has THAT much play, you would hear the turbine or compressor wheel scraping against the housing.
I'd say you either have a large crack in your vacuum hose somewhere or you lost some compression in one of the housing.
If your turbo has THAT much play check if the compressor nut didn't back out. When the bearings wear out, there's maybe 1-2mm play.
Did you pull the plugs and listen for the sound?

Cowzzz

its not that its a bad idle, it will stay strong at about 900. its just its real lumpy. befour my exhaust note was smoth. now it seems like it is coming out in clumps like blap blap blap blap and its causing the engine to shake a little. i hear exhaust coming from around the turbo aera so i dunno if it is just a seal or accually blow. i stuck my head by the intake one night and i could hear what i thought sounded like scraping. and today i took the intake off and wiggled the wheel around and i felt scraping and could hear it. so i dunno whats really wrong, im going to have to wait to get it off and really see.