Rough idle on my 97 Olds Achieva 2.4 (Solved)
Rogueknight
seen several post on different boards but noone really showing the
solution so I am posting this to let everyone know my expierience and
hopefully help you out.
Ok I bought the car with a rough idle on it and only getting 20 mpg.
It seemed to run fine soon as you gave it gas but at idle it would
shake and click a bit. As I do with any car I buy I consider no
maintenance has ever been done. So I change the standard:
Transmission fluid/ filter
Oil/ filter
Spark plugs (originally put in Bosh Platnum plus 4)
Air filter
Fuel Filter (I REALLY hate that quick disconnect)
wiper blades (love Bosh microedge)
flushed coolant
Rear shocks Monroe sensatrac
Anyway after all that I still had a rough idle.
So now I start digging into this problem (no check engine light but
can pull code for random missfire p0300, O2 sensor bank 2, running
rich, running lean)
I change:
Coils
spark plug isulators
Both Oxygen sensors
cleaned idle air control valve
throw some gas additive in
I then ask a couple mechanics about the car trying to figure out what
best to check next.
I then take it to the Chevy dealership and get the ignition recall
done. They didn’t give me too much confidence and took 2 months to
get part.
Now I take the car to the Pontiac dealership (no more olds
dealerships) and I submit the car to them cause they talked a good
game about how precise thier diagnostics are and how they could tell
me for sure what was wrong so I wouldn’t just be part swapping.
Boy that was an issue. I have to give them props though cause they
did find the coolant smell was from this plastic piece that goes in
the engine and has like 4 things that connect to it. well it was
deteriorated on the inside and it has such a minor leak you never
found the coolant just smelled it all the time. So they changed that
part out. they Also found the coil housing has a small crack in it
and told me I needed to change it. Well I didn’t see how a crack on
the side of the plastic would do it but ok I changed it ($85 part,
wasn’t paying them 130 to put it on). They also told me Bosh plugs
don’t work well in GM cars and that I also needed to put AC Delco
Platnums in. But then they said everything else checked out good and
all electronics check good. Didn’t get them from there O’Reillys was
cheaper for the same part, they have seen a lot of me lately lol.
Anyway at this point changed:
Coolant housing
Coil housing
put in the AC Delco Platnum plugs
Car still idles rough and still only 20 mpg.
durring this weekend I charge the AC system up and then put
Thermoquiet pads on the front brakes. I also got the Fuel injectors
cleaned.
Now on my way to college that Monday morning a new bug pops up, the
car has a hickup. at random while driving the RPMs drop about 3-500
just momentarily and then drives fine. There was no rhyme nor reason
so the hickup, you could sometimes drive 10 miles without a hickup or
you could have 5 in two miles. Then it had a big hickup and the
Cruise went off and check engine light came on and stayed on. Went
and had the codes read and it said crankshaft sensor. Drove the car
back to the city I live in and it was still a very intermittent
problem so I drive straight to the dealership. Parts guy didn’t think
it was a crank sensor cause then it wouldn’t have run if it was. But
they didn’t know off the top of thier head what it was. So after work
I get a crank sensor at Autozone and come home and go to put it in
(really two ways to change that thing either remove the intake
manifold which I didn’t wanna do, or jack the car up, go underneath
and remove the oil filter and then the crank sensor is just above the
oil filter) that works if you can work by feel cause you won’t be
able to see squat.
Anyway, started the car, rough idle and after the car warmed up sure
enough there was the hickup. The hickup kept throwing a code for a
crank sensor. I was also now getting a code for a camshaft sensor. I
changed that out and no good still throws code for crankshaft
sensor.The wierd thing about the hickup it seemed to only happen after
the engine warmed up and usually when going uphill or when a load was
on. So I swapped out the EGR valve, no help. So back to Pontiac I
go.
Pontiac has my car all day and when I came to get my car they said
they were stumped and had no clue what was going on, it would do the
same thing for them if they took it for a drive but would never do it
at idle or sitting still. But the dealership said they give up they
don’t know whats wrong with the car but they said it could be the
autozone part, so I pick up a crankshaft sensor from the dealership
and go home to put it in.
To my surprise when I got home my factory service manuals I ordered
had come in that day. I changed out the Crankshaft sensor again and
then started her up and still rough idle and hickup not even 3 miles
down the road. I read up in the factory service manual and there is a
wierd learning proceedure for the computer anytime you move the
crankshaft sensor even if you remove it and put it right back. The
dealership didn’t know about this but I took my factory manuals in and
showed the the proceedure (you have to have a tech II computer to do
this proceedure) and let them use my manuals to get it done (another
$65).
It didn’t help.
So now I am checking wiring one wire at a time, I am ohming out every
part I can find. I try swapping out Idle Air control valves and
ignition coils and bought a vacuum tester and test all the vacuum
readings. Everything checks good but still idles rough and has a
hickup. So then I dig a little deeper, I pull the intake manifold and
clean it out, clean up the intake valves, and clean out the throttle
body.
No good.
So now I turn to Vacuum leaks. I gut out all those hard tubing vacuum
lines (I hate those things, they get hot and deteriorate SO fast). In
the process of doing this thanks to the factory service manual I
discover another problem. There is a check valve placed right in
front of the vacuum modulator which shoulnd’t be there. So that gets
chucked and all vacuum lines are replaced excpt the AC heater control
vac line that goes into that big wire bundle but I had vacuum inside
by the PCM.
Started the car up no go it was still rough idle and hickup if I drive
anywhere that was getting worse it seemed.
Getting extremely frustrated I then turn to the transmission for the
hickup problem as it seemed more vital.
Took the car to Ammco, and that was a joke. They said yeah the
transmission needed to be rebuilt but they couldn’t guarantee it would
fix it cause it keeps throwing crankshaft sensor code when it hickups.
Well I don’t think they looked at it more than 5 min even though they
kept it all day. I took it back and I put some brake fluid in the
transmission (not much just a little) cause that will clean up your
transmission. Still no help. So at this point I am still looking at
the tranny and I pull the fluid out to make sure it isn’t being
contaminated nor have a coolant leak into it.
Extremely frustrated it’s nowMonday and I go and have the muffler and
Catalytic converter changed (they said this was clogged and broken
internally) in case it might have been back pressure ( I couldn’t get
the ehaust manifold bolts off at the pipes to just try that). Now new
Exhaust and still rough idle and intermittent hickup.
Ok now I am getting mad and down to 13 MPG lol.
So I take it to a couple shops and they refuse to take it after they
hear the history of this problem. I found one that would take it but
they wanted to do thier own diagnistics so I set up to drop the car
off Tues morning. Well I never made it.
Monday evening at 10 pm I went to move the car and when I started her
she made this lound metal sound that I didn’t like. So that was it
the car wasn’t moving til fixed. I tore into the engine yet again.
At 6 AM (yes worked all night long) I finally found it.
:!: The timing chain tentioner was dead and the chain had jumped a
tooth on the exhaust cam. :!:
Not only that but someone had installed the wrong tentioner to begin
with and though the Haynes book (which showed this tentioner as the
old one on 91 and earlier models) said it was spring loaded. There
wasn’t a spring at all. So I got the correct tentioner from autozone
and installed it. I put the car back together after moving that
exhaust cam back a tooth and she purrs like a kitten.
Took her for a drive, no hickup, sitting at idle she is smooth as a
babys butt. So after all that, thats what it was, timing chain
tentioner and a cam off a tooth. A couple other mechanics I told
seemed surprised cause the car only had 72000 miles on it when I got
it (just under 74000 now), but after the two month fiasco I am glad it
is finally over. Good luck and hope this helps more people out.
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autowarrior
> the chain had jumped a tooth on the exhaust
> begin with and though the Haynes book (which showed this
> tentioner as the old one on 91 and earlier models) said it was
> spring loaded. There wasn't a spring at all. So I got the
> correct tentioner from autozone and installed it. I put the
> car back together after moving that exhaust cam back a tooth
> and she purrs like a kitten.
> Took her for a drive, no hickup, sitting at idle she is smooth
> as a babys butt. So after all that, thats what it was, timing
> chain tentioner and a cam off a tooth. A couple other
> mechanics I told seemed surprised cause the car only had 72000
> miles on it when I got it (just under 74000 now), but after
> the two month fiasco I am glad it is finally over. Good luck
> and hope this helps more people out.
Great read, good info! YOU THE MAN!
gfulton
"autowarrior" <DoNot...@AutoForumz.com> wrote in message
news:1_642551_bfb8cad7dac...@autoforumz.com...
>
> Great read, good info! YOU THE MAN!
Outstanding post, bud. Thanks for sharing it. I sure admire your
persistence and determination.
Garrett Fulton
oldsgirl
> the chain had jumped a tooth on the exhaust
> begin with and though the Haynes book (which showed this
> tentioner as the old one on 91 and earlier models) said it was
> spring loaded. There wasn't a spring at all. So I got the
> correct tentioner from autozone and installed it. I put the
> car back together after moving that exhaust cam back a tooth
> and she purrs like a kitten.
> Took her for a drive, no hickup, sitting at idle she is smooth
> as a babys butt. So after all that, thats what it was, timing
> chain tentioner and a cam off a tooth. A couple other
> mechanics I told seemed surprised cause the car only had 72000
> miles on it when I got it (just under 74000 now), but after
> the two month fiasco I am glad it is finally over. Good luck
> and hope this helps more people out.
ok i am having the same problem(same car 1997 acheiva) and i have my
brother (a mechanic)is fixing the car but we have run into a snag and
wonder if you know how to fix. the timing chain-tensioner-plunger is
stuck in and can’t get it out. so it knocks when you start it. hope i
explained it so you understand. how do i get it to move or is this
something i need to replace also. thanks for any help
Rogueknight
> ok i am having the same problem(same car 1997 acheiva) and i
> have my brother (a mechanic)is fixing the car but we have run
> into a snag and wonder if you know how to fix. the timing
> chain-tensioner-plunger is stuck in and can't get it out. so
> it knocks when you start it. hope i explained it so you
> understand. how do i get it to move or is this something i
> need to replace also. thanks for any help
you don’t remove the plunger you replace the tentioner assymbly.
Autozone has them cheap (less than $50).
oldsgirl
> you don't remove the plunger you replace the tentioner
> if you have any questions. Rogue...@cox.net
just got this sorry i appreciate your help will call my brother
tomorrow he lives 60 miles from me and no internet.