Primitive Archer
Main Discussion Area => Around the Campfire => Topic started by: NTD on June 16, 2010, 12:15:49 am
-
I have a 1988 Oldsmobile Delta 88 with a 3.8L V6. I bought the car only a month ago, it ran fine then but has developed a couple problems. At idle it makes a horrible rattling noise(sounds like a diesel :o) but the noise goes away if you give it even just a little throttle. Also sometimes when you come to a stop usually an abrupt stop it will stall. It does not stall every time but in a 5 mile trip might stall twice. It does not sputter before it stalls either, just dies.... It starts right back up and runs fine, except for the diesel like rattle at idle. The Harmonic Balancer has been replaced and I just put in a new Idle Air Control Valve. Anyone have any ideas what it might be. The car at cruising speeds runs beautifully....
Thanks guys for any help.
-
Nate...have you got an Autozone near You? If so take it in and let them hook up to the Computer Port...and check for Codes first and see what that may tell you... Could be an EGR Valve Problem...these Carbon up and quit working....could be a bad Cam Sensor....Oxygen Sensor...shouldnt be a Map Sensor...they didnt have them in 88....I don't beleive....but the list goes on....sorry I can't be more specific....maybe Tim Seelen will comment...He is more up to date ...I have not trained in over 12 years now...so as for being on top as a Tech....I am not!
-
Could be a stopped up catalytic converter too. :)
-
The rattling sounds like a loose heat shield.
-
nate, its been awhile since i have worked on one of them but i will blow out some cob webs and see what we can figure out.
first off i need a little refresher.a 1988 3.8l that carburated correct or is it thottle body injection or multi-port?
if its carburated then i would say the stalling at abrupt stops is more than likely a failed dashpot(its in a vacuum line)
there is a DATA link diagnostic connector under the dash,take a paper clip,straighten it ou then form a "u" with it.there will be two terminals in the diagnostic connector
that are side by side,when you place the paper clip in them with the key on (if your in the correct ones) it will cause the "check engine" light to start flashing
it will flash once then pause then flash twic then pause a little longer and then flash once them twice again(these are numeric codes) it will flash the code "12" 3 times(this is normal and shows its in diag mode)after the last of the code 12 flashes if there are codes in the system it will flahs them out in the same manner,count them and write them down.it will flash each one 3 times(i believe) then go on to the next code.once they have all flashed it will do code 12 3 times again.let us know what codes there are.
as far as the rattle at idle Patb is right on the money there.that is the first thing i would check is for loose heat shields.
what happens when an exhuast heat shiled gets loose it becomes quite sensitive to "harmonic vibrations".these harmonic vibrations change with engine rpm.
when you bring the car off idle the harmonics change and the vibration stops.hose clamps work quit well on exhaust heats shieilds ;)
if it was a vacuum leak it woiuld be more consistant and would run poorly at idle especially on a cold engine.as far as a plugged cat convertor,more than likely not.if that were the case after the engine warmed up you would loose power and would barely be able to accelerate.its possible an egr vlave,but im gonna say at this time doubtfull.these older ones when they fail they usually fail completly and if ythat were the case.lets say it fails in the stuck open position,then it would die at idle al the time as egr gases would be flowing constantly and at idle that will cause the engine to stall.if it fails closed then you would end up with poor accel at cruising speeds and other problems that you havent described.
as far as blowing into or sucking on the vacuum line goes,well it takes approx 17"-21" of mercury to pull enough vacuum to pull that diaphragm.if you got that kind o fpower i wan meet your sister >:D,beside you realy dont want to be sucking on a rubber vacuum line that has had years worth of carbon and petroleum vapors goinf thru it.not just unhealthy but it leaves some serious black marks on your lips to boot.
let me know whats what. o.k.
we will get this figured out for ya
peace,
tim
-
If you can't figure out the Paper Clip Trick Nate...AutoZone has the Keys for the older Vehicles too...they can plug it in and read the Check Engine Lights for You also...as for an 88...they were Throttle Bodied....the 3.8...or 3800 both were ...and are very good Motors...I have a 91 3.8 in a Grand Prix...and a 3800 in a 2000 Grand Prix...both exceptional Motors...and Josh is Right about the Converter wreaking Havoc too...might want to let someone else rev the Motor slowly and You listen to the Tail Pipe for the Telltale hissing sound...I know when my 91 Chevy Van's stopped up...it ran like shit...and when I beat the Crap out of the Converter with a 4 pound Shop Hammer...it now Purrs like a Kitten again! The only trouble I had with either of mine was a clogged EGR Valve...and I was lucky...I cleaned out all of the Carbon ...and reused it
-
Wow :o Quite the responses guys I appreciate it.
Mike (El D) is correct it is a fuel injected engine. And the reason I bought the car is exactly because of what you said the reputation of the Gm 3.8.
Autozone told me that unless the check engine light is on they won't get any codes. And my check engine light isn't on ::)
There is no black smoke.
Scott D, it idles fine, just rattles...just like a diesel. Also the rattle stays through out all gears including park but it stops the short time between shifting through the gears. I will check the hose to the EGR valve and don't worry Tim, my lips won't touch it...I've got an air compressor :)
And thanks for the advice on the heat shield, I will check that tomorrow.
Thanks again guys. This is my only air conditioned ride and well with 105 this week....AC is nice.....
-
Another possible simple fix that I run into commonly with throttle body injection is that right at the entrance to the throttel body where the butterfly is a slight carbon build up there will cause rough idle and dieing. It can simply bewiped out with a rag with a little brake clean or laquer thinner on the rag. Steve
-
Never ran many 3.8 but have had 25 or 30 4.3's in our fleet and the main trouble we had with all of them was the egr valve got carbon build up under the valve and held it open witch will cause just the kind of problem you are talking about.That would be my first check.When it hangs open it creates a huge vacuum leak. :)
Pappy
-
Like Pappy I never had a 3.8, but I have had a few 2.8 and 4.3. The EGR valve is where I would start also. Then check the heat shield right below the spark plugs.
-
if it rattles like a diesel, sounds like knocking.. that maybe from too low idle. have you tried seeing if the throttle plate is dirty? that can cause a stalling at stop
-
Okay some updates.
I pulled the belt off and the noise went away. Ruled out that it's any part of the engine. Listened around with a screw driver and think it may be the tensioner pulley. But it's still dying and now not always at idle. It seems to die more often on turns though. Maybe a fuel pump/sensor or something????????
-
NTD, when you pulled of the fan belt it may have just made the motor run a tad faster smoothing it out. So you may have not eliminated anything. If it were a pulley it would get louder as you accelerated the engine. Proably something loose like a heatshield as suggested. Have you tried any of the suggestions allready made such as your pcv valve or throttle plate being dirty. Several of us here are proffessional mechanics and see these problems all the time. Steve
-
take the intake tube off the throttle body. if the plate is dirty, it needs to be cleaned. get a shop rag and some carb cleaner. but a brick on the gas pedal, motor off of course ;D. spray just a bit inside the throttle body, and wipe out. repeat that till you get it really clean on the bottom and top of the throttle plate. make sure you get clean were the plate seals inside the throttle body. be sure not to spray too much inside the motor.
-
Had a few of these olds in my family with 3.8 or the 3800, the diesel noise might be coming from a tray under the intake, it's pretty common, and a lot of cars were brought into the scrap yard because of it where I was a wrecker driver............take the intake off, it the tray is loose .. replace it, the noise will be gone.... and check the egr first, then cam sensor, and don't forget to get a pressure test on the catalytic converter.....
-
It's not the heat shield we have ruled that out. As far as the EGR it seems most have concurred that the car runs too well otherwise for that to be the issue. I'd like to do the codes but was Autozone correct that it won't display codes if the Check Engine Light isn't on? I will clean the throttle body plate and let you know how that turns out.
The thing is from what I understand, most of the things that have been mentioned would cause much more consistant stalling, poor performance, idle issues, etc.
-
dirty throttle plate wont cause poor performance, just stalling at idle, because the iac has a hard time controlling the air intake.
-
I still say that it's either the EGR Valve....or a blocked Catalytic Converter...jmo....
-
The EGR will also act worse at idle,not running down the road,if it is hung open it won't idle good or die but other than a lean surge it will run ok on the road usually. :)
Pappy
-
soRRy i been away fo a bit on this
ok now knowing its tbi
im with pappy as to check the egr system next
egr at cruise wont hurt anything
egr at idle will cause stalling
if the egr is just slightly hanging up and can cause a surge
if it hangs open it can cause a stall on decel or at idle
i still say if it was a converrtor issue it would cause a lack of power as the engine warms up and the exhuast gets hot.
thats when the plugging gets noticed.it could cause stalling but at that point the convertor will be glowing cherry red.
and it wont start and run decent untill its cooled off again
stalling on turns,are you just coasting(decelerating)thru the turns?
if so check he egr ;)
starting to sound repetative here ;D
-
EGR VALVE....gee I think I read that in the first post somewhere.... O:)
-
ok ok ok....I will trouble shoot the EGR tomorrow. Thanks guys I really do appreciate it.
-
After you egr if that doesn't do it check your throttle plate, it takes about 5 min and will act exactly as you describe. I do this for a living as do a few others on here. I have fixed several by just wiping it out with a rag. Just a thin film is enough to cause your problem. Steve
-
five pennies its nasty throttle plate.. ;D
-
well i aint gonna say anything that will make me look silly later
after all i aint worked on nothing but FORDS (for the most part) in 15 yrs,thats why i couldnt remember if it was carb or tbi
i still say check the egr next.if you can pull it off and check it with a vacuum gun,that would be best.you can check it on the vehicle but alot of the times its hard to see if the diaphragm is moving its full range on the car.dont just go by "it holds vacuum it must be good".the diaphragm doesnt have to be bad for the egr to be bad ;)this rattle that you isnt the heat shields,can you tell where the noised is coming from?engine area,under chassis,etc?it is possible the valley pan came loose
but as a side note: you said you bought the vehicle becuase of the reputation of the 3.8l engine
now if memory serves me right the tbi 3.8l is not the same engine as the mpi 3800 engine
not saying tht the 3.8l tbi isnt as trustworthy,but the 3800 mpi is the engine that has the great reputation.
if i remember right the 3.8l tbi was just a revamped 260 c.i. carb engine that they revamped and chopped the back two cyl's off of.
at the time they created that engine they need a 6 cyl that would have some performance and fuel economy to be competitive in the
market at that time, and was the predecessor for the infamous 3800 engine.now the 3800 has hade several versions to date each slightly better than
the last.i believe GM is on the third generation of the 3800 now.
i suppose this is enough of my early morning ramblings. I NEED COFFEE ;D
-
it is a 3800. But a 3800 IS a 3.8 liter engine ::) got me confused now.
-
yes 3.8l and a 3800 are both 3.8l engines
however the designation of 38oo was given to new designed engine of that size ans was designed as a multi-port fuel injected engine
like i said the carburated version was a small block v-8 that they quickly enginered with the back 2 cyl's removed to be a v-6 engine.
after running the carb version for a few years GM then designed a whole new v-6 engine that was a true v-6 and not a modified v-8.
this new engine was,like i said,given the designation 0f the "3800".they did this to keep them seperate since they realy were not the same engines.
the true "3800" is probably one of the best designed engines of all time,virtually indestructable.
they like to develop carbon on the valves and in the upper combustion chambers over time.
minor problem,this can seem much worse.can cause a very loud preignition on accel,lack of power not so much stall really
if this is an issue get an "induction service" done.
i did this on an old temp with a v-6 that was so carboned up it couldnt get out of its own way.after the induction service that 3.0l v-6 could sit still and smoke the front tires >:D
anyhoo if ya got the 3800,excellent choice very good decision.
-
Okay thanks Tim. Not confused anymore. ;D It is the "3800" ;D Taking the car over to Frank's place in a few to play with a few of the suggestions here. I'll keep ya posted.
-
Cleaned the throttle plate. And cleaned it very well. And Aero ya owe me those five pennies ;D Cause it didn't fix it. Tried to check the EGR but the hose that goes to it is copper. Not sure how I'm going to get that off and blow air through it. Any other ideas on how to check the EGR?
-
there should be a small rubber hose on the top side of the egr valve ???
and you want to pull vacuum on the valve not blow air thru it ;)
the only pipe i have ever seen on egr valves is the one that connects it to the exhaust system.
-
I'm not a mechanic at all, but I had a GMC van that always had EGR problems. They came out with a gasket/filter for it. Once I had that installed I never had an EGR problem again. It was pretty cheap too. Something to think about if it is the EGR.
-
Hmm not sure how I am going to pull vacuum on it? That's saying I can find it. I found a picture of the part and what I am looking at is not the EGR....
-
Nate ...the EGR on a 3800 V6 is behind the throttle body...it looks like a motor facing downward toward the exhaust manifold..... it connects the tube from the exhaust to the lower intake.....it will look like one of these...
(http://i282.photobucket.com/albums/kk247/yankeemongiat/mp-egrvalve.jpg)
(http://i282.photobucket.com/albums/kk247/yankeemongiat/88Oldsdelta88EGRValve.jpg)
-
(http://i282.photobucket.com/albums/kk247/yankeemongiat/PICT0370-600x450.jpg)
This should be where the EGR Valve is located on the 3800....
-
Yep that's where I was looking and what I thought it was. Problem is I can't find a hose on it and even if I did no way to put vacumm on it. I'm downloading a video right now to show ya what I mean about the hose.
http://www.youtube.com/watch?v=glQUX006kfE
-
Oh and thank you Scott! If I can get a check on the EGR I will check on that next.
As far as the dying, well it has changed a bit. It will stall sometimes at about 25-30, but it stalls a little differently than before. It will cut off but not stall completely...hard to explain...I will try to give it gas and it just won't go, or rev, and then after a few seconds it will completely die, with all the lights coming on etc. Again this is an intermittent problem, not everytime. Stalls much more frequently at decel just before or at stopping.
EDIT
just want to clarify a few points on this post. When I said all the lights coming on I mean the dash lights. And it has probably only done the new type of stall 3 or 4 times.
Aero, When I pulled the hose off and saw how dirty the plate was I really though you had nailed it, but unfortunately not.
-
wow, this one is just throwing shots out in the dark. one of us needs to go out there and take a look at it!
-
ok the type of egr it has,its and electroniv egr valve.no vacuum on that one i believe
they are a known problem on them motors
however if it is stalling at cruise speeds then i would be leanint alooking at the crank shaft postion sensor next
taht is also a known problem .but so is the coil pack along with the ignition module or any combo there of
so now knowing about the stall at cruise this is where i would go
as far as testing goes,yu will pretty much need to get tat info from a service manual
as these parts resistance readings change as theier temp change,therfore their ohms will vary over a wide range
-
Other than low idle speed, what about timing?
Wayne
-
Ntd, it is not the plate itself that you have to clean but the area on the housing where the plate makes contact when it is closed as in the idle position, a thin film of dirt changes the size of the gap between the plate and the housing causing rough idle and stalling. Steve
-
This may sound off the wall but, I had a Jeep once that kept doing that and drove me nuts. It turned out the battery and alternater was bad and couldn't hold enough charge when the AC was running unless I was driving fast. Every time I would slow down it would stall out. Shortly after I got the alternater and battery replaced the AC compressor locked up.
-
Ok folks...New developments. Started the car today to let the AC run a bit before I took Mackenzie out. When I was walking to the car it stalled. I tried starting it back up and...yeah wouldn't start. Turns over but wouldn't start. Would an EGR failure or the Crankshaft position sensor cause it to not start? I hoping having a total failure now may make this easy to diagnose...
-
A loose distributor? Hey, on Sat. mornings on NPR at 10:00 am, at least here it is......they have Click and Clack the Tappit brothers.....actually tommy, and Ray Mazzioli, or however it is spelled. Anyway, they are auto engineers, and they have a radio show called car talk, and people send in their car problems, and then they call them, and talk them through the problem, or tell them what they believe the problem to be. Most of the time they are right on the money. They are actually pretty funny too. ;) They have a column in the newspaper also. You should be able to google them, at cartalk.com .
Wayne
-
I do know that it isn't fuel. Just replaced the fuel filter, today. And the fuel pump is working.
-
yup like my last post said, crank senor and or cam sensor/ign module
but im leaning towards the crank sensor
-
Alrighty This is SO MUCH FUN ;D ::) I have fuel and spark.....
-
have you checked the fuel pressure with a fuel pressure gage?
just cause some comes out when you push the shrader vavle doenst mean its the right pressure
next check for "pip" at the injectors
-
Going to rent a fuel pump pressure gauge tomorrow and see if I have enough fuel pressure. It is spraying out of the valve on the fuel rail but I suppose it may not be enough for the injectors.
-
Thanks Tim, posted at the same time you asked that ;D
-
you should have 30-35 psi at the fuel rail(minimum)
if this is good
then get a "noid light",this is a little light that plugs into one (any one of) of the injector connectors
once you have this plugged into an injector connector have some one crank the engine while you watch the light
it should be a flashing rapidly as the engine cranks and should be bright
if i remember right on this engine,like most engines,the crank sensor sends the "pip" signal to the injectors
if you have no "pip" at the injector then definatly chase the crank sensor
note:a test light can be used instead of a "noid" light,just dont force any thing to large into the connector pins,as this will cause them to spread and that could/can cause a poor connection and a misfire ;)
its to bad you dont live closer.i hate hearing people need to "rent" such things like pressrue gages etc.if you were close i would borrow you mine,hell i probably would just come over and lend a hand too :)
-
Tim,
I got a pressure test gauge. It is reading 42 PSI at the Schrader valve. I also got a noid light test kit while at autozone and I checked that. All injectors are blinking when I turn over the engine. So I'm guessing it's not fuel delivery related. Any more ideas?
Oh and don't worry about the renting, it's actually a loaner program. I give them a deposit and they give me all of it back when I return the tools. Not a bad deal. Just a lot of money out of pocket up front, since I don't use plastic money.
-
Started before that. The Harmonic Balancer was a repair in an attempt to fix the stalling. It was also rattling itself and needed to be replaced based on that but yes the problems started before the replacement. When I returned the test kits I picked up a crank sensor. I will be putting that in this afternoon. I'll let you all know how it goes
-
Yeah that's what I thought too Scott. But sensor was cheap enough that I'm willing to throw a hail mary and toss a new one in and see what happens.
-
So I was getting ready to reef on the harmonic balancer Bolt to remove it and I just about fell over. I was actually able to finger loosen the darn bolt. When I pulled it off this is what I found.
(http://i95.photobucket.com/albums/l144/NDanforth83/101_0960.jpg)
(http://i95.photobucket.com/albums/l144/NDanforth83/101_0961.jpg)
Now I'm not sure what would cause this to happen. Both Frank and I tightened the hell out of this thing so I don't suspect it being loose was our fault. So was it a harmonic balancer all along, and the one I replaced it with was bad???
-
well glad ya found it
i never seen that before,but last week i did have an explorer that snapped the front of the crank shaft off
the puley was laying on top of the steering linkages with the bolt in it ad it was still tight on the end of the crank shaft that was stil in the pulley
as far as torquing the next one,call ashop and find out on he spec,or maybe auto zon can tell ya.
ya might want to check and make sure all the other pullies are turning freely,even the ac compressor pulley and clutch.
and i wouldnt use any thread lock on the bolt for the pulley
also i would us a little silicone sealer on the key way of he pulley to prevent an oil leak
-
Well I'm hoping this is actually IT, and not that another problem caused this. Do you think I should call and ask the company I bought this from if they will warranty it. I mean I only put this in 2 weeks ago and it has not been driven daily. Also while I have this off should I go ahead and put the new Crank Sensor in? Or return it and use the money for a new balancer? ::)
-
i would call the company that made the balancer and ask about warranty,they may and they may not but it cant hurt.
now if you want my "professional opinion" here it is
to me it looks like it may have been installed improperly.
it doesnt look like the key way was lined up properly
if you look just to the left of the groove(in the photo) for the key way there is an indent that looks just like a key way
it looks like it was (pressed on)in the wrong position.this style of balancer should pretty much slide in place most of the way with little resistance.
if one is to force the pulley on using the retaining bolt and the key way is not ligned up properly then this sort of damage can happen,or worse you could wreck the crank shaft itself,so i would look closely at that before i did anything else at this point.
on the crank shaft there will be a key that sticks up less than a 1/4" high,this key should fit into that groove.
good luck
-
Thanks Tim, I can understand that you would think that. But I did have help when isntalling the balancer and we made very certain that the woodrow key was lined up. I would think the car wouldn't have run at all if it hadn't been lined up, right?
-
NTD, I would say the odds the ballancer was installed wrong are about 102%. LOL. I am a lifelong diesel mechanc so don't say too much on cars. But anyone can make a mistake, find out the correct procedure and follow it to a tee. I bet next time will be a charm for you. Steve
-
steve, your right about anyone being able to make mistakes
i made one two weeks ago that only a real rookie should make
22yrs in shops and i had never made that mistake before,and now take extra steps to make sure it never happens again
only reason i mentioned it being installed wrong is because of the witness marks on the end and inside of the pulley
you can see on the end of the pulley collar where there is an indent the size and shape of the key way
on the inside of the collar(pieces)you can actually see the marks from where the key way had slide around the inside of the pullley
when he mentioned that him and another fellow tightened it as hard as they could made me look real well at the pulley
you know as well as i do that this style should go on pretty easily,i dont believe the toruque on it is much more than maybe 125 lb ft at most(but need a spec book to know for sure)
-
Thanks ::)
-
It should slip on just about all the way before tightening, possibly lightly tapping with a small hammer, if it doesn't it is probably off. I missed a key way on a trans counter shaft when pressing on a gear and it cost me a thousand bucks. Very easy to do. Steve
-
It did slip on relatively easy. The first time we attempted to put it on it was a bit rough so we marked the line up and tried again. It when it smootly. I thinking that we may just not have tightened it quite enough. A buddy of mine asked if we had run it and then checked tighteness, we didn't. He thinks we might have had it 95% tight and then when it ran it loosened it up. He reccomended when I do it again to run it a few minutes and then snug it up again. I'm just hoping I didn't mess up the crankshaft.
-
....Drum roll please.......It was the crankshaft senosr!!!! My car is now up and running guys. Thanks for all the help.