Bogging Down Briefly

[CincyGXP]

98 SE, 104000 miles, has bogged down twice in the past 4 days. Once on deceleration, once on acceleration. Doesn't stall, but check gages lights flash and bells ding. Then continues to run fine. Also, today, noticed a metallic clanging coming from under the car when accelerating up hills. Stops as soon as you let off the gas. Any ideas? Igniton problem on the bogging down? Not sure how old plugs/wires/coils are, but I got the car from my Dad when he died. It had about 92000 when I got it from him, and he got it about 78,000 miles, and he never changed them. Not sure about previous owners.

Thanks

[JMH1950]

has bogged down twice in the past 4 days. Once on deceleration, once on acceleration. Doesn't stall, but check gages lights flash and bells ding.

That sounds exactly like what mine was doing for awhile. Drove me nuts trying to track it down. It wouldn't set a code most times and when it did, it wouldn't set the same code twice in a row.

Turned out to be a bad PCM. Glad I had a spare to try.

[CincyGXP]

Yea, it's not throwing a code, unless it's stored. It's running awesome, except for the two times it bogged down.

[Echo SSEI]

Make sure your battery terminal connections are clean, tight, and secure. Loose or corroded connections have been known to result in stalling/bogging issues. A general tune-up may also be in order, but cleaning and tightening the battery cables is a free check.

[GXP_vince]

Check your alternator wires also. I recently ran into something like that.

[CincyGXP]

Battery cables clean, alternator wires ok. Now it has stalled a couple of times, but started back up. Crankshaft sensors?

[CincyGXP]

Got my front brakes replaced on the GXP today and was talking to my mechanic about the stalling/starting right back up on my 98 SE. He said in his experience, this is usually caused by a problem with the IAC. Can I clean this part up, or does it have to be replaced? Also, where is this located on the 98? Thanks for any help.....

[wjcollier07]

IAC should be under the TB, but I don't see how this would make any difference in power..as that merely regulates idle speed/closed throttle plate position.

My 98 SE was doing that for the short time I had it...ended up cleaning up the coils, ICM, plugs and wires and it stopped all its bickering it had with idling and with high load situations. It only was around 88k at the time, but still had all original wires and plugs.

Any sensor problems would more than likely throw a code. This sounds like an ignition problem to me, especially if its starting right back up...

If its got 104k, and by any chance you're on original plugs and wires, this is definitely about the time that crap would start rearing its ugly head. Original wires, old plugs and original oxygen sensor just got changed on my 93 at 105k and apparently made a few WORLDS of difference with general drivability and compliance with everything else being up to date.

If that doesn't fix your issues, check your fuel pressure. Could be a faulty FPR not holding the rail pressure, or causing intermittent pressure drops. Simple and cheap fix there.

[CincyGXP]

Thanks for the replies, will try all one by one. Does anybody have a pic of exactly where the IAC is?

[CincyGXP]

Took the car to Autozone and had it scanned (it finally threw a code). PO122, tps. They want $45 out the door for a new one. Any idea what size those bolts are that hold it on? Looks like a hex or allen wrench is required, but could you use something else in pinch?

Thanks for any help.

[00Beast]

I'm surprised John didn't post this, but make sure this list is up-to-date. If ignored, these things can cause strange issues.


Brand Suggestions are in the parentheses.

• 1987-2005 Bonneville / Buick 3800 Maintenance List
  
  Run Seafoam through gasoline and intake every 5,000 miles. One pint of Seafoam in a half tank of fuel is a good mix. The intake is optional, but recommended.
  
  Grease: Ball Joints, Tie Rods Every 8-10k ( recommended) [b]Air Filter[/b] [i]Every 15k[/i] [s ... Amsoil EaA, Purolator PureONE)[/size]
  PCV Valve Every 30k
  MAF Sensor Element Cleaning/TB Cleaning Every 50k viewtopic.php?f=48&t=1661
  Fuel Filter Every 15-25k (Purolator, AC Delco, WIX)
  Spark Plugs Every 30-50k (NGK TR55 or Autolite 605) (Never Bosch)
  Ignition Wires Every 30-50k (Napa Belden, AC Delco, Autolite Pro, NGK) (Never Taylor or Bosch)
  Oil & Filter Every 5-6k or Every 6 months (Mobil1 or Amsoil)(Mobil1, Purolator PureONE, Amsoil EaO or WIX) (Never Fram) viewtopic.php?f=45&t=214
  *Conventional Oil Every 3k/3 months(Pennzoil with a WIX (Napa), Delco or Purolator filter)
  Transmission Flush Every 15-20k (Always make sure filter is changed when flushed)
  Cooling System Flush Every 25-50k or Annually (Peak or Prestone Green Coolant Only) (Never Dexcool)
  Oxygen Sensor Every 80-100k (30k for non-heated) (AC Delco or Denso) (Absolutely never Bosch) viewtopic.php?f=48&t=794
  Accessory Belt Inspect every 15k, replace every 100k, or as needed
  Cabin Air Filter Inspect and Replace every 15k, or as needed in dusty conditions. (Note: 00+ Only)
  Evap Core Cleaning Whenever Needed (Note: 99 and older only) viewtopic.php?f=45&t=2432
  
  *Special Considerations*
  All 3800s, LG3, LN3, L27, L36, L26, L67 & L32, especially important on vehicles factory installed with orange Havoline Dexcool Antifreeze/Coolant: http://www.dex-cool.net/
  Lower Intake Manifold Gasket Replacement, every 80-100k (ignorance of this can allow coolant to enter your engine oil, this happening can cause irreversible lower engine damage, requiring replacement of subject engine)
  
  Series II, Naturally Aspirated, RPO:L36:
  Upper Intake Manifold Plenum Replacement, Every 80-100k (ignorance of this can allow coolant to enter your intake manifold, possible damage to occur can be hydrolock, irreversible damage to emissions devices, misfires, etc. Most times, engine replacement is required if ignored long enough.) viewtopic.php?f=53&t=1061
  
  Series I, II, III RPO Code L67 & L32:
  Change Supercharger Oil; Every 30-50k. (Intense Racing or GM Dealer) viewtopic.php?f=56&t=1690
  Supercharger Belt (Series II and III only); Inspect Every 15k, Replace Every 100k or as needed.
  
  Rev. 6/7/09 By 00Beast

[CincyGXP]

Ok, after a thorough cleaning of the IAC and MAF sensor, the stalling has stopped. The IAC was really gunked up and the MAF was pretty dirty too. Just posting this in case anyone else has a stalling issue......

[LeSabre in Buffalo]

Might want to clean your throttle body also. If the IAC and MAF were as bad as you said, the throttle body must be in need of cleaning too.

[CincyGXP]

He actually did clean the throttle body. It has stalled twice since he cleaned everything. He said even though he cleaned it, it could still be bad, (IAC valve). Does anybody else think this could be the Crankshaft Sensor? Sounds like the classic symptoms (stalling, starting right back up)?

[CincyGXP]

Just an update: car threw a code the other day. Throttle Position Sensor and Crankshaft Position Sensor. Had both replaced, and car is running great with no stalling issues. Hope this helps somebody in the future.

[spoiledred94]

I think it will be a big help to me when I get back down to my 94 SE that is having that same set of problems. Great you figured it out!

[LeSabre in Buffalo]

Glad to hear that's what it was!