2001 4.0 & stalling

[New442]

Hi All,

I have an 01 Aurora 4.0 that has an intermitent stall problem. This happens when the car is just about at operating temp(first 5-10 minutes of driving) If at a light it will sometimes stall. While driving it either hesitates or acts like I turn the key off & then back on. Sometimes after re-starting it will not idle correctly for a few minutes. It also has a skip @ idle. Anybody has these symptoms before? Thanks in advance.

[kobalt]

Honestly it could be a lot of things - You might have to be a bit more specific for a better diagonose. How are the spark plugs and your air filter looking? Does the car idle rough? How is the acceleration and gas milage? I would check the crank positioning sensor as well as fuel pump relay(s) and the filter.

[New442]

Kobalt:
It has a clean K&N air filter, New fuel filter, & so far I've replaced Mass Airflow sensor, & Cam shaft sensor. Accelleration is good and I'm averaging 24.5 MPG according to the DIC. It does have a slightly rough idle.
I'll be replacing the rear brakes this weekend and may as well replace the plugs as the car now has 50k miles.
What do you think, & thanks.

[kobalt]

Does the check engine light come on? Even if it does not, go to a local auto parts store and get a OBDII code reading from them - some codes are stored and this might point you in the right direction.

Try simple remedies first - make sure you're running premium fuel and get some BG44K injector cleaner from a local GM deler.

- A new MAF sensor usually needs to be calibrated by the dealer for your specific car. When you replaced the MAF sensor did you disconnect the battery for an hour or so to reset the ECM? The ECM has to adjust to a new MAF sensor.

- Misfire at idle might have to do with a specific cylinder - remove spark plugs one by one and check for fouling.

- Is that K&N in properly? Check for vacuum leaks in the intake and a dirty throttle body plate - these can cause the car to run lean. You can also try replacing the fuel pressure regulator and fuel system relays.

Hope this helps!

[rocketman]

I'm not sure if you are the same person that posted the same question on the Edmund's board or not so I'll answer here as well.

My wife's '01 4.0 had a rough idle and it wanted to stall. The dealer reprogrammed the crank sensors (2).

About a year later, the car would stall periodically at 35-45mph. The dealer replaced the 2 sensors. The problem has not recurred. All this before 30,000 miles.

There is a TSB on this so I would recommend checking it out.

Here is a link for TSBs.

www.alldata.com/TSB/43/014330EP.html

Good luck!

[New442]

Thanks Rocketman & Kobalt
Update:
I replaced the questionable crank sensor, spark plugs & PCV valve (What a pain in the ass getting to the back 4) It also came from the factory with Nippon Denso plugs. Anyway the problem still exist'. Code is now on that second crank sensor-go figure, why did it not display that before. Also while doing the brakes I discovered a bad wheel bearing, (not cheap)

Also went to a dealer to inquire about the paint bubbling on the hood & trunk. Dealer says panels must be replaced (Aluminum) Oldsmobile must approve this and have flat blown me off on the approval. Also inquired about water leaking in the trunk, front drivers side floor & got we'll look into it & get back to you. Ya right.

[dred98]

New442 said:

It also came from the factory with Nippon Denso plugs.

I would have expected these in a Toyota but not an Oldsmobile - Auroras would have had AC Delco as original equipment.
Not that it matters if you've already changed them.

[Aurora40]

I believe the AC iridium plugs are actually made by Nippon Denso. They may have a patent on iridium plugs.

[dred98]

Aurora40 said:

I believe the AC iridium plugs are actually made by Nippon Denso. They may have a patent on iridium plugs.

OE is platinum plugs - is iridium the same thing or are they better?

[rocketman]

I don't know the answer on why the second crank sensor is now bad but I am positive my dealer replaced them in pairs. Maybe they altered the voltage setting or something so NOT changing them in pairs would create a mismatch. Just a guess really. I'd replace the second one but ask the dealer if you should do 2 not 1.

Here's one for you. The same car had both outer tie rods replaced before 10,000 miles. When was the last time you heard that one?

Good luck, let us know.

[kobalt]

dred98 - Iridium electrodes offer the durability of platinum and the conductivity of copper - the best of both worlds in a way.

[Aurora40]

dred98 said:

OE is platinum plugs - is iridium the same thing or are they better?

I believe OE on the new Aurora V8 is not platinum, but iridium. The new engine is quite different than the old, and no longer has waste spark. For some reason or other iridium can be made with even smaller electrodes than platinum, so you get a more open spark. I don't know that much about it, though.

[dred98]

OK, now it's all making more sense.
thanks guys.

[erw38]

so, would the iridium make more sense on the classic?

[dred98]

erw38 said:

so, would the iridium make more sense on the classic?

Not to me they wouldn't.
I had new platinum plugs put in a week ago

[New442]

Update:
2nd crank sensor on order & will install Saturday.
After installing new plugs (AC-Delco) still idles rough.
Oldsmobile now refuses to cover the trunk & hood because it's not rusted through. But dealer advises they should be replaced-wtf

[dred98]

Aren't the trunk and the hood both aluminum ?

[New442]

On the V8 they are both aluminum. Dealer's body shop says to do it right the panels must be replaced. GM says unless there's a rot hole it won't be covered.

[rocketman]

Any update on the stalling issue after the second crank sensor replacement?

I was talking to a guy at the service counter for my motorcyle this weekend and he told me how he used to work at a Caddy dealer. One day there was a guy who showed up with a stalling Caddy. He said the guy was rude and even though he knew what the problem was, he refused to service the car. I said "Yeah, I know too - crank sensors". I thought he was going to die. When he asked how I knew, I told him I had 2 second generation Auroras. End of story.

[New442]

Update:
Parts store sent wrong sensor, so we'll see come this weekend.

[kobalt]

erw38 - Lower resistance plugs are always beneficial, so if it's time to replace them I say go for it.

[Aurora40]

kobalt said:

erw38 - Lower resistance plugs are always beneficial, so if it's time to replace them I say go for it.

Provided they are plated/padded on both sides of the plug. Don't forget the classic has waste spark, the new does not.

[ottoracefan]

New442, did you change the second CPS and what was the result?

How difficult is it to replace the crankshaft sensors?

I recently purchased an '01 V8 and it has stalled 3 times in the first 2,000 miles (it has 75k total). It has never happened while I was driving, but apparently each time was soon after starting and between 10-40 mph.

Thanks,
otto

[New442]

Otto-The sensors are easy enough to replace. You need to do it from the underneath of the car. Drop the plastic cover and right in the middle of the engine you'll see the two sensors (Hope you have small hands)

I've given up on this car & GM. Never again sorry to say that but it is what it is.

[ottoracefan]

I replaced both sensors last week and it totally solved my stalling problem.

You're exactly right about the sensors being easy to replace IF you have small hands. I don't and my forearms are large enough that I could barely touch the sensors, wiring connectors, and fasteners. A job that might take someone else a half hour took me 3 hours.

But I am very happy! $70 for sensors, compared to $300-400 job at the stealership - - and the car runs great!! ;D ;D

[rocketman]

Boy am I glad it was the sensors after I made all that noise about them. Hope it helped out.

[ottoracefan]

rocketman, it depends on what you mean by "helping out"

Yes, the Aurora runs perfectly now and hasn't stalled since I changed the crank sensors. But in retrospect, I'm not sure I should have changed them.

You see, my wife had quit driving the Aurora until I fixed the stalling - - and now that I have, I've lost my driving privileges............... I only get it when it needs gas or a wash!

[rocketman]

I know the feeling all too well. That's why I had to buy the second one. She wouldn't allow me to buy her a new car to get hers.

[kdjohnson2002]

Hmm. My '01, 48K mi, has a similar problem every now and then. Yesterday, I drove it to the store- maybe a mile drive- and when I started it back up, it stumbled a bit but no trouble lights came on. After a few sec, it picked up, I backed out & started driving in the parking lot when all of a sudden there was a wham! & the engine picked up & started running perfectly- I guess I was unknowingly opening the throttle just a bit more than normal to compensate for whatever was happening. Interesting huh? I'll have it scanned tonight.

[bksss]

Is it possible for a saturday afternoon mechanic (handyman) to replace the two crank sensors or is this a dealer job only? I have had stalling problems and took it to a GM dealer and after paying close to 40 bucks for a diagnosis found out that it needs two new crank sensors. Are the crank sensors available from an aftermarket source or do I have to go to GM. Thanks for any info.
Kim, Saskatchewan, Canada