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power surging 2004 gm 3800


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repairdad
User

Sep 4, 2013, 3:45 AM

Post #1 of 33 (5898 views)
power surging 2004 gm 3800 Sign In

2004
GM
Grand Prix
3800
250,000 km

Just purchased , loosing up as driven must have sat or at least not pushed hard lately.
Surging of power when slightly accelerating . Notice on uphill grade with cruise set.
Mechanic tested cold an said transmission major issue.
Drives nice . Seems less prevalent when hotter ?
No codes except gas cap P0455 ( large leak ) not found cause yet.

Any suggestions would be welcomed .
Thank You


Discretesignals
Ultimate Carjunky / Moderator
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Sep 4, 2013, 4:40 AM

Post #2 of 33 (5885 views)
Re: power surging 2004 gm 3800 Sign In

Does it surge going up hill when you don't have the cruise control engaged?





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.


repairdad
User

Sep 4, 2013, 3:22 PM

Post #3 of 33 (5873 views)
Re: power surging 2004 gm 3800 Sign In

Yes


Discretesignals
Ultimate Carjunky / Moderator
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Sep 4, 2013, 3:54 PM

Post #4 of 33 (5866 views)
Re: power surging 2004 gm 3800 Sign In

Has your mechanic watched the misfire counters while the problem is occurring? If so, where there and misfires counting up?

What is the major transmission issue?





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Sep 4, 2013, 3:55 PM)


repairdad
User

Sep 4, 2013, 3:58 PM

Post #5 of 33 (5861 views)
Re: power surging 2004 gm 3800 Sign In

  Misfire on 6 solved with spark plug replacement.
Surging as per road test. Worse at 1800 rpm +_ 200.
Shifting fine.

I hate to think this mite be a PCV valve only issue as I have not found it on this series 3 yet. Location ?


(This post was edited by repairdad on Sep 4, 2013, 4:13 PM)


Discretesignals
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Sep 4, 2013, 4:34 PM

Post #6 of 33 (5845 views)
Re: power surging 2004 gm 3800 Sign In

Are the misfire counters still counting up when the surging is occurring?


The PCV valve is located underneath the MAP sensor. You have to unlock the cap the MAP sensor sits on to get access to the PCV valve. Be sure to install a new oring at the bottom of the valve when you reinstall it.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.


repairdad
User

Sep 4, 2013, 5:39 PM

Post #7 of 33 (5841 views)
Re: power surging 2004 gm 3800 Sign In

 
Sorry to say but the only way I found that cyl 6 was misfiring was by observing my remedial code reader for pending problems while opening up on the hwy.

Map is that the vertical mounted thing on the passenger side of the intake manifold ? With some clip lock I see beneath it ?


Discretesignals
Ultimate Carjunky / Moderator
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Sep 4, 2013, 5:48 PM

Post #8 of 33 (5829 views)
Re: power surging 2004 gm 3800 Sign In

Most shops have an enhanced scan tool that can look at datastream information on the manufacture side of the PCM. The datastream include misfiring information in the form of counters. It displays these counters as current and history misfires.

The thing with misfire codes is they might not set until the misfires reach a certain threshold. It is important to determine if misfiring is going on and which cylinders are missing while driving the vehicle during the surging to get an idea what is going on.




Yours might have a spring that is not shown in the pic. It is also important that you install the lower o ring. If the o ring is missing or leaking, the engine will burn oil.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.


repairdad
User

Sep 4, 2013, 5:59 PM

Post #9 of 33 (5826 views)
Re: power surging 2004 gm 3800 Sign In

  Would it be a possible that this power surging @ aprox 1800 rpm is caused by PCV valve being faulty ?
Found PCV .
In process of extracting MAP , diaphragm like square with press. inlet port attached separated from electronics.

Would think PCV faulty would generate a code ?

Thank You for diagram.
I was out checking under the MAP now I know it is it for sure there.



.


(This post was edited by repairdad on Sep 4, 2013, 6:14 PM)


Discretesignals
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Sep 4, 2013, 6:13 PM

Post #10 of 33 (5814 views)
Re: power surging 2004 gm 3800 Sign In

 

Surging caused from a PCV valve, would be unusual. Not saying that it is impossible. I've seen wrong PCV's cause fuel trimming problems and other kinds of weird things because the orifice in the valve wasn't sized correctly. It is important to use an OEM valve or an AC Delco brand.

You don't have to remove the MAP sensor to get the cap off, but too late.. If you busted the nipple off the bottom of the MAP sensor, you'll need to replace the MAP sensor.

Like mentioned in the previous reply, you really need to see if misfiring is going on during your surging episode. Datastream information would tell you a lot what is going on with the fuel and ignition system, so you can get some sort of idea where to look for the problem.

When it comes to drive-ability that is where DIY gets in the grey area. Most of the time you need expensive tooling and knowledge to diagnose drive-ability issue such as the one your having. That's unless you get lucky and see something visually or you replace enough parts and fix the problem (which gets expensive).





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Sep 4, 2013, 6:15 PM)


repairdad
User

Sep 4, 2013, 6:17 PM

Post #11 of 33 (5810 views)
Re: power surging 2004 gm 3800 Sign In

  You are the best .
I will resume this tomorrow.


repairdad
User

Sep 6, 2013, 11:41 AM

Post #12 of 33 (5790 views)
Re: power surging 2004 gm 3800 Sign In

  Good Day

Had transmission mechanic take it for an evaluation . No issues. Suggested misfire not felt either . Have spark plugs on order 41-101 for sure.
Throttle position sensor or stepper motor may have to much play at 1800-2000 rpm ? Thoughts.


Discretesignals
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Sep 6, 2013, 12:25 PM

Post #13 of 33 (5786 views)
Re: power surging 2004 gm 3800 Sign In

Good to hear the transmission is doing alright.

Were they able to drive the vehicle and watch the misfire counters?

If you do the plugs, would be a good idea to slap a set of delco spark plugs wires on there also. Wires do wear out and if they have white powdery flash burns on them, they are probably due. Worn out or leaking plug wires can cause misfiring under load.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.


repairdad
User

Sep 7, 2013, 2:06 PM

Post #14 of 33 (5766 views)
Re: power surging 2004 gm 3800 Sign In

  Good Day

It was a transmission shop that I went to. Changed all but one spark plug now ( you know the one ) #2 will be done after the emission testing I require. There was initial #4 misfiring issues as I had to run temp. up once to dry out the spit lube I use when reinserting boots onto spark plugs.
No problem with wires. I know that the old SUN™ oscilloscopes would show that even good looking wires can be marginal.
After emissions testing is complete ( soon ) I intend on swapping the PCV valve then if req. the throttle position sensor.
Why it only does this under a light load at 1600 to 1800 is a bit of a mystery. Seems that the feed back to the throttle body has slack in it A highly used position . Throttle air valve could have to much play in it also.
Really not wanting to disturb anything till after emissions testing has been done ( see broke MAP sensor ) .

Thank You ------------------------------------------------------------------------------------------------------------------------Absolutely Delco 41-101 s


(This post was edited by repairdad on Sep 7, 2013, 2:17 PM)


repairdad
User

Sep 9, 2013, 10:04 AM

Post #15 of 33 (5744 views)
Re: power surging 2004 gm 3800 Sign In

  Good Day

Off to the local shop guy with all the tools. This is my regular mechanic that has not seen the car yet ! Why because I have done a thorough evaluation to my knowledge level and now require the safety and e-test to be done without any distraction from these very important requirements. No additives in gas not even an oil change yet. Had to change e-brake cables and equalizer (GM dealer parts) , Monroe vert.stab.and tie rod.

The surging issue is evolving as so much as the terminology used by some is " hunting " ? I did do a reset with my simple code reader allowing me to do as follows.
Start cool engine with A/C and rear defroster on idle in drive (parking brake with new cables set) with out moving vehicle AKA foot on brake peddle, observing RPM changes ( slight ) for three minutes minimum of running with these loads. I am sure this is not news to you but the PCM requires this as well as some drive cycles to process O2 data for optimal mixture(s). Also takes time/drive cycles to complete other things such as catalytic evaluation etc. No codes all compete save for the last on that requires days to satisfy " evap." so off to the shop for tires etc. ----- This reprogramming/auto config. worked in so much as this surging/hunting is now at somewhat different loading RPMs.

Thank You I apologize for the unnecessary details however they may be significant in resolving this issue. After all it is a GM 3800III , year one of series III and possibly the best internal combustion engine made for mass production.


repairdad
User

Sep 14, 2013, 6:46 AM

Post #16 of 33 (5717 views)
Re: power surging 2004 gm 3800 Sign In

    

Good Day

Have not dropped the post , Just still trying unsuccessfully mind you the little things.
-removed 3 qts of transmission fluid , drove , no change
-unplugged MAP sensor , drove , observed codes are being generated , no change
-purchased actual MAF sensor cleaner and no change
-Ran vehicle with PCV blanked off and with it removed , no change
-new oil ,filter Lucas in oil and fuel , no change
-removed TPS and observed slack in the stepper motor tension. This is my main suspicion , however this is with the power via the TPS disconnected . You can hear and feel the TPM energizing when ignition is turned on

Off to purchase what I can re pump out of Dextron ??? transmission fluid, and Lucas transmission fix.

Thoughts ?? - -- Ignition wires are not forgotten . There is an issue WRT assess to replace # 2 and it is removing/disturbing plug connection.

Plan next :
- Remove TPM ,clean


(This post was edited by repairdad on Sep 14, 2013, 7:42 AM)


repairdad
User

Sep 16, 2013, 6:40 PM

Post #17 of 33 (5685 views)
Re: power surging 2004 gm 3800 Sign In

 Observed very dirty throttle body . Only cleaned what was removable with wire (brass) brush , butterfly and throat.
Still surging/hunting.


(This post was edited by repairdad on Sep 16, 2013, 6:45 PM)


Discretesignals
Ultimate Carjunky / Moderator
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Sep 16, 2013, 7:08 PM

Post #18 of 33 (5679 views)
Re: power surging 2004 gm 3800 Sign In

Unplugging the MAP sensor really won't do much because the engine computer is using the MAF sensor to calculate engine load. If the MAF's signal wasn't getting to the PCM, the PCM would default to speed density and use the MAP sensor for calculating load.

Don't understand why you would be plugging off the PCV system.

The TAC system is redundant in that it uses two TPS sensors and two APP sensors. If the actual throttle position didn't match the desired throttle position, the PCM would be in some type of throttle limiting mode and the check engine light would be on for some type of TAC related code.

Like I stated earlier, you really need to have someone connect up a scanner and monitor misfire counts and other datastream parameters to see if anything sticks out.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Sep 16, 2013, 7:10 PM)


nickwarner
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Sep 18, 2013, 3:19 AM

Post #19 of 33 (5658 views)
Re: power surging 2004 gm 3800 Sign In

If you plug off the PCV the crankcase pressure is going to blow out your front and real main seals if it hasn't yet. Unplug it right away.


repairdad
User

Sep 20, 2013, 1:06 PM

Post #20 of 33 (5646 views)
Re: power surging 2004 gm 3800 Sign In

 
Good Point Just a short trial run. No oil dripping. Yes there is quite the air flow via the PCV valve.

Just up the local hill @ 1800 +_ 200 rpm . I think it wants to shift down a gear. Mufflers do enhance this surging but only to the ear as I blocked one side off and no change.
New dex VI x 7qts and filter. Found a good layer of what appeared to be powdered aluminum on bottom of pan.
#2 iridium plug installed ( last of 6 ) , easy install with heater core tubing and coolant reservoir removed. New dex cool all 50/50 in.
Currently running Ultra 94 octane. ABS and traction alarming still once in awhile which has no correlation to this surging issue. I what to change the front RHS hub assembly as ABS and traction alarming on sharp LH turns and this side "" seems "" to be the trigger. No disconnecting of one side or the other, want to isolate but only flushed with water so far.


Discretesignals
Ultimate Carjunky / Moderator
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Sep 20, 2013, 4:58 PM

Post #21 of 33 (5639 views)
Re: power surging 2004 gm 3800 Sign In

This is all confusing. Your doing all these weird things like plugging off the PCV system and dumping trans fluid. Like I stated you should have a shop take a look and hook up a scan tool to see if there is anything going on wacky in the datastream.

If you have aluminum in the transmission pan, you have something coming apart probably in the torque converter or something is eating away at transmission case. You sure that isn't friction material you saw on the bottom of the pan because a little bit of friction material is normal.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.


repairdad
User

Sep 26, 2013, 1:43 PM

Post #22 of 33 (5619 views)
Re: power surging 2004 gm 3800 Sign In

 " Like I stated you should have a shop take a look and hook up a scan tool to see if there is anything going on wacky in the datastream." Absolutely going to happen ...

!!! Appointment for next Wednesday (2nd). !!!

What I have got from having payed out in tips $40 $20 $20 To mechanics who own their shops is Dump this car it is the transmission. It is not the transmission. I would not take on this problem ( this guy has been in business for 20 plus yrs. same location,successful and honest all the tools). ! All test drove the vehicle.

Real tempted to change the fuel filter , as it is also as you know on these GMs a regulator . Suspect there should be something in this data stream that monitors the fuel pressure as well as the flow appropriate for all the running load conditions.



"" little bit of friction material is normal " I certainly can see this as there was 3/16'' over the whole pan. No magnet , just a rubber pad under filter. Great news as I was really at odds as to what/why all this silvery deposit is there.

Thank You Follow up after next Wed.


nickwarner
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Sep 26, 2013, 2:57 PM

Post #23 of 33 (5611 views)
Re: power surging 2004 gm 3800 Sign In

 Changing the fuel filter is normal maintenance and won't hurt, but you seem to be bouncing around on theories about this without really testing much. Thats a very expensive thing to do if you just throw parts at it. Plugging the PCV like you did, even just for a test, likely has damaged seals that are now a decade old. Seriously, you are making work for yourself that need not be done.

If you suspect a fuel issue, hook up a fuel pressure tester and see what the pressure is during the fault. I don't see 3 different shops all saying your trans is junk after driving it and it not being a trans, but I guess people can be wrong. What I wonder about is why you think they are wrong but yet do not seem to have the knowledge to contradict their diagnosis with facts.

The ECM has no idea what the fuel pressure is.


repairdad
User

Sep 26, 2013, 8:11 PM

Post #24 of 33 (5605 views)
Re: power surging 2004 gm 3800 Sign In

  Post actually says one mechanic not willing to trace this issue (very established respected shop). One transmission shop saying it is not the transmission . And the first one said dump it as it is the transmission (this guy only works on GM products). Again all own their shops and test drove the car.
That makes one for the transmission.

Willing to replace the normal stuff , all of it as required. . Pressure regulator portion of the filter is what would be questionable for me at a particular flow rate . Most likly would require additional hardware installed in the supply line with data recording capabilities. Lots of high flow avail. and I can wait out this problem one thing at a time so as there is no confusion as to it's root cause.

Just what is it that generates this high crankcase pressure ?? As there is no port/line after the air cleaner and I do not see a manufacture sucking non filtered air into their crankcases ?


Surging not just a little , very noticeable . Again to a mechanic next week . 4th one. But I have faith.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

"" little bit of friction material is normal " I certainly can see this as there was 3/16'' over the whole pan. No magnet , just a rubber pad under filter. Great news as I was really at odds as to what/why all this silvery deposit is there.

Thank You Follow up after next Wed.


(This post was edited by repairdad on Sep 26, 2013, 8:47 PM)


repairdad
User

Oct 2, 2013, 1:58 PM

Post #25 of 33 (5584 views)
Re: power surging 2004 gm 3800 Sign In

4th mechanic who owns his own shop " not the transmission " , " no data on his larger ( did not question about what he was using ) device " , " requires two mufflers" yes it is a little loud without holes in either ," throttle body is likely the problem " but lets change mufflers 1st as they are a probable cause.

Purchased a throttle body from a wreckers on the way home and installed it. Still surging same. --(included a TPS) -- from 04 Grand Prix non turbo. Now I have a spare as mechanic said famous flaw with GM.
Mufflers will be available for install tomorrow aprox $ 400.
A little miffed I changed the fuel filter/regulator as a frustration item.

Now I know that the likely-hood of this being resolved by replacing the two mufflers is slim to good luck , I am beside myself to stop with this mechanic.


(This post was edited by repairdad on Oct 2, 2013, 2:02 PM)






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