acts like it wants to stall
#81
09-10-2014, 06:31 PM
Just want to add this: 2006 h3 with 111,569 miles. I had the same check engine light, almost stalled condition and the code reader said "Random Misfire". I decided to change the plugs, as recommended on this forum...thank you all. While changing plugs, I found that the forward most ignition cool pack was corroded. I called the local parts house and changed it out. Replaced all plugs and cleaned the throttle body.
result: runs perfectly.
I also corrected the "climate control" issue yesterday.
Thank you to all who post useful information on here, it has been a big help.
result: runs perfectly.
I also corrected the "climate control" issue yesterday.
Thank you to all who post useful information on here, it has been a big help.
#82
09-11-2014, 09:00 AM
There's no such thing as a dead thread on the web!
From my experience a 4 year old thread is a "new thread" to anyone searching for answers. People that 'live' on the forums don't seem to understand that point.
H3 "acts like it wants to stall" ... yea that problem is plenty 'live' for anyone experiencing it.
However gp1192, your a member of this forum ... start a new thread ... a compression test would be pertinent in your case.
For those of you that stumble upon this thread and are suffering from the "acts like it wants to stall" problem ... this is a common occurrence with the Hummer H3's. Many times its a symphony of problems that combine to create this situation. You should see this symptom as an opportunity to perform some routine maintenance that has no doubt been neglected on your ride.
Below is a list of common items that can cause this situation in order of priority. Many times the stumble slowly improves but does not completely go away until you complete more ... or all of the routine maintenance.
#1 Clean the throttle body (And I mean properly clean it)
#2 Check the coil packs for corrosion. (Many times water gets inside)
#3 Remove, inspect, & even stretch the springs a little in the coil packs.
#4 Install new sparks plugs. (Don't cheap out, buy them from a GM Dealer)
#5 Clean the Mass Air Flow Sensor (Use a spray cleaner made just for this)
#6 Change the fuel filter (It may be slightly clogged affecting the idle)
#7 Change the thermostat (If your water temp reads below half ... it's shot ... the farther below half the more defective it is "i.e. it's stuck open")
Don't underestimate this one, this is what finally cured the last little ****le on mine)
Still a rough idle ... first thing first .. do a compression test to make sure your valve seats are not leaking. If the compression is good then you may have a weak coil pack, unlikely but possible. (A simple test at home it to pull off one coil pack at a time a see if the stumble is even) You may also have low fuel pressure, bad fuel pump!
If the idle stumble still has not gone away, you're now in need of some professional help.
Understand most mechanic's will start by a redo of everything you did, just to make sure you did it correctly. Carefully weigh your mechanical ability, tooling, and time available before you head down the DIY path. Finding a good mechanic, well, we all know how hard they are to find.
Sometimes ... and I hate to admit it ... the best option in the long run is to take is straight to the GM dealer.
Your milage my vary .........................
From my experience a 4 year old thread is a "new thread" to anyone searching for answers. People that 'live' on the forums don't seem to understand that point.
H3 "acts like it wants to stall" ... yea that problem is plenty 'live' for anyone experiencing it.
However gp1192, your a member of this forum ... start a new thread ... a compression test would be pertinent in your case.
For those of you that stumble upon this thread and are suffering from the "acts like it wants to stall" problem ... this is a common occurrence with the Hummer H3's. Many times its a symphony of problems that combine to create this situation. You should see this symptom as an opportunity to perform some routine maintenance that has no doubt been neglected on your ride.
Below is a list of common items that can cause this situation in order of priority. Many times the stumble slowly improves but does not completely go away until you complete more ... or all of the routine maintenance.
#1 Clean the throttle body (And I mean properly clean it)
#2 Check the coil packs for corrosion. (Many times water gets inside)
#3 Remove, inspect, & even stretch the springs a little in the coil packs.
#4 Install new sparks plugs. (Don't cheap out, buy them from a GM Dealer)
#5 Clean the Mass Air Flow Sensor (Use a spray cleaner made just for this)
#6 Change the fuel filter (It may be slightly clogged affecting the idle)
#7 Change the thermostat (If your water temp reads below half ... it's shot ... the farther below half the more defective it is "i.e. it's stuck open")
Don't underestimate this one, this is what finally cured the last little ****le on mine)
Still a rough idle ... first thing first .. do a compression test to make sure your valve seats are not leaking. If the compression is good then you may have a weak coil pack, unlikely but possible. (A simple test at home it to pull off one coil pack at a time a see if the stumble is even) You may also have low fuel pressure, bad fuel pump!
If the idle stumble still has not gone away, you're now in need of some professional help.
Understand most mechanic's will start by a redo of everything you did, just to make sure you did it correctly. Carefully weigh your mechanical ability, tooling, and time available before you head down the DIY path. Finding a good mechanic, well, we all know how hard they are to find.
Sometimes ... and I hate to admit it ... the best option in the long run is to take is straight to the GM dealer.
Your milage my vary .........................
BS is called. A compression test for a false stall with no CEL?
#4... you can buy the current AC Delco plugs at nearly any auto parts.
Your #6 is WRONG, H3s have NO fuel filter. Virtually no domestic autos have no serviceable fuel filters post 2002.
Please consider this, if you continue to encourage anyone to break our rules, you will be no longer welcome. Just because you find an old thread that seems to be your "exact same issue" does not mean you have to dig it up.
Post a new thread and link to it.
https://www.hummerforums.com/forum/n...bumping-23220/
#83
09-12-2014, 05:57 PM
Whats up Doc!
Who said there was no CEL On? (Check Engine Light)
I challenge anyone to go to 10 different auto parts store and see & compare what you get when ordering Spark Plugs for a Hummer H3. For such an important part that you change only every 100K miles, IMO its not worth saving a few dollars and risk getting the incorrect or possibly inferior plugs.
By bad, on the H3 fuel filter, I was thinking the Hummer H2 which does have a filter.
"Live On"
Who said there was no CEL On? (Check Engine Light)
I challenge anyone to go to 10 different auto parts store and see & compare what you get when ordering Spark Plugs for a Hummer H3. For such an important part that you change only every 100K miles, IMO its not worth saving a few dollars and risk getting the incorrect or possibly inferior plugs.
By bad, on the H3 fuel filter, I was thinking the Hummer H2 which does have a filter.
"Live On"
#84
09-12-2014, 07:00 PM
Whats up Doc!
Who said there was no CEL On? (Check Engine Light)
I challenge anyone to go to 10 different auto parts store and see & compare what you get when ordering Spark Plugs for a Hummer H3. For such an important part that you change only every 100K miles, IMO its not worth saving a few dollars and risk getting the incorrect or possibly inferior plugs.
By bad, on the H3 fuel filter, I was thinking the Hummer H2 which does have a filter.
"Live On"
Who said there was no CEL On? (Check Engine Light)
I challenge anyone to go to 10 different auto parts store and see & compare what you get when ordering Spark Plugs for a Hummer H3. For such an important part that you change only every 100K miles, IMO its not worth saving a few dollars and risk getting the incorrect or possibly inferior plugs.
By bad, on the H3 fuel filter, I was thinking the Hummer H2 which does have a filter.
"Live On"
Last time they put an external fuel filter on the H2, was in 03.
The H3 NEVER had an external fuel filter!
Original Equipment Replacement Spark plugs for the H3 are ACDelco 41103 (I5) ACDelco 41110 (Alpha)
ACDelco Iridium plugs are available at any auto parts store and come with a 100,000 mile warranty
http://s7d9.scene7.com/is/content/Ge...64410pdf?$PDF$
#85
09-13-2014, 04:11 PM
That's it, come on there has to me more conductive deconstruction of my post than that.
Deconstruction - Definition and More from the Free Merriam-Webster Dictionary
Thread dogs rule.
Deconstruction - Definition and More from the Free Merriam-Webster Dictionary
Thread dogs rule.
#87
09-22-2014, 09:17 AM
Ok
Thank you for answering. And I apologize for the lateness of my response.
The car actually hesitates at low idle, but will eventually start to turn off.
I got a "Misfire" code from Onstar and Pepboys gave me three codes which are P0300, P2101, P0102, and P0151.
The parts changed are:
Radiator
Thermostat (although it is is not a dealer thermostat)
Engine coolant
Mass air flow sensor
All coils
All spark plugs
Throttle body has been cleaned three times at 75,000 plus miles, at 77,000, and at 78,000.
The dealer put something they call “Additives” (it goes into the gas tank).
So far nothing has worked. At the most, when the thermostat was changed, the car was fine for exactly three weeks. After that it went back to a rough idle (it wants to turn off but it does not).
Then I noticed that the car really acted out after I put the vehicle thru a car wash. This hesitation was really shaking the front of the car. Then the engine light came up. Again I got a “misfire” from Onstar.
So I called my mechanic who said he will have it checked by some specialist on electrical system.
The car was checked this Saturday.
So this guy said that the computer was fine and that it was “probably” a
Cranshaft sensor. I was told the sensor was cleaned and to drive it and see what happens.
I picked the vehicle, like 45 minutes ago and drove the car to my job.
Lord and behold, the car acted as it would turn off (hesitation at low idle). By the time I got to work, it turned off. I turned it back on and it did not turn off anymore.
The mechanic is ordering the sensor as I write this.
I really would like that if you answer, please send me an email so that I can get back to this thread. Quite honestly I’m trying to read anything and everything on any thread possible on the web and it’s kind of hard to recall where I have been on the web. Please email me at gp1182@gmail.com
Thank you for answering. And I apologize for the lateness of my response.
The car actually hesitates at low idle, but will eventually start to turn off.
I got a "Misfire" code from Onstar and Pepboys gave me three codes which are P0300, P2101, P0102, and P0151.
The parts changed are:
Radiator
Thermostat (although it is is not a dealer thermostat)
Engine coolant
Mass air flow sensor
All coils
All spark plugs
Throttle body has been cleaned three times at 75,000 plus miles, at 77,000, and at 78,000.
The dealer put something they call “Additives” (it goes into the gas tank).
So far nothing has worked. At the most, when the thermostat was changed, the car was fine for exactly three weeks. After that it went back to a rough idle (it wants to turn off but it does not).
Then I noticed that the car really acted out after I put the vehicle thru a car wash. This hesitation was really shaking the front of the car. Then the engine light came up. Again I got a “misfire” from Onstar.
So I called my mechanic who said he will have it checked by some specialist on electrical system.
The car was checked this Saturday.
So this guy said that the computer was fine and that it was “probably” a
Cranshaft sensor. I was told the sensor was cleaned and to drive it and see what happens.
I picked the vehicle, like 45 minutes ago and drove the car to my job.
Lord and behold, the car acted as it would turn off (hesitation at low idle). By the time I got to work, it turned off. I turned it back on and it did not turn off anymore.
The mechanic is ordering the sensor as I write this.
I really would like that if you answer, please send me an email so that I can get back to this thread. Quite honestly I’m trying to read anything and everything on any thread possible on the web and it’s kind of hard to recall where I have been on the web. Please email me at gp1182@gmail.com
Hope you feel better after that rant?
Since you just jumped in to a 4 year old thread 78 posts in and claim to "have the exact same issue".... I have to ask what exact same issue?
Are you talking about acting like it wants to stall (false stall), or some form of the other banter in this thread, because for the most part this thread is pretty useless? False stall is almost always caused by a sticky (ie. god damned dirty) Throttle Body.
I can explain why if you want, but it don't matter when it comes to correcting it.
I need an answer to this question before I can help: Have you cleaned your throttle body? If so, at what mileage, and how many miles do you have now?
I get that you chased parts all over, but you did not mention the ole cleaning the TB.
Since you just jumped in to a 4 year old thread 78 posts in and claim to "have the exact same issue".... I have to ask what exact same issue?
Are you talking about acting like it wants to stall (false stall), or some form of the other banter in this thread, because for the most part this thread is pretty useless? False stall is almost always caused by a sticky (ie. god damned dirty) Throttle Body.
I can explain why if you want, but it don't matter when it comes to correcting it.I need an answer to this question before I can help: Have you cleaned your throttle body? If so, at what mileage, and how many miles do you have now?
I get that you chased parts all over, but you did not mention the ole cleaning the TB.
#88
09-23-2014, 10:48 PM
This was my fix from last year:
"So finally got the word from multiple mechanics. The valve seats are bad. The valves are not sealing properly and the seats are being pushed down under idle. Losing compression in the cylinders. When the motor is under load, the compression is enough to temporarily overcome this problem, but the seats are continually being pushed further down. GM wanted to replace the head (at $1000 for the bare head casting PLUS all additional parts and labor). A local machine shop wanted to shave down the valves to keep them from pushing in the seats, but this is a hit or miss fix (uhhhhh, no). Found a machine shop in Odessa, FL that has dealt with this problem enough times that they knew EXACTLY what the issue was and how to fix it. Apparently, it's a semi-common problem with the 3.7. The machine shop portion is $450, plus the money I'm going to be in this thing to my mechanic for the labor. Not happy, but better than the $3000-4000 head job this was going to be. Should have it back within a week and I will let you all know how that works, but I've gotten a guarantee from the machine shop that it will be fixed."
Ever since the new head and valves were replaced she hasn't shut off or low idled once. I don't know if anyone else had to resort to this, but it seems to have completely fixed our problem. I know everyone is going to have different issues and different fixes. But since that shop in Odessa had to do this multiple times for H3s, it seemed like a common problem around here. Sucks that your truck isn't running right and there really hasn't been a "quick fix" to clean up any of the other owners problems. It took us about 6 months and a couple hundred dollars but now she's been purring like a kitten! And from what my mechanic said, GM KNOWS about the problem and was supposed to put out a bulletin, but they still won't fix it for free.
"So finally got the word from multiple mechanics. The valve seats are bad. The valves are not sealing properly and the seats are being pushed down under idle. Losing compression in the cylinders. When the motor is under load, the compression is enough to temporarily overcome this problem, but the seats are continually being pushed further down. GM wanted to replace the head (at $1000 for the bare head casting PLUS all additional parts and labor). A local machine shop wanted to shave down the valves to keep them from pushing in the seats, but this is a hit or miss fix (uhhhhh, no). Found a machine shop in Odessa, FL that has dealt with this problem enough times that they knew EXACTLY what the issue was and how to fix it. Apparently, it's a semi-common problem with the 3.7. The machine shop portion is $450, plus the money I'm going to be in this thing to my mechanic for the labor. Not happy, but better than the $3000-4000 head job this was going to be. Should have it back within a week and I will let you all know how that works, but I've gotten a guarantee from the machine shop that it will be fixed."
Ever since the new head and valves were replaced she hasn't shut off or low idled once. I don't know if anyone else had to resort to this, but it seems to have completely fixed our problem. I know everyone is going to have different issues and different fixes. But since that shop in Odessa had to do this multiple times for H3s, it seemed like a common problem around here. Sucks that your truck isn't running right and there really hasn't been a "quick fix" to clean up any of the other owners problems. It took us about 6 months and a couple hundred dollars but now she's been purring like a kitten! And from what my mechanic said, GM KNOWS about the problem and was supposed to put out a bulletin, but they still won't fix it for free.
#89
09-24-2014, 08:31 AM
This is exactly why this thread has become useless for the most part. People keep wanting to add their experience with an entirely different problem claiming it is exactly the same as the OP.
Look at the beginning of this thread, obviously not valvetrain head issues, just the same old clean the friggin TB. Then post #17 adding in the bad head thing because of different symptoms. Then all over the map.
Post #48, cleaned the TB after posting up the bad head leaky radiator paranoia and ..... it worked. #59, chased unnecessary parts only to find the answer was to clean the TB.
Let me clean up the protocall for false stall, then let's allow this mess of a 4 year old thread DIE.
Look at the beginning of this thread, obviously not valvetrain head issues, just the same old clean the friggin TB. Then post #17 adding in the bad head thing because of different symptoms. Then all over the map.
Post #48, cleaned the TB after posting up the bad head leaky radiator paranoia and ..... it worked. #59, chased unnecessary parts only to find the answer was to clean the TB.
Let me clean up the protocall for false stall, then let's allow this mess of a 4 year old thread DIE.
#90
09-24-2014, 09:01 AM
False stall (acts like it wants to stall), rough idle with no check engine light 3.5L L52 or 3.7L LLR:
1) Clean the TB with TB cleaner only.... there are multiple threads on this, the best way to do it is remove it, clean it, re-install it;
2) Clean the MAF sensor using MAF cleaner only... there are multiple threads on this (might as well while you have the intake apart to clean the TB);
3) inspect the coil on plug packs and their connectors to the wire harness and any obvious signs of corrosion from water on top of the head;
3.5) Check to see if ALL of your intake manifold fasteners are tight (they do vibrate loose on occasion) to 10 N.m/89 lb in.
If the problem still persists, and you have more than 70K miles (plugs should go damn near every bit of 100K in these trucks). If you do not have more than 70K miles, skip to #6 or feel free to change plugs for the sport of it:
4) change the spark plugs and inspect them for evidence of any fouling;
5) while the plugs are out, look closely at the plug on coil packs to see if there is internal corrosion, if so clean them with electrical cleaner spray and allow to dry before placing them back on the plugs.
If the problem still persists:
6) Pull the camshaft position sensor and look for crud on the sensor, on the screen in the motor, or a missing screen... replace if necessary, tighten mounting bolt to 10 N.m/89 lb in.
If the problem still persists:
7) Then do a compression test, a normal read would be appx 1482 kPa/215 PSI. You can follow that with a leak down test. According to Hummerz when a leak down test shows a valve not seating properly, he performs an induction cleaning first, worked on his rig, and many of his customer's vehicles.
Watch the temp gauge, better yet get a scanner an observe actual operation temp. If that is lower than normal, or coolant is low (like at the 1/2 level) consider a T Stat replacement.
1) Clean the TB with TB cleaner only.... there are multiple threads on this, the best way to do it is remove it, clean it, re-install it;
2) Clean the MAF sensor using MAF cleaner only... there are multiple threads on this (might as well while you have the intake apart to clean the TB);
3) inspect the coil on plug packs and their connectors to the wire harness and any obvious signs of corrosion from water on top of the head;
3.5) Check to see if ALL of your intake manifold fasteners are tight (they do vibrate loose on occasion) to 10 N.m/89 lb in.
If the problem still persists, and you have more than 70K miles (plugs should go damn near every bit of 100K in these trucks). If you do not have more than 70K miles, skip to #6 or feel free to change plugs for the sport of it:
4) change the spark plugs and inspect them for evidence of any fouling;
5) while the plugs are out, look closely at the plug on coil packs to see if there is internal corrosion, if so clean them with electrical cleaner spray and allow to dry before placing them back on the plugs.
If the problem still persists:
6) Pull the camshaft position sensor and look for crud on the sensor, on the screen in the motor, or a missing screen... replace if necessary, tighten mounting bolt to 10 N.m/89 lb in.
If the problem still persists:
7) Then do a compression test, a normal read would be appx 1482 kPa/215 PSI. You can follow that with a leak down test. According to Hummerz when a leak down test shows a valve not seating properly, he performs an induction cleaning first, worked on his rig, and many of his customer's vehicles.
Watch the temp gauge, better yet get a scanner an observe actual operation temp. If that is lower than normal, or coolant is low (like at the 1/2 level) consider a T Stat replacement.
Last edited by Doc Olds; 09-25-2014 at 08:29 AM. Reason: Important additions