Engine Or Transmission
06-17-2017, 05:11 PM
#1
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Join Date: 06-17-2017
Location: Texas
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Engine Or Transmission
Newbie here to the forum.
I have a 2010 HHR 2.2L with 141K miles that ran like new up until about a week ago. First thing I noticed was occasionally I would really have to get on the gas to get up to speed. Then it got worst. As of now to get up to and maintain 60-65mph I have to run it at 3.5K RPMs. To get it up there I have to hit 4K RPMs. No OD. Shifts through first and second ok but to hit 3rd and OD I have to floor it. Only when I floor it does it throw a misfire code and a code for the CAT /BANK1.
I am at lost for which it my be, engine performance or bad transmission so here's what I have done thus far. First, changed spark plugs, coil packs, injectors, air filter, MAF sensor, trottle position sensor changed along with throttle body and exhaust including cat and the gas presure was checked for 50-60 psi. Engine idles OK, but nothing indicating misfire or clogged intake valves.
As for the tranny, I checked the level and replaced the speed sensor on it. I am getting the same result. This problem exist hot or cold doesn't matter. No OD and seems to lack power when shifting between 2nd and 3rd. Hills kills and coasting only in 3 at 3-3.5K RPM. The few times that I floor it (out of frustration) the car dropped off as if I had thrown it into neutral and through misfire and cat codes. The misfire codes were on random cylinders and the cat code was P0420.
I have a 2010 HHR 2.2L with 141K miles that ran like new up until about a week ago. First thing I noticed was occasionally I would really have to get on the gas to get up to speed. Then it got worst. As of now to get up to and maintain 60-65mph I have to run it at 3.5K RPMs. To get it up there I have to hit 4K RPMs. No OD. Shifts through first and second ok but to hit 3rd and OD I have to floor it. Only when I floor it does it throw a misfire code and a code for the CAT /BANK1.
I am at lost for which it my be, engine performance or bad transmission so here's what I have done thus far. First, changed spark plugs, coil packs, injectors, air filter, MAF sensor, trottle position sensor changed along with throttle body and exhaust including cat and the gas presure was checked for 50-60 psi. Engine idles OK, but nothing indicating misfire or clogged intake valves.
As for the tranny, I checked the level and replaced the speed sensor on it. I am getting the same result. This problem exist hot or cold doesn't matter. No OD and seems to lack power when shifting between 2nd and 3rd. Hills kills and coasting only in 3 at 3-3.5K RPM. The few times that I floor it (out of frustration) the car dropped off as if I had thrown it into neutral and through misfire and cat codes. The misfire codes were on random cylinders and the cat code was P0420.
06-17-2017, 05:30 PM
#2
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Join Date: 05-01-2014
Location: California
Posts: 7,787
Hi chessplayer41, 
to the forums!!
Sorry to hear you're having these issues. Just to be clear, the only codes you've had are P0300 and P0420, is that correct?
You've thrown a lot of parts at this, in just a week or so. Have you inspected the wiring for the O2 sensors? Sometimes they get chafed or burned. Are you still using the original O2 sensors?
to the forums!!Sorry to hear you're having these issues. Just to be clear, the only codes you've had are P0300 and P0420, is that correct?
You've thrown a lot of parts at this, in just a week or so. Have you inspected the wiring for the O2 sensors? Sometimes they get chafed or burned. Are you still using the original O2 sensors?
06-17-2017, 05:45 PM
#3
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Join Date: 01-23-2009
Location: Fredericksburg, Virginia
Posts: 24,662
What about compression and leak down?
After you replaced the cat you are still getting P0420?
Misfire on what cylinder? What code numbers?
Has the trans fluid been changed, ever?
Have you hooked up a scanner capable of reading the transmission codes.
Have you popped the cam cover off to inspect the timing chain? Any slop indicates stretching.
You sure did throw a lot of unnecessary money at the problem. Just about everything you replaced has codes associated with their failure.
What is the state of the battery?
Description of codes tell us nothing, we need the number. What about stored codes? The P0420 will prevent some other test from running, as will some other stored codes.
After you replaced the cat you are still getting P0420?
Misfire on what cylinder? What code numbers?
Has the trans fluid been changed, ever?
Have you hooked up a scanner capable of reading the transmission codes.
Have you popped the cam cover off to inspect the timing chain? Any slop indicates stretching.
You sure did throw a lot of unnecessary money at the problem. Just about everything you replaced has codes associated with their failure.
What is the state of the battery?
Description of codes tell us nothing, we need the number. What about stored codes? The P0420 will prevent some other test from running, as will some other stored codes.
06-17-2017, 06:19 PM
#5
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Join Date: 06-17-2017
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Questions Answered
I have not tried checking for compression, that was on my next list along with changing the tranny fluid. After replacing the cat I still get the P0420 code and the misfire is random on each cylinder which caused me to replace all coil packs and spark plugs yet I am still getting it only after gunning the engine to the point of shut down. The scanner that was hooked indicated that 1-2, 2-3 noids in the tranny are working but the some sensor (speed shaft control sensor...?) reads 0 RPMs inside the tranny. Yet the speed sensor that appears to work because my tach and MPH dials work and the speed sensor only have two wires indicating that it's doing it's job as far as giving a proper read out. The two codes for both misfire and cat are the only ones stored. Normal driving does not throw codes, only when I attempt to get on the highway and up to speed. Also, I forgot to mention that it lacks power when shifting through 2-3.
I am also using the original O2 sensors. I have been told that if that engine can do 4000 RPMs then the engine is doing it's part.
I am also using the original O2 sensors. I have been told that if that engine can do 4000 RPMs then the engine is doing it's part.
06-17-2017, 06:26 PM
#6
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Join Date: 06-17-2017
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Forgot to add, the scanner used to monitor the car was only good for car up to 2008 even though the guy informed me that it would still communicate with my car so I am not holding much stock in it's read out
06-17-2017, 07:24 PM
#7
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Join Date: 01-23-2009
Location: Fredericksburg, Virginia
Posts: 24,662
1996 is when OBD2 started, however the "up to 2008" part is why you disregard the verbal part of the code, use only the NUMBER. The OBD2 code numbers are still the same.
If the "misfire is random" means P0300, you are misunderstanding the meaning of the code. It does not mean all of the cylinders are misfiring randomly. It means that there is a misfire happening at a random time, could be 1 cylinder is randomly misfiring, just not consistently.
If it was actually "misfire is random on each cylinder" you would also have P0301,P0302,P0303 and P0304.
The transmission has no internal computer; that is the TCM that is right behind the ECM in front of the fuse box. The TCM will show P07xx codes and maybe some Uxxxx or Cxxxx codes if there are sensor or electronic failures.
All sensors have OBD2 codes associated with failures. Sometimes the failure doesn't get to the warning threshold.
Look at the timing chain. Do a compression and leakdown. Check the fuel pressure. Take it to a trans shop for a diagnostic. I am taking a flying guess at a bad fuel pump assembly.
If the "misfire is random" means P0300, you are misunderstanding the meaning of the code. It does not mean all of the cylinders are misfiring randomly. It means that there is a misfire happening at a random time, could be 1 cylinder is randomly misfiring, just not consistently.
If it was actually "misfire is random on each cylinder" you would also have P0301,P0302,P0303 and P0304.
The transmission has no internal computer; that is the TCM that is right behind the ECM in front of the fuse box. The TCM will show P07xx codes and maybe some Uxxxx or Cxxxx codes if there are sensor or electronic failures.
All sensors have OBD2 codes associated with failures. Sometimes the failure doesn't get to the warning threshold.
Look at the timing chain. Do a compression and leakdown. Check the fuel pressure. Take it to a trans shop for a diagnostic. I am taking a flying guess at a bad fuel pump assembly.
06-17-2017, 08:14 PM
#9
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Join Date: 06-17-2017
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Don, great point and thanks!! No TCM codes and the fuel delivery system is optimal, check for fuel pressure at the injector rail and it's at the correct PSI. In the process of elimination I disconnected the data cable from the tranny and drove the car to see if the gears were changing due to pressure or computer control and the result was only first gear. This leads me back to engine and as you suggested, a compression check. This will be done first thing tomorrow along with timing chain/belt check. One thing for sure, after this I too will be an HHR expert. Quick question, does the speed sensors on the wheel also get factored into the speed control or is it just for the ABS?
