HOLD ON NOW. You have a P0305 code, a misfire on #5 cyl. The Bulletin is for a P0300 random misfire. Totally different animals. You most likely have a bad coil. Get one and install it. #5 is the last cylinder right next to the fire wall. Do the plugs too if you are due or close to it. I've changed a few on these motors. Your mechanic is trying to rape you in my opinion.
06 Colorado, Dreaded P0305 Code...GM says SOL
- Thread starter Brigadier
- Start date
- Status
Originally Posted By: GMBoy
HOLD ON NOW. You have a P0305 code, a misfire on #5 cyl. The Bulletin is for a P0300 random misfire. Totally different animals. You most likely have a bad coil. Get one and install it. #5 is the last cylinder right next to the fire wall. Do the plugs too if you are due or close to it. I've changed a few on these motors. Your mechanic is trying to rape you in my opinion.
read the entire thread...
Quote:
Scanned for codes and found:
P0300 Random Misfire detected
Checked misfire data screen and found misfire counts on every cylinder.
Cyl 1 170
Cyl 2 4 Cyl 3 4
Cyl 4 2 Cyl 5 3000
Cylinder 5 is dropping the hardest, but
did experience misfires on #1 during road test. The misfire only seems to
happen at idle and never under full load. This would typically rule out
ignition components.
Researched and found a TSB for faulty valve sealing causing issues. Performed
a relative compression test and noticed the pulls were uneven after a road test.
Pulled the #5 plug and did a cranking compression test with pressure
transducer. Found the compression tower was thinner on the right side,
indicating cylinder pressure leakage. Performed a running compression test and
the exhaust pocket is rounded and has less vacuum than before the compression
event. Both lower values should be the same. This indicates valve leakage. Max
compression cranking was 180 psi on cylinder #5. Checked cranking on #2 and
found 167 psi compression. This cylinder also shows leakage. The TSB does apply
and the cylinder head will require replacement due to leaking valves.
HOLD ON NOW. You have a P0305 code, a misfire on #5 cyl. The Bulletin is for a P0300 random misfire. Totally different animals. You most likely have a bad coil. Get one and install it. #5 is the last cylinder right next to the fire wall. Do the plugs too if you are due or close to it. I've changed a few on these motors. Your mechanic is trying to rape you in my opinion.
read the entire thread...
Quote:
Scanned for codes and found:
P0300 Random Misfire detected
Checked misfire data screen and found misfire counts on every cylinder.
Cyl 1 170
Cyl 2 4 Cyl 3 4
Cyl 4 2 Cyl 5 3000
Cylinder 5 is dropping the hardest, but
did experience misfires on #1 during road test. The misfire only seems to
happen at idle and never under full load. This would typically rule out
ignition components.
Researched and found a TSB for faulty valve sealing causing issues. Performed
a relative compression test and noticed the pulls were uneven after a road test.
Pulled the #5 plug and did a cranking compression test with pressure
transducer. Found the compression tower was thinner on the right side,
indicating cylinder pressure leakage. Performed a running compression test and
the exhaust pocket is rounded and has less vacuum than before the compression
event. Both lower values should be the same. This indicates valve leakage. Max
compression cranking was 180 psi on cylinder #5. Checked cranking on #2 and
found 167 psi compression. This cylinder also shows leakage. The TSB does apply
and the cylinder head will require replacement due to leaking valves.
Last edited:
Originally Posted By: Brigadier
Originally Posted By: GMBoy
HOLD ON NOW. You have a P0305 code, a misfire on #5 cyl. The Bulletin is for a P0300 random misfire. Totally different animals. You most likely have a bad coil. Get one and install it. #5 is the last cylinder right next to the fire wall. Do the plugs too if you are due or close to it. I've changed a few on these motors. Your mechanic is trying to rape you in my opinion.
read the entire thread...
Quote:
Scanned for codes and found:
P0300 Random Misfire detected
Checked misfire data screen and found misfire counts on every cylinder.
Cyl 1 170
Cyl 2 4 Cyl 3 4
Cyl 4 2 Cyl 5 3000
Cylinder 5 is dropping the hardest, but
did experience misfires on #1 during road test. The misfire only seems to
happen at idle and never under full load. This would typically rule out
ignition components.
Researched and found a TSB for faulty valve sealing causing issues. Performed
a relative compression test and noticed the pulls were uneven after a road test.
Pulled the #5 plug and did a cranking compression test with pressure
transducer. Found the compression tower was thinner on the right side,
indicating cylinder pressure leakage. Performed a running compression test and
the exhaust pocket is rounded and has less vacuum than before the compression
event. Both lower values should be the same. This indicates valve leakage. Max
compression cranking was 180 psi on cylinder #5. Checked cranking on #2 and
found 167 psi compression. This cylinder also shows leakage. The TSB does apply
and the cylinder head will require replacement due to leaking valves.
I got too excited - thanks. I should have read more. I usually do but not this time
Originally Posted By: GMBoy
HOLD ON NOW. You have a P0305 code, a misfire on #5 cyl. The Bulletin is for a P0300 random misfire. Totally different animals. You most likely have a bad coil. Get one and install it. #5 is the last cylinder right next to the fire wall. Do the plugs too if you are due or close to it. I've changed a few on these motors. Your mechanic is trying to rape you in my opinion.
read the entire thread...
Quote:
Scanned for codes and found:
P0300 Random Misfire detected
Checked misfire data screen and found misfire counts on every cylinder.
Cyl 1 170
Cyl 2 4 Cyl 3 4
Cyl 4 2 Cyl 5 3000
Cylinder 5 is dropping the hardest, but
did experience misfires on #1 during road test. The misfire only seems to
happen at idle and never under full load. This would typically rule out
ignition components.
Researched and found a TSB for faulty valve sealing causing issues. Performed
a relative compression test and noticed the pulls were uneven after a road test.
Pulled the #5 plug and did a cranking compression test with pressure
transducer. Found the compression tower was thinner on the right side,
indicating cylinder pressure leakage. Performed a running compression test and
the exhaust pocket is rounded and has less vacuum than before the compression
event. Both lower values should be the same. This indicates valve leakage. Max
compression cranking was 180 psi on cylinder #5. Checked cranking on #2 and
found 167 psi compression. This cylinder also shows leakage. The TSB does apply
and the cylinder head will require replacement due to leaking valves.
I got too excited - thanks. I should have read more. I usually do but not this time
Originally Posted By: GMBoy
Originally Posted By: Brigadier
Originally Posted By: GMBoy
HOLD ON NOW. You have a P0305 code, a misfire on #5 cyl. The Bulletin is for a P0300 random misfire. Totally different animals. You most likely have a bad coil. Get one and install it. #5 is the last cylinder right next to the fire wall. Do the plugs too if you are due or close to it. I've changed a few on these motors. Your mechanic is trying to rape you in my opinion.
read the entire thread...
Quote:
Scanned for codes and found:
P0300 Random Misfire detected
Checked misfire data screen and found misfire counts on every cylinder.
Cyl 1 170
Cyl 2 4 Cyl 3 4
Cyl 4 2 Cyl 5 3000
Cylinder 5 is dropping the hardest, but
did experience misfires on #1 during road test. The misfire only seems to
happen at idle and never under full load. This would typically rule out
ignition components.
Researched and found a TSB for faulty valve sealing causing issues. Performed
a relative compression test and noticed the pulls were uneven after a road test.
Pulled the #5 plug and did a cranking compression test with pressure
transducer. Found the compression tower was thinner on the right side,
indicating cylinder pressure leakage. Performed a running compression test and
the exhaust pocket is rounded and has less vacuum than before the compression
event. Both lower values should be the same. This indicates valve leakage. Max
compression cranking was 180 psi on cylinder #5. Checked cranking on #2 and
found 167 psi compression. This cylinder also shows leakage. The TSB does apply
and the cylinder head will require replacement due to leaking valves.
I got too excited - thanks. I should have read more. I usually do but not this time
Understood. I was hoping that it was a coil. The spark plugs were done in November.
Originally Posted By: Brigadier
Originally Posted By: GMBoy
HOLD ON NOW. You have a P0305 code, a misfire on #5 cyl. The Bulletin is for a P0300 random misfire. Totally different animals. You most likely have a bad coil. Get one and install it. #5 is the last cylinder right next to the fire wall. Do the plugs too if you are due or close to it. I've changed a few on these motors. Your mechanic is trying to rape you in my opinion.
read the entire thread...
Quote:
Scanned for codes and found:
P0300 Random Misfire detected
Checked misfire data screen and found misfire counts on every cylinder.
Cyl 1 170
Cyl 2 4 Cyl 3 4
Cyl 4 2 Cyl 5 3000
Cylinder 5 is dropping the hardest, but
did experience misfires on #1 during road test. The misfire only seems to
happen at idle and never under full load. This would typically rule out
ignition components.
Researched and found a TSB for faulty valve sealing causing issues. Performed
a relative compression test and noticed the pulls were uneven after a road test.
Pulled the #5 plug and did a cranking compression test with pressure
transducer. Found the compression tower was thinner on the right side,
indicating cylinder pressure leakage. Performed a running compression test and
the exhaust pocket is rounded and has less vacuum than before the compression
event. Both lower values should be the same. This indicates valve leakage. Max
compression cranking was 180 psi on cylinder #5. Checked cranking on #2 and
found 167 psi compression. This cylinder also shows leakage. The TSB does apply
and the cylinder head will require replacement due to leaking valves.
I got too excited - thanks. I should have read more. I usually do but not this time
Understood. I was hoping that it was a coil. The spark plugs were done in November.
4WD
$50 site donor 2024
Correct ~ Canyon does not have AFM … the Tahoe does, but newer generation …
Originally Posted By: Trav
Originally Posted By: Bottom_Feeder
Those are basically wear item that get replaced with a 'good' reman job. I wouldn't write off a reman from a good known shop. I'm sure the problem is well-known by most folks in the business.
+1 on that! If that's all it is its an easy fix for any competent automotive machine shop, have old head redone with new seats and guides. This is a big performance over nothing. Yank the head, give it to the shop, get a gasket set and put it back together. I bet its not hitting a grand done and dusted.
This solution must make too much sense...
Originally Posted By: Bottom_Feeder
Those are basically wear item that get replaced with a 'good' reman job. I wouldn't write off a reman from a good known shop. I'm sure the problem is well-known by most folks in the business.
+1 on that! If that's all it is its an easy fix for any competent automotive machine shop, have old head redone with new seats and guides. This is a big performance over nothing. Yank the head, give it to the shop, get a gasket set and put it back together. I bet its not hitting a grand done and dusted.
This solution must make too much sense...
Well, the shop took the valve cover off and noticed that the front timing chain was extremely loose when they turned it over, and the tensioner was inoperative. So, to fix the timing chains, the engine must come out of the truck. The estimate is as much or more than KBB for the truck. So I am walking away from it and gonna sell it as is for what I can get for it.
114k miles and the engine is toast...not a good look for GM.
114k miles and the engine is toast...not a good look for GM.
Originally Posted By: Brigadier
So, to fix the timing chains, the engine must come out of the truck.
.
Now that's just poor design from a repairablity standpoint. Is the timing chain in the front of the engine, or did GM move the cam drive to the back of the engine as a matter of NVH since 5-cylinder engines can run/sound "rough"?
So, to fix the timing chains, the engine must come out of the truck.
.
Now that's just poor design from a repairablity standpoint. Is the timing chain in the front of the engine, or did GM move the cam drive to the back of the engine as a matter of NVH since 5-cylinder engines can run/sound "rough"?
Originally Posted By: nthach
Originally Posted By: Brigadier
So, to fix the timing chains, the engine must come out of the truck.
.
Now that's just poor design from a repairablity standpoint. Is the timing chain in the front of the engine, or did GM move the cam drive to the back of the engine as a matter of NVH since 5-cylinder engines can run/sound "rough"?
Both. There are front and rear chains.
Originally Posted By: Brigadier
So, to fix the timing chains, the engine must come out of the truck.
.
Now that's just poor design from a repairablity standpoint. Is the timing chain in the front of the engine, or did GM move the cam drive to the back of the engine as a matter of NVH since 5-cylinder engines can run/sound "rough"?
Both. There are front and rear chains.
From the looks of it, I don't think the engine needs to come out at all - the rear timing chain and sprockets are there for the balance shaft assemblies. The timing chain for the cams is in the front. But you already made your decision, this was an interesting read.
http://www.expertswrite.net/techtales/142-gm-2-9l-engine-crazyness-what-were-they-thinking.html
http://www.expertswrite.net/techtales/142-gm-2-9l-engine-crazyness-what-were-they-thinking.html
The Timing Chain Tensioner is activated with OIL PRESSURE!!! If it was bad.....You would KNOW it. You weren't complaining of noise or Camshaft position/correlation trouble codes? There is a special tool that allows removal of the cylinder head without removing the Timing Cover......Kent Moore EN48464, It prevents the tensioner from ratcheting out of place.
Your Balance Shaft chain (If the vehicles was maintained) is probably Okay!!!!
Your Balance Shaft chain (If the vehicles was maintained) is probably Okay!!!!
Well, I ended up walking away from the truck with $1250 in my pocket. The owner of the shop bought it from me as is....it is now his problem.
So, now I get to go car shopping....yay!!!
I did enough research into this issue to know that this was probably the best route given the problems with the Colorado in general.
So, now I get to go car shopping....yay!!!
I did enough research into this issue to know that this was probably the best route given the problems with the Colorado in general.
Last edited:
Originally Posted By: DevilsRule
I despise this bias toward American vehicles [censored]. Sick people, no pride.
You want pride?
How about making a higher quality product?!?
Don't come in here and coast on your own bravado.
Put out a better product and shut the competition up with your outstanding quality. Set yourself apart but a positive way.
The problem with the Big 2-1/2 is that they have definitely set themselves apart, but not in a way that anyone would want to lay claim to.
Come back when you can espouse Deming and know the difference between Cp and Cpk.
Looking forward to your response!
I despise this bias toward American vehicles [censored]. Sick people, no pride.
You want pride?
How about making a higher quality product?!?
Don't come in here and coast on your own bravado.
Put out a better product and shut the competition up with your outstanding quality. Set yourself apart but a positive way.
The problem with the Big 2-1/2 is that they have definitely set themselves apart, but not in a way that anyone would want to lay claim to.
Come back when you can espouse Deming and know the difference between Cp and Cpk.
Looking forward to your response!
Originally Posted By: Brigadier
Well, I ended up walking away from the truck with $1250 in my pocket. The owner of the shop bought it from me as is....it is now his problem.
So, now I get to go car shopping....yay!!!
I did enough research into this issue to know that this was probably the best route given the problems with the Colorado in general.
The shop owner that said the chain was "loose" with the engine off? Interesting.
Well, I ended up walking away from the truck with $1250 in my pocket. The owner of the shop bought it from me as is....it is now his problem.
So, now I get to go car shopping....yay!!!
I did enough research into this issue to know that this was probably the best route given the problems with the Colorado in general.
The shop owner that said the chain was "loose" with the engine off? Interesting.
Originally Posted By: Rolla07
GM really doesnt have a solid track record..they dont seem to take care of their customers either. Friend of mine has a 2011 Buick Regal with the 2.4. Not only did his engine need a rebuild, but the transmission went out as well. Pure junk. He has 126,000kms on his car too, like really? I think automakers need to stand by their products better. I dont blame you for being upset. We as customers must demand better as a collective. Not saying any major auto maker is better but trends are evident.
They've taken care of me with many repairs covered past the warranty, including a 2008 Express Van that blew out the transmission at 115,000 miles. They paid half and put a brand new, not rebuilt, 4L80E in it for 2 grand, and put a 36k mile warranty on it from there. I've had many GM vehicles and loved them all, and I never got shafted by them, but was always treated better than I expected.
GM really doesnt have a solid track record..they dont seem to take care of their customers either. Friend of mine has a 2011 Buick Regal with the 2.4. Not only did his engine need a rebuild, but the transmission went out as well. Pure junk. He has 126,000kms on his car too, like really? I think automakers need to stand by their products better. I dont blame you for being upset. We as customers must demand better as a collective. Not saying any major auto maker is better but trends are evident.
They've taken care of me with many repairs covered past the warranty, including a 2008 Express Van that blew out the transmission at 115,000 miles. They paid half and put a brand new, not rebuilt, 4L80E in it for 2 grand, and put a 36k mile warranty on it from there. I've had many GM vehicles and loved them all, and I never got shafted by them, but was always treated better than I expected.
Originally Posted By: DevilsRule
The next week, his brand new Nissan is leaving their driveway on a flatbed. I despise this bias toward American vehicles [censored]. Sick people, no pride.
If the the Detroit 2(but GM has Chinese ownership as well in stock and joint ventures) and the Italian-American in Auburn Hills actually let the people at the factories and labs do their jobs instead of giving the C-suite and shareholders nice payouts and dividends maybe the American people would have more respect for Detroit as it did before the 1970s rolled around.
Lee Iacocca said it best - it you can find a better car, buy it.
The next week, his brand new Nissan is leaving their driveway on a flatbed. I despise this bias toward American vehicles [censored]. Sick people, no pride.
If the the Detroit 2(but GM has Chinese ownership as well in stock and joint ventures) and the Italian-American in Auburn Hills actually let the people at the factories and labs do their jobs instead of giving the C-suite and shareholders nice payouts and dividends maybe the American people would have more respect for Detroit as it did before the 1970s rolled around.
Lee Iacocca said it best - it you can find a better car, buy it.
Last edited:
4WD
$50 site donor 2024
Originally Posted By: clinebarger
The Timing Chain Tensioner is activated with OIL PRESSURE!!! If it was bad.....You would KNOW it. You weren't complaining of noise or Camshaft position/correlation trouble codes? There is a special tool that allows removal of the cylinder head without removing the Timing Cover......Kent Moore EN48464, It prevents the tensioner from ratcheting out of place.
Your Balance Shaft chain (If the vehicles was maintained) is probably Okay!!!!
Interesting comment from someone who is clearly a top notch mechanic … watched a couple Canadian mechanics change them without pulling the motor … so I’m puzzled ?
The Timing Chain Tensioner is activated with OIL PRESSURE!!! If it was bad.....You would KNOW it. You weren't complaining of noise or Camshaft position/correlation trouble codes? There is a special tool that allows removal of the cylinder head without removing the Timing Cover......Kent Moore EN48464, It prevents the tensioner from ratcheting out of place.
Your Balance Shaft chain (If the vehicles was maintained) is probably Okay!!!!
Interesting comment from someone who is clearly a top notch mechanic … watched a couple Canadian mechanics change them without pulling the motor … so I’m puzzled ?
4WD
$50 site donor 2024
Originally Posted By: nthach
Originally Posted By: DevilsRule
The next week, his brand new Nissan is leaving their driveway on a flatbed. I despise this bias toward American vehicles [censored]. Sick people, no pride.
If the the Detroit 2(but GM has Chinese ownership as well in stock and joint ventures) and the Italian-American in Auburn Hills actually let the people at the factories and labs do their jobs instead of giving the C-suite and shareholders nice payouts and dividends maybe the American people would have more respect for Detroit as it did before the 1970s rolled around.
Lee Iacocca said it best - it you can find a better car, buy it.
I still like a pushrod engine … run forever and can’t hurt them … no repairs on my Canyon nor our 1/2 Company product …a 2007 Chrysler 300 has never seen a dealer/shop at 200k … been a great car …
Did get the timing belt done at 100k … but that’s listed in the OM as a PM schedule item
(Did proactively slip in an inexpensive water pump while easy to get to = it had not failed)
Originally Posted By: DevilsRule
The next week, his brand new Nissan is leaving their driveway on a flatbed. I despise this bias toward American vehicles [censored]. Sick people, no pride.
If the the Detroit 2(but GM has Chinese ownership as well in stock and joint ventures) and the Italian-American in Auburn Hills actually let the people at the factories and labs do their jobs instead of giving the C-suite and shareholders nice payouts and dividends maybe the American people would have more respect for Detroit as it did before the 1970s rolled around.
Lee Iacocca said it best - it you can find a better car, buy it.
I still like a pushrod engine … run forever and can’t hurt them … no repairs on my Canyon nor our 1/2 Company product …a 2007 Chrysler 300 has never seen a dealer/shop at 200k … been a great car …
Did get the timing belt done at 100k … but that’s listed in the OM as a PM schedule item
(Did proactively slip in an inexpensive water pump while easy to get to = it had not failed)
Last edited:
Originally Posted By: 4WD
Originally Posted By: clinebarger
The Timing Chain Tensioner is activated with OIL PRESSURE!!! If it was bad.....You would KNOW it. You weren't complaining of noise or Camshaft position/correlation trouble codes? There is a special tool that allows removal of the cylinder head without removing the Timing Cover......Kent Moore EN48464, It prevents the tensioner from ratcheting out of place.
Your Balance Shaft chain (If the vehicles was maintained) is probably Okay!!!!
Interesting comment from someone who is clearly a top notch mechanic … watched a couple Canadian mechanics change them without pulling the motor … so I’m puzzled ?
I was a GM Dealer Tech when the 4.2L Atlas engines first came out. I went through all service issue headaches that come with a all new engine design.
First off.....The Altas can be be completely overhauled with the Block in the vehicle, Even the Cylinder Bore Sleeves can be changed! Weather or not it's FASTER to do a "In-Frame" is up for debate?
The Oil Pump is bolted to/part of the front cover, To remove the front cover.....You must first remove the Oil Pan & Pick-Up Tube. Not a big deal on a 2wd model....Quite a bit more work on a 4wd model.
There are NO referencing Timing Marks on the engine ANYWHERE! The ONLY way to cull a Timing Chain is IF the PCM is setting Camshaft Position error codes P0014 &/or P0016.
Now....There are Timing Chain noise issues that can arise from worn out Timing Chain/Guides-Shoes/VTT Phaser Wear/Maxed out Tensioner. Although it's been my experience that this also sets P0014 &/or P0016.
As I stated already (Completely Ignored by most).....Free Play in the Timing Chain with the engine off is 100% normal!!! FACTS sure are pesky problems when they don't fit the narrative.
I have NO clue how the Balance Shafts Chain got brought up in this thread? Other than to "Pile-On" by the OP or the Mechanic/Shop Owner.....Or a combination of all three??
In the end......Using the Kent Moore tool, Having the cylinder head repaired along with some gaskets/head bolts/fluids would have got this truck back into service without a huge bill. I guess that doesn't make for a good DRAMA filled GM bashing thread?
Originally Posted By: clinebarger
The Timing Chain Tensioner is activated with OIL PRESSURE!!! If it was bad.....You would KNOW it. You weren't complaining of noise or Camshaft position/correlation trouble codes? There is a special tool that allows removal of the cylinder head without removing the Timing Cover......Kent Moore EN48464, It prevents the tensioner from ratcheting out of place.
Your Balance Shaft chain (If the vehicles was maintained) is probably Okay!!!!
Interesting comment from someone who is clearly a top notch mechanic … watched a couple Canadian mechanics change them without pulling the motor … so I’m puzzled ?
I was a GM Dealer Tech when the 4.2L Atlas engines first came out. I went through all service issue headaches that come with a all new engine design.
First off.....The Altas can be be completely overhauled with the Block in the vehicle, Even the Cylinder Bore Sleeves can be changed! Weather or not it's FASTER to do a "In-Frame" is up for debate?
The Oil Pump is bolted to/part of the front cover, To remove the front cover.....You must first remove the Oil Pan & Pick-Up Tube. Not a big deal on a 2wd model....Quite a bit more work on a 4wd model.
There are NO referencing Timing Marks on the engine ANYWHERE! The ONLY way to cull a Timing Chain is IF the PCM is setting Camshaft Position error codes P0014 &/or P0016.
Now....There are Timing Chain noise issues that can arise from worn out Timing Chain/Guides-Shoes/VTT Phaser Wear/Maxed out Tensioner. Although it's been my experience that this also sets P0014 &/or P0016.
As I stated already (Completely Ignored by most).....Free Play in the Timing Chain with the engine off is 100% normal!!! FACTS sure are pesky problems when they don't fit the narrative.
I have NO clue how the Balance Shafts Chain got brought up in this thread? Other than to "Pile-On" by the OP or the Mechanic/Shop Owner.....Or a combination of all three??
In the end......Using the Kent Moore tool, Having the cylinder head repaired along with some gaskets/head bolts/fluids would have got this truck back into service without a huge bill. I guess that doesn't make for a good DRAMA filled GM bashing thread?
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