Just thought I would post a warning to all Silverado fans regarding a serious problem with the Duramax which can bite you even if you religiously maintain your vehicle. Chevrolet Customer Service was contacted and the District Specialist's quote to me was that the problem was "not uncommon", and no assistance (even as a shared cost) is available for an out-of-warranty truck.
My particular truck is a 2006 2500HD crew cab LT2 with a multi-thousand dollar Waldoch interior and exterior conversion installed by the original dealer prior to intially being offered for sale. I bought it used, but with a known history and an inspection by a Chevrolet dealership. It has always been a garage-kept, middle-aged owned, unmodified, pleasure vehicle primarly used to pull light snowmobile or boat trailers on long Interstate highway trips. It had 65K miles, never had any problems, all fluids are synthetic Mobile One , with oil changes at 5K and fuel filters at 10K miles. Not a rusted out, abused, neglected work truck in any fashion, and although exposed to Mid-Western salted winter roads, it was kept clean and never used to plow snow or have other exposures to excessive salt.
Last month it showed a continuous check engine light with the underlying code PO677 (a failed glow plug on the number 7 cylinder). The local Chevy dealership found that the bad glow plug was also seized into the aluminum head. I had them check the other seven plugs (one per cylinder) and the same plug on the opposite side (number 8 cylinder) was also seized in place.
For those who have never seen one, a glow plug is a 5 1/2" long, hollow, galvanized steel tube the same size as a Number 2 lead pencil. There is an electrode running through the center of the hollow tube, and the exterior of the tube has approx 1/2 " of threads located at its midpoint which screw into the aluminum heads. The nut to remove it is approximately 1" up the tube from where it enters the head, so torque to remove it is in this unsupported area of the hollow tube. The Chevy tech says no anti-seize is used by the factory during intial assembly. One per cylinder, a glow plug is a little heating probe which assists in igniting the fuel. Like a spark plug, they do not last for ever, and are designed to be easily accessible and replaceable.
Per the dealership, three Chevy techs with a combined 75 yrears of experience used all their knowledge and techniques, including heat and extended soaking with penetrating oils, to free the stuck bad glow plug, yet (as they warned was possible) it still broke off. The electrode pulled out of the hollow tube while still attached to the nut portion, leaving part of the hollow tube still in the head.
They worked for three hours on the other seized plug, and it finally came free. The other six plugs were removed without any major issues, but the thin galvanization on several was rusty in patches, and one showed a whitish residue similar to aluminum oxidation on the threaded area. To remove a seized and broken glow plug the entire head must come off of the engine and taken to a machine shop. Per the dealership, the quickest method to remove the head involves lifting the entire cab and front end off the frame and into the air in order to have access to the complete engine, and this is what they did with my truck.
A total of 30 hours of shop labor was required (not counting the machine shop work). If the seized plug on the other side of the engine had also broken off, it would have meant also removing that head and an additonal eight hours of labor (and hundreds of dollars more in parts such as gaskets which are part of head removal and replacement).
The primary Chevy tech on the job commented on how clean my truck was, and that no signs of abuse or other problems were present. I had all eight glow plugs replaced (and the tech did use anti-seize on the threads) in order to prevent a re-occurence of this problem. Total repair bill, including the $125 machine shop fee and the extra seven glow plugs, was $4,500. After my own research and talking to the tech, it was my decision to replace all the glow plugs at the same time because it is not uncommon for them to go out within as early as 100,000 miles (I saved those which were still funtioning for spares).
I contacted Chevrolet customer service (case reference number 71-1218942853) because I felt that this kind of repair should not be necessary for a well-maintained, low mileage, seven year old truck. My belief was that either the factory over-tightened the glow plugs or should have used anti-seize on the threads, the design of the plug itself is poor (disimilar metals --aluminum head and galvanized steel tubes-- increases corrosion, and a nut located in an unsupported area of the tube just increases the chances of sheering it off when removal torque is applied), and if this is a known problem area then the maintenance schedule should include periodic loosening and application of anti-seize to prevent the plug from corroding / seizing in place. Since my problem, I have researched on forums and found that these seizures have taken place with many others: if you are lucky they come out without breaking off, if not then the head has to be removed.
Chevrolet contacted the dealer about my problem (after first asking me such questions as how do I know my truck wasn't abused or off-roaded, was it maintained by a dealer (not just major things, but also windshield wiper replacement and oil changes), how long have I been Chevy owner, and what did I want from Chevy--full coverage of the costs or splitting costs 50/50). I said I would be happy to have some kind of shared expense, because I realized it was out of warranty. I've owned Chevys of all types since my first car in 1972, including three new ones, and six late model used Chevys, and all repairs other than oil changes or wipers are done by dealers. My late uncle was a Chevy tech/service mgr and our entire family has been very loyal to GM products. The local dealership had the body stripped off this truck and found it very clean and no signs of abuse, and the dealership I had it inspected by initially had found no modifications, problems, or service history other than a warranty-covered computer update.
The Chevrolet Customer Service District Specialist got back with me after talking to the dealership's service department manager, and stated that because this repair was "not an uncommon problem", it was not covered in any fashion (including under 'customer good will') because the warranty had expired.
Obviously I am disappointed in Chevrolet for creating a product in which a $40 part, which like a spark plug is designed to be replaced, would have a "not uncommon problem" of $4,000 repairs on one of their top-of-the-line, over $50K vehicles. Because this problem has evidently surfaced repeatedly since the 2001 introduction of the Duramax, I am also disappointed that at the very least Chevy / GMC did not have loosening and the application of anti-seize paste to the glow plugs as part of the preventative maintenance schedule of these vehicles.
My warning to everyone is that if you own a Duramax equipped vehicle, particularly a truck more than a couple of years old, that you do preventative maintenance on the glow plugs. If you are considering the purchase of a used Duramax, I would suggest that you make any purchase (dealer or private sale) contingent on having a dealership loosening the glow plugs and putting anti-seize on them prior to the purchase. Otherwise it is all on you, because Chevrolet will not stand behind their product on this issue once the warranty expires.
It's good for the dealers who make thousands on repairs, good for Chevrolet in parts sales, and I'm sure it's a calculated risk for Chevy--- probably better that this "not uncommon problem" remain little known rather than risk the possible multitude of repairs which might have to be covered under warranty if people started bringing them in for inspection prior to the end of the five year engine warranty. It's not so good for the consumer.
On a side note, a friend who used to be a F*rd tech says that in this era of '100K mile' spark plugs and aluminum heads, seizures could also take place in gasoline engines. Once again, a situation where the average 10-15 thousand mile per year driver will be out of warranty by the time you realize just how screwed you are.
Corey
A few pics of the truck and glow plugs:
My particular truck is a 2006 2500HD crew cab LT2 with a multi-thousand dollar Waldoch interior and exterior conversion installed by the original dealer prior to intially being offered for sale. I bought it used, but with a known history and an inspection by a Chevrolet dealership. It has always been a garage-kept, middle-aged owned, unmodified, pleasure vehicle primarly used to pull light snowmobile or boat trailers on long Interstate highway trips. It had 65K miles, never had any problems, all fluids are synthetic Mobile One , with oil changes at 5K and fuel filters at 10K miles. Not a rusted out, abused, neglected work truck in any fashion, and although exposed to Mid-Western salted winter roads, it was kept clean and never used to plow snow or have other exposures to excessive salt.
Last month it showed a continuous check engine light with the underlying code PO677 (a failed glow plug on the number 7 cylinder). The local Chevy dealership found that the bad glow plug was also seized into the aluminum head. I had them check the other seven plugs (one per cylinder) and the same plug on the opposite side (number 8 cylinder) was also seized in place.
For those who have never seen one, a glow plug is a 5 1/2" long, hollow, galvanized steel tube the same size as a Number 2 lead pencil. There is an electrode running through the center of the hollow tube, and the exterior of the tube has approx 1/2 " of threads located at its midpoint which screw into the aluminum heads. The nut to remove it is approximately 1" up the tube from where it enters the head, so torque to remove it is in this unsupported area of the hollow tube. The Chevy tech says no anti-seize is used by the factory during intial assembly. One per cylinder, a glow plug is a little heating probe which assists in igniting the fuel. Like a spark plug, they do not last for ever, and are designed to be easily accessible and replaceable.
Per the dealership, three Chevy techs with a combined 75 yrears of experience used all their knowledge and techniques, including heat and extended soaking with penetrating oils, to free the stuck bad glow plug, yet (as they warned was possible) it still broke off. The electrode pulled out of the hollow tube while still attached to the nut portion, leaving part of the hollow tube still in the head.
They worked for three hours on the other seized plug, and it finally came free. The other six plugs were removed without any major issues, but the thin galvanization on several was rusty in patches, and one showed a whitish residue similar to aluminum oxidation on the threaded area. To remove a seized and broken glow plug the entire head must come off of the engine and taken to a machine shop. Per the dealership, the quickest method to remove the head involves lifting the entire cab and front end off the frame and into the air in order to have access to the complete engine, and this is what they did with my truck.
A total of 30 hours of shop labor was required (not counting the machine shop work). If the seized plug on the other side of the engine had also broken off, it would have meant also removing that head and an additonal eight hours of labor (and hundreds of dollars more in parts such as gaskets which are part of head removal and replacement).
The primary Chevy tech on the job commented on how clean my truck was, and that no signs of abuse or other problems were present. I had all eight glow plugs replaced (and the tech did use anti-seize on the threads) in order to prevent a re-occurence of this problem. Total repair bill, including the $125 machine shop fee and the extra seven glow plugs, was $4,500. After my own research and talking to the tech, it was my decision to replace all the glow plugs at the same time because it is not uncommon for them to go out within as early as 100,000 miles (I saved those which were still funtioning for spares).
I contacted Chevrolet customer service (case reference number 71-1218942853) because I felt that this kind of repair should not be necessary for a well-maintained, low mileage, seven year old truck. My belief was that either the factory over-tightened the glow plugs or should have used anti-seize on the threads, the design of the plug itself is poor (disimilar metals --aluminum head and galvanized steel tubes-- increases corrosion, and a nut located in an unsupported area of the tube just increases the chances of sheering it off when removal torque is applied), and if this is a known problem area then the maintenance schedule should include periodic loosening and application of anti-seize to prevent the plug from corroding / seizing in place. Since my problem, I have researched on forums and found that these seizures have taken place with many others: if you are lucky they come out without breaking off, if not then the head has to be removed.
Chevrolet contacted the dealer about my problem (after first asking me such questions as how do I know my truck wasn't abused or off-roaded, was it maintained by a dealer (not just major things, but also windshield wiper replacement and oil changes), how long have I been Chevy owner, and what did I want from Chevy--full coverage of the costs or splitting costs 50/50). I said I would be happy to have some kind of shared expense, because I realized it was out of warranty. I've owned Chevys of all types since my first car in 1972, including three new ones, and six late model used Chevys, and all repairs other than oil changes or wipers are done by dealers. My late uncle was a Chevy tech/service mgr and our entire family has been very loyal to GM products. The local dealership had the body stripped off this truck and found it very clean and no signs of abuse, and the dealership I had it inspected by initially had found no modifications, problems, or service history other than a warranty-covered computer update.
The Chevrolet Customer Service District Specialist got back with me after talking to the dealership's service department manager, and stated that because this repair was "not an uncommon problem", it was not covered in any fashion (including under 'customer good will') because the warranty had expired.
Obviously I am disappointed in Chevrolet for creating a product in which a $40 part, which like a spark plug is designed to be replaced, would have a "not uncommon problem" of $4,000 repairs on one of their top-of-the-line, over $50K vehicles. Because this problem has evidently surfaced repeatedly since the 2001 introduction of the Duramax, I am also disappointed that at the very least Chevy / GMC did not have loosening and the application of anti-seize paste to the glow plugs as part of the preventative maintenance schedule of these vehicles.
My warning to everyone is that if you own a Duramax equipped vehicle, particularly a truck more than a couple of years old, that you do preventative maintenance on the glow plugs. If you are considering the purchase of a used Duramax, I would suggest that you make any purchase (dealer or private sale) contingent on having a dealership loosening the glow plugs and putting anti-seize on them prior to the purchase. Otherwise it is all on you, because Chevrolet will not stand behind their product on this issue once the warranty expires.
It's good for the dealers who make thousands on repairs, good for Chevrolet in parts sales, and I'm sure it's a calculated risk for Chevy--- probably better that this "not uncommon problem" remain little known rather than risk the possible multitude of repairs which might have to be covered under warranty if people started bringing them in for inspection prior to the end of the five year engine warranty. It's not so good for the consumer.
On a side note, a friend who used to be a F*rd tech says that in this era of '100K mile' spark plugs and aluminum heads, seizures could also take place in gasoline engines. Once again, a situation where the average 10-15 thousand mile per year driver will be out of warranty by the time you realize just how screwed you are.
Corey
A few pics of the truck and glow plugs:
