This is a description of our experience with Polk Diesel.
On 4/30/08 I picked up my Duramax Diesel motor (for our pull truck) that was rebuilt and had machine work done for $4290.59.(Inv #108943) We installed the motor in the truck and experienced low power. Eventually the motor overheated, we took the motor out and did a compression test. The compression was low 150psi (should be 300-400psi).
We returned the motor to Polk Diesel on 7/18/08. I complained of low compression and coolant leak in the heads. I told them to diagnose the problem and thoroughly check the motor. They found the injector cups were leaking and cylinder walls were glazed. They replaced the injector cups, injector hold downs, tested the heads, removed pistons, and deglazed the cylinders. The pistons were reinstalled with new rings. The cost of all of these parts was $1738.30 (Holz Watertown Inv#3035) The heads were then bolted back down with new head gaskets with a labor cost of $1093.29 (Inv.#110615). Included in this price was the cost for Pressure testing 2 cylinder heads.
We picked it up on 7/24/08. Brought the motor home, did a compression test and the results were the same as when I dropped it off. We were very disappointed that Polk would send us a motor that did not fix the problem we complained about - compression. On 7/25/08 I took it back to Polk and told them about the low compression. They found the valves to be leaking. On 7/28/08 we went back and discussed the problem and distrust and decided that it was in our best interest to take the motor elsewhere. At that point Polk issued a rebate for (Inv.#110615) of $1093.29 and the cost of new head gaskets for a total of $1355.
We decided to take the motor to Curtis Halvorson of Performance Diesel Research in Sheboygan, WI. On the day of delivery Curtis noted other issues with the machining and assembly of the motor. His report states that the cylinder bores were inconsistant and inaccurate. For example each cylinder should measure the same on the top, middle, and bottom and all 8 cylinders had different measures therein. The piston cylinder wall clearance was also larger than requested recommended by the dealer. This inaccuracy caused the pistons to rock at top dead center and contact the head. Curtis also determined that the reason the valves were leaking was because they were all bent - which occurred because the valve seats were installed at the incorrect angle.
Diesel Performance Research redid the heads, new valves, valve seats reinstalled properly. Also the cylinder walls were machined too large/inconsistant by Polk so DPR had to machine them .020 larger and we had to buy larger pistons for $2500 (from TTS). Shortly after the faults were noted, we contacted Polk. They said they would send a technician - however he never came/contacted us. DPR is still working on the motor. His estimate for labor and machining is $3688.00.
In an attempt to compromise with Polk we returned on 11/13/08 and spoke with Gerald Kalscherer (service manager). We showed him the engine report from DPR with the inaccuracies defined and asked for a refund of the initial bill (Inv. #108943 - $4290.59). We pointed out that the reason we had all of the problems was because of the machining that was not done correctly nor was it done to the specs we asked. We don't understand how the motor could be returned the second time without them catching the problem. However, we were told that Gerald didn't have the authority to give that refund. We were told Jim Polk did, but was not in that day. We asked that Jim call us the next day with an answer. The following day Gerald called and stated that Jim said no refund would be given. I asked Gerald to have Jim call me in person and I never heard from him.
I feel that this is a fair compromise given the extreme costs for parts and labor to fix/repair the damage that Polk did to our motor. Not to mention the loss of the competition season, sponsor monies, possible winnings, overnight shipping for many parts, transporting/fuel, and time.
I have since spent time trying to reach a compromise with Polk. They will do nothing but to deny they made mistakes. My purpose here is to advise as many others as possible of the unprofessional business practices at Polk diesel.