The Forbidden Tap Dance: Clyde the K2EC at 300,000 Miles

[CadillacLuke24]

Jun 13th, 2024 brought 300k miles. Clyde is still trucking, though there have been some developments. Currently north of 326,000.

 

Drivetrain: at 252,064 miles in August of 22 I developed a substantial misfire that significantly affected drivability. Made it home and attempted to diagnose the issue. New plugs and wires didn't solve the issue, and a new MAP sensor (was throwing a MAP sensor code and Cylinder 2 misfire). Injectors did not solve the issue either. Compression testing on Cylinder 2 suggested a massive issue as there was none, so I limped to the dealer. A teardown found likely the intake valve failed and eventually took the exhaust valve with it. The cylinder head took a beating, as the valve seats were damaged severely in a couple spots, and the piston was cracked all the way through. Due to costs related at the least to a removal and replacement, I decided on an engine replacement. I found a brand new engine out of Michigan Motorz for truck applications at $8,000, and the dealer installed it for another $6,000. I had initially suspected the original engine was toast, but I didn't have to turn it in for a core so I stuck it in storage. After a brief inspection the cylinder 2 wall appears to have survived. Unscathed. Further inspection is naturally merited, but I believe I have a rebuildable block on my hands. 

 

The new engine runs like a top, burns no oil, runs at temp, and gets slightly better fuel economy. Break in was textbook as I followed a 55mph speed limit with a rev limit of 3,000, no racing starts, no lugging, and generally gentle driving for the first 500 miles. Oil analysis shows the engine wearing in well. Interestingly the oil analysis showed no signs of failure prior to the valve drop. A couple hours prior to the valve drop I completely drained the tank and coasted to a stop at a pull off on the side of the interstate. I did 2 cranks at 10 second intervals, so that may have have something to do with it. I've been much more vigilant about gambling with fuel economy, and ran out once since then with immediate shutdown and no restarts. I leave myself a buffer of about 10 miles to empty before I stop to refuel.

[CadillacLuke24]

The catalytic converter started failing at about 290k, with a P0420 code recurring. Cataclean did nothing so I opted for a new assembly to maintain full functionality. Problem solved and fuel economy slightly improved. 

 

Transmission is behaving well. No concerns at fluid changes and the trans cooler line (factory part) was replaced at 293 due to a persistent weep at the rubber/metal junction in front of the right frame rail. Following my thermostat delete I opted to take the guts from a revised 6 speed tstat (opens fully at 158) and install them into a body for the 8 speed at 221k. Following that mod I have consistent temps from about 140-158, and temps have gotten only as high as 185 with spirited mountain driving. 

 

Four Wheel Drive is operating flawlessly. Front hubs were replaced at 242 for suspected sound, though there were no other wear indicators. I suspect I was being far too cautious.

 

Struts and shocks in the rear were serviced at 306k. The Pinion seal for the rear differential was serviced at 312k and I did it right because no more leaks and no new vibrations or sounds. Followed the shop manual for the most part. 

 

Frame is good. Surface rust that responds well to frame wax sprays and/or Amsoil MP HD. 

 

Right Rocker was replaced due to incompetent prior shop, as well as the RF fender. No more Prazma work present anymore. Some rust on the LR wheel well outer surface above the tire and the right inner rocker was removed and the area repainted. No issues since. Both inner rockers were bombarded with cavity wax. 

 

Edited April 8, 2025 by CadillacLuke24

[CadillacLuke24]

The inner wheel well gaps were collecting rocks so I followed the TSB and BURIED both cavities with frame wax. No wheel well rust through and no more rocks. 

 

Box is doing well and Line-X liner is holding up well. Color match is wearing well. I finally installed my tonneau cover at 304k and should have put it on in 17 when I got it. So nice to have the bed contents out of the weather, not as involved with removing it as I had thought, and I got a nice fuel economy bump from it. 

 

Interior is mostly stock, RF door panel (crack), RR door panel (scratches), RR and LR C pillar trim (gouges) have been replaced following body shop trips but otherwise no issues. Driver seat foam was replaced at 215K. Infotainment, interior lighting, and dash lights all function as designed. 

 

No issues with the cooling system, radiator was replaced at 252K with the engine and cooler lines for concerns of metal in the oil. Alternator and belt drive were replaced at 256k for noise concerns but otherwise make it about 90k. 

 

Brakes were last touched at 150k. No issues whatsoever. Fluid flushes continue at 45k intervals. 

 

Waxing the wheels after stripwashing, claybar treating them, and polishing works very well. Now on Michelin Defender LTX M/S2 tires. They are amazing and work very well. 

 

Battery was replaced with the engine as I discharged it limping to the dealer. Replaced for free under warranty. 

 

U joints were serviced on the main driveshaft when I did the pinion seal. Front shaft looked, felt, and operates fine so I have new parts but continue to monitor. 

 

Excellent all around vehicle. Great on long drives, great for bombing around town, great for work (usually save that for the work car), and great for hauling. 15/10, would buy again. 

Edited April 8, 2025 by CadillacLuke24

[richard wysong]

You may want to rethink your refueling strategy, The fuel cools the fuel pump so running it that low can damage the fuel pump, also the lean condition caused by running out may have very well contributed to the valve failure

[diyer2]

richard, 

Makes no sense to me to run the gas tank so low let alone the cooling part. The cooling has been mentioned before and I believe the gas lubricates the pump also which relates to cooling. 

[Grumpy Bear]

Well done. Clyde LIVES!!!

 

Question on the old motor. Did bore inspection show any polishing? 

 

[Ed S]

Nice! What year is your truck? I have a 2014, only 56,000 miles on it. Gives me hope for the future although I already had to replace the both seat cushion heater pads plus a behind the dash vent control solenoid and also a fuel tank vapor control solenoid that failed already. All mentioned seemed premature failures to me with the low miles.