Sunday, August 5, 2007

We get questions...

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We are at a rest area on I-40 east of Flagstaff, Arizona (map). We are actually just north of the Barringer Meteor Crater, a major feature of the landscape in these parts. This rest area has, in addition to normal truck and car parking areas, a truck overflow lot that is a bit more distant from the freeway, as well as darker, and we should have a relatively quiet night here. In accordance with Arizona policy, we are not camping (prohibited), but "resting" overnight in our vehicle (permitted).

We pulled in just at sunset, and the temperature was pleasantly in the 70's, in stark contrast to last night's stop. A lightning storm in the distance provided us with the evening's entertainment -- quite spectacular.

Before I delve in to the problem du jour, we get lots of questions over here at Our Odyssey, and lately they have concerned the engine rebuild and what we learned.

First off, let me say that Virgil and his team at PEDCO were wonderful, as they were on our first visit. We had the run of the shop for the week, were able to borrow a vehicle as needed in the evenings to go out to dinner, or shopping, or whatever, had ample electric power (although I had to make another of my famous adaptors, this time from 208-volt 30-amp three-phase, to provide us with two legs of 30-amp by 120-volt single phase), and were always treated courteously by all the technicians. We were also very fortunate to have the same technicians that worked on us last time, so things happened more smoothly and quickly without the weird-bus learning curve to climb.

We did find dirt in the engine, and we knew from the last oil analysis that it was also in the oil. So that meant everything had to be replaced, from the liners and pistons, to the heads, to the turbocharger. We also replaced the main bearings as a matter of course, and we sent the injectors out to be tested, since they only had 40,000 miles on them (and there was no dirt in the fuel, as far as we can tell). Four of the injectors were "slobbering" a little, and PEDCO successfully negotiated on our behalf for the injector shop to replace them at no charge.

The key question, of course, was how did the dirt get into the engine? I fully expected to find a giant gap in the air induction system, either a hole worn into part of the intake, or a separation between intake components. But we found no such problem.

Fortunately, I had kept the old air filter that I replaced in Lake Tahoe, and we determined that therein lay the problem, and it is one for which I must take the full responsibility. The filter was sold to me by Danny Allison at one of the bus or FMCA shows, and I believe this is a filter that he was having custom made for the purpose. It is an oiled cotton type of filter, as opposed to pleated paper media. There appeared to be two problems with it: First, the neoprene (I think) gasket at the bottom of the cartridge was not thick enough, and it appears that the gasket did not properly seal against the back of the housing. I suspect that this issue alone was responsible for the lion's share of the dirt.

Secondly, it also appears that there was not enough oil impregnated in the cotton media, and this type of filter simply will not work without the oil. (The filter came to me pre-oiled from the factory.)

To be fair to myself, with the type of filter housing I have, which accepts a filter where the lid of the housing is an integral part of the filter, the fact that the filter gasket was not making contact was not obvious, and not really easy to detect. There is also a gasket around the lid end, so pressing the filter into the housing feels like you are compressing a gasket no matter what. In hindsight, a smear of grease around the bottom gasket would have informed me whether or not it was sealing (and would have helped trap anything trying to get past the seal anyway). And there was plenty of dye indicator on the media when I installed the filter as well as when I inspected it at the usual interval. By the time I found myself wondering why the restriction gauge was never moving, there was probably already a fatal dose of dirt in the engine. (Two cups of dirt is the lifespan of a big diesel -- whether over 250,000 miles or 2,500 miles.)

At that same show, Danny sold me an Aero-Turbine muffler as well, which ended up not fitting (it was 5" and my exhaust is 6"), but he also gave me a polo shirt. Henceforth, said polo shirt will be referred to as the $13,000 shirt -- that would cover the $12,600 and change for the in-frame, plus the $300 or so for the damn filter (which we promptly threw away after implicating it in this fiasco), and the re-stocking fee he charged me on the muffler.

Today's problem: our overheating issue is, apparently, still with us. Yesterday we noticed the needle climbing at several points along the various grades, notably Cajon Pass. Given the extremely high outside temperatures, and the fact that the access panel between the radiator intake and the engine seemed a bit loose, we were not quite ready to push the panic button.

Today, however, on the 12-mile, 6% grade between Laughlin and Kingman, it became clear that something is still very, very wrong. Before the in-frame, I had been thinking that the overheating issue was related to the low power and black smoke. The rebuild cured those, but the heat is still with us. Now, I'm hoping that this is a completely separate but coincidental problem, but part of me is worried that there is still some sort of issue with one of the cylinders -- after all, we found one cylinder with seized rings during the tear-down. But with all new liners, pistons, valves, and heads, it's hard to imagine what sort of cylinder problem could still be with us.

At this point, I am hoping it is something simple, like a bad impeller in the water pump. Of course, it's too bad we did not think to look at that while all the coolant was out of the engine, and we were in a shop surrounded by hundreds of water pumps. Monday morning we will try to find a Detroit shop that can look at the water pump for us, and maybe the thermostats. I have my fingers crossed that it is not a plugged radiator, but, knowing what other stupid things the previous owners did to this coach, it would not surprise me in the least. (Radiators don't plug at 100K unless you've filled them with tap water, or stop-leak.)

Also on Monday, we will try to find a replacement for the fuel pressure starter safety. Feedback from the bus boards suggests it is easily replaced with a 10PSI pressure switch from NAPA. In the meantime, we are enjoying the cool air at these higher elevations.

Photo by alexanderdrachmann

1 comment:

  1. Sean, Danny passed away this spring. He had closed down his business and was working for K&N. We saw him at an FMCA event in Memphis this spring and then learned that shortly after that, he passed away.

    Jim Shepherd


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