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Letter 12

Isuzu Trek Owners Infoletter #12

August 2003

Driving in hot temperatures

If you are planning a trip through areas where temperatures may exceed 90° F., I refer you to John McHale’s great ideas in newsletter #6.

 Here are some additional things that Trish and I do:

The engine driven air conditioner was designed to handle a space the size of the NPR truck’s cabover cab which is a lot smaller volume to cool than that of our Trek.  So, we put up a bedsheet as a barrier to decrease the cooled volume.

 If it is not too darned hot, the bedsheet is tucked into/over the aft edge of the EMB bed by lowering the bed from the ceiling an inch or so, tucking in the sheet, then raising the bed to the full up position. Clothespins or clips hold the edges of the sheet out to the sides at the rear EMB racks and a pillow on the couch keeps the sheet on the couch. The sheet hangs down to the floor, thus effectively keeping the cool air in the front part of the coach.

 If it gets too hot for the engine driven air conditioner to handle the cooling job, we relocate the sheet, tucking it between the aft edge of the rooftop air conditioner and the ceiling at the two rear corners of the air conditioner, then clipping to the aft bed rails. A file folder tucked in between the aft edge of the air conditioner and the ceiling and another tucked into the front the same way, curved downward, does a good job of directing the cold air into our space. We then start the generator and run both air conditioners. We usually close the bathroom door, all windows and the overhead vent in the galley. This way we can stay cool in 100°+ temperatures and, if we need to shut off the engine driven air conditioner so we have more power to pull a grade, we don’t suffer much because the roof air conditioner is doing a pretty good job.

 We have never seen conditions where the Trek’s engine would overheat. We have seen rarely times when towing that the transmission temperature moved above 230° F. in which case we pull over and idle for a bit which cools the tranny temp. One time when ambient temperature was 110°, the tranny temp would not go down. A few squirts from a water spray bottle on the radiator changed that right away and we continued on our merry way.

Engine driven air conditioner failure (Dale again)

On our way from our summer place on the cool coast of Oregon to the big airshow at Oshkosh, WI, we encountered some brutally hot temperatures in eastern WA, ID and MT.  Naturally, the engine driven air conditioner didn’t work when called on so, during a brief stop in ND, we had a local shop troubleshoot it.  They found that the brackets holding the air conditioner’s radiator had broken and one bolt was missing, another had failed, allowing the radiator to drop down until it was touching the top of the front leveler jack where vibration and road bumps had worn a hole in the radiator causing loss of coolant. So, we left the radiator with the shop to be sent off for repair and retrieved it on the way back through.

 So, add the radiator bolts/brackets to your periodic inspection list!

 Cruise Control Fix

Frank (FR140 (at) shares: Dale, you asked for cruise info.  Here’s what I did when mine acted up.

It started to act erratic and finally wouldn’t turn on.  I pulled the electrical connections on the unit in front under the hood.  Found they were pretty corroded.  Cleaned them, replaced them and sealed them with liquid electric tape.  By the way, did the same with the connections to the water heater and the refrigerator to discourage future corrosion

problems.  I then found the real culprit.  If you look on the under side of the cruise control lever–near the steering column, you’ll find wires coming out of the lever before entering the steering column.  The hole on the lever had sharp edges and cut through the wire insulation and was shorting out the cruise control.  I smoothed those edges, pulled he wire a little so as not to rub on the edges, and taped the wire with a couple of layers.  Cruise has worked OK ever since.

Frank, ’94 Trek 24′

 An interesting story about Exhaust Manifold bolts

J. White gives us another interesting, lesson-filled story from their last odyssey:

White’s Odyssey:  Gardnerville Nevada to Williamsburg, Virginia and back. (A 7,915 mile Shake Down Trip), Installment 3:

 Ching, Ching, Ching goes the Trolley (TREK, that is)!

After our visit in NW Arkansas, we traveled east to Nashville, where we saw some live shows in some of the smaller clubs.  Mike Snyder and his string band were great and we bought 3 CD’s of their music and recorded shows.  I did not have a great fondness for country music of that type before, but seeing it performed made a great difference.  We could not stay long enough to see a performance at the Grand Ole Opery,  maybe next time!

Anyway, the Trek was doing pretty well, but I noticed that anytime another car or truck passed us (which happened a lot!  Especially on hills!) there was a loud “Ching, Ching, Ching” metallic noise that decreased if I let off of the accelerator pedal, or got louder if I accelerated.  Otherwise, we were doing OK, but the performance of the engine was getting much weaker in the afternoons at first, and then started losing power on hills earlier in the day.

Finally, we reached our next destination:  Dandridge, Tennessee.  This was just before the 4th of July, and we were visiting dear friends from our days in California.  Since I could not expect any service or repairs over the holiday, we parked the Trek and waited until the next week.  In the mean time, we visited the Smokey Mountains and the Vanderbuilt’s Biltmore Mansion.

Since the nearest Isuzu Dealer was more than 60 miles away, I asked our friends if they knew of a good mechanic in their town. They called some friends, and recommended a local mechanic.  He was located out in the countryside, and I mistakenly found a small used car dealer in that same area with a similar business name.  In checking with the owner, he was not able to work on trucks or motor-homes, and recommended the same fellow that we were looking for!

 Problem  Diagnosis

We found John, at his shop/garage with several cars that he was working on, and after a brief description of the noise and symptoms, he listened and confirmed my suspicion that it probably was a bad exhaust manifold gasket.  We took off the engine  cover, and discovered that the rear top exhaust manifold bolt was completely out of the hole and was lying totally rusted on top of the exhaust manifold!  Feeling for the lower bolt, it was gone completely!

I was completely amazed at what we found!  Just before the trip, I had taken the Trek to a local RV mechanic, and had the chassis lubricated,  the oil changed and the tappets adjusted (as specified in the Isuzu Service recommendations).  Since the engine cover had to be removed to put the new oil in, anyone but a blind mechanic should have seen that exhaust manifold bolt that was already completely rusted to the top of the exhaust manifold.  I would have never started such a trip with that type of a problem, and it might not have cost much to fix it, just 2 new bolts, torqued to specifications.  This was a clear case of negligent service.  Needless to say, I will never use that shop again, and will tell this story to anyone that asks for a recommendation for service or repair.

 Repair Plans

Since the exhaust manifold is integrated into the turbocharger, John said he would have to disassemble it to remove the manifold and determine what repairs were needed.  I left the Trek with him, and called him the next day to see what the situation was.

When I called, he said that the manifold was warped and he was not sure that a new gasket would hold.  I went back to see how bad it was (I have worked on engines and rebuilt my own when I was younger… I don’t do that anymore!)

The combination of the heat and pressure from the exhaust gases had warped the mating surface of the manifold by at least 1/16 to 3/32 inches on both ends.

 Repair or Replace??

We discussed the options.  One was to buy a new exhaust manifold from Isuzu.  Another was to see if the existing manifold could be milled or resurfaced to be flat again.  Another was to put a new gasket on the warped part and hope that I would hold as a somewhat temporary fix.  (It was possible that we might be able to use double gaskets on the ends of the manifold but that might not work… we did not know.)

I decided that since we had more than 3,000 miles to go to get home, that we needed a guaranteed, permanent fix.  I asked John if there was a machine shop in town, and he said there was in a nearby town about 20 min. away.  A new part would no doubt be expensive (did not know how much it would cost) and could take a long time to locate and ship to this small town.  We decided to try the milling solution.  Since I was anxious to get on the road again (we had imposed on our friends longer than we intended!), I took the part to the machine shop that morning.

When I asked if they could turn it around that day, they said “no way, takes at least 2, maybe 3 days”.  The manifold would have to be mounted securely to mill the face flat, and it had 4 studs protruding out of it on the opposite side of the face to be resurfaced.  They did not know if they could remove them easily or not, I suppose.

Solution:  Reface the Exhaust Manifold

Any way, when I called John the next day, he said that the machine shop delivered the repaired part that afternoon, but he needed the other parts (gaskets, and the new bolts I asked to replace all of the original ones).  As it turned out, they sent the wrong parts, and it took 2 more days before he could put it back together.  Total cost, ~ $380.

The new surface was successful, and we have had no problem with the engine since then.  And, the repair cost less on the road, and I got a better job than I would have at home!

And, no more “Ching, Ching, Ching”!!

 Lessons Learned

    1. Be sure that any work you have done on your Trek is done by careful, experienced mechanics.  Also, you should have the bolts on the exhaust manifold checked at each oil change, at least.

  1. You can get a Trek fixed anywhere, if you find a good dealer or competent mechanic.  (need a minimum of 2 GOOD references from local people..  Auto parts store owners/managers, Used car dealers that don’t repair trucks, etc.)      Ask them where they take THEIR car or truck for service and repair.

  2. If there is any question about the exhaust manifold bolts, like if one comes loose, have them replaced with the proper high strength bolts (see Isuzu part specifications).  Note that the exhaust manifold runs at very high temperatures (more than 800 degrees F.) and, at those temperatures, loose bolts will cause the cast iron exhaust manifold to actually deform or “warp”.  If you ever have to take the manifold off, have them replace the bolts with new ones, just to be sure the heat has not softened them.

  3. Don’t be afraid to ask for special favors if you need to have repairs done quickly.  There are lots of good people out there that can service your Trek, but it helps to pick the proper type of service.  Chassis, electrical, mechanical problems, say that you need someone who knows and can service an Isuzu NPR 1994 truck chassis.  RV problems need a good RV mechanic.  Check for references the same as for truck repair.

Next installment:  When the Show Stopped  (Video Camera/TV  Diagnosis and Repair)

 Editor: I’m a gonna rush right out and check my exhaust manifold bolts NOW!

Other contributors (Ken) have indicated that it may be a good idea to replace the bolts with studs (see infoletter # 7)

That’s all for now, folks!   Send me your Trek experiences, please!!!

Happy Trekking,