[Vwdiesel] OT, problem with a different diesel engine

[David Cook]

As I drove it, I was thinking fuel filter like Val
mentioned.  I wondered if the reason it took so long
for it to exhibit any symptoms had something to do
with the fuel temp--the fuel is cold for some time,
but after an hour of being run through the engine and
the excess, now warm, fuel going back to the tank, it
would cause it to warm up.  

The only reason I'd think that is because the fuel is
about the only thing I can think of that might take
that long to warm up.

I'll be sure to mention it to the mechanics on Monday
(I didn't have to work yesterday) and see what they
think.  

I didn't know that those IH engines took valve
adjustments, because I've never heard of or seen them
doing it on any of the busses and I spend a lot of
time talking to them about whatever they may be
working on at the time I happen to go through the
garage.  "Whats bus 58 doing in here"  "Oh, just doing
maintainance"  etc

I always thought that they seemed to keep up on doing
the regular maintainance, but I do know that the fuel
is bought from the lowest bidder.

I'll let you know what happens to bus 45--The Most
Awesomest Bus Ever!

David



--- Scott Kair <scott3491 at insightbb.com> wrote:

>  
> 	We've been using the IH/Navstar 466 engine with
> Allison automatics
> for several years in our work trucks.  They're far
> from delicate, but
> institutional maintenance procedures are often
> determined by bean counters
> rather than mechanics. What you describe should be
> brought to maintenance's
> attention, if only to cya.
> 	In the pre-electronic models, we've had a few
> instances of
> accelerator linkages having to be replaced due to
> wear on the pivot points
> and springs.  While there might be some linkage
> involvement aggravating the
> problem, I don't think it's the primary problem.
> 	The first check would be the fuel filters, and then
> a thorough check
> for contamination.  Institutions tend to buy low-bid
> fuel, and while the 466
> isn't as sensitive as a current generation Eurospec
> VWD, it's not unknown
> for low-bid suppliers to stretch their supply with
> questionable additives.
> The newer, electronic versions are particularly
> sensitive to fuel quality.
> In the electronic versions, the first step the
> dealer takes in investigating
> possible injector issues is a cetane test. If the
> fuel measures below the
> required standard, which most does, the warranty
> doesn't cover the repair. 
> 	Valve adjustments tend to be overlooked, too. 
> Since it requires
> specialty tools and some shop time, it often has to
> be farmed out to the
> dealer, where shop rates are truly frightful. The
> injectors seals can also
> fail, allowing extra air into the chambers. 
> 	We've also had a couple of episodes of injector
> tips detaching and
> dropping into the combustion chamber.  That usually
> leads to a very quick
> catastrophic failure, but one of them went a couple
> of days with smaller
> chunks rattling around.  An infrared thermometer
> will reveal one or more
> injector & chamber running cold if the engine and
> turbo haven't turned to
> shrapnel yet. 
> 	Finally, keep an eye on coolant and crankcase oil
> mixing.  We've had
> four in for teardowns and rebuilds in the last year
> for this.  Two instances
> were caused by kids not watching coolant levels and
> temp gauges, but the
> other two are still damifinos. The parts bill for
> sleeves, pistons, rings,
> gaskets, etc. isn't pretty, and dealers seem
> required to send at least one
> set of wrong parts.
> 	Keep us posted, and hth,
> 	Scott Kair     
> 
> Hey all-
> 
> My school bus exhibited a couple strange symptoms
> while on a field trip
> tonight.  I was wondering your thoughts before I
> mention it to the
> mechanics.  (I want to look smart!  Well, that and I
> am just really
> curious.)
> 
> Anyway...
> 
> The bus is a '94 model International turbo diesel
> engine, it has no computer
> controls or anything like that.
> 
> If I'm driving along really pushing it, the engine
> will start making a
> rattling noise.  It is such a rattling noise that at
> first I thought it was
> the door handle rattling.  
> 
> It will rattle for a half second or so, then stop
> briefly, then rattle
> again.  Like "da-da-da-da-da...da-da-da-da-da...etc"
>  When it is rattling, I
> notice a very slight reduction in power, though the
> bus doesn't really slow
> down.
> 
> Also, during a time it is doing this, I have noticed
> that accelerator pedal
> action is delayed.  I mean, if I press the pedal
> down, it will act like it
> didn't know I did that for about half a second or
> so.  And then, if I let up
> on the pedal, again there is about a half second or
> so delay before the
> engine speed drops.
>  
> 
> The pedal itself still moves smoothly.
> 
> The really odd thing is that the bus has to be
> driven for a long time before
> this happens--at least about an hour.  I can drive
> it as hard as I want for
> up to about an hour before it will start making this
> noise.
> 
> Today, after my afternoon route, I took an athletic
> trip.  After driving the
> afternoon route with no issues, we took off for the
> athletic trip. 
> 
> It wasn't very long before the rattling started.  At
> one point, we came to a
> stop light.  I slowed down slowly, and put it into
> neutral as we approached
> the light.  The engine stumbled just a tad-dropped
> to slightly lower than
> normal idle speed-for a second or so, then settled
> at normal idle speed.  
> 
> After the light changed, I took off again.  We drove
> a few minutes  before
> it started rattling again.  As we came to an
> on-ramp, I put it in neutral
> again to see what would happen.  To my surprise, the
> engine immediately
> died, but started up again.
> 
> At the next stop (a few miles of rattling down the
> road to get on another
> highway) I again let it slow down slowly, then put
> it in neutral as we
> waited at the stop sign.  It idled normally.
> 
> On the new highway, I decided to not push it as
> hard, and kept it right at
> about 55 mph.  We went the whole rest of the trip
> (about 45 minutes) with no
> rattling.
> 
> I decided to do an experiment on the way home.  As
> we got on the highway, I
> drove pedal to the metal the whole way.  
> 
> It was a whole hour before it started rattling.
> 
> The reason I ask is that this seems so odd to me,
> the fact that it has to
> have driven so long before acting funny.  Its not
> like it just waits until
> the engine warms up or something, obviously the
> engine has been at full
> operating temps for a very long time by the time
> this happens.
> 
> Anybody have any ideas?  Again, the engine is all
> mechanical, as in no
> computer controls.  It also has a 4-speed allison
> auto trans.
> 
> Thanks,
> 
> David
> 
> David Cook
> Red '86 Cabriolet Diesel Powered
> Red '90 g60 Corrado
> Brown and White '78 Westy Campmobile "Bear"
> and others in various states of disrepair Pictures
> here:
> community.webshots.com/user/superdave5599
> 
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David Cook
Red '86 Cabriolet Diesel Powered
Red '90 g60 Corrado 
Brown and White '78 Westy Campmobile "Bear"
and others in various states of disrepair
Pictures here: community.webshots.com/user/superdave5599

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