Posted to Technical Tips Forum on 11/1/2008
3.2 Isuzu. Timing Belt Nightmare
I had a learning experience too good not to share. This
involved the timing synchronizing of the above mentioned
vehicle. It seems technical information is a little obscure
on this application and even following the instructions step
by step listed on Isuzu TSB 1B00-S005 it yielded no good
results on this one. By the way, I found a short cut related
to this procedure and found out that the TSB leaves out a
key piece of information. A little more on that later, first
off a little background on this particular one:
Vehicle came in a hook from another shop for a "No start"
complaint. At the other shop the heads had been removed for
a seized camshaft, the timing belt had snapped and the water
pump damaged. Both cylinder heads had been sent to a
reputable machine shop, the water pump and the timing belt
got replaced and there was the "Never runned afterwards".
First thing done at the shop was verify complaint. Sure
enough, crank wont start, backfire every-now-and-then.
Timing synch suspected. Pulled timing cover off and verified
every timing mark aligned with their respective marks. Not
being familiar with this engine is time to pull tech info.
Pulled valve covers to verify proper cam-to-cam synch, is a
mess. Nothing lines up. MOD lists the procedure (and the
aforementioned TSB), followed it and for some reason the
lobes don't point to where the info says they should.
Hmmmmmmmm, thinking cap on, realize "some" inaccuracies on
ANY information system. Called MOD and had them fax factory
information. Same thing. Followed the factory information to
the letter to no avail. At this point I start to doubt my
reading comprehension ability.........and then a light turns
on in my head!
Paying close attention I noticed this: [2001 Isuzu Rodeo
LS, Engine/Propulsion photo]. The right bank intake
camshaft drive gear wasn't flush against the lip on the
camshaft. I then compared it to this: [2001 Isuzu Rodeo
LS, Engine/Propulsion photo]. Hmmmmm. A call to the other
shop verified the right intake camshaft was the one that
seized. Ok then time to hunt for another camshaft. Once
another cam was located, the damage was obvious. This is the
good camshaft: [2001 Isuzu Rodeo LS, Engine/Propulsion
photo] Notice the position of the lobe related to the
letter "R". Compared to this: [2001 Isuzu Rodeo LS,
Engine/Propulsion photo]. You can see the difference on
this picture: [2001 Isuzu Rodeo LS, Engine/Propulsion
photo] Pay close attention to the 5mm locking bolt and use
that as reference.
As for the key piece of information missing from ALL
sources: The exhaust camshafts are the same for both sides
and as a result they have 2 sets of marks: A single dot and
a double dot (and they are both stamped RE and LE) The
intake camshafts are different and thus labeled LI and RI.
Looking real close at the LI (left intake) you'll see it has
a double dot and you are supposed to align this to the
sub-shaft and use THE DOUBLE DOT from the LE. Funny, Isuzu
TSB calls for using the sigle dot. An easy way to remember
this is USE ONE DOT ON BANK ONE and TWO DOTS ON BANK TWO.
As for the short cut. The TSB is a 9 page procedure that
calls for aligning the dots on the drive gears to the
subshaft and turn the cam sprocket up to 9 times on the
right side and a few times on the left side until the
sprockets spring to the 12'o clock position on the right
bank and 9'o clock position on the left bank then turn 90
degrees BEFORE installing the timing belt on. SHORT CUT:
Align the dots on the R bank and DONT turn it, then align
the dots on the L bank and TURN it 90 degrees, then install
your belt. You are done!
Sorry for the long post. Whoever had a hard time with this
application knows exactly what I'm saying. And I hope that
whoever hasn't had the "joy" of working on one of this finds
this post useful.
Ciro from Texas
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