Discussion:
noticeable symptoms if timing belt is off by one tooth ?
(too old to reply)
H***@gmail.com
2007-02-03 04:57:41 UTC
Permalink
I just replaced the timing belt in my 2000 Camry 4-cyl.
I checked and triple-checked the camshaft alignment
and that of the crankshaft pulley against the plastic scale
on the lower cover. (Neither I nor a neighbor could find
timing marks on the oil pump body or on the crankshaft
timing pulley. Is the service manual wrong?)

The main question is this: Would I notice an error of
one tooth? The car seems to idle at 600 rpm with
the lights on, but somehow it "feels" different.

Thanks,
Herb
j***@hotmail.com
2007-02-03 06:14:46 UTC
Permalink
The TDC crankshaft mark is more easily aligned with the timing cover
on. But the timing belt needs to be tightened at 45 deg BTDC! Not TDC.
So for the 45 deg mark you have to look at the thick line marking on
the pump body. Look again, it's there.

So after you tightened the tensioner pulley at 45 deg BTDC, put the
lower cover on, then the crank pulley and bolt. Turn two revolutions
to 0 deg TDC and then recheck the cam mark. They should both line up.

Advanced timing causes engine overheat and retarded timing causes loss
of power. Emissions probably go up quite a bit. So you really should
try to adjust it again properly.

If you bought a timing component kit from Gates, you'll have the
AllData installation sheet included. But no matter which one you
follow (Toyota, AllData, Haynes, Chilton, etc), do exactly what the
words tell you, no more, no less.
Post by H***@gmail.com
I just replaced the timing belt in my 2000 Camry 4-cyl.
I checked and triple-checked the camshaft alignment
and that of the crankshaft pulley against the plastic scale
on the lower cover. (Neither I nor a neighbor could find
timing marks on the oil pump body or on the crankshaft
timing pulley. Is the service manual wrong?)
The main question is this: Would I notice an error of
one tooth? The car seems to idle at 600 rpm with
the lights on, but somehow it "feels" different.
Thanks,
Herb
H***@gmail.com
2007-02-03 07:21:00 UTC
Permalink
That's just what I did, John. BTW, the 45-degree mark according to
the
factory service manual is "a mark at 45-deg of the timing belt cover".
It looks like a short groove in the timing belt cover. And then I
cranked and checked three times.

Thanks, Herb
Post by j***@hotmail.com
The TDC crankshaft mark is more easily aligned with the timing cover
on. But the timing belt needs to be tightened at 45 deg BTDC! Not TDC.
So for the 45 deg mark you have to look at the thick line marking on
the pump body. Look again, it's there.
So after you tightened the tensioner pulley at 45 deg BTDC, put the
lower cover on, then the crank pulley and bolt. Turn two revolutions
to 0 deg TDC and then recheck the cam mark. They should both line up.
Advanced timing causes engine overheat and retarded timing causes loss
of power. Emissions probably go up quite a bit. So you really should
try to adjust it again properly.
If you bought a timing component kit from Gates, you'll have the
AllData installation sheet included. But no matter which one you
follow (Toyota, AllData, Haynes, Chilton, etc), do exactly what the
words tell you, no more, no less.
j***@hotmail.com
2007-02-03 19:20:25 UTC
Permalink
If the marks line up, with the crank pulley mark pointing at 0 TDC on
the plastic scale and the hole in the cam spoke lines up with the
indentation on the backing plate, you should be fine. But sounds like
it isn't. However, there may be a metal tab on the edge of the cam
sprocket, this isn't the mark used to align.

The other thing is belt tension. The tensioner needs to be able to
move freely without allowing the belt to skip tooth when you turn the
2 revolutions to tension the belt (and then after you tighened the
tensioner turn 2 more to check marks). It's a little hard because
valve springs will try to push the cam either way as you turn to
tension the belt.

If the marks line up then I would suspect belt tension. Another thing,
while at it have the cam, oil pump, and crank seals been replaced?

Keep us informed on how you solve this. Thanks.

I use the following with each timing job:
(www.rockauto.com prices for 5SFE)
GATES TCK199 (kit of timing belt with two pulleys and instruction)
$84.79
GATES Part # K030295 PS belt $4.32
GATES Part # K050435 Alt/AC $12.12
FEL-PRO TCS45641 Cam seal $4.11
FEL-PRO TCS45920 Crank seal $6.04
BCA Part # 221820 Oil pump seal $2.71
Plus Airtex pump from local NAPA store.
Post by H***@gmail.com
That's just what I did, John. BTW, the 45-degree mark according to
the
factory service manual is "a mark at 45-deg of the timing belt cover".
It looks like a short groove in the timing belt cover. And then I
cranked and checked three times.
Thanks, Herb
H***@gmail.com
2007-02-04 01:47:23 UTC
Permalink
Today's road test was somewhat reassuring:

* 2000 rpm at cold start briefly
* 700 rpm at warm idle
* 2400 rpm at 65 mph on flat highway
* normal running temp
* climbed steep hill without pinging (and usual
lack of zip)

It still feels different, but I may be overly anxious
as this was my first timing belt change. BTW, the
old belt at 63,000 miles looked fine except for the tooth
with the visible threads, all worn through.

Thanks again,
Herb
Post by j***@hotmail.com
If the marks line up, with the crank pulley mark pointing at 0 TDC on
the plastic scale and the hole in the cam spoke lines up with the
indentation on the backing plate, you should be fine. But sounds like
it isn't. However, there may be a metal tab on the edge of the cam
sprocket, this isn't the mark used to align.
The other thing is belt tension. The tensioner needs to be able to
move freely without allowing the belt to skip tooth when you turn the
2 revolutions to tension the belt (and then after you tighened the
tensioner turn 2 more to check marks). It's a little hard because
valve springs will try to push the cam either way as you turn to
tension the belt.
If the marks line up then I would suspect belt tension. Another thing,
while at it have the cam, oil pump, and crank seals been replaced?
Keep us informed on how you solve this. Thanks.
(www.rockauto.comprices for 5SFE)
GATES TCK199 (kit of timing belt with two pulleys and instruction)
$84.79
GATES Part # K030295 PS belt $4.32
GATES Part # K050435 Alt/AC $12.12
FEL-PRO TCS45641 Cam seal $4.11
FEL-PRO TCS45920 Crank seal $6.04
BCA Part # 221820 Oil pump seal $2.71
Plus Airtex pump from local NAPA store.
m Ransley
2007-02-03 22:45:11 UTC
Permalink
Try a timing light, basic.
H***@gmail.com
2007-02-04 02:40:17 UTC
Permalink
Post by m Ransley
Try a timing light, basic.
Not a bad idea. Since the camshaft position triggers the
spark and since the crankshaft pulley has 24 teeth, every
tooth of error should displace the timing by an obvious 15
degrees (360/24). But that much timing error should be
obvious from the behavior of the car. Do you know the
normal timing at 700 rpm idle?

Thanks, Herb
m Ransley
2007-02-05 13:30:08 UTC
Permalink
Unless you use a light and set it to your specs you wont get anything
right. Figure 1 mpg reduction for every degree retarded, just as an old
stretched belt can loose you 3-5 degrees. You have wires to jumper, so
buy a 10$ light, use your manual and get it right or Preignition might
ruin your motor or poor milage and power will cost you, you cant guess
on this one..
H***@gmail.com
2007-02-06 01:05:57 UTC
Permalink
Post by m Ransley
Unless you use a light and set it to your specs you wont get anything
right. Figure 1 mpg reduction for every degree retarded, just as an old
stretched belt can loose you 3-5 degrees. You have wires to jumper, so
buy a 10$ light, use your manual and get it right or Preignition might
ruin your motor or poor milage and power will cost you, you cant guess
on this one..
If "an old stretched belt can lose you 3-5 degrees", a new belt can
win back
3-5 degrees over the "norm" and cause the perceived slight increase in
rpm.
I like theory with my data. You've probably given the explanation,
and to be
sure, I'm going to inspect and retension per Daniel's append.

Thanks,
H.K.
m Ransley
2007-02-06 03:28:03 UTC
Permalink
You dont get it, do you, unless you use a timing light you wont know
anything, now you know nothing of its timing. Get a light and quit
guessing
H***@gmail.com
2007-02-06 04:16:59 UTC
Permalink
Post by m Ransley
You dont get it, do you, unless you use a timing light you wont know
anything, now you know nothing of its timing. Get a light and quit
guessing
Ok, I'll get a timing light. :-) What was the brand of that $10
light
you mentioned? At the risk of asking a stupid question, which
triggers
the spark: position of the the crankshaft or of the camshaft?
There's
a position sensor on the crankshaft for sure. If it triggers the
spark
then the timing light won't answer my question.

Thanks,
Herb
m Ransley
2007-02-06 12:36:45 UTC
Permalink
Im guessing at 10$, point is its cheap. The truth is your ignition
system needs a baseline setting to work right, only a light will set it
to the base setting. You probably have to jumper some wires so read your
manual.
j***@hotmail.com
2007-02-07 04:33:12 UTC
Permalink
I think Autozone or Pep Boys have free loaners in most locations.
Haynes manual will tell you which pins in the diagnostics connector to
jumper to put timing into "default mode". (Don't know at the moment).
Post by m Ransley
Im guessing at 10$, point is its cheap. The truth is your ignition
system needs a baseline setting to work right, only a light will set it
to the base setting. You probably have to jumper some wires so read your
manual.
Daniel
2007-02-05 14:49:11 UTC
Permalink
Post by H***@gmail.com
I checked and triple-checked the camshaft alignment
============
You check the camshaft mark and crankshaft mark then turn the engine
over two revolutions and check again.
If the belt tension is correct, and the timing marks align there can
be no error.
Sometimes it is awkward to get the correct belt tension since the
spring doesn't really exert enough pressure by itself so you pry up on
the tensioner pulley, then release it allowing the spring to hold the
correct tension, then tighten the tensioner bolt, turn over the engine
twice, re check marks, you're done.
If the engine is not running right after a timing belt change, remove
the upper cover, re tension, and re check cam timing marks.
Better to be certain than guess by secondary characteristics.
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