Quick Timing Belt/ Camshaft question

noev70t5 · Post by **noev70t5** » 24 Aug 2016, 13:55

Im replacing a front cam seal on my 98 v70t5

While setting the timing I noticed that when I have my crank marks aligned, my cams are off from the original markings that were already there.

I dont have an issue driving or accelerating but I want to set it back as close as possible. When idling for over 15 minutes I hear a clicking from the rear cam.

My question is :

Should I line up the crank marks at the bottom, then set my cams to what was originally marked? Or should I replace the seal and have the timing serviced professionally later?

Post by **erikv11** » 24 Aug 2016, 15:12

Since you already have the belt off and the cam sprockets off, I would definitely re-zero the timing yourself now.

1. Put the crank exactly on the mark.
2. Use the slots on the rear of the cams to align them perfectly horizontal (i.e., do your best, doesn't have to be *perfect*).
3. Put the sprockets on so that the marks are right in the notches.
4. TIghten the sprocket, install the belt, wrap things up.

The car isn't due soon for a TB change is it? A timing belt definitely stretches over normal service life, can lead to a 1/2 tooth discrepancy, which would be irksome if you are trying to get the timing back to factory settings.

Post by **kahl** » 24 Aug 2016, 16:14

Following up on erikv11 point #2 here is a crude sketch of the rear cams for aligning. I would find some way to lock the rear cams.

noev70t5 · Post by **noev70t5** » 24 Aug 2016, 16:41

yeah... im pretty sure its due, so ill just replace only the seal. but now i have a different issue

i have not put the hydraulic tensioner back on yet, but my shafts look like this (below)

How do i make sure i can line everything up again? I need to do it before the belt gets tightened again

the exhaust side only wants to move clockwise, i need to go counterclockwise about a notch or two

thanks yall!!

noev70t5 · Post by **noev70t5** » 24 Aug 2016, 17:13

what is not shown in the picture is the intake cam has a ziptie where the belt originally started so i know where it should be.

What i want to do is:
- rotate the intake cam proportionate to how the exhaust one moved (a notch or two clockwise)[should eliminate the slack between the cams]
-after, there should be slack created between the intake and crank
-turn the crankshaft until the belt is a bit more fit between the intake and crank
-return the tensioner and let it pick up the last of the slack

does that sound resonable?

Post by **Ozark Lee** » 24 Aug 2016, 17:26

Just because it was timed one way before doesn't make it correct. About half of the whiteblocks that I have purchased have had the belt off a tooth when I go to change the first belt. They don't run terrible with the timing off but they run better when it is correct.

...Lee

noev70t5 · Post by **noev70t5** » 24 Aug 2016, 17:30

Ozark Lee wrote:Just because it was timed one way before doesn't make it correct. About half of the whiteblocks that I have purchased have had the belt off a tooth when I go to change the first belt. They don't run terrible with the timing off but they run better when it is correct.

...Lee

No doubt Lee, I totally agree. When i get a new belt i want to have it timed properly then.

As of right now for what im doing, is it ok to do what i described in my lastest post?

Post by **erikv11** » 24 Aug 2016, 17:58

When the crank is on the mark, both cams can be spun freely in either direction. Well, there is resistance, but there is no risk of damaging anything. Just get a long screwdriver in there between two of the three cam sprocket bolts, and rotate the exhaust cam to exactly where you want it to be. The exhaust cam likes to slip out of place, but just keep putting it back until you can get the belt back on.

Even though you are replacing the belt, attempt to set the timing to factory position, not to where it was. See Lee's comment. Your car's belt will likely do that just fine, or within half a tooth anyway (which is just fine!). If you don't want to eyeball the back of the cams at this time, at least eyeball the lines along the bottom (exhaust) and top (intake) of the triangles formed by the cam sprocket bolts. Each line should be parallel to the engine mating lines, e.g. the line that seals the head to the bock, the cam cover to the head, etc.

noev70t5 · Post by **noev70t5** » 25 Aug 2016, 07:39

I appreciate the help guys as I only had some printouts

my crank was not 100% lined up and I have a very slight bumpy idle (my mom rushed me out the garage)

about to tune it to get it as close as I can to the factory settings

Thanks again! Always great advise

Post by **bmdubya1198** » 25 Aug 2016, 09:15

It's hard to see, but those cams will line up at the rear as so nicely illustrated by kahl

. Once it's lined up back there you can loosen the sprocket and slowly turn it to line up with the factory alignment marks on the timing belt cover. It definitely helps to have the cams locked. For something like this you can make your own cam locking tool if you really want to. For me, that's the easiest way to set the timing.
Keep in mind, that is assuming that the cam sprocket was removed at some point. If it is on the camshaft the way it was from the factory, you should be able to turn the sprocket while attached to the camshaft to align it.