I purchased the TL used earlier this year with 90k and am unsure of what occurred previously outside of me being the 3rd owner. It has operated well as I continue to "tinker" with it (i.e. new struts, throttle bottle cleaning, seafoam treatment, spark plugs, etc.), but this is a new one on me.

Being the adventurer I decided to take on the challenge/opportunity of changing the timing belt on my 2002. I have followed everyone's instructions (great job - by the way) so far to a "T" with great success (only disassembled at the moment). I started the reassembly and was double checking everything prior to the new timing belt being installed and have found the front and rear cams are 180 degrees off. Is this normal? Why would have this occurred?

I'm a little lost as I did mark the cams prior to removing them with the old belt on to keep on the up-and-up. Do you have any suggestions? Should I go ahead and turn them around?

BTW - Everything operated fine (fuel economy approx 31 miles/gal) prior to me finding this potential issue.

Any help would be appreciated to help me continue my adventure.

Thanks.

Mr. Bill

 

"I did mark the cams prior to removing them"

What is 'them'? Did you remove the cam gears - the toothy critters that the belt slides onto?

 

^^ Let's hope not..

 

Good catch.

I meant to say that I marked the cams prior to removing the old timing belt. (brain moved forward prior to the fingers catching up) The cams have not been removed.

Now that I think about this further, the car has always had a bit of an unusual vibration while idling. After replacing all of the engine mounts the vibration has remained. ( I had a '99 TL for approx 10 years that was in pristine condition prior to it be totaled last December and it never had the vibration issue)

Any ideas?

 

Your car would not run if they were 180 off. Your valves would be hitting the pistons making alot of noise.

Explain 180 off? Any pictures?

 

I have a photo to share, but don't know how to post it. Hence, I will describe the photo:

The photo is of the front cam that #5 is at the top and #1 is at the bottom. I saw this as a potential problem as the Acura service manual has #1 at the top for the front cam and the line directly up on the rear one; my TL has the direct opposite.

What are your thoughts? Both the front and rear cams seem to be 1/2 turn "out of wack" according to the service manual.

I can email you the photo, if that is easier.

 

ck the main thread list for how to post photos

some `slight movement` of the cams during belt removal is normal- just make sure the lines are back on the marks when putting it together

 

...but 1/2 a turn off on both cams. It is a little weird to me.

Let me ask this question - Were the cams on your TL lined up like what is described/defined within the Acura service manual? I did mark my cams prior to removing the belt, but am more than happy to flip them if the cams were not previously aligned correctly.

 

bill - what part of atlanta are you in?

 

An important note is that although the marks on the front and rear cams are off by 180 degrees (1/2 turn) that the main cam is correctly aligned. (that's how the timing belt came off)

Any additional insight would be appreciated.

 

Are you absolutely sure that before you actually removed the timing belt, that the bottom crank pulley/gear was at TDC *and* the cam gears were off 180 degrees at the same time (i.e., before the TB was removed)?

OR...did you first remove the TB, then turn the crank gear to TDC, *then* notice that the cams gears were off?

 

Exactly (thanks for getting my terminology correct), the bottom crank pulley/gear was at TDC *and* the cam gears were off 180 degrees at the same time prior to the removal of the timing belt. The can be confirmed by my paint markings on the cams and on the old timing belt.

 

Is there any performance increase (or maybe its more economical) by having the front and rear cams 180 degrees off?

...I'm still trying to get my head around why they are not set to factory specs.

Thanks.

 

bill, i would think if the cams were 180 off, then the car would be running like total shit if at all. i have no reason to doubt your readings and marks, but i'm baffled.

 

here are the pics he has...decided to help him out & post 'em for him:

rear cam


bottom crank


front cam


(click on each to enlarge)

 

The cams rotate at 1/2 the rate of the crank. Because of this, the marks on the cams line up every OTHER time the piston comes to top dead center.

 

Should I turn the cams by hand/wrench to align them properly or place the timing belt on them to ensure that they are in sync prior to turning them by hand?

 

It is not normal if you determined TDC on #1 cylinder correctly.

The manual states to:
'1. Turn the crankshaft so its white mark (on the stock crank pulley) lines up with the pointer.' The 'pointer' is that triangle extrusion molded into the block down by the crank. THEN

'2. Check that the No.1 piston top dead center (TDC) mark on the front camshaft pulley and the pointer on the front upper cover are aligned.'

That means if you have the white mark aligned on the crank with the pointer on the block, one must validate TDC #1 by peeking via the portal on the TB cover (or if the covers are off, the line on the cam plate aligning with the line on the front outer cam gear at #1). If any number other than #1 is there, true TDC #1 has not occured and additional rotation is needed following the two step process above.

Quote:

Originally Posted by bill_talbot

Why would have this occurred?

The only reason I can fathom that the cam gears would be 180 degrees from where they should be for #1 TDC is that only step 1 above was accomplished.

As TLer trash alluded to, it appears that any additional rotation of the camgears, to correctly determine TDC on #1, was not done, thus your predicament.

If you can 'confirm' that the two steps above where accomplished prior to removing the old TB and you still have them 180 d out of whack, then that is truly a mystery.

Otherwise, if step 1 above was only accomplished, and (with a couple Hail Marys) if no cam gears have been turned, as well as the crank; one could gently place the old TB back on and perform the additional rotations and get that #1 at TDC.

That's all I got. Good luck.

 

^ If they were 180 off the valves should be making contact with the pistons and you would know.

 

That's it. The crank gear will obviously be at TDC at the top of BOTH the compression stroke AND the exhaust stroke on cylinder 1. The cams on cylinder 1, however, will not be at TDC, although the valves will be closed because the cylinder will be at the top of the compression stroke. I'm thinking cylinder 5 will be at the top of its exhaust stroke. He probably has a mixed bag of open and closed valves on the other cylinders in the current position.

I say put the TB back on and turn the crank one more revolution, and all the markings will line up. Technically, you could change the TB with the crank and cams in any position, as long as it is exactly the same position both before and after. The markings make it easier visually to keep the gears in the same spot.

 

try PCV or EGR

 

I put the old timing belt on to give the crank one more turn and it all aligned correctly. The rest was cookie cutter just like the write-up.

Thanks of everyone's help is making it a success.

 

to your success. There is a real satisfaction in hearing that motor start for the first time after all that hard work AND in saving all that labor cash for yourself instead of paying it out

 

when dealing with timing issues you always have to be on the compression stroke and on TDC before you remove anything. Obviously this was the problem, maybe the instructions where off or they were not followed to the "t" as noted, but you always need to remove the #1 plug and make sure it is on the compression stroke when you are lining up the timing marks.