Toy Civic

Got a 2004 Pilot with 95K miles. I've owned it for three years. I'm posting this here also as all Honda V-6 motors have the same basic design.

I'm doing the timing belt now because I won't have the chance for the next several months as I will be on the road cross country, etc. I have a Helms manual. I've worked on Civics and Integra engines for years.

But this is the first major work I have done on a Honda V-6. The timing belt, water pump, seals, etc. are not the problem.

What is the problem is I made a mistake by aligning the crankshaft TDC mark properly, except that the bottom end is on the first cycle meaning #5 piston is at TDC, not #1 piston like the book says. I did not pay attention initially and noticed this AFTER I had the belt off. I know this because the #1 mark on the front camshaft pulley was pointed 180 degrees down and #5 camshaft pulley mark was pointed up.

I've always known that the engine block to camshaft rotation ratio is 2 to 1 meaning for every two rotations of the motor, the camshaft rotates once. But I forgot about, did not look at the camshaft markings, and only went off the crankshaft TDC mark.

The bottom end is still in this #5 TDC position as we speak. The rear camshaft pulley TDC mark is pointed down and will remain there as no valvesprings are compressed. The front camshaft pulley with #5 TDC mark pointed up DOES have compressed valvesprings and the camshaft quickly rotated about 90 degrees counterclckwise.

So..........

1) I could leave everything as is, put the belt on, while carefully wrenching the front camshaft pulley to line up the #5 mark.

2) I could rotate the bottom end 90 degrees counterclockwise, then wrench both camshaft pulleys so the #1 marks are pointed up, then rotate the motor the remaining 270 degrees counterclockwise to get the #1 piston to TDC, then install the belt as instructed in the book.

Am I missing something? Can I cause any valve or piston damage if I am wrenching the block and cams slowly by hand?

BLKFLSH

I'm no expert, but I wouldn't try turning the crank a full turn, without turning the camshafts. I would probably try turning half/quarter turns at a time. I would also take the plugs out, so I could better feel for if a piston comes in contact with a valve. Good luck

Toy Civic

Plugs are already out.

If I turn the camshafts, I would only do so as long as I knew that NO piston was at TDC. The question is, about how many degrees from the crankshaft TDC mark would it take to rotate the crankshaft to ensure that all pistons are in mid travel and NOT at TDC?

BMaDOHC

Just continue doing the job with it 180 out. Not a big deal at all, i actually prefer to do the v6 with number 5 up, when you have cylinder one up the rear cam tends to jump sometimes because its semi on a cam lobe. doing it 180 out isnt going to hurt anything. line up your crank mark, and the number 5 mark and just look over the rear cam directly down and you will see its completely straight.. just always remember slack in the back when routing the new belt that way when you pull the pin the tensioner pulls the slack out of the belt. A good trick to pulling the pin is using small vise grips, lock it on the pin close to the base, and use a pry bar and give it a little twist.....If your still nervous just rotate the motor afterwards to make sure.

ive been at the dealer 10 years btw, just did an 05 accord v6 6spd before i left work a couple hours ago

BLKFLSH

BTW, what's the weather like in URANUS? Couldn't resist.

Toy Civic

It is 98.6 degrees and gassy...............

Toy Civic

Here's another question. I bought crank and cam oil seals. I replaced the crank seal which was super easy. I then went to the cam pulley bolts.........after the belt was off. I used an air gun and the front cam pulley bolt came off. But the rear cam pulley bolt will not come off.

1) I could install the timing belt, then use the air gun with long extension and u-joint at a weird angle to remove the rear cam pulley bolt, remove the timing belt, change the cam seals, then install the belt for the final time.

2) But is there any other trick to removing the rear cam pulley bolt without having to temporarily install the timing belt?

BMaDOHC

ive never replaced a cam seal on any honda v6's so i couldnt tell ya, they never leak

justinsbg

Cam and crank seals are not a service item when doing a t-belt on the V6 motors. Unless there is signs of leakage I wouldn't worry about them. They rarely leak. I've done many t-belts on these V6 cars and have never replaced cam or crank seals.

justinsbg

Just carefully rotate the cam. You shouldn't hurt anything.

slomofo

iTrader: (1)

I've never seen cam seals leak on any of the V6 engines, but I change them all the time per customer request. Both the cam gear bolts are always on super tight and I usually use cam gear pliers to take them off. The pliers I have are actual "Camshaft holding pliers" meant for Ford 2.0 ZETEC engines, but they look damn near identical to oil filter pliers.



Just remember to torque the cam gear bolts to proper spec (67ft. lbs.) when putting them back on.

Toy Civic

Everything is cool and the engine is running great. I left #5 piston at TDC. I followed the advice of BMaDOHC where it is preferable to change the belt at #5 TDC versus #1 TDC. Reason being is the camshaft alignment.

When #1 is TDC, both cams have some valvespring compression going on. It is much harder to align two camshafts when routing the belt.

But with #5 at TDC, the rear cam is perfectly aligned and has ZERO valvespring compression. The front camshaft does have fully compressed valvesprings. But wih the rotating assembly at #5 TDC, the front cam can be rotated counterclockwise or clockwise from the #5 mark on the cam pulley. I know this because when I aligned the front cam pulley to #5, you can EASILY over do it by a micrometer and the camshaft will jump clockwise. You must rotate the cam pulley back to where it was, then carefully wrench the pulley clockwise a micrometer at a time to get the #5 mark to line up.

Once I did that and the front cam pulley stayed in place, then I routed the belt counterclockwise. In that process, I ever so slightly moved the rear cam pulley clockwise. I did this to allow for any slack once I pulled the new autotensioner pin and not be off by a tooth.

The trick I used to pull the pin was a set of vise grips and a pry bar. Grip the pin the vise grips, the use the pry bar as a fulcrum.

Water pump, autotensioner and pulley, idler pulley were easy.

When removing the engine mount bracket, make sure you only loosen the bottom bolt and not try to remove it all the way using a standard rachet and socket. I wasn't paying attention, and the rachet base got butted up against the frame rail. Getting it off took a very long time.

Perhaps the most frustrating thing about this job was the re-installation of the 10mm bolt holding the oil dipstick tube to the side of the engine block. You can't see @#$! and big hands like mine will have a hard time trying to get the bolt started.

Crankshaft oil seal was super easy. For the cam seals, I bought them but did not replace. I should have unloosened the cam pulley bolts first before removing the belt. Because once the belt is off, those cam pulley bolts may not come off.

BMaDOHC

next time leave the 10mm bolt threaded a couple times and cut the dipstick mounting hole to be a upside down U. much easier to line up. trick i use everytime.

JAS5300

I have another issue. I'm in the middle of changing the timing belt on my 2012 Accord V6. When I pulled the harmonic balancer off the key came with it. I missed the significance of that. When I tried to turn the cams to #1 TDC with the crank I noticed that nothing was moving. Then I realized the key was missing so the crank shaft was not turning the cams. I lined it back up and put the key in. Then I realized I had only turned the crank one revolution. (I think). Is there any way for me to be sure where that cylinders really are? Should I turn the crank another revolution?