Timing Belt Replacement - TDC Verification

[johnsIslander]

I am replacing my water pump and timing belt on my 5vzfe and have a question. It’s a long story but after the TB was off I turned the crank shaft. I am 99% sure that I have only turned it once but I want to be 100% positive. How do I verify that cylinder one is in the right position before I button everything up? I want to make sure I’m not 180 out. Thanks.

 

[nevada]

I am replacing my water pump and timing belt on my 5vzfe and have a question. It’s a long story but after the TB was off I turned the crank shaft. I am 99% sure that I have only turned it once but I want to be 100% positive. How do I verify that cylinder one is in the right position before I button everything up? I want to make sure I’m not 180 out. Thanks.

just line up the timing marks.

you can pull the #1 plug to verify the piston is up. but the timing marks will do the same thing.

 

[LittleCaesar]

As nevada said, or I have on other cars used a small wooden dowel, laid it on top of the piston, then turned the crank while at the same timing looking to see if the dowel travels up or down. Then one should know. Or find someone who has an inspection camera you can put down the spark plug hole to tell.

Where off 162 are you?

 

[JRZEE2000TR4LTD]

I am replacing my water pump and timing belt on my 5vzfe and have a question. It’s a long story but after the TB was off I turned the crank shaft. I am 99% sure that I have only turned it once but I want to be 100% positive. How do I verify that cylinder one is in the right position before I button everything up? I want to make sure I’m not 180 out. Thanks.

Has to be lined up if the timing marks on the 3 gears are lined up. Once you get the TB on, Use a long ratchet and socket on the crankshaft bolt and turn the crankshaft 720 degrees. The marks on the gears should line up again.

 

[babowc]

^ like John said, there's an upstroke and downstroke TDC.
It is best to verify TDC with your timing marks.

 

[TheDurk]

^ like John said, there's an upstroke and downstroke TDC.
It is best to verify TDC with your timing marks.

No, there is not--at least until AFTER you have installed the timing belt--and it's not upstroke and downstroke. TDC is always between upstroke and downstroke. You can only be 180° out if the VALVES are in the wrong position at TDC or if the spark is applied at the wrong time. There is a TDC between Compression and Power and there is a TDC between Exhaust and Intake, but that is determined by the valves which are controlled by the camshaft. We use the TDC between Compression and Power for ignition timing because that is when spark is needed. It is irrelevant to the crank--TDC is TDC. Just line up the timing marks and you are good. The only way you are 180° out is if the crank is at TDC and the cam marks are at the bottom. If the cam marks and the crank mark are at the top and the belt is off, you can spin the crank 360° and then install the belt and you will still be perfectly in time.

Now, in the olden days, you had to worry about which way the distributor rotor was pointing because it rotated once for each two crank rotations, just like the valve camshafts. You had to get the rotor pointing to Cyl 1 plug wire or spark would be 180° out (the rotor would be pointing to some other cyl when Cyl 1 was needing spark). So you had to put your hand on the plug hole and feel compression so that spark timing matched valve timing. But the ECU in these motors determines spark by the cam and crank sensors, not mechanically. Plus, the waste spark setup fires at both TDC's anyway.

I hope this cleared things up rather than confusing folks.

 

[freshley]

what I ALWAYS do is remove the plugs and insert a plastic kitchen spoon (about 12" long) in the #1 spark plug hole and rotate until I am certain I'm TDC. As you rotate the crank, watch the spoon until it is at the very top point. Sometimes the timing marks are hard to find or see so that is my backyard mechanic advise.

 

[LittleCaesar]

Thanks Durk for making this much clearer than I ever could. Learn something new each day.

 

[sterbenlicht]

Are there no marks on your new timing belt?

With the belt off, you can move the crank anywhere you want as long as you put the belt in the proper place with all three marks lined up.

 

[johnsIslander]

Thanks Everyone, I am still waiting on my timing belt tensioner tool. It was supposed to be here last Thursday but nope. I will try out all of your advise this weekend hopefully and provide an update. I have a kick a$$ crank pulley tool BTW thanks to this forum.

I am up 162 near Stono Ferry closer to Charleston than "downtown" Hollywood.

 

[LittleCaesar]

Before or past Dixie Plantation Rd? I knew a guy who lived on Rantowles Creek.

I went to the College of Charleston up to 2001, and helped manage Dixie Plantation while I was there after they received from John Henry Dick some time before. I once saw a 8ft rattlesnake cross the road as well as a 12pt buck. I hated when they cut down some of the trees a decade ago, but oh well, as it goes.

Good luck with the install. Let us know how it turns out.

 

[csp]

I'm trying to remember what I did for the tensioner. I sure as heck didn't have a special tool for it and didn't find that one would have made it any easier.

 

[TheDurk]

I'm trying to remember what I did for the tensioner. I sure as heck didn't have a special tool for it and didn't find that one would have made it any easier.

If you change the tensioner, the special tool will be useless to you. The new ones come compressed with a lock pin inserted. The tool is only used to compress the old tensioner that is being reused so that you can insert a lock pin without removing it from the engine and placing it in a vise.

 

[babowc]

No, there is not--at least until AFTER you have installed the timing belt--and it's not upstroke and downstroke. TDC is always between upstroke and downstroke. You can only be 180° out if the VALVES are in the wrong position at TDC or if the spark is applied at the wrong time. There is a TDC between Compression and Power and there is a TDC between Exhaust and Intake, but that is determined by the valves which are controlled by the camshaft....

I have been schooled! I thought the same applied, as I've been working on earlier model distributor'd Nissans.

Thanks for the clarification! :cheers:

 

[nevada]

If you change the tensioner, the special tool will be useless to you. The new ones come compressed with a lock pin inserted. The tool is only used to compress the old tensioner that is being reused so that you can insert a lock pin without removing it from the engine and placing it in a vise.

IMO, on an interference engine, and one requiring so much time/effort to access the belt, replacing the tensioner is a must.

 

[TheDurk]

IMO, on an interference engine, and one requiring so much time/effort to access the belt, replacing the tensioner is a must.

It is NOT an interference engine. If you are changing the belt at 90k interval, I think doing the hydraulic tensioner every other TB is reasonable. Personally, I use a 120k interval and do EVERYTHING, including the hydraulic tensioner.

 

[TheDurk]

I have been schooled! I thought the same applied, as I've been working on earlier model distributor'd Nissans.

Thanks for the clarification! :cheers:

I thought there was some distributor-ingrained thinking there. I can relate; I am still recovering from the first, last and only time I installed a dizzy 180° out of phase, and that was over 20 years ago. Not a mistake you make twice in the same lifetime.

I still work on one regularly as my 1966 International Farmall 140 tractor has a 4-cyl 123 CID distributor ignition engine (converted to electronic ignition but still mechanical distribution).

 

[nevada]

It is NOT an interference engine. If you are changing the belt at 90k interval, I think doing the hydraulic tensioner every other TB is reasonable. Personally, I use a 120k interval and do EVERYTHING, including the hydraulic tensioner.

DOH. I didn't pay attention to what section I was in....

 

[sterbenlicht]

I can't speak for the aftermarket belts, but I can't recall ever seeing one of the factory belts breaking on a 3.4L. I'm sure it happens, but I only ever see the 5S 4 cylinder timing belts and the occasional 2UZ...which gets very expensive very quickly.

 

[TheDurk]

I can't speak for the aftermarket belts, but I can't recall ever seeing one of the factory belts breaking on a 3.4L. I'm sure it happens, but I only ever see the 5S 4 cylinder timing belts and the occasional 2UZ...which gets very expensive very quickly.

I agree--the only time they go is if something kills them: the WP leaks or seizes or an idler seizes or the hydraulic tensioner wimps out and it slips. The WP is more likely to die than the TB. That's why I let it go to 120k and then changed everything.