Rebuilt engine- crank wont rotate with timing belt on

[fourgsixthree33]

Rebuilt a 2g 7 bolt motor which is going in my 93 tsi awd. Im using my rebuilt 1g 7 bolt head. Last night we put the front case on followed by the head. Next we decided to put the timing belt on. At this point, the crank turned great by hand and could easily hear that it had compression. So we started puting the timing components on. Got it all together with the belt and timing marks were perfect. Went to rotate the crank with the belt on and it only turned about a quarter turn and it got hung up on something. Turned it counter clock wise a quarter turn and it got hung up again.

We are using the balance shafts and the engine is still on the engine stand. We took the belt off and the crank spun great. Then we rotated the cam gears. Both of them rotated fine.

Im thinking one of the timing components are getting hung up or causing problems. Hopefully someone can help me out so toss out some ideas.

 

[Alan11]

what about the oil pump and balance shaft? do they rotate fully?

 

[bryanwheat]

Rebuilt a 2g 7 bolt motor which is going in my 93 tsi awd. Im using my rebuilt 1g 7 bolt head. Last night we put the front case on followed by the head. Next we decided to put the timing belt on. At this point, the crank turned great by hand and could easily hear that it had compression. So we started puting the timing components on. Got it all together with the belt and timing marks were perfect. Went to rotate the crank with the belt on and it only turned about a quarter turn and it got hung up on something. Turned it counter clock wise a quarter turn and it got hung up again.

We are using the balance shafts and the engine is still on the engine stand. We took the belt off and the crank spun great. Then we rotated the cam gears. Both of them rotated fine.

Im thinking one of the timing components are getting hung up or causing problems. Hopefully someone can help me out so toss out some ideas.

Well first off, if that block truly is a 2g 7 bolt, it will not have the bolt holes for the front engine mount bracket. Sounds like you have the timing marks off and the valves are hitting the pistons. It is also possible that you have the 6 timing plate on the 7 bolt engine. The timing mark is in a different location.

what about the oil pump and balance shaft? do they rotate fully?

I second this, did you install the balance shaft or balance shaft stubby correctly? IF not installed the oil pump gears will bind with eachother.

This is what the front of a 2g block looks like. Notice that there are no bolt holes at the lower left corner.

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Here is what a 1g 6 bolt and 1g 7 bolt block look like. Notice the bolt holes in the lower left part of the picture. That is where the front motor mount bracket bolts to.

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[awdjosh]

Make sure the tensioner arm for the timing belt is tensioning the right way as its different for a 6 and 7 bolt.

 

[Black'95]

Now hang on, here, I'm confused. You have the assembled head bolted to the block, including cams installed and bolted in, right? then, with no timing belt on, you rotate the crank around? When you put the timing belt on, it won't rotate. Seems backwards, obviously, but what I'm wondering is how the hell does the bottom end rotate freely without the cams/valves moving? Wouldn't the pistons hit the valves that are open?!

 

[Guilty1s]

Now hang on, here, I'm confused. You have the assembled head bolted to the block, including cams installed and bolted in, right? then, with no timing belt on, you rotate the crank around? When you put the timing belt on, it won't rotate. Seems backwards, obviously, but what I'm wondering is how the hell does the bottom end rotate freely without the cams/valves moving? Wouldn't the pistons hit the valves that are open?!

With no timing belt on, the cams are most likely in a resting position where no valves are pushed down. Allowing the pistons and crank to move without hitting the valves.

OP, you would be able to turn the crank some direction if the valves were hitting pistons. That leaves either, oil pump pully, or balence shaft pully... make sure they both rotate by hand.

also make sure the cams are able to rotate. I once got a head with cam caps from another head (BIG NO NO) and it would cause the cams to not be able to spin. IF YOU TRY TURNING THE CAMS ALONE.... MAKE SURE NO PISTON IS AT TOP POSITION. ALL 4 MUST BE IN THE MIDDLE.

edit... i see that you said it did rotate a quarter turn in each direction... which would mean that valves are hitting piston.... either they are bent and stuck down or your timing is off.

Since it spun freely before the timing components where installed, i would guess the latter.

You can check for stuck valves with the timing belt off if you take the valve cover off. A stuck valve with a cam lob in the up position will cause the rocker arm to be loose.

 

[dalesocks]

Looks like the timing is wrong and valves are hitting the pistons. Check the marks and make sure the crank timing bracket is not put on the wrong way.

 

[romeen]

Did you insert a screwdriver into the back of the block to keep the rear balance shaft from spinning? If so, did you remember to remove it? Would likely notice it with engine on stand but silly things do happen.

 

[brane_97talon]

Please let me know what happened, I had the same issue with a 6 bolt rebuilt engine but no timing components installed. Would turn halfway, stop, and turn in the other direction halfway. No belt, just head torqued down. Both cams were in resting position btw

 

[Toly1993]

Please let me know what happened, I had the same issue with a 6 bolt rebuilt engine but no timing components installed. Would turn halfway, stop, and turn in the other direction halfway. No belt, just head torqued down. Both cams were in resting position btw

I have the same issue

 

[dwb]

no timing components installed. Would turn halfway, stop, and turn in the other direction halfway. No belt, just head torqued down. Both cams were in resting position btw

I have the same issue

Your pistons are hitting the valves. Look up an "interference engine."

 

[pauleyman]

I have the same issue

If you have cams in and no timing belt you may have already bent valves. You may be better off removing cams and doing a leakdown test. You cannot turn the crank with no belt IF the cams are in place.

 

[Mech Addict]

As I started reading I thought of the screwdriver in the balance-checking-hole. Romeen already mentioned that, but I thought since OP hasn’t replied about it, I’d throw my bet down too.just the same kind of thing I would do. Ya get all the hard stuff right but forget the trivial part.