Dsalillas

Okay,

I've got a 90 S2 that suffered a chain tensioner failure about a year and a half ago. The valves look fine but the mounting boss broke leaving the plug hole intact. I bought a rebuilt head anyway and finally got around to putting it in.

Here's my problem. I have the flywheel at TDC and put the cams in per FSM and Mr. Mitros Pics(thanks BTW) now I can't turn the crank by hand. With the belt off and the cams set the crank turns fine. As soon as I put the belt on I get about a quarter turn and that's it. Could it be the rebuilt head has been in my garage so long that its frozen? I 've been at this for three days now and about to give up. If I can't get it running by tommorrow, off to the shop it goes. Any suggestion before it comes to that would be greatly appreciated.

TIA,
Drew

Dsalillas

Well it looks like I'm done with tinkering with it, more like cursing at it, for the day. I won't be able to get it towed until Wed. so I have a couple of days to work at . Any suggestions? Bueller... Bueller...

Thanks,
Drew

jonnybgood

The only thing different between belt on and belt off is that the valves must be correctly timed in order to miss the pistons. I just did this with my S and I was one tooth off on the timing belt and sure enough the valves hit the piston. I was just turning by hand and fortunately I did not bend the valves, a compression check later showed it was good. Just one tooth on the timing belt can cause interference. check and double check. Did you set the lift on the #1 exhuast (edit:should be Intake) valve at TDC? If that is not set correctly you could also have problems.

Dsalillas

I'm pretty sure the cams are in right. I follwed the FSM and used Joseph Mitro's Pics plus all my pulleys are marked with paint. I doubt I bent any valves turning by hand since the cams didn't move at all when I tried to turn the crank. You think I could try to turn the crank with only the exhaust cam in? Just wanna to try and single out which cam is binding.

peterjcb

I'll be following your progress on this as I will be doing this in the very near future. I'm in the process of replacing a broken valve spring.
There are basically three things that have to be exactly correct simultaneously.
1. You must be at TDC
2. The mark on the exhaust camshaft pulley must be aligned with the index mark on the distributor housing.
3. You must have seven chain links from tit to tit on the camshafts and they will be facing upwards. ( links measured from middle of first link to middle of seventh link - tit to tit)
With the belts on and your flywheel lock off, the engine should turn without the valves hitting the cylinders. Could you possibly be feeling just the resistance from the cylinder compression or possibly a valve is hitting the piston?
Keep us posted.

Dsalillas

I don't think it resistance from compreesion since the plugs are out and I don't think I'm hitting any valves since none of them are opening. With the cams at TDC all the valves are closed I believe and the first to open are #4 intake and #2 exhaust. The pistons don't even move high enough to hit either of them sice I don't even get a quarter turn It's more like sixteenth turn without the cams moving at all. This really has me stumped.

Dilberto

Your header post looks like it can be misconstrued very BADLY...FYI

Zach
No, my mind is NOT in the gutter!

Dsalillas

We'll mine was until I changed it. Originally it was "Looking a for a little head HELP".

jonnybgood

Cams have to be moving 1 rotation per two crankshaft. Have you torqued the camshaft pulley bolt? You also need 3 M5 bolts in place of the distributor rotor bolts to hold the camshaft pulley in place to make sure it doesn't move while you set the timing. If you can move the crank 1/16 without the exhaust cam moving then the timing is off and there is some other problem.

Dsalillas

I have torqued the cam bolt but I didn't put the holding screws in. I'll give that a try tommorrow. Thanks

jonnybgood

I thought of one other thing that could cause this. When tightening the cam bearing bridges you need to do it incrementaly in order to not bend the cams. If you had a bent cam perhaps it is binding.

The three M5 bolts are only for when you are timing the valves. If you have torqued the cam bolt then it should be secure.

Good Luck

Dsalillas

I followed the torque sequence accordding to the FSM. Is there any way to tell if the cam is bent? Luckily I have an extra set of cams from the old head.

jonnybgood

Since you say you can rotate the cams without the belt in place then I suppose they must be straight. If they were bent you couldn't rotate them under any condition.

I am out of ideas...

Dsalillas

Actually I said I can only turn the crank by hand. Here's an update. I removed the intake cam and just used the exhaust cam by itself and it turn effortlessly. So I narrowed it down to the intake side. How do I troubleshoot this?


Another update. I put the exhaust cam from my old head in and I got the same results. It won't turn either. So I've narrowed it down to the two#4 intake valves since they are the first to open.

Now what?

michaelathome

I'll throw my .02 in since I have read things. Once you have gotten everything back together you will once again have compression.

There are so many questions left to be answered.
1. Where are your pistons at? Are any of them at the top?
2. Where are your valves at? There is going to be some that are up, some down and some in the middle.

Do you have your starter off and a flywheel lock in place? Jonnybgood mentioned "You also need 3 M5 bolts in place of the distributor rotor bolts to hold the camshaft" So you in fact need to have two locks in place?

Think out question 1 and 2 above and think about where the valves need to be before placing the cam tower. If you have been using the same gasket this whole time is it pinched? I ask that because I am unfamiliar with the later 16 valve engines but the 8 valve engines are interferance engines, too low and you have a problem. I am guessing yours is too.

Once again I am not familiar with the 16 valve engines but I would be looking for sure.

Michael