What did I do wrong now?!
 

Just did a waterpump/timing belt job along with AOS seals, and the hoses under the intake.

I just got everything back together and took it for a test drive.

It was vibrating a lot more than when I started the job. As well as I noticed the balance belt seemed to be nicking the front roller looking thing on the waterpump.

Could the vibrations be bad timing?
What about the belts?

My best guess is the balance shafts are not lined-up properly. Re-check marks for both top and bottom balance shafts, and also ensure the proper tension is set. If you have the Porsche factory manuals for the 944, the procedure is in there. If you do not have the Porsche factory manuals then visit Clarks Garage for the proper process on ensuring your balance shafts are properly set-up.

If your timing was off, your pistons would be running into your valves.

Good luck.

Belt: did you put the rollers back on with the shoulders on the proper side? Stumbling: Check your AFM plug for contact and recheck the vacuum line routing on the throttle body. It's easy to get those two little ones on the wrong stubs. Check your connections on the injectors. A noid light (cheap at the auto parts store) will help you check to see if an injector's not pulsing. Perhaps a spark plug insulator got bumped and broken. If in doubt, pull the plugs and see if one's not firing (look for wetness on the plug).

+1--^-- every thing mytrpl777 said.

Double check the balance belt rollers mentioned by TibetanT

Photo

http://forums.pelicanparts.com/uploa...1381968813.jpg

My input---lower the balance belt by the WP pulley by tensioning the BB tension roller CW-clockwise

J_AZ

Yes and don't drive till you check..

Ok so I pulled each plug on the injectors and they seemed fine. I also switched the vacuum lines and that didn't seem to change anything.

So this would loosen the tension?
And from what I remember it was in line just like the picture. I guess I'll have to recheck.

Dare I ask why? haha

Although everything 777 said could be a problem, My best guess is a BB problem. Pay particular attention to the O-U markings on your BB sprockets and the pic that John AZ posted. very easy to install the sprockets improperly. The BB can def cause your vibration, Timing belt will cause your engine to cease operation very quickly.

As mentioned, Clarkes has an excellent DIY instruction!

He said that the balance belt was "nicking" the water pump pulley. If the belt was doing that doesn't it sound like it's really loose? I'm thinking if it's that loose then it's probably jumped out of time as well, which would cause this vibration..Yes?

^ Yes, too loose. May skip. Remember: bal shaft keys BOTH face up, then sprockets go on with their notches at the rear, aligned with the timing marks on the inner cover.

Ok I will definitely check that out. I know I had the notches lined up perfectly but I may not have had the bottom balance shaft key facing up. I'm not sure though.

I did take it for about a 2.5 mile test drive. Do you think I really screwed something up by doing this???

It is possible to drive without the balance shaft belt connected so I don't think you "screwed something up". However, a loose balance shaft belt that breaks and binds the timing belt could be catastrophic. I don't think the balance shaft belt is specifically the issue with why they are advising you to not drive, but the chain of events that could happen as a result from balance shaft belt failure.

Your issue is lower bal shft is 180 out of time. Trust me i did it too. Sprocket on bottom BS needs to be intalled180 off of mark (turned 180 degree off of top shaft orientation).

Also, as John mentioned, BS tensioner needs to be rotated counterclockwise to provide .5mm clearance between belt and idler. The only golden rule is Keyways Up.

I'm pretty sure the BS tensioner (the eccentric roller at the very bottom left of the loop) needs to be rotated clockwise, otherwise the belt will be too high and it will hit the water pump pulley.

mike 944 you can ask the answer is I did not have this issue but we all know what could happen if things go sour:confused: I'm just trying to help some save their engine..

+1 easy mistake, common error. Will do no real harm but the vibration will annoy the hell out of you. Generally goes away above 4000rpm and not too noticeable at idle but it's there in the most used rev range.

And those vibrations, if left uncorrected, can cause cracks to show up in the oil pickup tube.

Thanks everyone! I haven't driven it since so I'm gonna take care of that ASAP!

BB tensioner roller is Tensioned Clockwise!!

This is from Pro tech Techno Duck (now installing the LS1 engine in the 951)


http://forums.pelicanparts.com/uploa...1382068778.jpg

(where is that bottle!!)

J_AZ