968workaholic

If you have the cam installation blocks then you don't have to keep the vario-cam unit compressed, this aids in keeping the cams in proper time. If the blocks are not available to you then yes keep the unit compressed as it will make installation easier.

Apex

OK that makes sense.

LOL! Nice username "968workaholic" - exactly how I feel these days.

RajDatta

Yes, that is the correct way of doing it. Even the manual tells you to compress the cams 1st using the cam blocks and then pull the variocam clip off.
You are understanding it 100% accurately.
Raj

FRporscheman

I also made a tool out of a (thick) wire coat hanger. It took a few tries but I finally got the shape right. I can't imagine the actual tool being that expensive; I've been meaning to get one.

To get the tensioner in and out of the chain, I just squeeze it with my hands while my brother holds the cams. When I feel lazy, I compress the tensioner in a table vice (or c-clamp) and stick in the coat hanger tool.

Glad our efforts could help you out!

Apex

I checked last week and the tool was $42.80 from Sunset and a month away in Germany. So a coupla tries with the wire bender seemed like the ticket.

Yes - thank you for all your help. My nice clean head is back - looking forward to next weekend when I should have all the other parts in hand.

dprantl

So I did this yesterday on my wife's 1993 968 tip. When I started the car up today, it ran really rough and I had to give it gas to keep it running (like it was missing on some cylinders). If I revved it up past around 2,800 RPM I heard a loud BZZT sound. If I disconnect the variocam connector and rev past 2,800 RPM I do not hear this.

1) Should the car run properly when the variocam connector is disconnected?
2) When taking out the oil tube to the tensioner, I did not see any check valve or o-ring. I just saw a tiny ball on the tensioner itself.

So wtf did I mess up? Maybe I lost the check valve without noticing, but that wouldn't make the car run rough at idle, correct? Please help!

Dan
'91 928GT S/C 475hp/460lb.ft

dprantl

Ok so I took off the valve cover again and looked closer. It turns out I do have the check valve in there just fine. I also verified that the rotor is on properly (pointing upwards at TDC) and the wires are in the proper order. Any ideas of what could be the problem?

Dan
'91 928GT S/C 475hp/460lb.ft

rob76turbo

Dan,

When you reinstalled the cam shafts, did you match them up exactly as they came out? When I did mine, I locked the motor at TDC, and marked the cam shafts so that I could reinsert them exactly as they came out. Upon initial start up, there was a sound like a chain against metal, but that went away as soon as oil started flowing again.

dprantl

Yes, as best as I could. I used the two notches on the cams and tried to match the picture on the first page of this thread. Looking at them side to side, I believe I got it spot on, but maybe not?

Dan
'91 928GT S/C 475hp/460lb.ft

dprantl

On a similar note, does anyone actually have a picture of what the crank TDC mark location is supposed to look like on a tiptronic? The workshop manual references the dual-mass 6-speed flywheel like 7 times, but nothing for the tiptronic. I was using what I thought to be it under the car, but maybe I'm wrong... It is a little window just forward of the starter at the 6 o'clock position, and there is a ~5mm wide notch on the flywheel. Is that it?

Dan
'91 928GT S/C 475hp/460lb.ft

RajDatta

Dan, not having much experience on tiptronic, I would assume there has to be a notch on the tiptronic damper just like the dmf. Do you have an inspection hole on a coverplate on the bell housing?
That is the proper way to get tdc as per the factory manual.
Another option would be to use a dial guage in cylinder #1 to get tdc.
Did you test the engine by turning it a few times before you ran it?
Raj

dprantl

Yes, I turned the engine over by hand many times to verify nothing was off. I'm going to get back to it this afternoon to double-check all timing marks again.

Dan
'91 928GT S/C 475hp/460lb.ft

kwikt

Or.... go to your local auto parts store and pick up one of those TDC finders to make sure you're on track. When I did mine, I used a dial indicator instead of the flywheel marks at the inspection hole.

Kevin

jeffbarn

I too just completed a chain and guide replacement.

For me engine is now weak/flat and does not want to rev. I just checked the fault codes and it says bad hall-signal. Connector was cracking, but I thought I was able to get it reconnected ok. Would this be my problem as well as Dan's?

I had a hell of a time finding the TDC timing mark. When I disassembled, I had used a flywheel lock with the cam timing mark at TDC, but with new belt, it was off 1/2 a notch. Inspecting the flywheel site hole I saw 2 lines shaped like this "<<" instead the the TDC mark, moving in the direction of the "arrows" I then found 2 lines with a dimond shaped mark in the middle (which is kinda lwhat it looks like in the shop manual, just more elongated in the manual). It seemed more than one "notch" of movement however.

I thought about checking the TDC of the piston, but since it looked like the shop manual diagram, I proceeded. I did rotate engine several times to make sure nothing was "binding"

Anyway, is the hall sensor likely my problem (and possibly Dan's) or should I recheck the timing?

BTW, can the hall sensor be replaced with out taking the cam gear off?

Thanks

User 41221

The hall sensor comes off from the back side, no need to pull the cam gear. Once you dig into it, you'll see its not hard at all to replace. I just did mine about 6 months ago and it will definitely make a difference.

Regards,