Posts: 516
Threads: 22
Joined: Dec 2011
Reputation:
0
My first batch of parts finally arrived today, which included the flywheel lock, so I started tearing things apart..
However, when I removed the timing belt tensioner I had a bit of surprise...
Hydraulic Timing belt tensioner by
mbardeen, on Flickr
So what to do.. buy a new one? Get it welded? Leave it as is? My feel is that the bit that's missing shouldn't receive a lot of pressure, so a weld should work, but.heating the hydraulic unit might be bad.
Other discoveries from this process:
Camshaft timing by
mbardeen, on Flickr
Cam Timing seems to be off a tooth.
Upper balance shaft by
mbardeen, on Flickr
Upper balance shaft timing is way off, lower balance shaft is similar.
-Matt
1993 Midnight Blue Porsche 968 Cabriolet (toy! Currently under restoration)
1995 Jeep Cherokee (war wagon, Zombie Apocalypse Response Vehicle)
2015 Mazda 3 (my reliable, nice car)
Posts: 516
Threads: 22
Joined: Dec 2011
Reputation:
0
Yes, I'm using the flywheel marks. Harbor Freight doesn't ship here, so that's out. I'll have a troll around the tool shops here to see if I can find a dial indicator. I'll have plenty of time to search, since I'll probably end up ordering the automatic tensioner from DC Auto (these aren't something that should go bad, right?).
My impression is that whoever last changed the timing belt wasn't very careful, just judging on how far off the balance shafts were. Definitely not a Porsche trained mechanic! It wouldn't surprise me at all if the timing belt was off by a tooth.
I didn't really get enough seat time in the car to be able to judge if there were a lot of vibrations or not.. I'll set them as the manual shows and go from there.
-Matt
1993 Midnight Blue Porsche 968 Cabriolet (toy! Currently under restoration)
1995 Jeep Cherokee (war wagon, Zombie Apocalypse Response Vehicle)
2015 Mazda 3 (my reliable, nice car)
(This post was last modified: 04-28-2012, 11:32 PM by
mbardeen.)
Posts: 687
Threads: 19
Joined: May 2011
Reputation:
0
I think you'll find that the tensioner is cast iron, not an easy weld fix. And, if you put any heat into the tensioner, you'll likely due damage to the seals, or some part of it. You should just purchase a new unit.
'92 Midnight Blue 968 Coupe
'94 ProbeGT, Eaton SC@9psi, Quaife, TecGT ECU, 300+HP, body sold, parting out
'98 3000GT VR-4, 400+HP AWD beast, didn't fit w/race helmet, Sold
'93 Bone Stock MX-6 Sold (in '05) sadly to the crusher in 2010
'61 Triumph TR-3, White with red leather interior; My First Car
Posts: 516
Threads: 22
Joined: Dec 2011
Reputation:
0
It's not terribly expensive, but there have been whole bunch of not terribly expensive things that, combined, have put me a bit over budget. Though, as a fairly critical part of the critical timing belt system, I'll suppose I'll replace it with a new one rather than chance it on a used piece.
I wonder what fun gifts I'll find when I get the water pump off tomorrow?
-Matt
1993 Midnight Blue Porsche 968 Cabriolet (toy! Currently under restoration)
1995 Jeep Cherokee (war wagon, Zombie Apocalypse Response Vehicle)
2015 Mazda 3 (my reliable, nice car)
Posts: 516
Threads: 22
Joined: Dec 2011
Reputation:
0
I'm trying to keep a sense of humor about this whole process. In the end, I'll have the only 968 Cab in Chile.. that has to be worth something. So, I'll keep buying parts until it's running again and hope I have enough left over for the cosmetic issues.
I just wish that every broken part I find along the way didn't mean a month delay in getting it back on the road. I want drive the damn thing!
-Matt
1993 Midnight Blue Porsche 968 Cabriolet (toy! Currently under restoration)
1995 Jeep Cherokee (war wagon, Zombie Apocalypse Response Vehicle)
2015 Mazda 3 (my reliable, nice car)
Posts: 516
Threads: 22
Joined: Dec 2011
Reputation:
0
The car has 66000 miles. The variocam pads, chain, and cam teeth all look to be in good condition.
[sharedmedia=gallery:images:2055]
I checked the position of the cam lobes in the car with the cam shaft pulley set like it was... noticeably different than what it should be according to the workshop manual. Advancing the pulley one tooth put them where they should be. So it looks like it was just carelessness on the part of the previous mechanics. It's a wonder this car hasn't self-destructed!
-Matt
1993 Midnight Blue Porsche 968 Cabriolet (toy! Currently under restoration)
1995 Jeep Cherokee (war wagon, Zombie Apocalypse Response Vehicle)
2015 Mazda 3 (my reliable, nice car)
Posts: 976
Threads: 63
Joined: Jul 2006
Reputation:
0
I just replaced mine (tensioner) and have a good used one that you can have gratis. Worked fine when I pulled it off.
-Scott
SOLD! 1992 - 968
2002 Lexus LS 430, Silver/black, "Ultra Luxury", with reclining, heated, massaging back seats, and 4 cup holders.
(This post was last modified: 04-29-2012, 02:09 PM by
Scott Collins.)