hot-J

I just bought a 968, and it seems slooooow. Doing a tune up this week, but how do I know when its time to do the chain, tensioner and pads?

tamathumper

You'll have to take off the cover to inspect the chain, tensioner and pads, but that's not the reason your car is slow. There are many things it could be, but probably the simplest (no tools required) is to look at the Hall Sender first, the connector might have gotten crumbly over the years from all the heat - it's right above the exhaust manifold.

RajDatta

As suggested, check the hall sender to make sure the system is good timing state.
Next would be to make sure your timing belt is not off by a tooth.
BS belt alignment is also a factor because it would make the engine very hard to rev past 3k rpm.

Raj

odurandina

as Raj also educated me about this stuff... here's what i would do;

i go about 6 k miles on synthetic oil and filter.... then about every third oil change (20 k miles), i would change the air and fuel filters, transmission and brake fluids... and at every belt time (40 k miles or 4 years), i would do the timing, balance shaft and accessory belts, spark plugs, distributor rotor, and a coolant flush (or a few weeks before winter each year).... at the second belt change (80 k miles), you should install a complete timing belt kit, H20 pump, AC compressor (my compressors failed at 78 k and 159 k), all the stuff you do every belt change.... add hoses (including fuel hoses and high pressure PS hose), distributor cap and rotor, spark plug wires, plugs etc.... at this time you should switch your PS pump for a new or rebuilt unit (they're well on the way to seal failure anyway).... and then at your third set of belts *(some people will do this stuff at the second belt change), you should install a new cam chain, pads, seals, hall sensor etc, along with all the stuff you do every belt change.....

Cloud9...68

First of all, congrats on the "new to you" 968. Before doing anything else, you should do a blink test to make sure all your sensors and various systems are operating correctly. Basically, the blink test is the poor man's (pre-OBDII) code reader. I haven't done one in a long time, but it basically involves sitting in the drivers seat, turning the key (to the accessory position?), depressing the gas pedal, holding it down for a few seconds, then releasing. The dash light will flash in a morse-code style, and the pattern of the flashing will tell you if any of your sensors and such are not working properly. Do a search, and it will walk you through the procedure much more accurately than my vague recollection I've posted here, and you'll also find the pattern of the blinks that you'll need to interpret. Good luck!

docmirror

Congrats on the purchase. We'd like to know where you are, so that we can help you get the assist you need, in person depending on where you are.

The chain and tensioner are typically good for 150k miles, but there are stories of failure as low as 60k miles by what I've investigated. You will need a 6mm allen, an 8mm socket and a few other hand tools to check it. Remove the plug wire and injector harness cover with the logo, then remove the plug wires from the spark plugs. Now, you can take the cam cover off and you can inspect the chain. This is a good time to take the plugs out so you can roll the engine around. Grit and goop tend to get into the plug wells, so I blow them out carefully before removing the plugs.

Once the plugs are out, put the car in 4th gear, get a hi intensity light, and gently roll the car forward, as you inspect the teeth of both cams. I roll the car through four revolutions to check both cams carefully. You can barely see the lower tension pad which is the really important one.

The upper tension pad runs in take-up, the lower tension pad runs in torque delivery(exh to int). If you see modest wear on the upper pad, the lower pad is worn out already. If the upper pad shows little wear the lower pad will be moderately worn. If your car is at or near 150k miles you might as well plan the replacement job before inspecting.

The parts for the pads are the same as a 928, and my good buddy at 928sRUS has the best price on them. You will also need the cam cover seal, and the hold down bolt seal kit. Roger can be reached at 817-430-2688

RajDatta

There is really no of checking the lower pad wear with any certainty besides removing it. At that point, you might as well change them.
Chain and pads should be a 75k-80k items. I have seen them fail as low as 60k miles.

hot-J

Thanks guys! The car has 171k, so I had planned on replacing them.... Now i defenetly will.

docmirror

Outstanding. Now, a few words of caution. When you take the cams out, and you take the tensioner assembly off, there is a small shaft and spring that hold the barrels together. Don't let go of that assembly until you are sure you can catch all the bits!

Next, when you take the bolts off the cam caps, they are a weirdo cheesehead or Torx type of tool. Don't try to use an allen tool in there or you will be grinding some cap bolts off with a die grinder.

Finally, cams are brittle. I mean they are really brittle. Undo the cam cap bolts a little at a time, and when you put them back, do them up a little at a time along the length of the cam. If you don't have the cam alignment tool handy, make sure you mark both cams with a bit of paint so they go back the right way. Replace the pads, and the chain as it stretches as well.

RajDatta

Guys, there is a sustantial DIY put together by Arash. Search is your friend.
It is frustrating that such DIY's are not sticky's.

RajDatta

https://rennlist.com/forums/968-foru...oner-pads.html

We absolutely have to have this as a sticky!!
By far the best DIY done on a 968.