79 928 backfired and stopped running

[Pete R]

I think that's just his coolant hose tucked up out of the way.

[Eric Drewes]

It's actually the hose that goes to the oil fill pipe on the oil pan. I had to remove this and the dipstick housing to get the lower timing cover off. I've plugged both those holes with paper towels while I'm doing this work, especially since I took the opportunity to pressure wash this area to make it easier to inspect for oil leaks.

[JhwShark]

Good news...thought some reason, could tell it was an oil line...

[Eric Drewes]

Progress update. HTD gears installed on cams, oil pump, & crankshaft. New water pump installed. Will tackle the tensioner & belt installation tomorrow. Just might be running again by this weekend.

[Mrmerlin]

you need new pivot bushings. for the pivot bolt and you should also replace the pivot bolt.
Go to ACE hardware and buy a new set of bolts to swap out the old WP bolts, there are 2 sizes and also one longer one for the timing cover, using the old bolts almost gaurantees that one or more will snap off in the block next time.
Put PTFE pipe sealant on the threads this will keep coolant from leeching into the holes and corroding the bolts into the block

[Mrmerlin]

if not already done remove the thermostat and replace it as well as the O ring and the rear seal in the housing.
Clean the corrosion off of the outlet so the hose wont leak

[Eric Drewes]

Originally Posted by Mrmerlin

you need new pivot bushings. for the pivot bolt and you should also replace the pivot bolt.
Go to ACE hardware and buy a new set of bolts to swap out the old WP bolts, there are 2 sizes and also one longer one for the timing cover, using the old bolts almost gaurantees that one or more will snap off in the block next time.
Put PTFE pipe sealant on the threads this will keep coolant from leeching into the holes and corroding the bolts into the block

Merlin...just saw this advice today while at work and was wondering if you could knew those bolt sizes off the top of your head. I pass an ACE hardware on my way home and would like to pick those up. Also... not to sound dumb, but when you're referencing the pivot bushings are those the two white sleeves with the split that were on the bolt that secures the belt tensioner into the roller on the water pump? Where would I even find something like that...ACE? Or is this going to be a special order part?

Thanks

[Landseer]

Gotta have those white plastic pieces.

I've made the mistake of reusing a set before, in my case trying to economize.


Bolts are as follows:

5 each of M6 X 20
8 each of M6 X 25

They are very lightly torqued with an inch-lb torque wrench on reinstallation.


I like to carefully clean the holes, at least flush with WD 40 via straw.

[Mrmerlin]

Roger has new bushings

[Mrmerlin]

PET callout for WP bolts is
5 M6 x 20
8 M6 x 25
1 M 6 x 73 this is for the timing belt cover this bolt passes through the waterpump
Buy new washer also you need 13
NOTE also replace the 2 M6 bolts that hold the water outlet
2 M6 x 25

M6 is bolt diameter
25 is the thread length in MM
Put loctite PTFE pipe thread sealant on the new bolts,
that way they wont be corroded when removed next time

[Eric Drewes]

I am having difficulty finding the pivot bolt and new pivot bushings. I definitely cannot re-use the ones I have because the tensioner is cocked at a slight angle and the belt is walking off the tensioner when I turn the engine by hand. I looked thru the engine section where timing belt/accessories are, but they are nowhere to be found. Can anyone here tell me the best place to locate these parts?

[Eric Drewes]

Never mind...found part #'s from original Porsche catalog and was able to track them down that way.

[Eric Drewes]

Update...patiently waiting for parts...Replacement pivot bolt & bushings still have not arrived yet.

[Eric Drewes]

Oh happy happy joy joy...NOT. After 2 weeks of waiting, the pivot bolt I so carefully picked from the schematic and ordered by OEM part number does not fit. It is too large for the bushings and too large to go through the hole in the tensioner arm.

[Landseer]

Where exactly did you get it?

[Eric Drewes]

Ordered through Pelican...have already sent an inquiry to their customer service dept regarding this.

[Pete R]

I have dealt with this a lot on my car. There are a few arms. a few bushings and a few bolts made. They all have to match or it won't work right. which is obviously what your finding What's in your car doesn't necessary match the year. I hate to mention someone else other than our host, but 928 international was always able to send me the right stuff by the measurents and discriptions I gave them... they deal with it everyday so the have a bit of an unfair advantage on Pelican in these areas

[Landseer]

Pelican is wrong place for this part. Their online catalogue doesn't show it. Very weak in 928, strong in 911, by their choosing. Its okay, we just need to expand the sourcelist if its not an easy buy from pelican.

[Eric Drewes]

These parts were all ordered from the original 78-81 Porsche catalog. I've checked the part number on my tension roller carrier arm and it is identical to the part number shown in the 78-81 catalog. The part number for the bolt is the same as what's specified on the bag they shipped me. These all appear to have come directly from Porsche. Maybe I just had the good fortune to get a bolt that was improperly sized during the machining process.

[Mrmerlin]

call Roger@************ he has the bushings and new bolts just tell him the bolt size , he had special ones made for this application and get the correct bushings