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so the guy I bought my 928 from had done the timing belts but neglected to install the covers
i picked up a complete set of covers from a junkyard in Monterey and decided to put them in. So I took off the accessory belts, a couple hoses and maybe some other stuff before I was able to fit the bottom belt cover on.
In my haste, I mistakenly assumed that what I now think is a bolt which holds on the tension roller housing needed to be removed in order to hold the belt cover on. I removed this bolt (pictured) and coolant came spilling out.
realising I made a mistake I tried putting the bolt back on once the stream had subsided, but as I was attempting to screw it back in this pill shaped object dropped out from somewhere and the belt went loose.
do I now have to redo the timing belts? Or is there some other way out of this?
you would do well to invite a seasoned 928 owner over to assist your re assembly,
you have a tensioner pin in your hand the fact its out could also mean the boot needs to be changed,
the idler roller that was where the leaking bolt came out should be blown out then put into a cap with WD 40 for 10 mins,
then blown out again,
then soak it in some 90 wt for a few hours,
then put it on a rag to drain.
or buy a new roller.
Yeah, you are into a timing belt re-string. That tensioner needs to be rebuilt as MrMerlin said. Get one of the write ups online here and go through it. Too bad the PO didn't know what he was doing. This may have been a blessing in disguise, as the whole job that was done is highly suspect at this point, plus anything else he did.
by the way, mr. Merlin said it would be a good idea to have someone a bit more knowledgeable around. If anyone lives close to Palo Alto please message me. I’ll find some kind of compensation for your time
Last edited by Brian Pines; 10-07-2021 at 12:03 AM.
Yes, you need to be incredibly careful and know exactly what you are doing, or you will bend the valves, because this event occurred when you were not at 45 degrees BTDC.
If you are not extremely familiar with these engines, you may want to not touch anything else (definitely do not turn the engine) and tow the car to someone who is very knowledgeable about these cars.
Your picture is like a "test" to see what is wrong with what has been done!
Quickly:
On the bolt that you removed to cause this problem, there is not supposed to be a washer under the head of the bolt.
There are no bleeders in the tensioner, so it can't have much oil in it.
The timing pointer on your water pump (to tell you where TDC and 45 degrees are located) is upside down.
Someone used a pair of pliers to hold the crank pulley to remove and tighten the crank bolt.
You will need to make sure that bolt is properly torqued.
Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!
Thanks Greg. Very helpful. I’m not really dealing with a budget where I can bring it to a professional but I’ll look into all this, take my time, and try to make sure I do it right.
I'm trying to figure out what year model you have there. It looks like a 16v car, but that seems to be a round tooth belt (there is a square and a round tooth belt). I'm wondering if it is even the correct belt on there.
A common theme for 928 owners is the Ignorant Previous Owner theme, and most of us suffer from it's effects. The most usual symptom is a timing belt job stunningly botched. Since you have found the fountain of 928 wisdom, you will not be one such, but you are clearly a victim. Basically, you probably want to do a melt and re-pour on your timing belt jib.
1-Move it to the correct timing marks. I wonder if you can gently stuff something in where the tensioner is supposed to be while you do this, just so you have enough belt tension for all the parts to rotate together. Many 16v cars are non interference so safe to turn over the crank with out the cams, but I'm not sure I would risk it. But you don't want to accidently go too high on belt tension since you can break a cam.
2-Pull and inspect the water pump. Did he change it? What is it? Does it have plastic or metal impeller?
3-Decide what to do about your tensioner. It is likely needing a few parts (boot, plastic bushings, etc), and it is likely assembled wrong. Or you could simplify your life and go with a porkensioner.
4-Confirm you have the right belt there. Hard to tell from here but that looks to me like a square tooth oil pump pully and a round tooth belt.
5-Put it back together with care, the correct little parts, the correct timing, and the correct belt tension.
If you budget is low, it does not have to be super expensive. Water pump gasket, tensioner gasket, boot for tensioner, a couple of plastic bushings for tensioner, and the 'kemp' tension checking tool. Some antiseize for the water pump bolts, etc. You may or may not find you need rollers, but inspecting them is a very good idea.
Thanks Karl,
It is an 83, which I think is the year they changed to round tooth? Very much appreciate the advice and will do some more research on this
by the way, mr. Merlin said it would be a good idea to have someone a bit more knowledgeable around. If anyone lives close to Palo Alto please message me. I’ll find some kind of compensation for your time
You have one of the best 928 enthusiasts anywhere right in your backyard - Dennis Hager - @Dmhager here. Maybe reach out to him and see if he can come by and issue spot for you. Could be a good assist with his son too, who also helps Dennis with work on his shark collection.
Hey! That's Good News: It's a non-interference engine.
I've done two timing belts and tensioners and, as anyone can tell you because I detailed the process here, the second one (on a 32-valve car) did not go well. That one cost my buddy a new engine (for which he graciously did not accept my offer to pay him back).
So, I can tell you from personal experience that a timing belt and tensioner on your car is a painstaking process, but not insanely difficult.
One thing to remember is that the rebuild kit for your tensioner is going to be for the later years, so the rubber dome won't fit exactly right.
I think I have 3 or 4 tensioners that I'll never use after installing a Porken tensioner on the 83 4.7L motor that's in my 79, as I'll also be fitting one to the 81 Euro S whenever I do that TB & WP job.
PM me or email me at petza914@gmail.com and we'll figure out a price for one if you're interestsd.
10-06-2021, 04:50 PM
Help an idiot plz...
