the flyin' scotsman

4 gears, a water pump, a belt and the Porken tensioner........wheres the rev limiter?

Tazzieman

It's like worrying you will have a stroke or coronary whilst going for a jog. Do the preventative stuff and get on with life! That includes visiting the redline.

m750rider

I don't worry about it at all because I have an experienced 928 mechanic do this job instead of me doing it.

I think the car was designed and engineered well enough that if put together correctly, the timing belt system and everything that it runs is perfectly good as is. I don't worry about a belt failing on its own if replaced at the recommended interval and checked during oil changes. I don't let oil or other fluid leaks foul the engine - they get fixed. I don't worry about a water pump bearing locking up when using a good Porsche pump. Long before that happens I'll see indications of a seal failure with a coolant leak.

The timing belt might not be the brains, but it is certainly the heart of this engine. And I'm just not a heart surgeon. I don't have the training, skill, experience, or the tools to do this job the way it should be done. And I'm not willing to make a mistake on a system this important just to say I did it myself. A man has got to know his limitations.

So, no worries about the belt, and more time to do things I can do well.

danglerb

Driving my US 83, not really worried about anything.
Driving my Euro 85, cuffed and stuffed is a regular thought.

GlenL

Can you give some examples of common and fantastic mistakes?

The Fixer

Randy,

I have a similar phobia (somthing might break, and i'll have to work on this thing) when 'getting on it' in any on my cars, always have. I'd rather drive them than fix them.

Juan Manuel Fangio was said to have this feeling too when racing,

He always considered the car and it made him a little slower at times.

GregBBRD

Well, I'll just take the one I'm doing, right now, and tell you about that one.

It's an '86.

Wrong belt. Had angled tooth version, not round tooth version.

All gears ruined by the wrong belt making incorrect contact with them.

Special washer to properly space the tensioner arm completely missing. This washer also retains the idler pulley onto the boss on the water pump. The belt therefore ran completely off of the tensioner pulley on one side, but fortunately was kept from completely coming off of the tensioner pulley by rubbing on the actual tensioner arm....chewing up the belt. But the idler bearing, not held captive by the special washer did migrate back and forth on the aluminum boss....chewing up the boss and making removal of the bearing very easy.

No lubricant on the piston for the tensioner going into the idler arm. Rusty mess/wear in the hole, from the metal to metal contact and resulting wear. This is so common that we are totally shocked when someone actually smart enough to put a dab of high pressure grease in the hole. (I'm betting I've seen 20 of these things where the pin has pushed it's way almost entirely though the idler arm.)

Washer between the spring on the tensioner and the plastic missing....another one of the super common things that occurs so much that we are always amazed when it is actually there!

Tensioner dry. Boot leaking.

Water pump 1st Version Laso (three versions prior to their current experiment.) Impeller had migrated, but had not contacted block....yet. (I firmly believe that if Laso had never produced a single 928 water pump and the only option that people ever had was to buy the factory water pump, 928 owners, as a entire group, would be hundreds of thousands of dollars ahead! That being said, I put Laso pumps on at the rate of about 10 to 1 over factory pumps....even though I refuse to warranty the labor to replace one that fails. Cheap is almost always better....no matter how many times people have to pay to have it redone!)

Every special thickness spacer washer for the accessory belts missing. Not a single one present!

Other than that stuff, almost perfect.

Alan

Just do the periodic maintenance right, keep an eye on things and then just get out there and drive it!

This one though... yes...! Especially when the V1 blerts out when/where it shouldn't do...

Alan

dr bob

Well, I'll just take the one I'm doing, right now, and tell you about that one.

It's an '89.

PET calls for a couple washers in that post that my car doesn't have. Hmmm.

I passed that one. Dab of EP moly works wonders. Long fiber stuff, in a tube labeled "brake caliper slide grease". Figure that temp and crud environment is similar.

Passed both of those tests OK.


Looks like it's still Lions 5, Christians 3. And I need a trip down to visit Tom in the morning for some washers.

----

Just the casual spillover knowledge is incredible. I carefully disassemble each section, recovering bolts/washers/pieces and laying them very carefully on my worktable, in the order that they were removed. Clean each group just as carefully, put it right back where it was. Then reassemble in the reverse order of disassembly. You could do this stuff with your eyes closed. If I can get down there at lunchtime tomorrow, it's on me.

jcorenman

I don't worry about the timing belt. The timing belt is not evil, and it is never the problem-- it's the other stuff. Water pumps, bent shoulder screws (on early cars), missing washers, worn bushings, worn sprockets. That stuff is all easy to replace or check when replacing the belt, and it is simple to peek down the belt-cover vents periodically and make sure the belt is tracking where it usually does.

Water pumps are make me nervous. Water pumps are a key piece of this whole arrangement, and our choices are rebuilts that we don't trust, sand-castings that I personally dislike for this application, and factory pumps which seriously impact the wine budget.

But we can drink cheap wine for a while. I've got the S4 taken apart at the moment because of a "funny noise" at high RPM (probably the water pump, a rebuilt from a few years back when we all thought they were OK) and found a loose belt (a Conti that we all used to think were OK), loose apparently because the PKT hadn't taken up the slack when the engine cooled.

Nope, I don't worry about the belt, it's fine. The problem is all the other stuff, and hopefully with a little care I don't have to worry about that either. Change the sprockets when needed, refresh the tensioner, change the bushings and tension roller, and make sure the right parts are all where they belong. And drink cheap wine as needed.

Cheers, Jim

69gaugeman

Wait, whaaa ?.... can you elaborate?

Gretch

A 5 speed would provide more confidence........

ease in, ease out, listen all the way.

BTW, full service inspection on a regular basis will also limit the heebee geebies........

auto tranny in a shark......... they should have been banned in 1978.

dr bob

Would have eliminated 80+ percent of the market. Can't expect the dentists' wives to be rowing on the way to the country club for tea, can we?

Gretch

would have made them worth way more.............. hell with dentists and their consorts.......

hacker-pschorr

I only get timbephobia when driving the 355.

Dual belts, neither touches the water pump.

I put them on about 10,000 miles ago, since they haven't snapped yet, I must have done something right.