Mongo

ok...first gear on the auto ran to 5500 RPM and upshifted to second and then to third at 4500 rpm, when i come to the stop sign 5 blocks away the timing belt tension light is on. I drive home immediately, I wait to start the engine after an hour and a half...when i turn it on...no timing belt light on.....is this a short or is this a warning?? <img src="confused.gif" border="0">

LastV8

Well without more information on the car such as mileage and last timing belt change or tensioning I'll just mention one thing it could be.

When you're revving the engine out there is tension on the belt if it's set correctly to begin with. Between shifts, that slight pause between shifts up or down is when the tensioner does it's work to keep the belt tight. If it's low on oil then it's not quite doing the job it's designed to do so the light gets triggered. You may be getting near the end of the life on that belt and waterpump too.

That is just one scenario though but I'm willing to bet this is the case. My last timing belt went about 45k on my 88S4, with regularly scheduled checks and retensions. Upon removing it, the belt was in great shape but my waterpump was juuuust starting to let go and the tensioner was low on oil. The waterpump hadn't started leaking yet but was almost there. It's also a daily driver and frequent roadtrip car.

<img src="graemlins/yltype.gif" border="0" alt="[typing]" />

WallyP

It's not a short - the system doesn't work like that. It probably is a real warning in this case.

If the belt on your '87 strips or breaks, it will usually do enough damage to make it cheaper to buy another engine.

The belt should be retensioned and replaced on a regular basis. Porsche say replacement at 60,000 miles. More realistically for most owners, the belt should be replaced every five years, and retensioned every year. The tensioner should be refilled each time the belt is retensioned, and rebuilt every time that the belt is replaced.

Many owners, and a surprising number of mechanics, think that the 928 timing belt is self-tensioning. It is NOT automatically adjusted or tensioned. It must be retensioned using a gauge. We - and the other vendors - sell both the fancy (and very expensive) current Porsche belt tension gauge and a repro of the original (and very inexpensive) Porsche belt tension gauge. The repro gauge (by Jay Kempf) works very well, is easy to use, and should be a required item (along with the Workshop Manuals) for every DIY owner.

In your case, I would strongly advise that the belt should be visually inspected, and that it should be either retensioned or replaced, depending upon its age.

Thom1

Hi Euro,

DANGER WILL ROBINSON... PARK IT UNTIL YOU CHECK AND/OR ADJUST THE TENSION. OTHERWISE YOU COULD BE PARTING WITH SAY... $6,000 REAL SOON.

The Jay Kempf tool is a piece of cake to use. On my 86.5, I just pull the front right timing belt cover, air intake hose, and maybe the upper fan cowling, to adjust the belt. Some procedures call for removal of some other hoses. But, I can get the tool to clear without removing much. See my response to your earlier timing belt post for timing belt essentials, and links to tightening procedures.

Thanks Wally. I did not realize that the fluid level in the tensioner should be checked so often.


HTH,
Good Luck,
<img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

Mongo

thanks for the replies. My father and I would like to change and tension the belts ourselves. is there any written procedures on this other than the factory manual? I've heard TONS of things need to come off before accessing the timing belts. Has anyone done this a quicker and easier way? I'm good at changing waterpumps myself...i did it on my 944 but i've never messed around with the timing belts on a 928 before...and yes i know i need the tensioning tool from the factory...does anyone know the quick and easy way (if there is one) to change timing belts on an 87 928 S4???? <img src="confused.gif" border="0">

BC

Hey Euro.

TheTB work ona 928 is TECHNICAL, but in reality, EASIER to do than on a 944. Some may disagree, but I have done both.
The 944 has the balance belt, and all those concentric rollers. Its actually more complex, and less user freindly.

I just did my 89 (Just? ...in August, Sept). Its indepth, but I did it without the manuals. It was fine, but I was using internet info, and it sometimes scares me how much I trust it. Listen to Wally, we all do too. He said to get the books, and get the jay tool. Its a 350+60 buck investment you will never, ever, regret.

INFACT, I would be very happy to help you out, if you will be doing this in your garage, with any "BTDTs" that I can muster. I understand that personally, once I get in there, I wish not to be disturbed in my work, but I am in Mission valley, so if you need some hands-on info, I would be happy to stop by.

As a matter of fact, I do believe that I have a LOOOONG list that I compiled of all the parts I replaced, and thier respective part numbers. This will be different in some numbers (most, actually) since mine is an 89, and yours an 87, but it will give you an idea.

You need, as a basis:

A breaker bar that can slide onto whatever ratchet you will use to turn the crank bolt,

A flywheel lock

A real good look at what Loctite has to offer in anti-seize, threadlock, and gasket-maker.

The tensioner tool

Since I did not know when anything was replaced, I went all the way down to the crank seal. I did EVERYTHING, knowing then that I will do it all again in 60k, after I replace the belt and maybe the pump at 30k. Personally, I will also have to replace most of the cogs for the oil and cams as they were showing signs of wear. That was my one mistake, but I ran out of cash (2k in parts including tune up).

Once you get in there, you want to do EVERYTHING you need so you can rest assured that you will only go back in for prevention, not failure.

HTH,
brendancampion@att.net <img src="graemlins/icon107.gif" border="0" alt="[icon107]" />

Thom1

Hi Euro,

Why are you getting into the big maintenance job now? What is the mileage on your belt and pump? If they have been changed within the last 35kmiles, it may be premature. The belt can be tensioned in an hour or two. See the timing belt essentials document that I referred to earlier. I would buy the Jay Kempf tool, not the factory tool.

If you need to do the major maintenance now, see the timing belt essentials document. The included link to John Pirtle's page includes a pictorial procedure for the entire job on an 87 model. (Except for perhaps the front crankshaft and oil pump seal replacements?)
<img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

Dave A

Hi Euro - I also agree, I have done the TB on a 944S, a 944 and my '83 928. The 928 is the easier job, more room to work and no balance shaft belts. The hardest thing I had to remove was the crank pully nut, this baby was really tight. I had to use heat and an air wrench. I used the "Jay Kemph" tension guage from "928 Specialists" it's a great tool, very easy to use and comes with instructions. As for routing the belt it's pretty self explanitory.

Go for it. <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />