924Board.org

[cgalyon]

Hello everyone, I'm (obviously) new here and just recently acquired a 1988 924S. I just got back from the mechanic and it looks to be in great shape (except for some minor fixes). Unfortunately, I don't know when the timing belt was last changed and I was wondering if there is a relatively easy way to tell.

The quote I got for replacing the belt is about $971, which is a bit higher than I remember for my 944 and really rather higher than I'm comfortable paying out right now. Naturally if it has to be done, it has to be done, but if I can wait I'd rather.

I'm not very heavy into mechanics yet, and I certainly wouldn't endeavor to change the belt myself (as I understand, it is a fairly precise process), but I noticed that listed on the quote is "Timing Belt Tensioner". Is this required for each instance of changing a timing belt or am I being given a bit of a raw deal? The parts price listed for that piece is $321 and it sounds like a re-usable tool...

Anyway, thank you very much in advance for your help!

[thirdgenbird]

that quote is almost identical to the service i recently had done on my 87 a month or so ago. i called another dealer and they were very close to that as well. it sounds crazy but it must be the norm for these cars...
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17in caymans, koni yellow coilovers, hypercoil springs, kla solid upper mounts, 968 sway bars, kla drop links, kla strut brace, fidanza flywheel, dansk catback, wilwood front calipers, ss brake lines, e-codes, 944 duckbill, manual rack,momo steering wheel

[cgalyon]

I've shopped around a bit for parts and can shave about $150-$200 off the parts cost (Pelican Parts and such), but that still leaves it at about 4.5 hours of labor (and $80/hour labor) and that tensioner at about $300. Quite pricey all around... I'm hoping it isn't actually due for a change, but I'm not sure if there is a way to determine that without dismantling a portion of the engine.

[thirdgenbird]

i was in the same boat so i just changed it. i figured a new belt, while expensive, was cheaper than bent valves.
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17in caymans, koni yellow coilovers, hypercoil springs, kla solid upper mounts, 968 sway bars, kla drop links, kla strut brace, fidanza flywheel, dansk catback, wilwood front calipers, ss brake lines, e-codes, 944 duckbill, manual rack,momo steering wheel

[John Brown]

No way to tell just looking.

The complete tensioner may not need replacement; but any shop is going to want to do the whole thing as they must stand behind the work. And...

The labor to get to everything is not hard but just non-trivial. It's actually two belts being done (or should be).

FWIW, I never ask a shop to use parts I've brought. A slight markup on the parts is standard.
_________________
John
80 931 - #931 44Cup
99 Escalade - tows track cars
gone but not forgotten: original 924.org car - 82

[gohim]

There is no way to accurately inspect a used belt to determine how much time the belt might still be good for. If you didn't get any service records with the car, you need to immediately get the Front of Engine Service done, so you can start your own "time to die" clock on the Front of Engine Service.

$971 for a Complete Front of Engine Service is dirt cheap. I suspect that you are not getting all of the parts necessary to help prevent belt failure. If you were buying parts at an authorized Porsche Dealership $971 would not even buy all of the parts necessary to complete the job properly.

Why don't you look at what you are getting (what they are actually going to change). The last thing that you want the shop to do in only replace the timing and balance shaft belts. Figure six to eight hours labor at $100-$150 an hour, plus anywhere from $600-$1500 for parts (depending on where you buy them, and what brand the parts are).

A full (Front of Engine) Service will including the timing belt, balance shaft belt, front of engine oil seals, waterpump, belt rollers, and belt pulleys.

A unique feature of the late 87 924S, 88 924S, and 87 and later 944 engines is the spring loader belt tensioner. This may in fact be the belt tensioner that is quoted to you at $300. Many people do not understand how the spring loaded belt tensioner works, so they don't understand that IT DOES NOT NORMALLY NEED TO BE REPLACED.

The spring loaded belt tensioner normally is not even tensioning the timing belt. It comes precalibrated (there is an adjustment, but you are not supposed to monkey with it). The way that the tensioner is used, is this. You replace the timing belt, and then you release the locking bolt on the tensioner, and allow the tensioner to tension the belt. then, you lock the tensioner down, and double check the belt tension with the P9201 belt tension tool to make sure that the spring loaded tensioner did it's job. The spring loaded tensioner only loads the belt momentarily when you release the lock hardware, so it never wears out, because it is not used to dynamically tension the belt.

On earlier 924S and 944, there is a tensioner pulley that you use to set the belt tension, and that part should always be replaced along with the rest of the pulleys and rollers on the timing belt, and the balance shaft belt.

So, if you are considering replacing the spring loaded tensioner, don't waste your money, replacement is not suggested or necessary. Do change all of the other rollers, and pulleys.

If the shop that you are planning on taking the car to doesn't know the difference between the earlier 87 924S engine, and the spring loaded tensioner 924S engines, you need to run away, because that shop is not competent or experienced enough to service you car. Odds are the shop does not know how to tension your timing belt using the spring loaded tensioner, or that they still need to check the tension (with the P9201)after loosening and retightening the lock on the spring loaded tensioner.

[cgalyon]

Great info, thanks! The parts list includes:
Timing Belt, Timing Cover Grommet, Timing Guard Rail Nut, Timing Guide Rail, Timing Belt Roller x 2, Timing Belt Tensioner, and Balance Shaft Belt.

I see no mention of engine seals, waterpump or pulleys. I'm guessing the waterpump is a pretty expensive part, so even if they remove the tensioner from the list, I'm probably still looking at about $1000+ for the service. I think the main reason for the sticker shock is that hourly rates have gone up tremendously since I had my 944 and had it serviced. Hourly rates seem to be 80+/hour; they used to be about 40-50/hour.

The main mechanic is good, he's done work on my 944 before (several years ago) and it ran beautifully. However, because he's good a lot more people have been coming to him and he's had to hire additional help. I'm not as confident in the additional help... I'll ask him about the tensioner and waterpump when I go back to talk to him about the service.

Thank you again for your help and information!

[bcblase]

Gohim = the 924S guru

Heed his advice well... and your car will survive.

BC
_________________
1987 Porsche 924S - track toy
1986 Mercedes 190E 2.3-16v - autocross
2007 F-150 5.4L Lariat Supercrew - tow beast
1994 Volvo 850 Race Wagon - 24 Hours of Lemons Car
2001 BMW 325xi - daily driver

[skytrooper]

The cheapest I could get it done was $ 1279.00 and that was at my old high school friends German car repair shop
_________________
Matt

1987 - 924S "Black Pearl"
1982 - BMW 633CSi
1984 - BMW 528e
1983 - 944 N/A "Blue Max" (Gone)
1981 - 931 "Scarlet Harlot" (Gone)
1976 911S Targa (Gone)

[gohim]

cgalyon ,

As I wrote to you before, what you are getting is not a complete Front of Engine Service. You are missing many parts from the replacement list, and you are going to pay the same labor charge whether they are replaced or not.

I noticed that the guide rail and nut are on the list for replacement. Those parts are not normally replaced, because like the spring loaded belt tensioner, they are not wear items. Purchase of the belt guide rail and nut normally only needed when you are installing a newer/improved version of the waterpump that is designed to use the belt guide rail, AND YOU HAVE THE OLDER STYLE WATER PUMP THAT NEED NOT USE THEM. The original waterpumps for the 944 and 924S did not use a belt guide rail, and cannot be modified to use one. The older style waterpumps are not recommended by Porsche, who does not sell new or rebuilt waterpumps of the older style. After you convert to the newer style waterpump that uses the belt guide rail, when you replace the waterpump, you take your belt guide rail and hardware with you, YOU DON'T BUY THEM OVER AGAIN.

The number of rollers and pulleys on the parts list is WRONG. All of the pulleys and rollers on the balance shaft belt and timing belt need to be replaced.

YOU NEED TO RUN AWAY. THE SHOP YOU ARE PLANNING ON USING DOES NOT KNOW WHAT THEY ARE DOING. DO YOU REALLY WANT TO BE A GUINEA PIG?

[cgalyon]

Again thank you for your advice and information, gohim. If I understand you correctly, with the waterpump, if I upgrade to the new waterpump, then I will replace the belt guide rail (or as it sounds, add one). If I'm using the old waterpump, then there is no belt guide rail, so it doesn't need to be "replaced." However, as part of the service, the waterpump should be replaced with the new model, which will necessitate the belt guide rail anyway.

You mentioned that the number of rollers and pulleys is wrong, but what is the correct number? The kits I've seen online seem to indicate two of each (and they included no pulleys, but two rollers). I'm guessing that might also be incorrect though? I've got another shop I can go to (a dealer's shop), but before I go in, I'd like to know exactly what I SHOULD see on the estimate's parts list. I'd rather not have to go back and forth with them as well... frustrating that it would be so hard to find a good mechanic! Thank you again!

[Rasta Monsta]

According to Paragon, HERE is the parts list, less the water pump, seals, and seal races.


_________________
Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[cgalyon]

Thank you Rasta, that's rather informative as well. I'm getting two other quotes today and will be comparing their itemizations with the information provided here. Hopefully there is someone in town that has the knowledge and expertise with 924's/944's for me to feel comfortable with them working on the car. I suppose on the positive, I got a great deal on the car, so I at least have a little room for repairs.

[bcblase]

I bought that same kit from Paragon - it does not include the balance shaft sprockets, and I have not seen them included in any of the timing belt kits out there.

Gohim - how important is it to replace balance shaft sprockets?

BC
_________________
1987 Porsche 924S - track toy
1986 Mercedes 190E 2.3-16v - autocross
2007 F-150 5.4L Lariat Supercrew - tow beast
1994 Volvo 850 Race Wagon - 24 Hours of Lemons Car
2001 BMW 325xi - daily driver

[gohim]

The balance shaft spockets do not need to be replaced. The balance shaft tensioner, and idler roller do, along with the timing belt tensioner pulley, and timing belt idler pulley.

Under both of the balance shaft sprockets, the camshaft sprocket (camshaft), and the timing and balance shaft drive sprockets (crankshaft) there are oil seals. These are the oil seals that need to be replaced during the Front of Engine Service.

The drawing posted by Rasta Monsta clearly shows the pulleys and rollers that need to be replaced. The balance shaft sprockets are attached directly to the balance shafts, therefore there aren't any bearings in the balance shaft sprockets, and they do not need to be replaced.

The waterpump mounted belt guide is not included in the photo.