924Board.org

l337r3dn3k · Joined: 25 Nov 2009 Posts: 2 Location: Illinois

I'm a proud "new" owner of a 1988 924S. Luckily, it came with a pile of receipts giving me an idea what has been done to it. Sadly, that includes a new odometer, and the replacement odometer also quit working some time ago. My best guess is that it has around 225K - 250K miles on it.

The cam and balance shaft drive belts and the water pump were replaced some time ago (I'm guessing 15K miles based on what the former owner told me). The owner at the time did the work himself, but I don't know whether he replaced the timing belt or not. His records are not always specific (etc means a whole lot, thanks!).

For some reason -- and maybe I'm overlooking something -- I can't find in the manual or in the Haynes 944 book how often the timing belt should be changed. Is this normally part of the 30K mile front-end maintenance, and should have been performed when the cam and balance shaft belts were replaced? I suspect the timing belt that's in there may have been installed in 1997, in which case I'm afraid to drive it until I replace the thing.

Also, while I'm bugging you, the car's exhaust smells rich -- noticeable amounts of unburnt fuel -- and it tends to stutter a bit on idle. I suspect the air filter is past due for replacement and it's not getting enough air into the cylinders to burn properly. If that doesn't help, I'll clean the IAC valve. I wanted input on the exhaust, though: is it supposed to smell somewhat rich? I've not worked on Porsche's before, let alone this particular engine.

Thanks!

gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

Welcome.

The first thing you need to do is buy a current version of the Porsche Factory Workshp Service Manual for the 944. that's where you'll find all the information you need to maintain your 924S.

The complete name of the cam belt is: camshaft timing belt. I would not take the PO's (Previous Owner) word for it as to when the timing belt was replaced (miles or years). Memory clulds over time, and the Seller's memory may be cloudier than average sine he/she was looking to put the best spin on the story to sell it. If you didn't get written documentation that proves what was done at the last FOES (front of engine service), it's best to plan on replacing everything (waterpump, camshaft timing belt, balanceshaft belt, ball bearing equipped pulleys and rollers, and front of engine oil seals (balance shafts, crankshaft/oil pump, camshaft pulley)).

You will get suggestions from people on when the FOES should be done anywhere between 30K and 100K miles, with 3 years to never as the time interval. I personally stick to 3 years or 30K-36K miles (which ever comes first) as my comfort zone. Timing belt failures start occuring before 40K miles, but some people get more miles out of them. You don't want to wait for a timing belt to fail before you change it. A timing belt failure can result in total engine destruction in rare cases, although most timing belt failures are simply very, very expensive.

l337r3dn3k · Joined: 25 Nov 2009 Posts: 2 Location: Illinois

I will stick with 35K miles, then. That seems reasonable. I knew it was an interference engine, and that a slip would be bad.

For some reason, as they're often listed differently on the receipts, I though for some reason there were separate cam timing and valve timing belts. Thanks for clearing that up, now I feel silly

The immediate previous owner was in the U.S. temporarily and just wanted to be able to say she'd owned a Porsche while she was here. She had only owned it a few months. I'm basing everything off the massive pile of service receipts in the glove box. The trouble is the most recent of these are parts receipts and notes from the then-owner who did the work, and I only have a date; no solid mileage numbers. I guess since it runs I might be able to trust his work, but I think I'll perform the front end maintenance anyway.

bcblase · Joined: 23 Oct 2007 Posts: 574 Location: Winchester, VA

Just FYI - the odometer fix is a pretty easy task. The gear slips sidways along the shaft and fails to turn the numbers.

You can either replace the main gear with a new one, or re-position the old one and hold it in place with some superglue or a slip/snap ring.

Brad
_________________
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

joecitizennn · Joined: 12 Sep 2005 Posts: 2096 Location: no mans land

What town in IL do you live in? I have two S-series cars, one an 87 and one an 88.

lostparrot · Joined: 26 Jul 2009 Posts: 23 Location: rockford il

"location: block away from hell itself."

you must live in rockford too.

joecitizennn · Joined: 12 Sep 2005 Posts: 2096 Location: no mans land

I live in Central Denial. Wait.. No I live in central Illinois. Hate this puke of a state. Anyway I dont mind helping fellow 924 owners with the timing belt job for something fun to do. I have the factory service manuals and plenty of tools.

bcblase · Joined: 23 Oct 2007 Posts: 574 Location: Winchester, VA

I'll vouch for "Joe" - I bought a tranny from him, and he showed me how to swap it out on my 924S when he lived in NC. I did it myself the second time.

(His real name is Beazlebub)...
_________________
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

joecitizennn · Joined: 12 Sep 2005 Posts: 2096 Location: no mans land

hey what ever happened to that old tranny? Did it actually fail or was it just annoyingly noisy?

bcblase · Joined: 23 Oct 2007 Posts: 574 Location: Winchester, VA

Just noisy - I still have it - keeping it as a backup. The 944 tranny I put in has the tall 5th gear instead of the short 5th gear. It's pretty annoying going up a hill/mountain in 5th , but it never gets used on the track anyway.

The 924S gets chauffered around on a trailer now...

_________________
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

joecitizennn · Joined: 12 Sep 2005 Posts: 2096 Location: no mans land

when i had it split I didnt see anything at all wrong with it. It was just pretty noisy at coast. My 1988 SE has a very sharp whine that sounds like a fighter jet. Always has, but it is a great tranny. My 87 has a very quiet tranny, but at idle it rattles. No clue why. It just always has rattled. I first thought it was the torq tube, but eliminated that out by swapping. Besides there is no rattle with the tranny disconnected but the torque shaft spinning. Who knows, but it never gets worse. I just tune it out.