924Board.org

GCN · Joined: 14 Mar 2006 Posts: 2 Location: North Florida

Hey, I am considerating buying a 88 924s that is said to have a broken timing belt and I am wondering if any of you can tell me how challenging it can be to change on one of these cars. Also I am wondering how likely it is to have bent valves, I am not familar with Porsche's and am not sure if the engine will or will not be likely to bend valves if the timing belt breaks while the engine is running. I have done many of timing belts on many different imports, mainly Japanese, but I am just looking for any input on the difficultly of changing a timing belt on a 924s because I am trying to figure out if it will be worth buying the beauty.

Any help is greatly appreciated. Thanks, Garrett.
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Paul · Posted: Tue Mar 14, 2006 2:20 pm Post subject:

Welcome to the board!

Several valves are bent if the belt broke while the motor was turning, even it if it was just being turned by the starter.

Piston and cylinder damage may have also been caused if any of the valves broke.

Do a search on "front end service" for more info.
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White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

GCN · Joined: 14 Mar 2006 Posts: 2 Location: North Florida

Oh, well thanks, but that doesn't sound very good. I was hoping that I may be able to just replace the belt and have it running again, but it doesn't sound that way. I don't know if it would be worth the $1500 that he wants for it now, espically when I know that those Porsche engine parts don't come cheap. But thank you for the info. Thanks, Garrett.
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gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

Whether the car is worth the $1500 risk depends on the overall condition and originality of the rest of the car.

If the body is beat, and or the paint is fried or ugly and non-original, no the car is not worth a $1500 gamble.

From what I have seen a broken timing belt will cost at least four valves, and maybe more, depending on how long or how many times the driver tried to restart it after the belt broke.

As has already been mentioned, there could be other damage like broken pistons, or broken rings, or a cracked cylinder wall (totals the engine block).

And for sure, you should budget to have the entire head inspected and serviced which will mean the replacement of additional valve guides (besides those damaged by the bent valves, $50-$100 per valve for the replacement valve itself).

And while you are in there, the rest of the front of engine service should be performed (parts $500-$1000).

Yes, if you are reasonable skilled as a mechanic (you don't have to be a paid professional) you could remove and replace the bent cylinder head, and do the front of engine service yourself, as long as you understand that some specialize tools and a Factory 944 Service Manual (recommended and expensive) will be required, that could cost you up to $800-$1000.

If the cylinder head is not too bad, and there isn't any other damage to the engine, and you do the complete front of engine service, you will be out $1500-$2000 for parts, plus the cost of the tools you will need (there are alternative tools if you are willing to take the risk).

The other way to go would be to buy a used engine from someone, but if you do that, I still recommend doing the front of engine service to the replacement engine (which will drive up the cost) before you install it. I have seen some selling on eBay for between $200-$1500, but I can't vouch for the quality of any of them, tread carefully there.

The car has a market value somewhere between $2000-$5000, depending on the condition of the rest of the car, if it was running with service documentation. If the rest of the car is near perfect, and the cost of repair does not exceed $3500, you would have a very nice car. As you can see, if the condition of the rest of the car is not perfect, then $1500 will probably be on the high side.

mhart · Joined: 24 Feb 2006 Posts: 170 Location: New York, NY

to be honest, if the timing belt is shot, $1500 is very high. If the body and interior are in great shape and the car has fairly low miles, then it could be a good purchase if the engine repair bill price is right. But, much as I love to see 924S's going for big bucks (like to see the relative value of mine go up hah), if you want the car, talk the owner down on the price
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'87 924 S - No sunroof and a few modifications