camboinc

Guys (and girls),

I bought an 87 silver 928 a few weeks ago off ebay. 77k miles, had a local porsche dealer do a PPI, it checked out. flew in to Kansas city and drove the car- it was sweet so i bought it and began the trek back to detroit. car drove excellent- no issues at all... about 300 miles into the drive i exited for some shut eye. i got through the exit turn and onto a straight- punched it and the car downshifted to 2nd. it revved just about 5000rpm and i let off. no big deal... or so i thought. i pulled into a motel and heard a soft tapping sound coming from the motor. not much i could do so i drove the remaining 500 miles home. the tapping sound stayed consistent- it is crank speed and increases with revs but doesnt really get louder. im two miles from home and the car dies. turns out it was the LH and andrew olsen was kind enough to come over and help diagnose the problem (sharks and big dave too- thanks!)
so i get the new lh in- $450.00 and the car starts right up. super... NOT! the tapping is still there. sounds to me like near the front of the motor. so i get the steth on it. sounds a bit louder from the driver side timing cover. im not convinced its coming from the front of the motor though. i get under the car and it sounds to me like the sound is more pronounced, now a rapping sound. i can feel the vibration from the sound at idle on all parts of the motor (belly pan, starter, bell housing etc). i decide to get a mechanics advice and limp over to two different 928 repair experts.. wait, better put that in quotes... 'experts'. both guys want to do the TB WP job- estimates from 1 to more than 3k! crikey! no F'n way bro!

i still think it is something deep and nasty. I asked roger tyson and from my description he suggested checking the thust bearing among other things. what a great guy roger is too. i made the hugest mistake ever by not buying one of his cars, but thought i had to have silver. d'oh!

so... the last time i drove it, i listened for a harder cranking issue (possible TBF)- didnt seem to be there. now the car really lacks power down low and the car shudders a good bit at 1000-2500 rpm. after that, the car seems to pull well. dont want to test it though for fear of what might be bad in there.

So... here is my dilemma. i thought i was buying a done car to drive. now i have a money pit (i think) and am not terribly inclined to try and do what could be major work myself (pull motor, rebuild motor). neither do i have the space. a third bad- winter is nigh and the garage ain't heated.

help! SOS! i am so bummed out! my 928 ownership experience so far has been evil. my red 930 just starts and goes. good regular maintenace, a tune up and replaced tranny in 8 years; peanuts compared to what i am facing. i feel like others on the board who just want to sell as is but id really like to try owning the 928 for longer than a month

can anyone help? im sure the local guys are gonna offer some good advice. they have already been terrific. just dont think i have big dave's gumption to rebuild a motor in the winter.

is there anyone in the great lakes area that could do a rebuild for less than a gazillion dollars? id be willing to transport the vehicle to someone who can help. i just feel like these local 'experts' would whack me for well over 6-10k.


rennlisters- help a brutha out! i just want to drive the dadburn thing!

advice on the sound? advice on what to do? and what color should i choose for those big drapes in the den? (trying to have a sense of humor about it! )

thanks--

brian

auzivision

Sorry I can't help, but I love the looks of your 930… that’s what started it all for me… the business guy next door to my office (a.k.a. my dentist) had one for sale… I checked it out, but it wasn’t what I remembered it being… It wouldn’t start, leaked oil, and somebody had keyed it… anyhow I passed, but caught the bug… a few weeks later after a few beers and playing on eBay I ended up with a 928… never drove one and can’t remember seeing one recently (never heard of a PPI)… if I’m ever in the position, I’d still like to have a 930… of course in guards read because that is the fastest color…

Mrmerlin

Hi jack the car up remove the bell housing probably have to remove the header pipes to get the 2 rear bolts out then mark the drivshaft where it goes into the front coupler also look at the flex plate that is bolted to the flywheel if it looks bowed to the front of the car then there is a good chance that there is excess peressure being applied to the trust bearing , now undo the clamp bolt that clamps the driveshaft see how much the flex plate moves you will also need to pry gently on the flywheel front to back and back to front to see how much movment you have on the crank, new clearances are in MM 0.110 to 0.312 wear limit is 0.40MM, hopefully you will not have excess clearance , if you do then you may have saved the block and crank if you catch it before it wears too far. another test you can do is to drain the oil and look for metal particles if you find particles then removal of the engine is the next step, good luck, Stan

neilh

928's get sold for 3 reasons:
1) The owner has to many of them
2) There is something wrong with it they don't want to fix, but you'll never spot it anyway.
3) or they are honest and its a parts car

They don't get sold because :
1) the owner has had it from new ( Me!)
2) They are a collector
3) not sure what the other reason is!

camboinc

Stan,
thanks for the advice. sounds about what roger told me to do. ill jack er up tomorrow or in between tiger games this weekend.

928saregreat

It's a good idea to check that I know excessive flex plate pressure can ruin the thrust bearing on an auto but could the timing belt have slipped a tooth? JMO but I would check the belt carefully. Maybe the cam towers too, just to be sure if it turns out that the runout on the flexplate is within spec.

Anyway don't dispair, your buying a 20 year old car and there's a saying, its rare to find a good used car, if it was really good why would anyone sell it? I guess my point is that they usually have some kind of issue-issues when you find them and part of the fun is finding out the best way to fix it. Even if the block is cooked I've seen lots of shortblocks around for a grand or less, that is if you look. Just analyze it and see it as a problem to be fixed and thats it. Maybe you could hit up the PO, a local porsche dealership and all, for a cashback or help fixing it. If I was in your shoes I'd DEFINITELY give them a call and tell'em whats going on. Or better yet let your lawyer call them...
When I got my 928 I found found that it needed new syncros. It was an annoying surprise but its not that big a deal to rebuild it cause in the manner that I drive can still compensate for their wear. I learned a lesson and I'll get around to rebuilding it but its still major fun to drive around. Yours will be too...
Don't give up, they all can be fixed and it will get better...

Mark

Nicole

In my observation, most 928s have a pretty lout tapping noise from the injectors - or maybe the valves, too! So I'm not sure, if yours is really that unusual.

In regards to the running problems - first you have an 87 with a pretty long rear end and 2nd gear start. It's not that fast off the line, unless you put your shifter into the "2" position and floor it. That launches you in 1st gear, and will go into 2nd when you reach the rev limit... Either way, check your ignition wires - a common problem on older 928s. Open the hood at night with the engine running. Spray a slight mist of water or windex over the engine, and watch for lightning shows. If you see any flashes, your wires are toast and might be causing at least some of your problems.

Nevertheless, you should check the flex plate and release any potential pressure. This is a good time to measure play - than you know whether you can trust your thrust bearing... How many miles on the car? From what we hear, this usually becomes an issue when you're into the 6-digits mileage.

Lastly, did you get records on the last timing belt and water pump chenge? If not, you should definitely have this done as preventive maintenance. Because it's cheaper than fixing 32 bent valves...

Hopefully you can figure things out without too much cost. But in my experience you spend between $2 and 6k in the first three months after acquiring a 928. Then things usually get better....

ROG100

Releasing the flex plate is a must.
Lets see after that.
Follow Stans instructions and tell us what you find out.
Very important you measure the movement.
Call me if you need to be walked through it.
I also agree with Nicole that there is always some tapping noise of some kind from the engine.
We need to make sure its not terminal.

IcemanG17

1st thing to check is the flex plate & thrust bearing play....if its within the spec stan listed then your okay.....I just checked my 93K 928 (122K on engine) and it was fine....."if" the tranny or torque tube has never been pulled it should be fine...but its easy to check too

Nicole is right about 928's making odd tapping noises....mine has always done it.....much louder than I would like....but it seems to be "normal"

camboinc

thanks all for the info. i will try Stan/Rogers suggestion.
nicole- thanks as well. the tapping is definitely not an injector noise as i heard that mild sound when the lh failed. regarding the slow start or sluggish bottom end- this is new and did not occur when i test drove nor during all driving before the 300 mile incident i mentioned. the shudder is most recent and did not occur until the last short test drive.

thanks again everyone. ill keep you posted

Larry928GTS

In addition to what's already been mentioned, I'd remove the oil filter, cut it open, and see if there's any metal in there.

928saregreat

Its true what Roger and Nicole said about tapping noises to a point being normal, I've noticed that myself on mine that it will tick it it hasn't been driven for a while and after a minute or two it does go away. I did some reading on that and apparently the lifters fill with oil during that time and that is normal. I also agree that these engines sound a little surreal when compared to an american V8, such is part of their charm.
What concerned me here is that the tapping noise wasn't noticed on startup, but 300 miles into the trip, after an accidental rev to 5000 rpm that appears to be most prominent from the driver side timing cover, according to Brian.
If I was there, while Roger was checking the Flex-plate, I'd be checking that timing belt pronto. Unless it was on a lift my arms aren't that long.... Another thing, if an oil change had been done recently on the car and somebody not knowing put some lightweight oil in it and then a new owner takes it on a long trip, 300k, lots of heat ect. and suddenly notices it ticking...well, you see my point.

Mark

blown 87

The other reson is because they have so much $ into the car that it is not worth taking a loss like that.
If you are like most of us, once you have put so much time in to it you just cant part with it.

T-belt or TBF will ruin your day.

The T-belt, water pump, tensioner, bushings and pulleys are not that hard to do.

Once you have a flywheel lock and a Kemph tool, it is all downhill from there.

Relasing the pressure on the crank is a 1 hour job at most and could save you a motor.

One thing that has really impressed me is how many of the 928 owners do all of there work.

Some start with no mechanical background at all.

Mike Simard

928's do have hydraulic valve lash 'lifters' (what is the proper term?). It may be possible for one to become compressed during a high rpm blast and get stuck in the compressed state, if that were to happen it would surely make an audible clicking. I don't know if 928's are prone to that but it's common on other cars. A stehoscope or long screwdriver with the handle pressed against your ear and blade end poked at various places can isolate the noise.

camboinc

keep the info comin, everyone. thank you. i did rebuild my 66 chevelle (tore it down to the bare block but that was a simple motor) in the early 80's and about 4 years ago, i put a crate motor in a 69 corvette (no longer in the stable). i can tune and tweak the small block chevy but again, very simple compared to the 928! I have the mechanical inclination but my wife says that wrenching makes me cranky. guess thats too bad as the alternative is big money! gooing to try and get under the car after lunch. ill start with the oil filter inspection and then the flex plate.