Just bought a TBF car
#46
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Thread Starter
I just cranked it again after charging at 2amps for a few hours, still dragging bad, and the dash lights and digital displays dim and flicker as the engine cranks. Definately feeling and hearing some grinding as it cranks.
I'm not seeing the rear driver's side engine hoist point where it is on my car. Are they in a different spot? Passenger side front point is where I expected it.
I just looked though my Craigslist RSS history in Outlook. I have a feed setup for San Antonio and found the original owners ad from Jan 18 of this year:
"I'm my 1989 Porsche 928 S4 with Automatic transmission. THE ENGINE IS BAD.If your a mechanic this would be an very nice project. Has several items that have been done and replaced.Tires are about 80% - paint job was done 4yrs ago same color -interior is beige in nice condition- chrome porsche wheels - power coated intake all hoses underneath the intake were replaced - matching valve covers with chrome idle brackets and hinges ,timing belts and water pump was replaced 2yrs ago ,,fuel regulators (4) replaced - wiring harness replaced new that connects the starter ,alternator ,oil sending unit and battery.A/c works -shocks about 3yrs old -throttle sound on muffler tips ,interior enhanced appearance pkg.Carpet very nice, floor mats and rear cargo mat with cargo cover new.Sunroof works! Have had the title and car since 2004.Engine cranks but heavy .Lots of over things replace to mention.Have Porsche car cover and 928 service manuals thanks for looking Martin 210-216-xxxx Will be posting on ebay soon. Cash or trades MAKE ME AN OFFER Nada list for 15000. (if the car were perfect) "
I'm not seeing the rear driver's side engine hoist point where it is on my car. Are they in a different spot? Passenger side front point is where I expected it.
I just looked though my Craigslist RSS history in Outlook. I have a feed setup for San Antonio and found the original owners ad from Jan 18 of this year:
"I'm my 1989 Porsche 928 S4 with Automatic transmission. THE ENGINE IS BAD.If your a mechanic this would be an very nice project. Has several items that have been done and replaced.Tires are about 80% - paint job was done 4yrs ago same color -interior is beige in nice condition- chrome porsche wheels - power coated intake all hoses underneath the intake were replaced - matching valve covers with chrome idle brackets and hinges ,timing belts and water pump was replaced 2yrs ago ,,fuel regulators (4) replaced - wiring harness replaced new that connects the starter ,alternator ,oil sending unit and battery.A/c works -shocks about 3yrs old -throttle sound on muffler tips ,interior enhanced appearance pkg.Carpet very nice, floor mats and rear cargo mat with cargo cover new.Sunroof works! Have had the title and car since 2004.Engine cranks but heavy .Lots of over things replace to mention.Have Porsche car cover and 928 service manuals thanks for looking Martin 210-216-xxxx Will be posting on ebay soon. Cash or trades MAKE ME AN OFFER Nada list for 15000. (if the car were perfect) "
#48
Rennlist Member
At least it's there ...
Seriously, I am liking the funky-starter theory... starters are cheaper than engines.
I also recall Bill Ball encountering a TBF engine that showed zero end-play-- as in zero, nada, nothing... until he got a bigger lever, then it moved a mm or two. Apparently trashed bearings have a lot of friction in every direction.
Have you tried turning the engine over by hand? Get out the 27mm socket and big handle, if the starter is struggling then you should be able to feel that by hand, also.
Keep digging, there might be an acorn there somewhere...
Seriously, I am liking the funky-starter theory... starters are cheaper than engines.
I also recall Bill Ball encountering a TBF engine that showed zero end-play-- as in zero, nada, nothing... until he got a bigger lever, then it moved a mm or two. Apparently trashed bearings have a lot of friction in every direction.
Have you tried turning the engine over by hand? Get out the 27mm socket and big handle, if the starter is struggling then you should be able to feel that by hand, also.
Keep digging, there might be an acorn there somewhere...
#50
Rennlist Member
Thread Starter
This video gives an idea how slow the cranking is, with a full battery.
I'd like to think it's the starter, but really do feel a lot of grinding going on, so thinking it's TBF.
Only downside to dropping the pan is that if I find TBF and it's time to pull the engine, the crossmember is off and there's nothing supporting the engine, except from the top. Then have to switch over from the 4x4 system, to the engine hoist and all that. Seems like it would be less work overall to just pull the engine, but of course it would be nice to verify the issue before going to all that trouble. I may know more after talking to the mechanic on Monday that looked at the car. I should be able to tell if he knows what he's doing and he may give me more info and observations that confirms TBF.
http://www.youtube.com/watch?v=m9KnD...yer_detailpage
I'd like to think it's the starter, but really do feel a lot of grinding going on, so thinking it's TBF.
Only downside to dropping the pan is that if I find TBF and it's time to pull the engine, the crossmember is off and there's nothing supporting the engine, except from the top. Then have to switch over from the 4x4 system, to the engine hoist and all that. Seems like it would be less work overall to just pull the engine, but of course it would be nice to verify the issue before going to all that trouble. I may know more after talking to the mechanic on Monday that looked at the car. I should be able to tell if he knows what he's doing and he may give me more info and observations that confirms TBF.
http://www.youtube.com/watch?v=m9KnD...yer_detailpage
#51
Under the Lift
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The fact that you got NO crank endplay at all is consistent with a stuck crank from TBF. If you pry hard enough with a big enough prybar it will probably jump. Good motors will always have SOME crank endplay with just an easy push on the prybar. We saw this recently in a local car. No crank endplay as far as we could see. I just kept pushing with bigger prybars and finally it jumped 1.65 mm. TBF!
#53
Under the Lift
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Well, that video seems to show the starter is drawing a lot of current. The battery might not be the greatest, but it seems to be providing a lot of juice. If the battery is low, the 89 digital dash will reset and show a firmware version when you crank the starter, and I didn't see that. You might just try to turn the crank over with a 2 or 3 foot wrench on the crank pulley bolt and see how it feels. Particularly, if you do this with the plugs out, you will easily feel the extra drag. Most likely the thrust bearing is spinning with the crank.
I think you already know from trying to measure crank endplay. You said there was none. That's not a good motor. The crank should move (factory lower limit is 0.11 mm or 0.004 in) and make a noticeable "clunk" noise by prying even with a small screwdriver.
I think you already know from trying to measure crank endplay. You said there was none. That's not a good motor. The crank should move (factory lower limit is 0.11 mm or 0.004 in) and make a noticeable "clunk" noise by prying even with a small screwdriver.
#54
Burning Brakes
Don,
You may be a lucky fellow if not TBF. No minute flakes of aluminum on a dark paper suggests maybe not TBF.
One thought comes to mind, after you charge the battery....the starter itself from the invoice you have was "used replacement starter". The starter itself maybe a problem...if it is dragging the armature it will eat all sorts of power and produce little...bad brushes usually fail differently, but I am just sayin'.......you might want to buy a lottery ticket too......I do have a fresh starter if you want to give it a try....
You may be a lucky fellow if not TBF. No minute flakes of aluminum on a dark paper suggests maybe not TBF.
One thought comes to mind, after you charge the battery....the starter itself from the invoice you have was "used replacement starter". The starter itself maybe a problem...if it is dragging the armature it will eat all sorts of power and produce little...bad brushes usually fail differently, but I am just sayin'.......you might want to buy a lottery ticket too......I do have a fresh starter if you want to give it a try....
Definitely worth pulling and checking it out!
#55
Addict
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Just drain the oil and look at it if it looks like metal flake paint...it is. Also cut open the oil filter spread out the paper filter media on some old newspaper let it drain awhile and look for gold in the creases....
#56
Rennlist Member
Thread Starter
Lots of good advice...
I could put a known good battery in it tomorrow. The battery is pretty strange looking, never seen one like it. Doesn't have a brand on top, and has two handles that sortof come together as you lift them. I had a charger on it, but it was a small 2 amp, so wouldn't have made much difference on cranking.
Wonder if I could catch a few ounces of oil from the drain plug? (take it out, cover hole with finger control the flow and put it back? Never tried it but may be doable)
A bit more trouble, but could try the starter off my 86.
Will also try turning the engine by hand.
Bill, thanks for your comments. I did see what was probably the firmware version at one point. I think it said "F04" or something like that. I thought it was an error code. Would that only happen if the battery was low, or also if there was a huge current draw that pulled down the voltage on the entire system?
I could put a known good battery in it tomorrow. The battery is pretty strange looking, never seen one like it. Doesn't have a brand on top, and has two handles that sortof come together as you lift them. I had a charger on it, but it was a small 2 amp, so wouldn't have made much difference on cranking.
Wonder if I could catch a few ounces of oil from the drain plug? (take it out, cover hole with finger control the flow and put it back? Never tried it but may be doable)
A bit more trouble, but could try the starter off my 86.
Will also try turning the engine by hand.
Bill, thanks for your comments. I did see what was probably the firmware version at one point. I think it said "F04" or something like that. I thought it was an error code. Would that only happen if the battery was low, or also if there was a huge current draw that pulled down the voltage on the entire system?
#59
Under the Lift
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Don: Well, get a good battery then. Still, I think the ZERO crank endplay has already answered the question, unless perhaps you haven't done this before and are doing something wrong. You do need a dial gauge or micrometer to measure endplay, and it is possible there will be no audible clunk when the crank moves, but I always hear it.
Tony's write-up on crank endplay is good: http://members.rennlist.com/v1uhoh/cranksha.htm
Here's mine too: https://rennlist.com/forums/928-foru...pictorial.html
Tony's write-up on crank endplay is good: http://members.rennlist.com/v1uhoh/cranksha.htm
Here's mine too: https://rennlist.com/forums/928-foru...pictorial.html
#60
Rennlist Member
The factory Porsche battery is designed like this... 2 handles that are inset into the top and when used together, you can lift straight up. Battery is white and will say "PORSCHE" on the side of the battery. May or may not have a distributor name on the top or side, IIRC.