Strange Sound Rebuild Rebound Thread
#121
Nordschleife Master
Another thought (probably a lame one)... is it possible that your new starter is NOT retracting from the ring gear and is spinning like mad with the engine running? That will certainly heat-soak that starter. Good luck tracking this down... we are all following this thread with interest.
#122
Burning Brakes
Thread Starter
Hey Peter, Glad you have her running again, that is the first major step. Shut down and Starter issues would not be related.
Is the car throwing a check engine light as it shuts down? If so would be good to get the codes if possible.
Do you have to boost it after the shut down? or is there enough charge in the battery? If it is shutting down and the battery is dying then there is a chance the alternator is at fault.
Checking the charge system as it is running could help check the regulator and alternator health, if the voltage is jumping around or low could be issue there.
I would also check the resistance of the Cylinder Head Temp sender located in cylinder #3, making sure it is working ok, I could shut down if it senses an overheat, same could be done for the oil temp sender as well. It may not be overheating but the sensor being faulty could send a false signal. Both of these should show up with a check engine light.
Good Luck.
Is the car throwing a check engine light as it shuts down? If so would be good to get the codes if possible.
Do you have to boost it after the shut down? or is there enough charge in the battery? If it is shutting down and the battery is dying then there is a chance the alternator is at fault.
Checking the charge system as it is running could help check the regulator and alternator health, if the voltage is jumping around or low could be issue there.
I would also check the resistance of the Cylinder Head Temp sender located in cylinder #3, making sure it is working ok, I could shut down if it senses an overheat, same could be done for the oil temp sender as well. It may not be overheating but the sensor being faulty could send a false signal. Both of these should show up with a check engine light.
Good Luck.
I assume I check resistance at the connector in back left engine bay. What value should I be looking for?
The oil temp sender seems to be operating normally at least according to dash gauge.
#123
Pro
When the engine shuts off by itself, have you tried to crank the engine manually? 19mm wrench on the crank pulley and check if it will rotate easily until you get to the compression point and beyond to the next tdc and so on?
Maybe your tolerances are too tight and the motor will stall due to friction? Side load on thrust bearings?
Just a thought.
Ed
Maybe your tolerances are too tight and the motor will stall due to friction? Side load on thrust bearings?
Just a thought.
Ed
#125
Three Wheelin'
#127
Race Car
No check engine light and no codes. Plenty of charge left in battery - starts up next day as if nothing has happened.
I assume I check resistance at the connector in back left engine bay. What value should I be looking for?
The oil temp sender seems to be operating normally at least according to dash gauge.
I assume I check resistance at the connector in back left engine bay. What value should I be looking for?
The oil temp sender seems to be operating normally at least according to dash gauge.
#128
Pro
Hi
I would ignore the problem for now, get the car driveable and then let Porsche swap the harness. I know it will be touch and go getting there (you could trailer it). They can swap the starter for you at the same time i'm sure. They have to undo a lot of gubbins to get the harness changed, so it may well clear the issue. Plus all bets are off with the old harness. Mine was burnt to a crisp. Literally.
Best of luck
Berni
I would ignore the problem for now, get the car driveable and then let Porsche swap the harness. I know it will be touch and go getting there (you could trailer it). They can swap the starter for you at the same time i'm sure. They have to undo a lot of gubbins to get the harness changed, so it may well clear the issue. Plus all bets are off with the old harness. Mine was burnt to a crisp. Literally.
Best of luck
Berni
#131
After reading this and seeing all the critcal pictures; no way am I trying to rebuild my 993 case internals! When I was younger I was casually rebuilding engines in a Jag E-Type and some PontV6 and 'Vette V8 and those were no problem(s), but these 993 engines are in a league all by themselves. I could handle the heads/cams and pistons, but the case itself seems daunting ! Wonder what Steve would charge to straightforward rebuild a shipped 993N/A or 993TT case shipped to him ?
#132
Addict
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After reading this and seeing all the critcal pictures; no way am I trying to rebuild my 993 case internals! When I was younger I was casually rebuilding engines in a Jag E-Type and some PontV6 and 'Vette V8 and those were no problem(s), but these 993 engines are in a league all by themselves. I could handle the heads/cams and pistons, but the case itself seems daunting ! Wonder what Steve would charge to straightforward rebuild a shipped 993N/A or 993TT case shipped to him ?
If you have done other engines, a 993 is well within your capability, and in fact you can do it twice for what a engine rebuilder would charge, given your labour is free. Its 30-40hrs min for a complete teardown and rebuild, with splitting the case, and then there is the cost of machining, new parts, gaskets, etc.
Unless something really major has happened to your engine, the bottom end of the 993 (possibility excluding a slightly weaker rod bolts) will last a long long time, so most rebuilds revolve around valve jobs and sometimes replacing the rings. I split the case on my rebuild just because I was there, but I found everything was in spec and it was not required. There was a bit of wear on the layshaft bearings (typical) but nothing that would not have gone for another 100,000 miles.
Cheers,
Mike
#133
Burning Brakes
Thread Starter
Here's the update. The posts about tolerances being too tight got me down but made me think through how this could have happened.
I went back and reviewed all my pictures of the tolerances (showing plastigauge) for both the mains and the rods. All were well within spec.
Additionally, I remembered that his symptom (shut down)happened BEFORE I even opened the bottom end. As I know, anything is possible, but I am hoping to find something else.
So I finally got my laptop running (another story) and was able to attach my scantool and read the codes. Lo and behold I got one: Code 1118, RPM Signal.
I was super careful when I attached the sensor to the case and carefully measured the gap. It was 1mm.
My next thought is could I have mixed up the connections in the back left engine area so I will be checking that next. IIRC, they are all color coded and I matched the colors but I'll have to do a double check.
I'm also gonna run the car until shut-off with the scan tool attached and see if I get strange RPM signals near the end when it gets hot.
Then I will try to advance the engine by hand and prey that it will move.
I went back and reviewed all my pictures of the tolerances (showing plastigauge) for both the mains and the rods. All were well within spec.
Additionally, I remembered that his symptom (shut down)happened BEFORE I even opened the bottom end. As I know, anything is possible, but I am hoping to find something else.
So I finally got my laptop running (another story) and was able to attach my scantool and read the codes. Lo and behold I got one: Code 1118, RPM Signal.
I was super careful when I attached the sensor to the case and carefully measured the gap. It was 1mm.
My next thought is could I have mixed up the connections in the back left engine area so I will be checking that next. IIRC, they are all color coded and I matched the colors but I'll have to do a double check.
I'm also gonna run the car until shut-off with the scan tool attached and see if I get strange RPM signals near the end when it gets hot.
Then I will try to advance the engine by hand and prey that it will move.
#134
Race Car
Hey Peter,
You are right with the color coded plugs for the Head Temp and reference sensor.
Check to see if the wire for the reference sensor hasn't been damaged, crushed etc.
There is a test for the reference sensor, however you need access to an oscilloscope to do the testing. If you have access you connect the oscilloscope leads to pins 48 and 49 on the DME and check the signal, you are looking for at least 3v and a good saw tooth pattern.
You are right with the color coded plugs for the Head Temp and reference sensor.
Check to see if the wire for the reference sensor hasn't been damaged, crushed etc.
There is a test for the reference sensor, however you need access to an oscilloscope to do the testing. If you have access you connect the oscilloscope leads to pins 48 and 49 on the DME and check the signal, you are looking for at least 3v and a good saw tooth pattern.
#135
Burning Brakes
Thread Starter
Hey Peter,
You are right with the color coded plugs for the Head Temp and reference sensor.
Check to see if the wire for the reference sensor hasn't been damaged, crushed etc.
There is a test for the reference sensor, however you need access to an to do the testing. If you have access you connect the oscilloscope leads to pins 48 and 49 on the DME and check the signal, you are looking for at least 3v and a good saw tooth pattern.
You are right with the color coded plugs for the Head Temp and reference sensor.
Check to see if the wire for the reference sensor hasn't been damaged, crushed etc.
There is a test for the reference sensor, however you need access to an to do the testing. If you have access you connect the oscilloscope leads to pins 48 and 49 on the DME and check the signal, you are looking for at least 3v and a good saw tooth pattern.