Sachin Misra

Does anyone have an update on the wiring harness issue for the 993s? I posted something about a month back and got lots of suggesstions. Thanks everyone.

I'm having all the typical problems. Starter Run-on, oil pressure gauge pegging etc. Took it to the dealer and they replaced the oil pressure sending unit twice and it now works. But my air-conditioning won't work now. They say I have a bad harnes due to an "open" on the air-conditioning circuit, and the main egine harness needs to be replaced. None of the physical clues are present, like frayed fuel injector wires etc. So the dealer is saying that it is not a typical wiring harness failure that was endemic to the 95 993s.

I looked on the USDOT report and my wiring harness part # is not the updated # provided on the report. The dealer just keeps saying that I have a 97 harness and it should be fine.

The dealer is basically saying I'm on my own since I'm the 2nd owner. Cost to replace $1,800.

Does anyone have any suggestions on whom to contact. I can afford the $1,800, but I think a low mileage car (31K miles) should not have a wiring harness failure, and if Porsche has seen these complaints, they should as customer good will provide some form of assistance.

Thoughts? Suggestions?

Regards,
Sachin

Flying Finn

Sachin,

Sorry, I don't have any new info on this but would you mind sharing some info how complicated & costly the oil pressure sending unit replacement was?

I think I have something wrong with my oil pressure gauge or sender but others have suggested that you need to drop the engine to change the sender and for that reason I haven't done anything.

E. J. - 993 Alumni

Sachin,

Go to my website and follow the directions of finding the harness part number and build date. Then get it to me and I will let you know. As for 1996 cars, according to the NHTSA report (available <a href="http://www.pcarracing.homestead.com/wiringharness3.html" target="_blank">here</a>), there were 74 wiring harness warranty claims paid on 1996 993s. This obviously does not count those not paid via warranty and covered by the owner.

I would say you are not alone, but certainly fighting an uphill battle. You can print out the actual report on my site to take to the dealer. I would say you should call PCNA directly if the dealer continues to avoid paying. If they just wont, you should find a good independant shop that can make the swap for you as $1800 is a lot of jack. The part should be about $550 bucks. should take about 8 hours max.

Good luck,

E. J.

Sachin Misra

Finn,

They are right, you need to drop the engine at least partially to get to the sending unit. Part cost is around $100, labor at a dealer is aprox $400. Definitely not a DIY, (at least for me).

If you go to an aftermarket shop, make sure you have them give you a warranty on parts&labor. The Porsche dealer will give you a 2 year unlimited mileage warranty.

I had the unfortunate experience of having it done twice. Once at an aftermarket shop (really nice guys) and again at the dealer (not so nice guys). They did reimburse me for the faulty part, but I had to eat the labor.

[quote]Originally posted by Flying Finn:
<strong>Sachin,

Sorry, I don't have any new info on this but would you mind sharing some info how complicated & costly the oil pressure sending unit replacement was?

I think I have something wrong with my oil pressure gauge or sender but others have suggested that you need to drop the engine to change the sender and for that reason I haven't done anything.</strong><hr></blockquote>

Sachin Misra

Thanks EJ. As soon as I get the car back from the dealer (the next day or two), I'll pass the info along to you. Thanks for your help.

PS: I'm trying to get the case re-opened at USDOT.

Flying Finn

Ah, thanks Sachin.

It's weird that factory manuals show the tool for checking the oil pressure but leave engine drop mentioned...

My oil gauge usually shows about 4.5 but sometimes it's above 5 (which I believe is normal) and I can't think it's electrics (that's why I'm not worrying) since if I had faulty oil pump, I think it would constanly show 4.5. And idle pressure is 2-2.5.

os993

My mechanic just replaced my oil pressure sensor unit, because my oil pressure gauge pegged to high and wouldn't move, key in or out..

Motor did not need to be dropped, at least on a 95!! Sensor cost $56 and I was charged $200 labor (they had to test the gauge, wiring harness, etc..)

What's interesting is the new sensor seems more accurate. Not sure if this is accurate, but now while driving the pressure isn't pegged max, but hoovers around 4-5, then drops to 2-3 at idle. Before, the gauge would just peg to max high whenever you hit the gas.

BTY, my 95 993 has original harness and I have 98k miles. Mechanic checked the harness, especialy in known problem areas (behind alternator) and saw nothing to make him concerned. We chatted about replacing the harness, but he just couldn't justify doing it. Nothing was brittle (I know, this can be hidden under the sheath), but car runs beautifully, without any electrical gremlins. Until I have any serious issues, the harness remains. If I did replace harness, engine would NOT be dropped and 8hrs of labor would be needed, so approx $680 total for labor and approx $500 for harness.

Sachin Misra

Very intresting! Maybe I'm just getting reamed by the dealer. I'm assuming that you are going to an aftermarket shop? If you are in Menlo Park, is it the german mechanic in downtown Palo Alto? I used to go there and he was awesome. Both the dealer and the aftermarket shop said that the motor has to be "dropped partially" whatever that means.

I found an aftermarket shop out here that is significantly less than the dealer, aprox $1,200 vs. $1,800 at the dealer (parts & labor).

If you are in CA you probably wont experience the harness problems becsuse the material decomposition issue only surfaces in hot & humid climates such as the Midwest, MidAtlantic and Southern regions. "This is due to the material used Arnitel, which is incompatible with rubber in hot & humid conditions." quote taken from the USDOT report.

[quote]Originally posted by oleg steciw:
<strong>
Motor did not need to be dropped, at least on a 95!! Sensor cost $56 and I was charged $200 labor (they had to test the gauge, wiring harness, etc..)

What's interesting is the new sensor seems more accurate. Not sure if this is accurate, but now while driving the pressure isn't pegged max, but hoovers around 4-5, then drops to 2-3 at idle. Before, the gauge would just peg to max high whenever you hit the gas.

BTY, my 95 993 has original harness and I have 98k miles. Mechanic checked the harness, especialy in known problem areas (behind alternator) and saw nothing to make him concerned. We chatted about replacing the harness, but he just couldn't justify doing it. Nothing was brittle (I know, this can be hidden under the sheath), but car runs beautifully, without any electrical gremlins. Until I have any serious issues, the harness remains. If I did replace harness, engine would NOT be dropped and 8hrs of labor would be needed, so approx $680 total for labor and approx $500 for harness.</strong><hr></blockquote>

E. J. - 993 Alumni

[quote]Originally posted by Sachin Misra:
<strong>I'm trying to get the case re-opened at USDOT.</strong><hr></blockquote>

Good luck, keep me updated please.

deltajetfixer

Hi E.J.,

I've been to your website and have determined through the broken insulation on several wires on the Engine Harness and my May '95 build date that I'm going to replace it myself.

Question: Following your instructions to open the Engine Compartment Electrical Box on the left side in an attempt to obtain the part numbers for the harness, I found ALL of the fasteners for the box cover "stripped out"!
How would you suggest I remove them?

By the way, Ms. Munson just sent me my Rennlist Membership Confirmation...but alas, my "Rennlist Member" notation is nowhere to be found...

Thanks!

Sachin Misra

My 993 had the same problem when I took it in. They needed to get to it to probe voltage.

3 of the screws were stripped. They had to break the box, and replace it. Cost aprox $100. It's in 2 pieces (cover + panel)

Good luck.

[quote]Originally posted by deltajetfixer:
<strong>

Question: Following your instructions to open the Engine Compartment Electrical Box on the left side in an attempt to obtain the part numbers for the harness, I found ALL of the fasteners for the box cover "stripped out"!
How would you suggest I remove them?
</strong><hr></blockquote>

Flying Finn

[quote]Originally posted by oleg steciw:
[QB]My mechanic just replaced my oil pressure sensor unit, because my oil pressure gauge pegged to high and wouldn't move, key in or out..

Motor did not need to be dropped, at least on a 95!! Sensor cost $56 and I was charged $200 labor (they had to test the gauge, wiring harness, etc..)...QB]<hr></blockquote>

Interesting! (mine is -95 also)

Can you share any info it there was any tricks that you need to do in order to do this?

I'll swap my sensor if this can be done w/out dropping.

Jim Sorensen

Seems like this thread has 2 issues: Wiring Harness and Oil Pressure Gauge. Had the same problem with oil pressure. Dealer changed sending unit on my '96 without dropping engine but he said he had to remove "a lot of stuff on top". New unit lasted about a year and now usually pegs above 5 when engine is running. Occassionally the needle will drop to the normal 2 when at idle but that's only about 20% of the time. I have not done anything about this for several DE's with no problem--the engine is getting oil. Their sending units are defective!

os993

Hey Flying Finn,
Pressure sensor is located behind air intake system, low on the engine block.. Mechanic said it was tough to get to, but no engine drop needed! By directing your mechanic to specifically do this (ie not check gauge, harness...), I don't see why more than 2 hrs labor should be charged! Seems to read the pressure more accurately

Flying Finn

Thanks guys,

Seems like I'll have my mechanic to change this next time I need to take my car there.