thank you !.....new engine, old car

[KK911C4]

I am the original owner of 1999 996 C4 now with 123,000 miles. I just want to say thank you for all those that contribute to DIY and give advice. I've learned a lot and I appreciate it.

My engine crapped out last year and I was lucky enough to find Jake Raby and Jud Fink at Flat Six. Sent my car in Jan 2018 and got it back in July 2018. awesome engine. Bad news is my 20 year old car is giving me problems around it! I have had some pesky coolant leaks since getting it back from a hose that finally I got fixed... then last Saturday my coolant expansion tank sprung a leak. I replaced that thanks to some good posts and even dropped my engine to do it !!! Thought I was home free, but last night after a drive got a CEL and 0300 0301 0302 fault codes. Idle is rough. I've pulled the coils on left bank under coolant tank. They look fine but I'm ordering some new ones. I hope that fixes it.

 

Once again, Jake Raby and team have been great. Too bad the rest of my car can't keep up. I am a little discouraged.

[Jake Raby]

We are always here to help.. Jud can get you some of our Flat 6 coils out tomorrow ?

[B3-CPO]

Don't get hypersensitivity disorder. I've noticed lots of 996 owners with coolant system problems this year. We own 20 year old cars... maybe it's just time? Heck, my 996 expansion tank just started leaking couple of weeks ago too. Just got the tank in from Porsche and will plan to replace it this week or next. I've known people that had to replace them multiple times partly because they chose to purchase aftermarket tanks instead of the more proven OEM. 

 

Now regarding the "rough idle"... have you tried to hooking up to a Durametric and evaluate the rough running indexes? I lot of the problems associated with rough idle can be attributed to our modern fuels. I'm sure lots of people immediately think it's faulty coil packs, but instead, it can be something simple like clogged injectors or a dirty MAF. Cross one bridge at a time. 

 

Flat 6 Innovations is the best in the business. Glad to hear you made the right choice to get them to reconstruct your engine. I would listen to Jake's advice before making any hasty moves financially. Lot of people overreact, start throwing money at the symptoms instead of the source of the problem. 

Edited November 5, 2018 by b3freak

[KK911C4]

Just want to add that Jake and Jud at Flat 6 continue to go above and beyond to advise and help. I'll let you know after new coils are in as Jake advised..If everyone ran their business like this..... WOW!!!!

[wyovino]

There is a high probability that the coolant leak made it down to the coils. I had a CEL for Cylinder 1 misfire after replacing my coolant tank. My coils were actually fine but I replaced them anyway because the effort required to remove and check them makes the cost of replacing them trivial.  In my case, coolant (and/or fuel) from the tank replacement procedure eventually seeped past the rubber seal and caused the misfire. The coil shaft was just a little wet. I tested all of the old coils with an ohm meter and they were fine. There were no cracks.

 

There was a significant amount of coolant left in the hoses after I drained the tank and it all came out. I also had to disconnect the fuel lines to remove and replace the tank. There was a lot of fuel spilled in the process as well.  After replacing the coils it was fine.  I replaced the plugs too even though they weren't due yet.

Edited November 8, 2018 by wyovino

[KK911C4]

Yes, all good after replacing coils that Flat 6 provided. Continue to learn lessons though. I thought it best to test coolant system for leaks before putting on new coils so after researching used Stant 12016 adapter (Volkswagen/audi) with Stant 12270 pressure tester.... the saga continues.... I think that adapter screwed up my threads on my new expansion tank.. it seemed to thread just fine but now new blue coolant cap tightens down then loosens! Stripped!.. After first ride cooolant was spewing out of an over filled expansion tank. I over filled ???? took some coolant off then tightened cap with some teflon tape on threads of coolant stem. Took a spin. Seems ok. Please don't tell me I have to get a new tank ! But I am suspect that despite what I read, the Stant 12016 was NOT correct adapter ( its 48mm x 3) though sure does look like same thread pattern as coolant tank stem. Boy am I learning a lot  !

[JFP in PA]

11 hours ago, KK911C4 said:

Yes, all good after replacing coils that Flat 6 provided. Continue to learn lessons though. I thought it best to test coolant system for leaks before putting on new coils so after researching used Stant 12016 adapter (Volkswagen/audi) with Stant 12270 pressure tester.... the saga continues.... I think that adapter screwed up my threads on my new expansion tank.. it seemed to thread just fine but now new blue coolant cap tightens down then loosens! Stripped!.. After first ride cooolant was spewing out of an over filled expansion tank. I over filled ???? took some coolant off then tightened cap with some teflon tape on threads of coolant stem. Took a spin. Seems ok. Please don't tell me I have to get a new tank ! But I am suspect that despite what I read, the Stant 12016 was NOT correct adapter ( its 48mm x 3) though sure does look like same thread pattern as coolant tank stem. Boy am I learning a lot  !

 

The Stant 12016 adaptor is correct for your vehicle.  You may simply have a bad tank cap; if its part number does not end in “-04”, I would replace it.  You may have also gotten air entrapped in your cooling system, which will need to be bled out before the system will be happy.

[KK911C4]

Thanks JFP,

 

I'm glad I used proper adapter. Cap is brand new OEM that ends in " 04"... but I really think I can't get it tight after using adapter. It's clearly a different fit than 1 week ago when both tank and cap were brand new and I had not used adapter. Wondering if a soft pipe thread PTFE paste, Gasoila, around tank threads would help. I'm running with coolant level just below "min" mark and I have no leak but hear a "hiss" after an aggressive drive from cap.  Thoughts ?

[JFP in PA]

12 hours ago, KK911C4 said:

Thanks JFP,

 

I'm glad I used proper adapter. Cap is brand new OEM that ends in " 04"... but I really think I can't get it tight after using adapter. It's clearly a different fit than 1 week ago when both tank and cap were brand new and I had not used adapter. Wondering if a soft pipe thread PTFE paste, Gasoila, around tank threads would help. I'm running with coolant level just below "min" mark and I have no leak but hear a "hiss" after an aggressive drive from cap.  Thoughts ?

 

I have not seen a tank threads strip, so I tend to doubt that.  I would try another new cap, being sure it is a factory cap and not aftermarket; we have had no luck with aftermarket.

[KK911C4]

Update. Turned out to be threads on "OEM supplier" tank ($300) I bought instead of Porsche genuine ($600 -700) in order to save $. Mistake. My cap was/is new, genuine, ends in "04" and tightens beautifully and fully onto genuine tank but not "OEM supplier". Removed fake tank and just installed genuine. One thing's for sure, the more you do, the better and quicker it goes ! Waiting now for Airlift to arrive so I can vacuum fill coolant. Once again, thanks to all with DIY advice on coolant tank replacement. In my case (MY1999 911C4 996) clearly had to drop engine to remove tank. Managed not to bust sensor the 2nd time! Changed fuel filter attached to tank while I was there ( fuel filter has to be removed ). Also, just take the emissions airpump out- gives you room to work. Hopefully those new coils Flat 6 sent on cylinders 1 and 2 are OK after the last bubble over of coolant from leak at cap/tank stem..

[Loren]

2 hours ago, KK911C4 said:

Update. Turned out to be threads on "OEM supplier" tank ($300) I bought instead of Porsche genuine ($600 -700) in order to save $.

 

I can not tell how many times we have seen this sort of thing with supposedly "equal" parts. The old term "Let the buyer beware" still holds true today (unfortunately).

[JFP in PA]

2 minutes ago, Loren said:

 

I can not tell how many times we have seen this sort of thing with supposedly "equal" parts. The old term "Let the buyer beware" still holds true today (unfortunately).

 

+1.  We have simply moved away from most aftermarket parts for these cars, simply to avoid "come backs" caused by inferior components.  We have taken to telling customers that if they insist upon aftermarket parts to save money, they should take the car else where.

[B3-CPO]

Totally, 100% agree with avoiding aftermarket parts. I also tried to save money on a window regulator. Ahsai told me to not waste the time and money and pay for the Porsche OEM. I didn't take his advice and bought the Chinese knockoff for about $60.00. Spent a half day on a nice Saturday installing it. After a month, the regulator crapped out. I learned my lesson the hard way. The same thing goes for Porsche expansion tanks, buy the Porsche OEM, not aftermarket. It's a pain in the butt to install and I've heard of people having to do it several times until they learned to buy the Porsche OEM part. Cheers brothas!

Edited November 15, 2018 by b3freak

[JFP in PA]

If you want to see the perfect example of aftermarket crap, look at the AOS.  We have seen units that were stone dead right out of the box.  So imagine how good you are going to feel about saving a few bucks after you spend a couple of knuckle busting hours to put it into the car, only to find out it is useless.

[KK911C4]

Also a lesson on parts.... genuine vs. OEM supplier v ..... I actually thought I was getting the same part as genuine Porsche based on my experience with oil filter on Cayenne diesel. In order to avoid the $440 dealer charge for oil service, I do it myself. The very 1st time,  I bought oil filter from dealer; nice "Porsche" box but inside was a Mann filter. I took numbers off filter and got exact same Mann filter in a Mann box for $10.50. So I thought that when online parts supplier listed "OEM supplier" for coolant tank, I was actually getting the shop that supplies tank to Porsche minus the  Porsche box. Wrong.. there were no markings on tank, no 996....... number, nothing. It did have a "made in Germany" sticker on it. Like Loren said, " Buyer be ware".

[KK911C4]

Finished repair and engine sounds better than ever. Happy Thanksgiving to all.

[B3-CPO]

Great! Enjoy your Christmas holidays with that nice 996!

[dporto]

I just sent my engine (actually whole car) to Jake/Jud for a "Track Performer" update/upgrade ? I can't wait 'til April to get 'er back !

Edited December 11, 2018 by dporto

[KK911C4]

You will be very pleased. My strong advice is to also have them replace whatever you can around engine like coolant tank, ignition coils etc.