Engine Advice/Guidance

[JFP in PA]

Great information. I will use my stethoscope tonight. can you provide the link to Jake Raby's article on how to listen to the sounds? Also, I read somewhere that loose spark plugs can also sound like bad lifters. I replaced the spark plugs a year ago with the OEM Bosch plugs. I torqued them to 28 NM because the spark plug box said to torqued it to that, however, Wayne's book and the bentley book said to torque them to 30 NM. Do you have any thoughts on this? Thanks so much for the assistance.

 

Loose plugs can make all kinds of sounds, depending upon how loose they are.  You would get anything from a tick like sound to a screeching sound.

 

Plugs should be torqued to 30 Nm +/- 3Nm, or 22 ft. lbs. +/- 2 ft. lb.

[Ahsai]

Thanks John for the info.

 

Jake's post is post #39 here http://rennlist.com/forums/996-forum/863686-noticed-a-rod-knock-noise-in-my-car-3.html

[questforbalance]

Thanks for all the information and assistance.

[questforbalance]

So I checked the torque on a few spark plugs, changed the oil and filter and used my stethoscope to listen to the tapping on the engine. Results: Spark plugs were tight, found a few silver shavings in the oil filter, and can hear tapping noise at top of engine and at bottom of right side of engine cam cover. Car drives ok, no loss of power, accelerates good, but tapping is noticeable, increases in intensity when accelerating and it appears that a rebuild (lifters) or new engine is in my future. Anyone have any advice or thoughts? I am now looking for a Porsche mechanic, certainly not a Porsche dealership, but someone who is fair and will check out car, provide honest advice and service.? Any thoughts would be appreciated. I live in central New Jersey, 20 miles west of Newark Liberty International airport.

[JFP in PA]

So I checked the torque on a few spark plugs, changed the oil and filter and used my stethoscope to listen to the tapping on the engine. Results: Spark plugs were tight, found a few silver shavings in the oil filter, and can hear tapping noise at top of engine and at bottom of right side of engine cam cover. Car drives ok, no loss of power, accelerates good, but tapping is noticeable, increases in intensity when accelerating and it appears that a rebuild (lifters) or new engine is in my future. Anyone have any advice or thoughts? I am now looking for a Porsche mechanic, certainly not a Porsche dealership, but someone who is fair and will check out car, provide honest advice and service.? Any thoughts would be appreciated. I live in central New Jersey, 20 miles west of Newark Liberty International airport.

 

Sounds more and more like a lifter issue.

 

Check with your local PCA chapter for a list of suggested shops in your area.

[questforbalance]

Thanks JFP. I will certainly follow your advice. FYI, I spoke with Jake Raby today and got an ear full of faults with the M96 engines and a quote for a "tank-like" replacement engine. He told me that noisy lifters are a common misdiagnosis for these engines, particularly in the colder regions of the country. His opinion is that my problem is not the lifters, but the cylinders caused by a faulty design of the cylinders by Porsche. This all ads to the inherent complexity and contradiction of Porsche automobile ownership. My only regret is that money is not unlimited in my family and my love of living, eating and surviving far outweighs my love for Porsches.

[JFP in PA]

Thanks JFP. I will certainly follow your advice. FYI, I spoke with Jake Raby today and got an ear full of faults with the M96 engines and a quote for a "tank-like" replacement engine. He told me that noisy lifters are a common misdiagnosis for these engines, particularly in the colder regions of the country. His opinion is that my problem is not the lifters, but the cylinders caused by a faulty design of the cylinders by Porsche. This all ads to the inherent complexity and contradiction of Porsche automobile ownership. My only regret is that money is not unlimited in my family and my love of living, eating and surviving far outweighs my love for Porsches.

 

Obviously, Jake sees a lot more engines completely disassembled than we do, so I would be the last to refute his observations, plus there are many instances we are aware of that ultimately turned out to be confirmed cylinder issues on the M96/97 engines.  He does have a valid point about cold start induced wear, particularly on engines that continue to run lower film strength 0W-40 oils as most engine wear occurs during cold start and warm up when these oils are at their weakest levels of wear protection, and the cars are often just cold started and then immediately driven without any real warm up period.

 

If you are concerned that Jake may be correct, I would pull the plugs and bore scope the cylinders looking for signs of unusual thrust side wear patterns, which are often quite obvious even to the untrained observer. 

[rbrindley1]

Provost Motorsports is located in Bordentown, NJ and is owned and operated by Robbie Provost a Schattenbaum Porsche Club member.

[fpb111]

Keith Peare, Mike Daino and the crew at Power Tech in Rockaway, NJ have a good reputation and a lot of experience with these engines.  They are also very active in the local PCA region NNJR.

http://www.pwr-tech.com/

Edited April 14, 2015 by fpb111

[318touring]

 

Thanks JFP. I will certainly follow your advice. FYI, I spoke with Jake Raby today and got an ear full of faults with the M96 engines and a quote for a "tank-like" replacement engine. He told me that noisy lifters are a common misdiagnosis for these engines, particularly in the colder regions of the country. His opinion is that my problem is not the lifters, but the cylinders caused by a faulty design of the cylinders by Porsche. This all ads to the inherent complexity and contradiction of Porsche automobile ownership. My only regret is that money is not unlimited in my family and my love of living, eating and surviving far outweighs my love for Porsches.

 

Obviously, Jake sees a lot more engines completely disassembled than we do, so I would be the last to refute his observations, plus there are many instances we are aware of that ultimately turned out to be confirmed cylinder issues on the M96/97 engines.  He does have a valid point about cold start induced wear, particularly on engines that continue to run lower film strength 0W-40 oils as most engine wear occurs during cold start and warm up when these oils are at their weakest levels of wear protection, and the cars are often just cold started and then immediately driven without any real warm up period.

 

If you are concerned that Jake may be correct, I would pull the plugs and bore scope the cylinders looking for signs of unusual thrust side wear patterns, which are often quite obvious even to the untrained observer. 

 

 

For clarification, when you said "the cars are often just cold started and then immediately driven without any real warm up period." this was talking about when people went past 3000rpms while the engine/oil is cold?

[JFP in PA]

 

 

Thanks JFP. I will certainly follow your advice. FYI, I spoke with Jake Raby today and got an ear full of faults with the M96 engines and a quote for a "tank-like" replacement engine. He told me that noisy lifters are a common misdiagnosis for these engines, particularly in the colder regions of the country. His opinion is that my problem is not the lifters, but the cylinders caused by a faulty design of the cylinders by Porsche. This all ads to the inherent complexity and contradiction of Porsche automobile ownership. My only regret is that money is not unlimited in my family and my love of living, eating and surviving far outweighs my love for Porsches.

 

Obviously, Jake sees a lot more engines completely disassembled than we do, so I would be the last to refute his observations, plus there are many instances we are aware of that ultimately turned out to be confirmed cylinder issues on the M96/97 engines.  He does have a valid point about cold start induced wear, particularly on engines that continue to run lower film strength 0W-40 oils as most engine wear occurs during cold start and warm up when these oils are at their weakest levels of wear protection, and the cars are often just cold started and then immediately driven without any real warm up period.

 

If you are concerned that Jake may be correct, I would pull the plugs and bore scope the cylinders looking for signs of unusual thrust side wear patterns, which are often quite obvious even to the untrained observer. 

 

 

For clarification, when you said "the cars are often just cold started and then immediately driven without any real warm up period." this was talking about when people went past 3000rpms while the engine/oil is cold?

 

 

While RPM's will obviously exacerbate the problem, the real issue is a combination of the design, plus the efforts by all of the OEM's to convince people that it is perfectly fine to start a dead cold engine in the winter and then just drive off.  While the OEM's want to max out the CAFE potential by not allowing the car to idle a bit to warm up, the pistons and the cylinders expand under heat at differing rates, the DFI tends it increase cylinder "wash" when cold, and the "preferred" oil is low in film strength.   Not a good combination for longevity.  

[questforbalance]

Well, just to report. After much research I found an independent Porsche mechanic in Yonkers, New York. ASE certified and Porsche factory trained. He did work for friends.  He checked out my car and found that cylinders 4, 5 and 6 were scored. Engine needs a rebuild. He will send heads out west somewhere to have the cylinders bored and nickie sleeves put in all six cylinders, then rebuild engine. Total $15,000 and will have to wait for the car about two months depending on how busy the machine shop is out west. Holy crap!!! Is this car worth it?!?!?! 100,000,C4s with tiptronic. Any comments?? I am thinking about selling the car as is and just buying a new jap car. Cheaper, not as much fun but certainly more reliable. Any thoughts? I need to make a decision this weekend. I really like the car and am attempted to go through with the rebuild, but concern. This car is a money hog.

[aztecw]

I am curios as to what your decision will be, and what others opinions are. I am in similar situation, 99 996 89,000 with the right bank in need of some major work. I haven't had the engine taken apart yet but there is coolant coming from one side of the exhaust. Mechanic wants 2k to take a look. I am not sure what I should do.

[Ahsai]

Well, just to report. After much research I found an independent Porsche mechanic in Yonkers, New York. ASE certified and Porsche factory trained. He did work for friends.  He checked out my car and found that cylinders 4, 5 and 6 were scored. Engine needs a rebuild. He will send heads out west somewhere to have the cylinders bored and nickie sleeves put in all six cylinders, then rebuild engine. Total $15,000 and will have to wait for the car about two months depending on how busy the machine shop is out west. Holy crap!!! Is this car worth it?!?!?! 100,000,C4s with tiptronic. Any comments?? I am thinking about selling the car as is and just buying a new jap car. Cheaper, not as much fun but certainly more reliable. Any thoughts? I need to make a decision this weekend. I really like the car and am attempted to go through with the rebuild, but concern. This car is a money hog.

Suppose your car is worth $5k as a roller and $20k after you fixed it. That is break even. So either you shell out $15k to keep it with a rebuild engine or sell the roller and start fresh. Either is painful but I think fixing it only makes sense if you plan to keep it for a long time.

[questforbalance]

Hello Ahsai, I have replaced and repaired many parts on this car. Things that needed repairs or replacement and things that did not need it. Before this incident, I was planning on keeping this car for a long time. The thing is, and I wonder what others think, what else can go wrong? Below is a list of things/parts I have repaired or replaced in the two years I have owned it:

-two front radiators

-coolant reservoir

-front drive axle gaskets

-oil fill tube

-brake rotors, pads and sensors

-ECT sensor

-IMS bearing

-rear main seal

-air/oil separator (what a PITA of a job that was)

-front seat pad

-Transmission rebuild, gaskets replaced

-catalytic converters with Fabspeed sport cats (because original cats went bad. Now I know why they went bad)

 

This car is an everyday driver, so reliability is critical. I am curious to hear from others who use their cars as everyday drivers.

[Ahsai]

I can think of the following for a 10+ yr/100k+ car, not including what you have replaced already.

Water pump

Guibo disc

Spark plugs and coils

O2 sensors

Alternator

Starter

Starter cable

Headlight switch

Ignition switch

Suspension components

Door lock actuator

SAI pump

Evap valves

Vacuum reservoir

Idle pulleys

Serpentine belt

All are DIYable and most likely can be done within a day or wkend.

Edited April 19, 2015 by Ahsai

[JFP in PA]

Well, just to report. After much research I found an independent Porsche mechanic in Yonkers, New York. ASE certified and Porsche factory trained. He did work for friends.  He checked out my car and found that cylinders 4, 5 and 6 were scored. Engine needs a rebuild. He will send heads out west somewhere to have the cylinders bored and nickie sleeves put in all six cylinders, then rebuild engine. Total $15,000 and will have to wait for the car about two months depending on how busy the machine shop is out west. Holy crap!!! Is this car worth it?!?!?! 100,000,C4s with tiptronic. Any comments?? I am thinking about selling the car as is and just buying a new jap car. Cheaper, not as much fun but certainly more reliable. Any thoughts? I need to make a decision this weekend. I really like the car and am attempted to go through with the rebuild, but concern. This car is a money hog.

 

You are at an obvious cusp point many owners reach:  Do I reinvest in a car that I enjoy daily in order to continue with it, or do I fold and move on.  As Ahsai pointed out, the answer to that question depends upon how long you intend to keep the car.  Unfortunately, you are the only person that can balance all the factors involved and make a decision the best matches your situation.

[AWDGuy]

that sucks man. looks like i was right with my 1st post. :(

15k for a properly rebuild motor is an amazing price. I took my motor out and disassembled myself and still sitting in the $10k range.

I really love the car hence my decision to rebuild.

Edited April 20, 2015 by AWDGuy

[questforbalance]

Hello AWDGuy. So after much angst, we decided to buy a new SUV and garage the car. we just love our C4S and cannot part with it. I had a few conversations with Jake Raby, a few Porsche mechanics and just could not part with so much money to rebuild the engine at this time. So the car will sit in our garage until which time we save up enough to have it reconstructed. I will either go with Jake Raby at $20,000 or a very reputable Porsche mechanic shop in New Jersey who can also reconstruct it. Or maybe I will try to do it myself. But maybe I will first buy a junk Porsche engine and practice with it. Anyone know where I can find a junk Porsche engine to practice with? Hey AWDGuy, did you finish your engine reconstruction?

[Ahsai]

There's a new option now, put together by Jake and Charles. Don't know the price point yet but it will be cheaper than Jake's engines for sure.

http://rennlist.com/forums/996-forum/870302-rnd-engines-direct-replacement-engine-exchange-program-company-introduction.html

[JFP in PA]

Potential buyers need to be aware that the RND engine program are not Jake prepared engines, but basically quality stock rebuilds with an LN IMS update and better cylinders (LN Nickies), but otherwise stock with quick delivery and a core exchange program.  This interesting program should help those with dead or dying engines by offering a quicker way to obtain and quality rebuilt engine and at a lower price point than one of Jake's ten-tenth's units, which also require a much longer lead time.  This is also not a retail level program (read they do not sell to the public), but one that supplies engines to shops that do business with the supplier, SSF.

[AWDGuy]

Hey AWDGuy, did you finish your engine reconstruction?

junked engines still sell for 2-3k. that's a lot of money.

I haven't gotten my cases back from LN Engineering yet. they have 6-8 weeks turn around and my cases haven't even been there for 4 yet so it will not be until mid June until I get started on the Re assembly.