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Old 09-27-2009, 05:43 PM   #1
Jake Raby
Engine Surgeon
 
Join Date: Aug 2008
Location: Cleveland GA USA
Posts: 2,425
Lessons learned: Buying a "used low mileage engine"(must read)

The story I am about to share here is still ongoing and continues to unfold. It rivals some of the stories that potential clients have shared with me over the last few months and because of that I felt that I should share it.

This is long and detailed, (17,881 characters) and lots can be learned from reading this post and being objective during the purchase of any "used" engine.

Before getting further into the story I'll state that with the knowledge of the M96 engine's internals being more manipulated these days these stories are becoming more wide spread. More and more people with limited knowledge and experience are making repairs and some of those "repairs" are being mis-advertised when engines are being sold. This is mostly occurring with, but is not limited to Porsche dismantlers. These dismantlers take the parts we'd throw away and take out of service, then patch engines up and sell them as "used" engines. They do this to limit their liability and so they can "play dumb" about the engine when it does fail. This is great for their profit, horrible for your wallet, your car and your morale.

So, here is the story, listen closely and don't let this happen to you. If it does no one will care and you'll lose your money like my client did, all that will happen is people passing the buck onto someone else.

One of my best clients who had the highest output 3.6 engine that we've completed to date experienced an engine failure due to the oil pump drive key. I posted that failure point elsewhere in this forum last week, if you'd like to see the pics. Till this point we'd never experienced this mode of failure, or heard of it and attribute it to the extreme throttle response that this engine had. As I type this a billet chromoly version of this drive is being machined to remedy this issue with all my future engines as we continue to make the M96 a thoroughbred.

This client wants to build a second Boxster next year anyway,(with a Stage IV Turbo FSI engine) so while I had his 3.6 apart on the bench enhancing it, he decided to buy a used engine for his track car to finish the season. Then next year he'd build a new car using this (second/ spare) engine as a platform for it.

I supported this decision and agreed to pay for the shipping of the engine that he'd buy to have it shipped to my facility and I also agreed to supply the necessary labor to install this engine at a seriously reduced cost, basically free as a sponsorship and to further the relationship/ friendship we'd built over the past year.

So, the client finds a "used low mileage" engine on Ebay. It was advertised by an individual that claimed it has 20XXX thousand miles on it and was pulled from a Boxster S that had been totalled in a front end crash. There was no mention that this engine had been repaired or that a wrench had even been put onto it's components after it left the factory, the seller disclosed that he had resealed the cam covers, lubed the valve train components and replaced the AOS to prepare it for conversion into his Boxster. He stated that he chose not to install this engine into his Boxster because he found a good deal on a broken 3.6 engine that he wanted to install into his car instead. The seller then stated it had come from a Porsche dismantler "In California".

The story seemed legit and the seller was someone I had some conversation with in the past, and he was a member of several forums that I frequent. We had no reason not to believe him and the pics of the engine illustrated it to be very clean, easily capable of being a 20,000 mile low mileage engine. The price was right, so my client asked the seller a series of questions and he was told what he wanted to hear so he fired off a cashiers check to the seller and we scheduled a pick up of the engine from it's mid-west location at my personal expense.

When the engine arrived I was impressed!! Very impressed! That was until I got within 5' of it and noticed that it was entirely too clean.. I looked closer and saw evidence that wrenches had been on the head bolts that were external to the cam covers. At that point I looked at the tabs on the head gaskets and could tell they were aftermarket and were also entirely too clean, without having any grit what so ever in their folds. This told me that someone had pulled the heads off this engine and that scared the heck out of me immediately because I know how few people can do this work correctly.

So, I call my client and start taking pictures. I instructed my team to complete a leak down test on the engine and start looking for other signs of intrusion by a foreign party.. At this point we used a borescope to peer inside the cylinders and inside the cam covers and everything appeared as advertised with the valve train well lubed and the AOS being brand new. The leak down test was successful and the worst cylinder showed 3% leak down, not bad for an engine with dry cylinders that hadn't been ran for a good while. The cylinder heads o the engine were too clean and basically appeared to be new and so did the hardware inside. Based on the parts used, we could only assume the labor was done by a competent and knowledgeable M96 technician. (WRONG read on!)

I contacted the client and told him that I was uneasy about status of the engine with the evidence that I had in hand. Since the story matched up pretty well and because he didn't have time before his next track event to have us pull the heads and etc we mutually decided to add a low temp T stat and an IMS retrofit bearing as preventives and hope that the story on the engine was true and the results would be positive as we didn't have time for any other hiccups.

So, I pull the IMS bearing and take a look inside, the IMS was starting to show wear but they all do, so I replaced it and peered inside with the borescope and found nothing else alarming inside.. We pulled the oil sump and cleaned the oil pick up tube and made a change to the scavenge oil return baffles/ de-foamers for track use
and sealed it back up.

After this was complete my team then installed the engine and beckoned me to start it up for the first time, as standard operating procedure. As soon as it fired it had 3 cylinders and threw a flashing CEL, I immediately knew what had happened! We pulled the codes from the ECU that reflected misfires on cylinders 4,5 and 6, exactly as I had suspected from the way the engine had ran.

At this point I knew we were ***ked because the person who had never set the cam timing on an M96 engine had been working on this engine. I knew this because this was the first mistake I ever made on an M96 when I had no direction and no no one to ask... It was clear that this person followed the instructions that came with the cam timing tools, but those directions do not include the fact that the engine must be rotated exactly 360* between setting the cam timing on the 1-3 bank and the 4-6 bank. This clearly illustrated how lost this person was, that really made us uneasy but luckily no damage was done and a cam timing alteration would be a time consuming, but effective means of repairing the issue. We had looked at the cam timing while we were being very objective about the engine before install, but since it was exactly 360* out and only on one bank nothing jumped out at us.. If it would have been 45, 90 or 120* out we would have seen it and it would have effected the leak down test- we would have found that.

So.. this happens on a Friday afternoon and now the engine is in the car.. I call my Wife and tell her that I'll be pulling a 3rd all nighter for the week and that she won't be seeing me till Sunday. I stay and finish the cam timing procedure to stay on track so my client can have the car delivered on time for his track event... I do this work without pulling the cam covers and risking another leak that we didn't have time to repair... I finish the night by sending the seller a nasty gram about the idiot that had been working on this engine, an engine that he maintained had NEVER BEEN REPAIRED... This "Phantom Mechanic" sucked even more than we had imagined... At this point my client assumes that the "phantom mechanic" was none other than the "seller" and I agreed, that it made sense because he was going to reassemble his own 3.6.

I pull this off and have the car back together for testing on Monday morning... The engine fires up and runs beautifully.. I pull the 3.6 flash from the ECU and within 3 runs I have cooked up a flash for this 3.2 that made 249 RWHP. Our worries had subsided and now it appears that our re-cam timing of the engine coupled to whatever these people did made a big power gain for the engine.. I continued to objectively dyno the engine while under full telemetry of my data logger and Dyno.. We monitored intermix and coolant levels and look for other signs of leakage- all was normal.

So at the end of the day I unstrap the car and take it home for a 83 mile round trip test drive before having my assistant, dean deliver the car back to it's Owner in time for the track day. My test drive is uneventful, the car was blistering fast and coolant temps never reach 190F. I get home, look under the car for leaks and check the coolant tank for intermix, still being very objective. I find nothing, all is well.. The next morning I drive the car to the shop, do one more dyno verification after the ECU had time to adapt to the engine and flash, the result was 251 RWHP and even more torque than the day before. This proved that there were no issues with the engine so we prepped it for shipping. It was clear that we had overcame the challenges and the client was going to make his track day.

The next day I had my assistant, Dean show up at 0400 to use my personal truck and the client's trailer to rendezvous with the client's friend at the 1/2 way point between my facility and the client's location. This resulted in a 600 mile drive for both parties, meeting in the middle and driving home. I didn't charge my client a dime for this for time or labor.

When the car arrived at its home location my client took it to the indy shop that has been maintaining the car for as long as he has owned it to have the alignment checked and the key switch replaced.. They did this work and took the car for a 35 mile test drive, they were also very impressed with the power and they did not see any leaks. They specifically checked for intermix in the coolant and the oil, and ZERO was present, they looked over our work and gave the car a clean bill of health...

Now is where it gets interesting:

The client shows up at their shop to grab the car.. He gets 10 miles down the road and a huge cloud of smoke emits from the exhaust system.. He limps back to the shop and they check the AOS, but it tests fine.. The problem is attributed to the accusump system engaging in a sharp corner and dumping oil into the engine under deceleration, (which has happened before) because there were no other symptoms and at that time there was no intermix and nothing wrong with the (new) AOS.

The client calls me and I concur with the Indy shop's account of the issue... He drives the car home with the accusump turned off with no recurrence of the issue.

The next day he drives several hours to the track, towing the car... He gets to the track and makes 1/3 of one lap before the engine does the same thing again..Huge billows of smoke out the exhaust system.

This time the accusump was still disabled, so there is no way the issue could have been the accusump...

The client calls me and I walk him through some checks.. He pulls off the hose leading from the AOS to the intake manifold and finds it filled with oil, like a failed AOS, but then he tells me the oil is really thick and milky, like a milkshake... At that point my stomach hit the floor and he loaded the car up and drove several hundred miles back home, dropping the car off at the Indy shop for another diagnosis... He was disgusted. I was disgusted. We had been lied to and we had both wasted hundreds of miles and thousands of dollars.

Very quickly the worst nightmare is confirmed, the coolant tank was filled with intermix... Something had failed big time.

So the next day I talk to the Indy shop and answer their 20 questions about the engine. This shop has been wanting to learn more about the M96, so this appears to be their opportunity, but at the cost of the client. I agreed to share tools and knowledge with them to support this issue and make it right, no matter what that may be (for free).

We agree that the intermix issues were probably emanating from the head gaskets and/ or a related issue like a slipped sleeve. At that point it was clear that the engine had an intermix issue that took it off the road prior to the failure and someone thought it was nothing more than a blown head gasket. They replaced the head gaskets, swapped out the heads with some that were damn near new castings and then set the cam timing- the only problem was that they did all of this the wrong way.. They basically sucked with their procedures and myself and my client have had to absorb this... Read on..

So... The Indy shop begins to pull off the cam covers and the heads looking for the culprit. My client (who is a Heart Surgeon) takes a day away from the office and heads down to photo document this procedure and the results. With the cams removed the head bolts were then started to be removed.... This took LESS THAN TEN FOOT POUNDS OF TORQUE to accomplish!!! The heart of the issue was that the "Phantom Mechanic" didn't freakin torque the head bolts correctly!!! What an idiot!! The head bolts were not even torqued to the point that they are prior to applying the additional "degrees" of torque specified for the head bolts.

By this point lots of mis-advertisements have occurred and lies have happened at some point, by someone. At this point its clear what the issue was and a round of emails have been well under way between the seller, the buyer and myself about what has happened and what should be done to make this right. I have maintained that this engine was not as advertised and was much more than just a used engine out of a salvaged car. No frontal collision would have required head gaskets to be replaced, heads not properly re-torqued and cam timing improperly set!

So.. The seller maintains that he has no responsibility for this engine, every email that has been sent to him has been partially responded to and the only info he gave us about the "salvage yard" that he sourced the engine from is that "He has called and emailed them with no luck". We have asked him to supply their contact info to us along with is invoice number to quantify that he did indeed purchase the engine from them, but he has not done this.
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