Had a spirited drive to work the other day and when I pulled up to the light the Cayenne started running pretty rough. Got it home and started puling codes for misfires.

Upon inspection I found three cracked coils and replaced all 8. Minor improvement but still pulling a code for cyl 2 misfire. I break the the handy ol' compression tester and viola, 0 lbs. on #2. All others were at 120-130 cold.

Pulled the intake manifold and the passenger side valve cover. Did a leakdown test and inspected the valve's. Made sure that all the valves were springing back up to the same height, they were. Intake valves hold liquid behind them, no leaks there. Seems that #2 will hold no pressure at all. So I guess I have a head gasket issue but there are no bubbles or combustion gas in the coolant. So either the problem is in the ring package or the head gasket between adjacent cylinders.

At this point I think I am just going to pull the motor. If anybody with any experience wants to chime in great!
I've seen online that its possible to pull the motor from the front without dropping the subframe. I even heard that the heads can be pulled while in the car. Any votes as to whether I should pull the pass side head in the car or just pull the engine and plan on rebuilding the short block.

Anyone with any suggestion or insight please feel free to chime in. I see that flat 6 innovations does cylinder sleeving and CTT engines so thinking about bumping the displacement and sleeving the block so I never have to worry again. Im even very leary about putting in a new short block from Porsche.

 

That really sucks. Good luck with the diagnosis.

 

Sorry to hear about the problem. What do you think caused it? Could your experimentation with e85 have caused a problem? Just curious...

 

I would say yes, e85 eats up standard seals and gaskets.

 

E85 on a turbo? Was any remapping of the fuel maps done? If not I could imagine something bad happening in a cylinder (ring cracked or a holed piston, hopefully not lost alumisil liner on the cylinder - that's new engine time.)

 

I'l be pulling the engine in the next couple of days, once I get the head off I will have a diagnosis. I wasn't running more than the normal 10% at the time but after doing some research it is possible that the e85 caused some carbon to dislodge and scuff the cylinder wall. The Cayenne Turbo block is Alusil and not plated in any way. Though, it is delicate.

Id be surprised if it were only a head gasket and still there is the cause of that to address, so I will be rebuilding the motor while I am in there.

Looks like I have a couple of options:

1. Used engine. -$5k plus and still on a time bomb, dont really want to do this twice.
2. New short block from porsche. -$5k, new, but still a fragile design.
3. Sleeve all the cylinders and throw some different pistons in.
4. Sleeve and saimese all the cylinders, overbore and stroke.

The Cayenne engine really has you by the ***** and no matter which way you go the cost are very high considering the value of the vehicle.
Then again, its my Cayenne and I really dont want anything else.
Im not arguing with Porsche engineering, but I like the idea of the 4.5 with more of a classic approach to the cylinder. For me and my future intentions, a ductile iron sleeve/alum piston/ taper face ring combo is going to serve me better and I know that it will be durable for a long time.

For anybody that is interested, Jake Raby is starting to develop the Cayenne engine and has gone to 5.1l & now 5.3l with this engine.

He said "Today the only Porsche engine that impresses me is the Cayenne, other than cylinder issues (stupid damn lokisil in the non TT versions) the Cayenne engine is built like a tank with serious heavy duty parts that do not break. I am currently designing a big bore, 5.3L Cayenne based engine that should hold together with over 1,000HP of output." over on Rennlist-

I'm going to give him a call after the holidays and see what he is willing to share with me since I'm pretty sure I cant afford or wait for his services. At this point I am leaning towards option #3.

 

Here is a link to some cool pics of Jake Rabys Cayenne Engine.

https://www.facebook.com/media/set/?...4914693&type=3

 

I sent my Boxster S too him to have some work done, and you will not be disappointed. He has a great shop and really cares about your vehicle. My car runs better than ever!

 

Engine is out of the Cayenne and I can answer any questions that any of you may have about that or things that you may not have access to or be able to see while it is in there.

On a side note, both turbine housings were cracked on the inside and wastegate diaphrams were a bit leaky. Shaft end play is not noticeable feeling by hand. Both primary cats are plugging up with what looks like ash from oil burning.

You can not buy just the turbine housing for the IHI rfh5, and parts are tough to get. After speaking with several turbo pro's they all seem to hate the IHI turbos. Since I can get new Performance Garrets for the cost of new IHI's, I am leaning towards a turbo upgrade. I do know that a certain tuner that offers a turbo upgrade says that they installed Garrett gt2860 cartridges into the IHI housings. Problem with changing turbine or compressor housings is the exhaust manifold outlet to turbo is a round hole, the turbine to primary cat is a one-off design, and the compressor outlet makes a 90 deg. to the front of the car. These turbos really are small and space is very tight.

 

Looks like I found the problem! All the cylinders look amazing and absolutely zero evidence of the valve striking the piston. The edge of the break in the valve head is all crusty too like it may have been cracked for some time before it broke off. I didnt find the piece in the primary cat and from an outer inspection the turbine wheel seems to be intact.

I purchased the vehicle as a one-owner with 65k on the clock. I now have 170k. Upon dissasembly I noticed that the timing chain guides and oil pump chain guides are all in amazing condition as well, barely worn. There is also blue sealant on the chain cover that I did not find anywhere else. Makes you say hmmmmm...

 

no pieces found make me think its been burned but, though hard to tell in the pic, it does look like it failed from a crack.

 

What brand and type of oil have you been using since ownership to have your internals in such a fine state?

 

I use Shell Rotella t6 5-40 sunthetic. I do not really know that the internals are in fine shape. I just thought that the cylinders looked great and the chain guides didn't seem to have 170k miles in wear, that they looked great for the 100k abusive miles I have put in!

 

All considering, why not upgrade to the OEM turbochargers on the 4.8 Cayenne? They are much more respected by turbo tuners since they are Mitsubishi TD04-18T and you maybe able to find a set used. These turbos are able to push much more CFM than the 4.5 IHI turbos and and will fit in the same place. You should be able to get OEM 4.8 lines that will most likely just bolt in place.

These are the same turbos used in a variety of high performance cars, including the WRX and older 3000GTs.

I have thought about replacing my turbochargers for added performance, but was going to drop the subframe. I think book says 38 hours labor. I have only seen one other person go from the front and remove the front carrier to remove the engine with a standard engine hoist.

• How many hours did it take to remove?
• Did you remove the engine with the transmission?
• Can you please post any pics that may have been taken?

 

I am looking into the parts diagrams to see if that is possible with the 4.8 turbos. There is not much data out there to determine if the manifold is the same, compressor/turbine-inlets/outlets geometry differences. Ideally, that would be the way to go. Surprisingly there are many differences between the 4.5 & 4.8. The heads are different and the crankcase is 20mm shorter. I also noticed that for the 4.8 Porsche went to a bi-mettalic valve instead of the standard sodium filled in the 4.5. A while back I posted up a pdf titled "after sales training" that has a ton of info.

One particular tuner that offers a turbo upgrade states right on the description that they are gt700 cartridges simply installed into the ihi housing. After speaking with them directly Im pretty sure it is just a garrett gt2860rs cartridge machined in. Which would make sense. We know from the scroll products turbo upgrade ( rhf55 cartride in the rhf5 housing) that a 60mm compressor wheel WILL fit. The gt28 supports around 350 hp each so that would make sense. Problem is both my turbine housings are cracked and ihi does not sell just the turbine housing per my investigating. Plus the IHI turbos have a low nickel content on the housings and just generally arent that great.

Another option I thought of was just having a set of tubular manifolds made with a flange for the t-series. But then I would have to adapt the intake piping and make new downpipes. The ihi turbos have the compressor outlet turned 90deg. to the front where as most aftermarket turbos simply come off the side. I'm not sure that there is enough room to make that connection work. Right now im at a tossup of finding some ihi cores or turbine housings vs. garrett turbos and all the connections. The price point is going to be very close with the latter making a lot more fab work for myself. A lot will depend on the condition of my short block when I tear it down.

Update: Porsche does not sell just a short block anymore.
While alusil blocks can be bored and honed witha special procedure, finding a machinist that will do it, much less do it right is another story.
LN engineering will sleeve a short block for you for $4400 with their nickies sleeves. Another 12-1500 for a set of je pistons and 200 for rings plus new rod bolts, main bolts and head bolts would put me close to 7k with shipping.
The stock rods cannot be resized. there are forged as a one-piece at the factory and then the big end is cracked in half. The resulting fracture is what locates the two halves. If you were to machine out that fracture to make the big end smaller the caps would then walk around.
I found one other place in the country that was excited and confident to sleeve my block with darton sleeves and has the capabilty to do it right. VAC motorsports specializes in BMW and they have been building the BMW alusil blocks for a while. Cost is about the same as the LN engineering with the drawback of a ductile iron sleeve in an alum. block.

I would guess that working slowly over a couple days( it was the holidays!) it took me 12 hours to get the engine out. Im sorry, I did not take any pics at the time but everything is apart now so no prob. Any kind of writeup just was not in the cards on this one.

What I did was take the entire front end of the car off. The bumper, bumper support, radiator support, radiator/coolers/fans. I intended to just take the engine out, but its really a simple design and meant for the whole assembly to come out together. It was really easy for the most part. There really are a minimum of connections to drop the engine, subframe, tranny, transfer case, front air shocks and suspension all as one unit so that is what I did. Other than being insanely heavy it was easy. I just used some lifting straps kind of like seat belt material and wrapped them around the subframe and dropped it all down and then pulled out the front. I have a height consideration to deal with as I am doing this in a two car garage. Anybody that does not have a four post lift will have to do it this way as you will not have clearance to get the vehicle high enough to slide the assembly out past the front bumper/ rad supp. As a side note, when it came time to set it all down it was very cumbersome and tricky. Like I said that whole assembly is insanely heavy and my two ton hoist was struggling on the 1 ton setting. I think if your just doing turbos then just hook up the hoist, drop it straight down for access, do your work, and lift it straight up back into position. I,ve seen your work Renn man and I don't think you would have a problem.

The tuner that does the 700hp conversion and I had a frank conversation as I made it clear I was not interested in soliciting his services, just having some shop talk and he was extremely nice. He told me that they got their cayenne new, did the upgrade and then raped it for 160k miles before selling and the Cayenne held up well at that level with no issues. So, that is nice to know. Porsche really put a lot of work into the Cayenne and the engine is a work of art and way overbuilt in my opinion. This is an incredible vehicle.

Is this a DIY at home? I guess so But definitly extreme and Im sure much much easier in a shop.