My First Porsche - 03 986 "blown engine"
 

Greetings,

This is my first Porsche and my first complete tear down. I am likely in way over my head here and thought I would share my experiences during the process.

Suspect blown engine. I have service records dating back to 03 and all by the same Porsche dealer. I was told "large cloud of smoke from exhaust and then engine stopped and would not restart".

I'm in the process of taking it apart and found quite a bit of oil in both exhaust manifolds and some fresh oil on the outside of the engine. I can see all valves through exhaust ports. Also looks like there has been a leak for a while as the trans is covered with dirt/oil. Going to scope the cylinders before taking off the transmission to check IMS bearing.

More to come with pictures!

~tehward


https://cimg8.ibsrv.net/gimg/rennlis...8e3501fe82.jpg

Look forward to seeing you progress. Good luck.

The is a guy on another forum that is just finishing up his rebuild.

http://986forum.com/forums/diy-project-guides/

Curious to know what condition your AOS is in.

Update#1

Just finished scoping the cylinders...pretty hard to see anything as everything is caked in burnt oil. I do not see any marks on the pistons and no debris other than burnt oil.

Pass Side

https://cimg1.ibsrv.net/gimg/rennlis...b679b39662.jpg

Spark Plug

https://cimg4.ibsrv.net/gimg/rennlis...fc3dd60b65.jpg

Drivers Side Air Box

https://cimg6.ibsrv.net/gimg/rennlis...ebcee8640f.jpg


I have been thinking AOS...

I'm looking for a way to bypass it now and see if I can roll the engine over manually without trying to start it or by removing the transmission.

after pulling the plugs put a wrench on the crankshaft pulley bolt and see if the engine is locked up. .i say this because you are not clear on .....stopped and would not restart....if you are lottery lucky you just might have bought a car that was misdiagnosed as a blown engine.aos/plugs a few other do dads and you are in. or you are cursed and the engine is not repairable. be advised if you need to replace the motor some rebuilders wont give you credit if you disassemble your motor.

Why not?

Update#2

Engine turns freely.

Cleaned spark plugs.

Left exhaust off.

Unhooked AOS from intake and blocked intake port and added filter to AOS line from unit(temp).

Started on 1st try. I let it run for about 15secs then had to vacate garage due to oil burn off.

Next step if the motor can be turned over.

There are 4 green plugs on the heads 2 on the passenger side on the front of the motor this is the number 1 # bank then the other 2 are on the driver side head the transmission side which is the #2 bank. These cover the ends of the camshafts each has a 1/8" notch in them which is slightly offset. This makes one half the split thicker then the other one.

Using the Bolt on the main belt pulley turn the motor over clockwise as you face the motor through the access panel in the passenger compartment. (only ever clockwise). There s a notch on the back lip of the pulley align it to the TDC line on the motor block it at about 1:00. There is a teardrop hole in the pulley, put a 5/16" or 8mm bolt through the hole and the motor block.

Next look into each of the 4 cam seal hole the notch in the cams should all align to the seam between the valve cover and the head. Also on one head the heavy half of the lobe should be toward the head. the other side it should be away from the head. If it passes this check the motor is most likely good and you have a b.ad AOS. If any one does not align then you probably have a bad motor with a failed IMS bearing

If the above looks good should I still remove the trans and check the IMS bearing for play? There was a clutch replacement not long ago...would an IMS check be part of that maintenance? I will need to order tools to remove the trans bolts and CV joints. This is a 2.7 and has over 200k on it.

Thanks everyone for your help and support!

Update#3

AOS is indeed at least part of the problem...with it all hooked up it sucks oil into the intake when turning the engine over slowly.

Inspected the oil filter and cannot find any trace of metal that I can discern.

Topped of oil.

Began cleaning oil off of engine and trans.

Consider your self fortunate.

Common problem and common mistake.

I had someone sell me one just like it.
Even after I told him it might just be an AOS issue and $100 part.

They wanted nothing of it. I fixed it, did the Ims just because, then sold it to the neighbors down the street and the family just passes it from kid to kid driving to highschool year after year.

See it just about every day :-)

That must have been 5 years ago!

Mike

If this engine ends up ok you can consider yourself lucky that there was no serious damage due to hydro-locking of the pistons with all that oil going into the engine.

It's alive and runs...now to decide what to do with it...

Over all the car is in very good shape. This car was serviced where it was bought over the last 12 years even the oil changes.

-Yearly inspections
-Engine has never been opened
-Couple of clutches over the years
-Alternator recently replaced
-AOS replaced twice, now a third time
-Break pads and sensors a quite a few times

I bought it with the idea to do an engine swap down the road but I'm not sure if that's the route I want to take.

I'm going to have to do something at some point with 200k on the clock.

Do I really want to drop 10-15k into a Boxster? I have never even driven a Boxster before. Maybe I need to put it back together and go for a drive to see what it's all about and then decide. I currently drive a modifed WRX and a stock BRZ.

Opinions are welcome!

Put it back together, drive it a while and see what you think. If you don't like it I am sure you could sell it and pocket a nice profit.

The Boxster will be very different than the WRX. It will be interesting to see what you think of it compared to the BRZ.

if i were you i would not push my luck. drive it easy but with a for sale sign on it.flip it and look for a 09 up po if you think you really need one. either way enjoy the profit

Very nice. I had this happen to a 2004 996c4s. Bought it "needing engine" for $12k. Pulled plugs and let it drain. Replaced the aos. Did the ims and rear main. That was almost a year ago and drives great still. My feeling is if it was a hard enough lockup to case a rod issue it would surface very very quickly. I'm just going to drive it and enjoy it. Why not do the same?