Boxster rescue problems

[bagpiperse]

Hi All,

I bought Boxster (2000 base) from my neighbor for $50. He reported that the car overheated about 18 months ago and he parked it and abandoned it. He denied that the car was showing performance problems when he parked it in his driveway, other than overheating and smoke coming from the engine compartment. I have no reason not to believe him, as he wasn't trying to make money on the sale (he sold me the car for $50) and seems like a pretty reasonable guy. I decided to take on the project to see if I could get the car working again. Here is what I have done and here are the new problems:

I drained and replaced the oil and filter. I did not see any coolant in the oil (or metal).
I put in a new battery.
I drained the gas tank and put in ~5 gallons of high octane gas.
I changed the fuel filter.
I did not find any obvious coolant leaks (the coolant volume was still ok) except there was some corrosion around the water pump, apparently coming out of the bearing seal, and some corrosion on the engine block where the coolant appeared to have been spraying/leaking. I thus changed the water pump and put a new low temp thermostat. The water pump was otherwise intact. However, when I replaced the thermostat there was a piece of plastic that matched the impeller blade of the intact old and new water pumps, indicating a previous water pump failure with impeller breakage. I added new coolant. I did not see any oil in the drained coolant, or in the coolant reservoir.

Once I did all that, I left the serpentine belt off, removed the coils and spark plugs and turned the engine over by hand, clockwise. I then re-assembled everything and started the engine. There was some light smoking on startup, which went away. I ran the engine for a while to get it hot and to see if it would overheat. The engine ran fine and did not overheat, and I checked the coolant level and added coolant at times with the breather valve open. The engine did put out some white smoke occasionally as I ran it for a while a various rpm. Since the engine seemed to run fine, with some light occasional smoking, I decided to move forward and I bought 4 new Michelin Pilot sport tires, and an aftermarket air oil separator. I installed the AOS today, hoping that this would solve the smoking issue, and hoping that I could try out the new Michelins.

First problem: when I jacked the car up oil drained out of the airbox. This was the first time that I noticed this issue (the rear of the car was jacked up several times while I was working on it and no oil came out of the airbox.

Second problem: at startup with the new AOS, a VERY LARGE amount of white smoke came out of the car (like I have never seen). I turned the car off and got out of my garage before I suffocated. Neighbors came out to see what was going on a passers by looked concerned. I waited a while for the smoke to clear, checked the 2 snap connections to the AOS to make sure that they were secure, then I started the car again.

There was a large amount of white smoke again, and this time I heard funny sounds, possibly coming from the secondary air pump, but I am not sure. I turned the car off quickly out of concern for the engine and also my breathing.

So, I am confused... Why did the car run mostly good before I changed the AOS. I may have filled the oil too quickly when I changed it, but the car sat for a few weeks from the time that I changed the oil and when I first started it after doing all the other work? Why did oil come out of the air filter after first startup? I checked the airbox after second start up and there is some residual oil there, but nothing like what poured out after first startup. The engine is very dirty with oil on the intake and heads, etc. etc. My neighbor denied that the car had performance problems before it overheated. There was a fair amount of oil in some of the spark plug tubes, so I bought new tubes/seals, and was hoping that alot of the oil on the engine was coming from the leaky spark plug tube seals.

I am now afraid to start the car again. I had never planned on taking this car to the shop, as paying someone to work on my car is not in my budget (my wife and I work in the public schools here in New Mexico :ah. I have about $1700 in the car now. Cosmetically it has seen better days. I was planning on driving it after I got is running, and didn't want to put much money in trying to get it going.

Admitting that I can't affort a Porsche may not be too popular on this forum, but I enjoy problem-solving and working on cars. I know that there is always a risk of these engines failing, but other than a non-preventable failure, I was thinking that I could work on the car myself and maybe keep it going with proper maintenance.

Please let me know if you have any ideas why the car is smoking so badly compared to first start up and after I replaced the AOS. I had a hell of a time getting the new AOS in, but I think that I got is right ()

Thanks in advance for your insights.

Scott

[ike84]

Congrats on the steal! That's probably the cheapest a running boxster has ever sold for?

Oil in the intake is the classic sign of a bad aos. Two questions

The oil draining from the airbox - did this happen before you installed the new aos or after?

What brand aos did you install?

It is possible that the old aos flooded the intake with oil and you are seeing the remnants of this. I would disassemble the intake tubing from the airbox to the TB, remove the TB and intake plenum, and try to clean everything as well as possible. (Be careful with the maf) Don't remove the runners - that's a very time consuming effort and you can get your hand in there easily enough with the plenum off.

It is also possible that your new aos failed on first startup. It has happened before.

I will admit though, I've not heard of oil dining all the way back to the airbox. Are you sure of this? It's there oil on the filter? You can have a cracked fillerl tube neck that causes an impressive amount of oil spillage on top of the motor.

Last question - what does the smoke smell like? If it's sweet smelling it's coolant. If it's putrid it's oil. This is quite important as it will take you down two very diagnostic pathways...

Best of luck, keep us posted!

Sent from my SO-02K using Tapatalk

[Stl-986]

Chances are that if you used an aftermarket AOS it's bad, even brand new. Been there. Also, make sure you got the rubber accordian tube on & secure. You will need a mirror for this mots likely.

Best thing to do would be to get the oil in the intake system cleaned out. Use blue paper towels for this. spray the towels with carb cleaner and then clean things. Do it multiple times Clean the plenum as well.

Very much doubt you had oil in the airbox as that would have to make it's way past the TB and the air filter.

Speaking of air filter, what kind is it? If it is a K&N....put it in the trash and get a paper one.

Also check for codes.

You didn't say, but did you actually replace the water pump or just put the other one back in after replacing the thermostat? If you didn't replace it, do it now and get one with a metal impeller not plastic. These are known to fail and cause many people to think the car overheated (could very well overheat). Each and cheap fix.

Worse case, even if you have to replace the engine, you only paid $50 for the car so a replacement engine would still have you well ahead. Doubt you need to replace it though. Just sounds like a bad AOS and a car that has been sitting for a long time.

[Stl-986]

Oh, another thing.

DONT RUN THE ENGINE WITHOUT THE BELT ON!!!! That is how the WP circulates coolant. It's ok to do this for about 30 seconds, but that is about it.

[bagpiperse]

Hi All,

First off, thanks for the very quick replies. To address the questions:

I forgot to mention that after I hand cranked the engine, I cranked it a few times (brief spurts) with the starter and without the coils/plugs in to get oil distributed. I never started the engine or ran it without the serpentine belt.

I replaced the water pump with a new aftermarket pump with the plastic impeller. I see no leaking from the water pump or thermostat install (my first ever on any car). The car did not overheat the first startup, and I ran it for a while (long enough for coolant to circulate...)

In regards to the oil in the airbox. There was no oil leaking from the car before the first start up. After the first round of work (waterpump, thermostat, fuel filter), I jacked the rear of the car up to put in the new AOS. A somewhat large quantity of oil started leaking from the car, which was a first. So the oil leaking from the airbox was after first start up (after the car sat for 2 more weeks) and before I replaced the AOS.
As I noted earlier, the engine and intake are very dirty with oil, but there was not a spot of oil on my neighbor's driveway, where he parked the car for years, and where the car sat for 18 months. I was concerned and bummed about the oil and it was definitely coming out of the bottom of the airbox (there is a drain tube there). I removed the air filter and saw the oil in the bottom of the box (and then removed what I could).

I am pretty sure the air filter is paper....It was not too dirty....with no oil stains (???)

I forgot to mention that at first start up there were no codes at all! I don't know what was going on at second start up, as I just needed to get the hell out of the car!

The smoke is definitely oil, and not coolant.

So, I have been reading alot on various forums to help me along the way. I guess oil in the airbox is not unheard of. I believe that I put the correct amount of oil in when I changed the oil. I have checked it a few times and it was good.

Thanks for your thoughts about the AOS. I bought an aftermarket URO brand, which had good ratings on Amazon. The bottom accordion tube with the clip went on fairly easily, once I unbolted the sensor that is in the way, and once I actually compressed the ring/clip enough to push the accordion tube onto the seat. The aftermarket AOS tube would not go all the way into the engine block, no matter how hard I pushed. I hate to admit that I worked on the AOS for more than 8 hours trying to get it back together....The lower clip also was extremely difficult to reattach....

So, based on your feedback, I am thinking that the AOS I got was bad or failed immediately. Perhaps I can return it. I will by the Porsche part this time. I will also follow your advice and take apart the intake system as you described and clean it up.

Thanks again. I am really wanting to drive this car! I am heading out of town for a couple of weeks to visit colleges/universities with my daughter, so I have to let the car set for a couple more weeks before I can do the new work. I'll post an update when I get to that point. I can't wait to remove and put in another AOS (although it should be a piece of cake this time!)

[blue62]

If you have "white" exhaust with little to no smell that is steam.
So a blown head gasket or coolant getting into the cylinders.

If you have "blueish white" exhaust that is excess oil getting into the cylinders.
From what you describe I think it is probably an AOS issue.
And that the smoke was most likely "blueish white"

You could pull a spark plug or two and look at them.
If the smoke is caused by oil the plugs will be blackish or oil fouled.
If the smoke was caused by coolant the plugs will be very clean almost unused looking.


You could buy a coolant system testing kit and pressure test the coolant system.
Testing the coolant system would either eliminate the coolant system as part of the smoking issue.
Or confirm it as part of the issue.
Harbour freight has them for around $90.00

But looking at a few of the spark plugs should tell you if the smoke was caused by oil or coolant.

[Gilles]

Originally Posted by blue62

If you have "white" exhaust with little to no smell that is steam. So a blown head gasket or coolant getting into the cylinders.

Blue, since he mentioned that he removed a piece of a plastic impeller from the thermostat housing, there is a possibility that he has a cracked head :-(

[blue62]

Originally Posted by Gilles

Blue, since he mentioned that he removed a piece of a plastic impeller from the thermostat housing, there is a possibility that he has a cracked head :-(

Just about anything is possible until proven otherwise.
But the oil in the airfilter housing is most likely the cause of what the OP says is "white"
exhaust smoke. The "white" exhaust smoke is probably "blueish White" so I am leaning towards a bad AOS. You have to generate some extreme heat to crack a head so although possible I don't think it is probable that he has a cracked head.

[Stl-986]

Agree with Blue. The plastic impellers on any car are known to break/wear down. BWM & Jeeps use these and they all fail. AOS is the most likely issue and the car sitting for so long.

Best thing to do is to just replace the AOS, clean out everything, drain the oil, replace the filter and fill to the correct amount. Would really replace that new WP with one with a metal impeller, then drain & fill the coolant.

All in all should be under $300 in parts plus a day in the garage to do everything.

[blue62]

In 50+ years of dicking with cars I have never seen a head crack from over heating.
Warp yes.
Burn hell out of the valves yes.
When I have seen cracked heads it is from freezing.
Over doing it when Porting.
Or just a bad castings.
I have seen a few engines get so hot they seized up, but the heads were rebuildable.

[bagpiperse]

Thanks again for the responses. The smoke is bluish and is oil. In regards to the spark plug check: yes the plugs do look rather fouled. I plan on replacing those when I do the spark plug tubes seals. So, the plan right now is to order an OEM air oil separator, install that, clean out the intake system and give it another go. Thanks again. Your comments and suggestions have been super-helpful. I think the old AOS was failing. I think the brand new aftermarket one failed completely!

Scott

[Boxstard]

I suspect a bad AOS out of the box… that’s the one thing you changed and run into massive smoke.

You should have read threads here about how aftermarket ones are bad…. reason why I spent extra on the OEM one while I often try to shop smart without paying Porsche tax. Buy one from FCP Euro and you can get a lifetime warranty if it ever fails again, which it will.

Failed AOS sucks (pun intended) oil out of the crankcase and flood air intake, not sure if that could have put oil in the air box but I guess it is possible. And cannot think of any other ways…

Quick and dirty check for functioning AOS, try removing the oil filler cap while engine is running, if you cannot twist it open then excessive vacuum meaning failed AOS. You should be able to remove it fairly easily with functioning AOS. This may not be easy to try, when it smokes right up…

Also if oil got in exhaust/ cat it may take a while to burn it all up. Not with my Boxster but I blew turbo before and it was my experience, took several miles to clear it up on my first drive after repair.

Hope new AOS does it and get the car back on the road where it belongs, good luck!

[moosport]

Like what others said. Use Porsche AOS. Clean out the oil from the C shaped hose before throttle body, throttle body and intake tubes. Pull one of the spark plugs. if there is oil on it, you can clean all with cleaner. The rest will burn off.

If its still smoking badly like before after all these work, you have oil in the cats. Try to find used cats.

[husker boxster]

Originally Posted by Stl-986

Would really replace that new WP with one with a metal impeller, then drain & fill the coolant.

While I generally agree with STl's advice 99% of the time, this will be the 1 time I disagree. If you have a metal impeller WP, as it ages and the shaft begins to wobble, the metal impeller will grind out the cavity as it will be the stronger metal in the equation. That will cause a sealing problem with the next WP and the reason why they come with plastic impellers - when the wobble begins, the plastic is the softer material and loses the rubbing battle. If it goes on for long, a chunk of the impeller breaks off.

It's considered a joke about the "lifetime" antifreeze in these cars because the WP fails before you have a chance to wear out the "lifetime" antifreeze. Water pumps are considered a consumable that should be replaced after a certain # of miles or yrs.

Blue's suggestion of a coolant pressure testing kit is a good one regardless if the smoke is from the AOS or not. Since there was a chunk lost on the wp, you need to test whether that caused an overheating issue.

[78F350]

I was hoping to avoid posting in this thread, but just a couple quick notes:
Cracked heads in model year 2000 986s seem to be more common than any other year. I do have an engine with a cracked head and a water pump impeller that broke down and deposited small pieces throughout the engine. A small piece of impeller blocking a coolant passage in the head makes a hot spot and cracks. You can have a crack without intermix.
http://986forum.com/forums/229328-post4.html
https://www.renntech.org/topic/47374-the-dreaded-oil-in-the-coolant/
https://www.callasrennsport.com/Blog/the-porsche-m96-engine-and-cracked-cylinder-heads

Not saying that this is a case of a cracked head, just adding to the discussion.
I'd be interested to see what a pressure test of the cooling system shows.

The best way to test an AOS is with a manometer checking the vacuum at the oil filler cap. Try a search like this: site:986forum.com manometer jfp aos in your favorite search engine and pick through a few threads.

If oil is getting into your intake from the AOS it is traveling through the tube that goes directly from the AOS to the intake (Duh). Check that tube for oil. Clean it. Run the car. Check that tube for oil. Is there significant oil in it again? It came from the AOS which is bad.

It can take a very long time to burn oil out of the exhaust system. These cars can put out a good puff of smoke on start up even with a healthy engine due to the flat design. If you really want to impress your neighbors and check if the smoke is just burning off residual oil, remove the exhaust and run it on open headers for a few minutes.

Good luck with it and let us know how things progress.

[911monty]

Let me take a wild a.. guess here. My thought is the vent tube to bank 2 possibly got cracked or broken when you changed the AOS (20 year old plastic does this if disturbed). This could cause the lack of sufficient vacuum in the crankcase causing the AOS to continue applying vacuum from the intake ( max intake vacuum at idle) and pulled oil into the system. Since you now have/had liquid in the intake be sure to pull the spark plugs and turn over before attempting to start again.

Oh and I second NOT using a metal impeller lathe.

[PLP]

If you have oil in CATs, can't you simply... burn it? Or push it through?

My thinking - on cold, start, let it run for maybe 20, 40 seconds. Shut down.
Let it cool off and repeat two or three times. Cold flow will not damage the cats (like excess heat from burning oil).
This way oil will be pushed out and not really burning on the cats.

Then, drive it and let the cats burn the rest.