Steve Koller

Total newb here. I recently purchased a 2003 Boxster S with 35k miles on eBay. Instead of dropping $1400 to ship the car East, I flew out to Las Vegas and drove it back home to Vermont. The car performed flawlessly over these 3200 miles though I did notice a valve tick on the right bank that only showed up after the car had been driven until warm and disappeared when the engine was cold. The tick has stayed stable over 3500 miles. I brought the car into my local Porsche dealer on arriving home to get the oil changed and to have them give the car a once-over (and to give the valve tick a listen- I know boxer engines can be a bit clattery in general but I don't know how much clatter is too much). They reported that, according to the identifying marks, the oil scavenge pumps were reversed and that the car ought not be driven until this was corrected!

Is it possible to mistakenly reverse the oil scavenge pumps on this engine? If so, what possible consequences could result? Could this result in aerated oil and valve noise?

Thanks in advance for your help!

Macster

If the head oil extraction pumps installed in the wrong heads who knows what outcome would be?

The pumps are marked 1-3 for the #1 cylinder bank and 4-6 for the #2 cylinder. Have you looked at the extraction pump covers and verified the pumps are at least installed in the right heads?

Not sure if the pumps can be installed upside down. The drawing in the applicable section of the engine repair chapter shows each pump oriented a specific way. Even if the pumps had the right numbering for their cylinder bank if the pump cover was upside down that's probably (almost certainly) not right.

I'd make sure before I went any further the pumps are correct for where they are installed and installed right side up, the right way.

If the dealer's diagnosis that the pumps were installed incorrectly is valid and the car shouldn't be driven then I'm at a loss to explain the apparently trouble free 3200 miles you have managed to drive the car. This of course assumes the engine doesn't go BOOM the next engine start.

But, before I drove the car any more I'd at least verify the oil extraction pumps installed correctly.

If they're installed correctly that's one thing.

If not, then I think it would be advisable to upon removing them to first before re-installing them in teh right cyliner to examine them both for signs of any distress. If you find any... well that's another post. Too much to cover here.

Couple of questions: Is the oil fresh? Is the oil the right oil? If the oil has some miles on it, if the previous owner used the wrong oil, a lighter weight oil, the wrong type of oil, this can possibly account for the noise you hear.

Now the problem is that while you can change the oil -- unless you're sure the oil's fresh, the right oil, etc., -- this may not be the source of the noise.

Furthermore, the risk is when you start the engine after the oil change that whatever's been going on is going to get worse, much worse, and quickly, that the oil played no role in this problem.

IOWs, you may have used up all the luck you possess in that 3200 miles of driving.

There are many possible and more benign sources of engine noises besides even bad/wrong oil.

If the engine's been at recently then most anything is suspect. What services have been done recently?

Plugs? If so, a loose plug could be the cause of the noise.

Could be a noisy fuel injector.

A bad lifter.

A broken valve spring.

A burned valve. (This though and the valve spring would almost certainly have the check engine light on. Not 100% certain but in other cases I know the check engine light was on.)

One thing you can do is carefully remove the oil filter housing and dump out the oil into a clean drain pan and very carefully and with a bright light and a clean gloved hand finger the oil looking for any signs of debris. Run a magnet through to see if it comes away with any ferrous metal "dust" (or larger) pieces stuck to it.

If they're dark colored material that's one thing. If they're lighter in color, sort of shiny, it could be (could be) signs of a failing IMS bearing.

Knowing as accurately as possible where the noise is coming from helps too.
This requires listening with the benefit of a mechanic's stethescope.

At the back of the engine, down low, that's IMS bearing territory though it could be a failing cam chain tensioner or guide. At the front and down low the chain drive from the IMS to the other head's exhaust cam.

Higher up and at the back or further forward away from the engine/tranny joining, then a zero lash lifter mechanism becomes more likely.

If the noise sounds like it is coming from directly underneath the camshaft cover -- with you and a tech listening with a mech.'s stethescope -- this could be a broken valve spring or a cam lobe gone flat.

It might even be something arising from the serpentine belt drive or an exhaust gas leak.

All of these are serious, some more so than others obviously, but fixable but make diagnosis a bit scary cause the less you run the engine until you know what's wrong and have it properly fixed the better off you and the engine are.

In short, you need to verify and deal with the oil pump extraction diagnosis. If you don't trust the dealer you have to verify this yourself. If you trust the dealer have the pumps put right. If there is collateral damage this complicates things.

If the pumps are ok then you need a mechanic to listen to the engine and quickly pinpoint the location from where teh noise is coming.

Based knowing this then the next steps can be planned.

Sincerely,

Macster.

Steve Koller

Thanks for the very thorough and speedy reply!

The car is in at my local Porsche Dealer now and they will switch the oil scavenger pumps (after I confrm that the pump markings do, in fact, indicate a reversed installation--it is my understanding that cylinders 1-3 make up bank one and are located on the right or passenger side of the car). We'll see what they find after that.

The oil in the car was fresh when I picked it up but it did cross my mind that incorrect grade could contibute to the tap. The oil has just been changed by the dealer as well, just in case. The tapping noise is non-existant when the car is cold and only becomes noticeable when the engine gets fully up to operational temp. This seems to suggest that a "hard" mechanical defect like a bearing, spring or timing chain may be less likely (said the newb hopefully).

I'll report what we discover. Thanks again!

-Steve

budmanv24

Correct me if I am wrong, but the oil scavenger pumps ARE interchangeable/identical. The pump on the driver side/front of engine/cylinders 4-6 should have the arrows facing up. The other pump should have the arrows pointing down.

Macster

The drawings I saw have the pumps numbered 1-3 for the pump that fits in the front of the engine on the driver's side of engine and 4-6 for the one that fit in the other passenger side bank back behind the flywheel.

The drawings also indicated which way was "up".

My reference has this which only adds to the confusion:

Note: The extraction pumps on the cylinder heads are identical parts. Therefore the installation position or direction of rotation must be correct.

However there is then this:

For the 1-3 pump (flywheel side) the arrow for the direction of rotation or the marking 1-3 must face the crankcase.

For the 4-6 pump (pulley side) the arrow for the direction of rotation or the marking 4-6 must face the crankcase or the coolant temperature sensor.

Ignoring the 1st paragraph above which contains contradictory info the 2 following paragraphs indicate the pumps have specific locations.

With that info I believe they are not interchangeable.

Sincerely,

Macster.

budmanv24

I'm pretty sure all we've accomplished is to get this guy thouroughly confused. Are the scavenger pumps on the 97-99 986 and 996 engines different from the 03 boxster S?

I thought they all used the same pumps?

Macster

I don't have any info on the 2003 Boxster S engine. However, I believe it would be the same as the prior model year Boxster engines at least to the 2.5l engine and maybe even to the 2.5l engine.

The 2.5l and both the 2.7l and 3.2l engines, according to my info, have the same numbering/lettering installation cautions. I can't be sure, but I don't believe Porsche revised the extraction pumps for 2003 and later engines.

But if someone is dealing with a 2003 engine then he needs the info for that engine.

Sincerely,

Macster.

Zba

As far as the ticking when warm is concerned, it sounds like a lifter or possibly a clogged lifter bore. I have also had a tick when warm that ended up being a rod bearing, but lets not go there yet.
As far as scavenge pumps go-
bank 1 arrows on scavenge pump point down with "1-3" on side closest to head
bank 2 arrows point up with "4-6" on the side closest to the head.

To Macster, the pumps are marked with 1-3 on one side and 4-6 on the other, therefore it IS possible to install them incorrectly.
Hope this helps, GL
Chad

Macster

Not clear to me. The pumps are marked 1-3 for bank 1 and 4-6 for bank two, but one can still install the pumps incorrectly if he ignores the markings?

That is the pumps are interchangeable but they are not intended to be interchanged then?

Sincerely,

Macster.

Zba

Yes. Each pump has BOTH 1-3 and 4-6 stamped on them with arrows that point in the same direction. If you put the one pump in upside down, or on the other side with the markings in the opposite direction, then they will be positioned incorrectly. It's a little confusing without any pictures. When I get a pump I will post some pics up.
Chad

budmanv24

And I thought I was going crazy. Here's a pic of what both scavenger pumps look like.

So it's the same pump for both cylinder heads, only one goes onw ith the arrows facing up, and the other with them facing down.

Steve Koller

Update from the newb. My local Porsche dealer swapped the scavenger pumps back to spec and put in fresh Mobil 1. The tick is gone and has stayed gone after a couple hundred miles driving. Thanks for the feedback and advice--especially the picture of the pump which makes it clear to me the difficulty in describing/installing/diagnosing this issue. I think might owe that Porsche tech up at Automaster in Burlington, who diagnosed the problem, a very good cigar.

PS. What a great-driving car!

budmanv24

BTW, you car might of had 15w-50 in it. Originally this was one of the suggested oils by porsche and is more than likely in your manual. Due to sticking lifters porsche lowered their recommended oil weights and now they suggest you use a 0w-40 or 5w-40. This applies to all water-cooled porsches.