Loud tapping noise coming from top of engine
 

So I just changed my oil, not like I haven't done that before, and now there's a loud rapid tapping noise coming from the top of the engine near the intake manifolds I also changed the fuel filter in the process - is there a chance that a air bubble could have gotten stuck in the fuel system somehow? The noise wasn't happening before the oil change. Help!

Possibly a sticking lifter. I would try seafoam and see if it stops or reduces.

Then do another oil and filter change.

Mike

or sticky injector - sent some crud down the line when you changed the filter. ticking is typically - lifter, injector, piston slap.

Thank you so much for the replies. One more bit of information. After I changed the oil, added 9 gts of Mobil 1 5W30, it registered full on the dip stick, but the oil indicator light is still on. Why would that be?

hmmm.... Is that a low pressure light?

Is there something about the oil filter canister that has a filter bypass, hopefully that doesn't
bypass back to the sump. someone know for sure?

Mike

Seafoam will cause ticking after every piece of crud ends up clogging the lifters because
they have the smallest orifice in the engine.

I have a set of lifters for sale, cleaned & tested. $150

Wrong oil.

How many miles on the car/engine ? With this oil change did you change the weight of the oil from what you were previously using ? Have you driven the car to get it up to full operating temp's ? Any change in the noise when warmed up ? Any change when RPM's are increased ?

169K miles, although I had a major overhaul at 136K. No change in oil weight/type ever. I have used Mobil 1 5W30. No, I have not brought the car up to normal operating temperature yet. As the RPMs increase, the tempo of the tapping seems to increase accordingly. Although the noise level varies. I'm considering trying an oil additive such as Sea Foam, but haven't done so yet. Thoughts?

A 40 weight oil is specified for these engines and with your milage a 50 weight may be in order. Above all make sure it meets the Porsche A40 spec. There is stuff in oil beyond just its viscosity and meeting the A40 spec ensures those minimum needs are met. Like I said in your other thread I did try some Marvel Mystery Oil a couple of years back when I had a tapping I attributed to a lifter sticking and it went away after 100 miles. With a name like Marvel Mystery Oil it has to be good! Nice minty smell too.:)

Thank you!

What was done when the " major overhaul " was performed ? All was well after the overhaul noise wise ? I don't want to start an oil discussion but I run either 10w40 or 15w40 .

I had a cracked head. Got a new head, both heads machined. Nothing done to the mid section. Pretty much everything replaced that could be. I'll be switching to 10W40 I guess, thanks.

If you have not had the tapping noise or the low oil pressure indicator light at any time before the oil change something is amiss.
I am going to assume you have not. If you have please correct me.
Your low oil pressure indicator light is telling you that you have low oil pressure. The tapping noise (most likely lifters) is an indication of low oil pressure confirming a low oil pressure issue. Seafoam or marvel mystery oil is not going to remedy the problem.

If you do in fact have low oil pressure you need to find out why.

The bypass in the filter only opens to bypass the filter media. This is done to prevent bursting the filter housing from a plugged or restricted media and
to prevent oil starvation (It's better to send dirty oil to The engine instead of no oil).

There is however an oil pressure relief valve that limits oil pressure from the oil pump and bypasses back to the sump. It is located on the bottom of the engine. You should check this as there is an upgraded part and it has been known to fail. If it fails open you will experience low pressure.

Living in So Cal you need at least a 40W and possibly a 50 W oil.

911
great info on how the oil bypass in the filter housing works.
I was think that it was the main oil pressure relief valve.

Thanks so much for the helpful comments. I ordered a new oil filter canister with the hope that this may be a simple fix. I also took the step of adding the recommended amount of marvel mystery oil to the crankcase; just to see if there was any improvement. I have run the car only a few times thus far, and not on the road yet. Proceeding carefully, and a bit nervously. Seems to run fine at RPM's up to 3K. No audible tapping, no oil pressure light, no CEL. I plan to change oil and filter again, this time with a 10W40 or 20W50 oil (any suggestion which?). One question: the oil pressure relief valve you mentioned - is that inside the engine? Meaning, in order to check it or replace it, does the engine need to be removed and disassembled? Thanks again for the help.

Oil pressure relief location.

http://986forum.com/forums/new-member-introductions/72787-oil-pressure-relief-valve-2000-boxster-2-7l.html

Thank you. Once removed, is there a way of telling just by looking at the oil pressure relief valve, whether it malfunctioned or failed open as you say?

if the piston is very difficult to remove or comes out scored, this could indicate an issue. Also if the spring is broken I think could cause issues.