2001 Boxster S Engine Noise - 986 Forum - The Community for Porsche Boxster & Cayman Owners

BYprodriver · 04-25-2013, 03:17 PM

Probably a clogged lifter from not changing the oil often enough. You should change the oil & filter & inspect the filter for anything other than oil in it. Adding any sort of engine cleaner will make the problem worse.

Oh, welcome to the best 986 forum!

Spinnaker · 04-25-2013, 06:21 PM

I'll take a guess - broken valve spring.

Timco · 04-25-2013, 09:47 PM

Quote:

Originally Posted by Spinnaker

I'll take a guess - broken valve spring.

This......

Wilson01S · 04-26-2013, 05:46 AM

A broken valve spring or collapsed lifter was what I thought to myself when I heard the noise and where it was coming from. Have any of you seen valve springs fail on such a low mileage, stock engine? A valve spring generally does not just fail without something causing it to fail. That "something" is what I am fearing ha!

Wilson01S · 05-23-2013, 09:31 AM

Well I ended up bringing the car home and tearing into it myself. I first changed the oil and inspected the filter to see if there was any major ferrous metallic particles in the oil/filter and if it would change anything. It didn't. Oil looked fairly clean/debris free. Some very, very, very small shimmering specs in the filter, but nothing I would say was major.

I next removed all the coils, and spark plugs to inspect for any obvious cylinder issues, oil/fluid contamination, detonation, damage. All looked ok, and all look like they were the correct color. No oil contamination.

Then I removed the accessory belt to see if that would stop the noise- again no change with engine running/belt off.

So yesterday I took the transmission out (fairly easy job and +1 for the pelican parts guide). Took me about 2 hours to get it out on my back. Anyway- I inspected the (recently new) clutch and flywheel area for any loose/backed out bolts or damage signs back there- all looked ok.

Removed the IMS bearing cover and the bearing looks brand new.

Now I am stuck as to what my next step should be. I guess I should have mentioned that myself, and a good mechanic friend took a second listen with the engine running and the noise seems to be coming from the area on the drivers side chain tensioner, and IMS bearing area. Originally the noise sounded like it was farther out toward the head, but with a good mechanics stethoscope, and a screwdriver to feel for vibrations it definitely seems to be coming from that tensioner/IMS area.

Has anyone ever experienced a bad chain tensioner that would make a noise like that? Mind you this car was checked for cam deviation and that was spot on. I checked the timing marks and it still appears to be in perfect time.

I'd hate to scrap this engine with the thought of it still being something simple, but I guess maybe it's time to look into replacements/reconstruction?

Wilson01S · 05-23-2013, 12:28 PM

Can the external tensioner (located on the rear of the even bank, near IMS bearing/flyhweel on the left side) be removed without locking the cams if the engine is not rotated?

I want to remove that tensioner to inspect for any obvious clues to the noise. Also it is leaking oil from that tensioner.

woodsman · 05-23-2013, 12:41 PM

whoa nelly! I'm pretty sure you need to lock those shafts in place. I don't know enough about this but my valves got bent when a 'Porsche trained" indy mech. installed a new LN IMSB. These engines are complex and my 2001S has 5 chains in there!!!

BYprodriver · 05-23-2013, 12:52 PM

Quote:

Originally Posted by Wilson01S

Can the external tensioner (located on the rear of the even bank, near IMS bearing/flyhweel on the left side) be removed without locking the cams if the engine is not rotated?

I want to remove that tensioner to inspect for any obvious clues to the noise. Also it is leaking oil from that tensioner.

You will need a new crush washer & O-ring to fix the leak.

See your post on Pelican forum.

BYprodriver · 05-23-2013, 12:50 PM

Quote:

Originally Posted by Wilson01S

A broken valve spring or collapsed lifter was what I thought to myself when I heard the noise and where it was coming from. Have any of you seen valve springs fail on such a low mileage, stock engine? A valve spring generally does not just fail without something causing it to fail. That "something" is what I am fearing ha!

When the engine is anywhere besides TDC there are valvesprings fully compressed. If the car sits for long periods of time (months) this can cause premature failure of the valvesprings.

I just posted on your thread in Pelican Parts with photo re: your next step.