Boxster Knock

[a99C4tip]

Attached is a sound clip of a 2000 Boxster S 3.2 Bank 1 knock.  The sound clip is with accessory belt removed.  Car has 106,000 miles.  Recently acquired, clean and original.  Knock started today. Prior to today, the car has been driven 1,000 miles. Its definitely coming from the motor. 

 

There are no warning lights. What do you think?  Rod knock, chain tensioner, cam shaft actuator, oil pump?  Could cold weather have caused this? All responses greatly appreciated. 

Edited January 10, 2015 by a99C4tip

[Loren]

Sorry, nothing attached?

[a99C4tip]

Tried posting the sound clip but I dont see it.  Here goes another attempt at attaching sound clip.

 

Boxster Knock.mp3

[a99C4tip]

Here is another longer clip.  Further in this sound clip-at 27 seconds into clip, the knock almost goes away with a little bit of acceleration.

Boxster Knock 2-1.mp3

Edited January 10, 2015 by a99C4tip

[wvicary]

Could you try disconnecting each ignition coil electrical connector  one by one with the engine running to see if it affects the noise or locates it to a cylinder. This will cause a check engine light and don't operate the engine in this condition but only for a few seconds on each cylinder. 

[a99C4tip]

Thanks for the suggestion wvicary

 

I disconnected each coil, ran motor briefly each time and, except for the slight misfire, there was no change in the knock.  

 

John

[Ahsai]

Have you checked if all the spark plugs are tight? I think that's what Wvicary is after. The knocking seems to have the same frequency as ignition on one of the cylinders. You may want to use a mechanic stethoscope to check the cam covers and locate the noise.

[RFM]

It seems that the knock is coming from the valve train, perhaps a hydraulic tappet that fails by low oil pressure (idle)and filled at higher pressure (+ 1K RPM)

[JFP in PA]

It seems that the knock is coming from the valve train, perhaps a hydraulic tappet that fails by low oil pressure (idle)and filled at higher pressure (+ 1K RPM)

 

Or excessive chain slap from a dying hydraulic chain tensioner on a badly worn wear pad.

[a99C4tip]

Using the stethoscope, the news is not good. Although it's hard to locate, the knock is loudest in the middle, ie oil pan, above crank pulley. Both sides sound the same. The drive train is quiet.

The only interesting part is that there was no knock when cold. Heads are probably OK.

Question: this car is tiptronic. Will engine from manual shift transmission work?

Any recommendations for a shop to do engine swap north of Chicago?

Edited January 12, 2015 by a99C4tip

[JFP in PA]

Using the stethoscope, the news is not good. Although it's hard to locate, the knock is loudest in the middle, ie oil pan, above crank pulley. Both sides sound the same. The drive train is quiet.

The only interesting part is that there was no knock when cold. Heads are probably OK.

Question: this car is tiptronic. Will engine from manual shift transmission work?

Any recommendations for a shop to do engine swap north of Chicago?

 

The M96 engines are all the same from a given year and model, it is all the other stuff (electronics, etc. associated with the transmission that are different, but you already have all that).

 

LN Engineering has an affiliate, Bilt Racing Service, that does mechanical work somewhere near Chicago; you might want to look into them.

[a99C4tip]

Purchased used motor with 43k. Waiting for its delivery. Double row IMS.

Questions regarding IMS: do I leave it alone and just upgrade flange, if it passes inspection; replace it with new OEM bearing; replace with LN bearing; or replace with roller bearing.

From what I understand, the roller bearing does not come double row and a spacer is used.

I get to keep the core. May do tear down, rebuild or who knows.

Thanks for all of the responses.

[JFP in PA]

Purchased used motor with 43k. Waiting for its delivery. Double row IMS.

Questions regarding IMS: do I leave it alone and just upgrade flange, if it passes inspection; replace it with new OEM bearing; replace with LN bearing; or replace with roller bearing.

From what I understand, the roller bearing does not come double row and a spacer is used.

I get to keep the core. May do tear down, rebuild or who knows.

Thanks for all of the responses.

 

I would not hesitate to replace the OEM bearing with a dual row LN bearing; LN has more than 12,000 successful retrofits on the road, so their performance and durability are beyond question.

 

At the same time, I would also update the RMS and AOS assemblies; both are relatively cheap and easily accessible during an engine swap, but much harder to get at later.

[a99C4tip]

Thanks JFP

 

Recently noticed a double row bearing from FVD Brombacher.  Its a sealed bearing similar to OEM.  Better bearing, better grease and better seals.  Any thoughts?

Edited January 24, 2015 by a99C4tip

[JFP in PA]

Thanks JFP

 

Recently noticed a double row bearing from FVD Brombacher.  Its a sealed bearing similar to OEM.  Better bearing, better grease and better seals.  Any thoughts?

 

A lot of people are "jumping on the bandwagon" with all sorts of bearing designs and materials.  Problem is, they have no history, and some have been shown to have problems all their own.  As a shop owner, I have to go with proven units with the highest installed base and proven performance.

[a99C4tip]

As I contemplate the engine drop/swap, I believe I figured out what doomed my motor.  After buying the car, I changed the oil and filter at my earliest opportunity.  I read online that we should change oil every 5,000 miles and filters every 2,500.  When I pulled the filter, I noticed that the filter canister was missing the metallic bypass at the bottom so I purchased one off eBay.  My understanding is that the bypass is there so that if the filter gets clogged the engine still gets lubrication.

 

I do not know how long or why it was missing.  Without it, the oil essentially was not filtered pumping all of the junk from the bottom of the sump to the IMSB and journals.  To make matters worse, as I replaced the spark plugs and the spark plug tube seals, as I typically do, I noticed that the tubes had traces of what appeared to be a sludgy substance stuck them.  I have had several of these cars and this is the first one where the tubes had the sludge on them.  

 

Here is a picture of the bypass, hard to see but its there.

Edited January 28, 2015 by a99C4tip

[mikefocke]

I'd also do the water pump as they do wear out and are easy to get to with the motor sitting out. Use the OEM one, not a metal impeller model.

[a99C4tip]

Pulled motor and trans as a unit since its a tiptronic.  Felt more comfortable removing rear suspension.  The car did not have to be raised as high to remove motor. 

 

Pulled IMS bearing and it was intact.  The bearing was original and seals were in place.  Removed one seal and there was no lube and no oil in bearing.  Just some moisture of oil or vapors.  These bearings must have the ability to run on a lick of oil.  No oil in shaft. Feel better about the product having handled the IMS bearing.  

 

Found milkshake like substance in the intake so Im looking at a crack in one of the heads.  

Edited February 1, 2015 by a99C4tip

[a99C4tip]

Update:  Got the replacement engine in several weeks ago and have been chasing what I will call a lifter tick... more on the solution later.

 

The original motor spun a bearing on rod 1 and the piston was coming in contact with the head.  Here are some photos

 

Milkshake from intermix

 

 

Sludge in oil pan from intermix

 

 

Piston Contact

 

 

Head Contact

 

 

Spun Bearing Rod 1

 

 

Crank - Not too bad.  Off to machine shop to see if it can be saved

 

 

[a99C4tip]

This may have been covered elsewhere but I could not easily find the answer with the search function.

 

The replacement motor, when warm, would develop what I would call a lifter tick for lack of a better word.  The tick was on bank 2, cylinders 4-6 and most pronounced on 2.  It was fairly loud and could be heard inside and outside of the car.  Noise was most prevalent at idle and up to 2000 rpm.  It would go away above 2,000 rpm with throttle.

The car also had a very, very slight misfire.

 

After much research and reading, I located the culprit.  It is basically a vacuum leak. The noise was coming from some sort of a purge valve located under the manifold.  Some have even removed valve cover and replaced lifters only to have the ticking there on re-assembly.

 

Here is a picture.  It is a PITA to get to and remove.  Part number 996-110-129-05

 

 

Sometimes this purge valve goes bad with another purge valve, part number 996-605-213-01.  This one is located under the gas cap and will cause a sucking "moose call" sound. 

Edited March 1, 2015 by a99C4tip

[JFP in PA]

This may have been covered elsewhere but I could not easily find the answer with the search function.

 

The replacement motor, when warm, would develop what I would call a lifter tick for lack of a better word.  The tick was on bank 2, cylinders 4-6 and most pronounced on 2.  It was fairly loud and could be heard inside and outside of the car.  Noise was most prevalent at idle and up to 2000 rpm.  It would go away above 2,000 rpm with throttle.

The car also had a very, very slight misfire.

 

After much research and reading, I located the culprit.  It is basically a vacuum leak. The noise was coming from some sort of a purge valve located under the manifold.  Some have even removed valve cover and replaced lifters only to have the ticking there on re-assembly.

 

Here is a picture.  It is a PITA to get to and remove.  Part number 996-110-129-05

 

IMG_0449.jpg

 

Sometimes this purge valve goes bad with another purge valve, part number 996-605-213-01.  This one is located under the gas cap and will cause a sucking "moose call" sound. 

 

That looks like the EVAP system purge line.

[a99C4tip]

Yes, you are right Jeff.

 

Something about fuel vapors being burned off.  When bad causes a nerve wrecking tick.

 

BTW Thanks for always being there and helping out!

 

John

[Schnell Gelb]

Very helpful observation.There are lots of threads alluding to "lifter ticking" that are unresolved. This is a useful diagnostic test - listen to the Evap Purge valve 996-110-129-05 with a stethoscope and to the cam cover separately .Since the two parts are so close I imagine this has caused some very expensive and ineffective diagnosis in the past. Much easier & cheaper to replace(or just clean?) the Evap purge valve that replace lifters! .

Thanks for the helpful postings.