Could this be the wretched knocking of the rod? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Ebell914 · 02-04-2017, 05:50 AM

2000 S with 74k miles. Driven with spirit, not reckless abandon...last Blackstone was less than 3k ago and came back with great marks! Could the video at the link below really be rod knock? It was a smooth ride home... no crazy corners suggesting starvation....how? Why? I am a sad panda...:-(

Any of you long timers, experts, artists of metal and grease...please chime in with thoughts and, hate to say it, confirmation of my hypothesis of a knocking rod...

https://youtu.be/4nLpIDi8lVs

thstone · 02-04-2017, 06:37 AM

To my imperfect ear, that doesn't sound like a rod. My first instinct would be to check the belt tensioner/idler pulley and the other belt accessories.

Can you tell what area the sound is coming from?

Ebell914 · 02-04-2017, 07:16 AM

Huh. It is most prevalent on the lower passenger side of the motor. You are talking serpentine belt? It has had a kind of rubbing sound consistent with engine speed that has been getting louder. I thought it was worn chain tensioner pads since my 4-6 bank is a bit off on cam timing. I will take a peek and report back. Thanks thstone!

BTW - running this thing momentarily with the belt off will not harm the engine, correct? Just enough to see if the sound completely disappears, of course...I just want to be sure :P

NewArt · 02-04-2017, 07:26 AM

The belt runs the water pump, alternator and air conditioning. No problem running it briefly.

356Guy · 02-04-2017, 08:06 AM

I agree with thstone. It doesn't sound like a typical rod knock. I wouldn't run it very long without the water pump.

thstone · 02-04-2017, 08:20 AM

Just my best guess. Its hard to diagnose problems via sound to begin with and almost impossible from a cell phone video.

dghii · 02-04-2017, 09:10 AM

Def. try removing the belt and running the motor. You won't overheat the car in a brief run.

Besides...what do you have to loose?

Gelbster · 02-04-2017, 09:11 AM

Quote:

Originally Posted by Ebell914

2000 S with 74k miles. Could the video at the link below really be rod knock? It was a smooth ride home... no crazy corners suggesting starvation....how? Why?
https://youtu.be/4nLpIDi8lVs

This should be an FAQ?
I had a similar problem 10 days after I bought my car.
The short version of the serious diagnostic procedure is to use an experienced M96 mechanic with an Engine Ear. All this keyboard mechanic speculation just prolongs your agony.
Ask here for a recommendation to an Indie near you- where in NC??. Meanwhile do not drive it.
Hint on where to listen first -as close as the probe will go to the rear-most main bearing.Yes, it requires getting dirty to do this.
I hope I am completely wrong !
And don't go with - oh it is just pulley bearings- if they seize and it throws the serp belt......this and w/p very easy to diagnose with a simple stethoscope (no Engine Ear req.)from the front of the engine.

Ebell914 · 02-05-2017, 09:30 AM

Well, M96 experience, no. But I have rebuilt plenty of Type IV engines in my 914 days, including recovering a precious GA motor from a spun bearing (perhaps my source of the paranoia). I know the only indie in CLT and he is a 35 mile tow from my house...The main reason I asked for input is I did not want to run the motor if it was rod knock, even to diagnose, simply to reduce any further damage.

I appreciate all the input! It turns out with the serp belt off, no noise. I have yet to find my stethoscope, but I am sure it is w/p, alternator or roller. I did not even get my primadonna hands dirty (yet). ;-)

bwdz · 02-05-2017, 10:44 AM

If you have the belt off and no noise I would pop a bottle of champagne and celebrate. Glad it is turning out to be nothing catastrophic.

PaulE · 02-05-2017, 10:48 AM

Quote:

Originally Posted by Ebell914

Well, M96 experience, no. But I have rebuilt plenty of Type IV engines in my 914 days, including recovering a precious GA motor from a spun bearing (perhaps my source of the paranoia). I know the only indie in CLT and he is a 35 mile tow from my house...The main reason I asked for input is I did not want to run the motor if it was rod knock, even to diagnose, simply to reduce any further damage.

I appreciate all the input! It turns out with the serp belt off, no noise. I have yet to find my stethoscope, but I am sure it is w/p, alternator or roller. I did not even get my primadonna hands dirty (yet). ;-)

In the scheme of things, if you have no friends with a trailer, a 35 mile flatbed is pricey but cheap in the long run! My introduction to my Indie was a 44 mile flat bed ride in 2012 - the issue turned out to be nothing, but if I drove it there and it was something, that would have been way more expensive.

BoxsterLS376 · 02-05-2017, 10:53 AM

Definitely not a rod knock. If no stethoscope then just use a long screwdriver. Shouldn't be hard to find. Run it without the belt, spin everything by hand.

benster · 02-06-2017, 01:10 AM

Was the engine hot when you ran it without the belt? Did you run it with the belt at the same time and notice a difference?

I had a similar sound on my 2000 S at about the same mileage, it turned out to be gearbox rattle. It only happened when the gearbox was warm, the clutch was engaged, and the car was left in neutral (idle or revving stationary). It wasn't noticeable while driving or when the car hadn't warmed up yet. I fixed my problem with a simple transmission oil change. It might be something worth investigating if you haven't already pinned down the problem.

Ebell914 · 05-23-2017, 02:47 AM

Ok everyone... sorry for such a late response on the outcome of this, but I feel I need to share the ordeal...or call Maury...

Found my stethoscope, and boy... all the pullies were chatty. I replaced the alternator one- I have the decoupler style. It got much quieter, but the noise was still prevalent.

I already knew the W/P was the culprit after following dghii's no-belt suggestion (thanks!!). I was just in denial of the fact i was certain I had to do the w/p, and it was SO MUCH BETTER than the fear of a rod knock...but still somehow feeling the need to smite the Porsche gods and be be lazy about the w/p... but I digress...

While in wait to get something done... I found an awesome deal on an OE water pump for $237!! But the P gods got their revenge and my car was seriously vandalized before any work was completed....4 slashed tires and two holes in my windshield... ouch!!!

She looked so miserable...and that was me looking at me in the mirror, so you can imagine the sight in the driveway!! I need to fully disclose that i was HOA president for 4 years and I am not terribly popular. But man, this was a stake in the heart :-(

So, yesterday I finally replaced the water pump... had Tread Connection come replace my tires (these guys and their mobile set up are awesome), and local indie is coming out to do the windshield in a day or two.

3 big things I learned:
1. The water pump replacement on the Box is much easier than any Asian car with which I have done the same.
2. Don't let a glass mat battery sit for so long
And of course...
3. Don't dishonor the Porsche gods!

No really though, thanks everyone who chimed in! She is nice and quiet now.

Oh yeah, I forgot to mention... when I evacuated the coolant.... I found my Porsche was an alien with green blood....that post is coming later tonight....

jcslocum · 05-23-2017, 03:23 AM

Vandalized... that blows and is such a low cowardly move. Yes, HOA members can suck (not having ever lived in one) but we need to live by the rules...

Glad to hear the noise is gone and she's ready to be driven again. We used safelite for a glass fix on the Box.

algiorda · 05-23-2017, 04:13 AM

Glad to hear it was "just" the water pump. Not so glad to hear about the vandalism. I would recommend to anyone to install Security Cameras. I live on a corner by the entrance to our gated community and have recorded more mis-deeds. The police captain, who I'm friendly with, lives 3 doors down and has contacted me 3 times to review my security footage looking for clues as to vehicle descriptions during certain overnight hours. He has apprehended 2 of those.

It's ironic you mention HOA president. I attended a very contentious HOA presidential election last evening! The incumbent won. She has been president for 17 years and the residents have had enough of her heavy handedness and spending 50% of our dues on Legal Fees for items such as residents hedges higher than 6 feet! However, she campaigned heavily and got reelected.

dghii · 05-23-2017, 12:16 PM

Lets not bring up HOA horror stories unless we want to make folks with expensive engine problems feel better!

I, too was the HOA president of two Gulf front high rise condominiums back in the 80's (while in my 20's!).

I spent money on fire pump rebuilds, fire hose replacement and emergency generators.
Out of town owners wanted palm trees and new sod.

I was not popular but I slept better at night.

I still own condos but will not serve on boards anymore.

Ebell914 · 05-27-2017, 12:48 PM

Thanks all for the support! I was HOA pres for 4 years, until they brokered enough votes to vote me out! They said I was too lenient! LOL!!

So box is up and running! I bought an airlift knock off for $50- it worked remarkably well! It was by FJC...and for the windshield I went with a local as recommended by Loren at import paint and body here in CLT- he is the best at Porsche cosmetic work!!! Any how, they used Pilkington glass, and it look outstanding! Just a little something for all those performing future searches in this vs factory. I was always a stickler for OE, but funny how unemployment can change perspectives. But you bet your bottom my w/p was OE! Sometimes it still makes sense!! Lol

Timco · 05-28-2017, 02:26 PM

Quote:

Originally Posted by dghii

Lets not bring up HOA horror stories unless we want to make folks with expensive engine problems feel better!

I, too was the HOA president of two Gulf front high rise condominiums back in the 80's (while in my 20's!).

I spent money on fire pump rebuilds, fire hose replacement and emergency generators.
Out of town owners wanted palm trees and new sod.

I was not popular but I slept better at night.

I still own condos but will not serve on boards anymore.

I'm a boiler contractor and service a condo high rise. I do their heating and cooling. Over 12 years or so I've watched presidents take trips to Africa with attorneys they hired on 5-year retainer contracts and allow their repairs and their buddies go on the HOA bill and not their own. Then the heat I've got from board members when their 45+ year old pump dies on Christmas Day and I'm good enough to make it fly until Jan 2....it's murder. HOAs can really suck, but there's no boat in their front lawn or derby car on the street.