Engine noise/click at idle, normal ? (video + sound)
#31
Drifting
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I had a 76 911S, supposedly the worst of the thermal reactor engines. Had over 120,000 miles on it when I sold it. It did have the chain tensioners collapse once on a trip to Florida, caused damage to the IMS sprocket (yes they did have IMS's) which meant the cases had to be split and a new IMS installed. But the studs never pulled. I know that the engine was finally rebuilt after 150,000 miles as I saw it at the shop. But I don't know why the rebuild was done.
#32
Rennlist Member
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
After a drive I use the screwdriver handle to ear trick and again the sound coming from cat#2 was, without a doubt, knocking whereas the cat#1 was not making any sound.
If anything, what's for sure it is on the bank#2, at least..
#33
Nordschleife Master
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Knocking with a hammer was not very conclusive, the sound is not really different from cat1. On the other hand, I noticed that the sound is a lot louder when the engine is fully warmed up.
After a drive I use the screwdriver handle to ear trick and again the sound coming from cat#2 was, without a doubt, knocking whereas the cat#1 was not making any sound.
If anything, what's for sure it is on the bank#2, at least..
After a drive I use the screwdriver handle to ear trick and again the sound coming from cat#2 was, without a doubt, knocking whereas the cat#1 was not making any sound.
If anything, what's for sure it is on the bank#2, at least..
#34
Rennlist Member
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
yeah i might get back under the car this weekend and try to poke a little more to the engine with the screwdriver/ear thing, trying to make sure the clicks are not coming from somewhere else. I just hate to get under the car too far, and so far I have not place the screwdriver onto the transmission, will do it this weekend.
#35
Nordschleife Master
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
The only thing near your transmission that is turning while in neutral is the throwout bearing. That is not a throw out bearing noise. (unless your bearing is square.)
#37
Drifting
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
If it was a spun rod bearing I would think you would hear the noise with the screwdriver trip pretty equally on both sides. You should be able to further isolate the noise by listening at the cat and then at the head. If you don't hear the noise as clearly at the head as at the cat then it is probably the cat. There are not supposed to be any moving parts in the cat (or the mufflers) but the internal baffles do come loose and make these type of rattle. Not al that uncommon.
#38
Three Wheelin'
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Knocking with a hammer was not very conclusive, the sound is not really different from cat1. On the other hand, I noticed that the sound is a lot louder when the engine is fully warmed up.
After a drive I use the screwdriver handle to ear trick and again the sound coming from cat#2 was, without a doubt, knocking whereas the cat#1 was not making any sound.
If anything, what's for sure it is on the bank#2, at least..
After a drive I use the screwdriver handle to ear trick and again the sound coming from cat#2 was, without a doubt, knocking whereas the cat#1 was not making any sound.
If anything, what's for sure it is on the bank#2, at least..
https://rennlist.com/forums/996-foru...s-not-ims.html
#39
Rennlist Member
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Did you try the 'screwdriver to ear' trick ?
I did point the screwdriver onto my headers today, the clicking noise is quite similar to when it is pointed onto the catalytic converter....
Can the noise propagate from the cat. to the header ?
Did anyone had this problem and try to listen to it that way ?
I 'feel' that the noise is a little lower on the header than the cat. but the volume is pretty close +- 15%. I really cannot tell.
I did point the screwdriver onto my headers today, the clicking noise is quite similar to when it is pointed onto the catalytic converter....
Can the noise propagate from the cat. to the header ?
Did anyone had this problem and try to listen to it that way ?
I 'feel' that the noise is a little lower on the header than the cat. but the volume is pretty close +- 15%. I really cannot tell.
#40
Rennlist Member
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
One more thing, if I decide to go to the dealer to make them replace the catalytic converter under the EPA wanrranty I assume I have to remove my FisterD mufflers ? or they are ok with that kind of thing... I think I know the answer but I wonder if your dealer ever gave you crap for this mod.
#41
Instructor
Join Date: Jun 2010
Location: Houston, TX
Posts: 120
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
With the CEL light on and the cat efficiency code you cleared previously the dealer would "love" to replace the cat at full price and charge off to warranty!
After clearing the code, my CEL will come on after driving, sometimes not for a few days but it will come on...
It is really hard to "armchair" diagnose a car from a video, but a cat rattle "usually" has a sound rattly-gravely sound that will often clear with higher revs...
If you warranty covers all internally lubricated parts, I would drive it until the CEL light reappears or the egine grenades...doesn't sound comforting, but unless you are willing to pay the price for a partial teardown you will have to wait for one or the other to have it covered!
My first cat went bad 45 days outside of the 8 year inservice date so the dealer told me I was out of luck!
**and your warranty should cover a rental, so you could be the proud driver of a late model Toyota camry or some other fleet car for a week or more!
After clearing the code, my CEL will come on after driving, sometimes not for a few days but it will come on...
It is really hard to "armchair" diagnose a car from a video, but a cat rattle "usually" has a sound rattly-gravely sound that will often clear with higher revs...
If you warranty covers all internally lubricated parts, I would drive it until the CEL light reappears or the egine grenades...doesn't sound comforting, but unless you are willing to pay the price for a partial teardown you will have to wait for one or the other to have it covered!
My first cat went bad 45 days outside of the 8 year inservice date so the dealer told me I was out of luck!
**and your warranty should cover a rental, so you could be the proud driver of a late model Toyota camry or some other fleet car for a week or more!
#42
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I had a similar noise. My first thought was a bad lifter. It was difficult to tell where it was coming from. (I used an electronic stethoscope) Sometimes it was more noisy that others. Turned out to be a VERY loose spark plug. It was backing itself out. Middle plug on passenger side. The rest were barely hand tight. Appeared to be original plugs a 100k.
Nice and quiet now and runs better (did alot of other upgrades at same time)
https://rennlist.com/forums/996-foru...ed-engine.html
Nice and quiet now and runs better (did alot of other upgrades at same time)
https://rennlist.com/forums/996-foru...ed-engine.html
#43
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Did you try the 'screwdriver to ear' trick ?
I did point the screwdriver onto my headers today, the clicking noise is quite similar to when it is pointed onto the catalytic converter....
Can the noise propagate from the cat. to the header ?
Did anyone had this problem and try to listen to it that way ?
I 'feel' that the noise is a little lower on the header than the cat. but the volume is pretty close +- 15%. I really cannot tell.
I did point the screwdriver onto my headers today, the clicking noise is quite similar to when it is pointed onto the catalytic converter....
Can the noise propagate from the cat. to the header ?
Did anyone had this problem and try to listen to it that way ?
I 'feel' that the noise is a little lower on the header than the cat. but the volume is pretty close +- 15%. I really cannot tell.
#44
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Mine didn't either. I put the car on the lift and with the listening device, it appeared to be coming from many areas of the engine - could not pinpoint. I would not of guessed plugs based on the noise. And this is a common problem on these cars.
#45
![Lightbulb](https://rennlist.com/forums/images/icons/icon3.gif)
You said the oil was in need of changing, change to a heavy oil like 10w 40. Add one quart of lucas stabilizer if the noise lessens the you know you've an engine problem if it's the cats this will not help.