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Uggh.. timing chain rattle?
Posted: Sun May 13, 2018 9:54 pm
by EPiK
I have a loud rattle from the left bank on startup. It quiets down as the engine settles to idle, but is definitely still there. As I blip the throttle it goes away, but is definitely still there once the idle settles out again.
From what I understand, my early 99 (3/1998) is a 5 chain engine? I guess I'm looking at an engine out service to change out the chain, pads and tensioners. And to think, this engine has only 175,400 original miles.. at least as far as I can determine it is original. I just wasted over $40.00 on a Carfax to try and find out if there was a swap in its past.. came up empty, but good thing was no accident history reported.
The IMS, clutch, engine mounts and a used air injection pump was installed in Texas in 2014 at RAC Performance at 161k miles. I have an email in to them to see if they may have any other info for me, and the type of components used for the clutch and IMS. I actually have this invoice from them. I'm also writing a letter to the owner at that time since his address is on the invoice. I have a phone # for him as well, I may try that tomorrow too. Got to figure this out quickly.
I'm DIY til I die so I'll be sure to post the progress. I just wanna drive my 911
Re: Uggh.. timing chain rattle?
Posted: Mon May 14, 2018 6:45 am
by B3DAWG
EPiK wrote: ↑Sun May 13, 2018 9:54 pm
I have a loud rattle from the left bank on startup. It quiets down as the engine settles to idle, but is definitely still there. As I blip the throttle it goes away, but is definitely still there once the idle settles out again.
From what I understand, my early 99 (3/1998) is a 5 chain engine? I guess I'm looking at an engine out service to change out the chain, pads and tensioners. And to think, this engine has only 175,400 original miles.. at least as far as I can determine it is original. I just wasted over $40.00 on a Carfax to try and find out if there was a swap in its past.. came up empty, but good thing was no accident history reported.
The IMS, clutch, engine mounts and a used air injection pump was installed in Texas in 2014 at RAC Performance at 161k miles. I have an email in to them to see if they may have any other info for me, and the type of components used for the clutch and IMS. I actually have this invoice from them. I'm also writing a letter to the owner at that time since his address is on the invoice. I have a phone # for him as well, I may try that tomorrow too. Got to figure this out quickly.
I'm DIY til I die so I'll be sure to post the progress. I just wanna drive my 911
Why not post a video of the noise? That may help some of the experts on this site lead you in the right direction. But sorry to hear you're having issues.
Re: Uggh.. timing chain rattle?
Posted: Mon May 14, 2018 6:50 am
by OceanBlue2000
Ugh, not a good noise to hear. What about changing tensioners and see what happens? Although an engine with that many miles I would assume need pads by now.
Re: Uggh.. timing chain rattle?
Posted: Mon May 14, 2018 12:34 pm
by EPiK
OceanBlue2000 wrote: ↑Mon May 14, 2018 6:50 am
Ugh, not a good noise to hear. What about changing tensioners and see what happens? Although an engine with that many miles I would assume need pads by now.
my thinking exactly about the pads. I mean if the engine is original to the car, at 175,400... aint mad at ya for getting a little tired... performance has always been great, and things wear out. I believe the engine itself is fine.
I will go out and take a video. She's been sitting since Saturday, so the tensioners will have leaked down and it will be pretty loud. I'm pretty confident that is going to be the source. I'm 99.5% sure its not bearing related.. but that last .5% kills me
Re: Uggh.. timing chain rattle?
Posted: Mon May 14, 2018 1:27 pm
by EPiK
here is the video. I also have a K&N intake that you'll hear hissing like Darth Vader at the beginning. At about 30 seconds in.. is that the tensioner that is weeping oil? I need to dig into the FSM.
thanks for looking
https://www.youtube.com/watch?v=f-bjDOcclwI
Re: Uggh.. timing chain rattle?
Posted: Mon May 14, 2018 1:36 pm
by gnat
Are you sure it's the chain?
Put some clean cardboard a foot or so behind your tail pipes and blip the throttle a bit. See if any oil shows up.
I'm thinking that might be scored cylinders. If you get oil on the cardboard, you next step would be to scope the cylinders ( through the plug holes and up from the sump) to confirm that it is indeed the cylinders.
Re: Uggh.. timing chain rattle?
Posted: Mon May 14, 2018 3:26 pm
by EPiK
okay I just poured in some Liqui-Moly and idled it to operating temp. sound is definitely less, practically gone.
I'll grab some cardboard and take your suggestion though to be safe. The tip is clean however, and with no cats it gets quite hot and I'm sure I'd smell oil burning too, which I don't.
I'm all for being thorough, so...back in a minute.
Re: Uggh.. timing chain rattle?
Posted: Mon May 14, 2018 3:43 pm
by EPiK
okay.. had my son standing 1' behind each tailpipe, spreading a sheet of white wrapping paper since I figured it will show oil vapor even better than cardboard. I even marked it Right and Left so I could have a comparison. Startup (very quiet btw, almost imperceptible rattle) and then idle and since she's alreadywarm I revved to to 6k on each side. Clean as a whistle..just rich smelling with no cats in place. Not even any carbon condensation spatter.
This is sounding good..no?
I just realized that I never did a cylinder compression test when I got this car. I usually always do that and keep a log..strange since I changed the plugs first thing and had the coils out obviously. I need to do that this weekend, and she's due an oil and filter change as well.
I think I'll take the 911 to work tonight and evaluate the noise (if any) on the road. At the very least I think that tensioner has earned a retirement so I'll probably at least order that also.
Re: Uggh.. timing chain rattle?
Posted: Mon May 14, 2018 4:05 pm
by EPiK
just climbed out from under and there is actually a single drip of oil on the driveway from under that big 32mm nut, which is covered in oil seep and road dirt. I probed the open center and found more seep oil and grit.
New chain tensioner should be easy, I have the 996 projects book from Pelican, and the FSM. I definitely think she's tired. So I'll swap that, oil and filter, and follow up with a compression test on Friday.
I'm interested to hear startup tomorrow morning after sitting in the parking lot all night.
Oh and I heard back from RAC in TX. They use L&N Eng IMS retrofits so that is what was put in her 14k miles ago, along with the new stock clutch.
Re: Uggh.. timing chain rattle?
Posted: Mon May 14, 2018 4:50 pm
by sweet victory
If it's the timing chain tensioner/pad, you should be able to measure the cam shaft deviation using a durametric.