Cold start rattle 2-3 seconds then gone.

[Slideways]

Here is a video of a DINAN car with 40k miles and it revs almost up to 2k RPM while making that cold start rattle sound:

And another car that only revs up to 1.5k RPM and does not have the rattle:

[Andratch]

I ordered BMW 10W60 M TwinPower Turbo Oil from FCP, and am planning to do an oil change over the weekend to see if that helps. At least it'll give me a chance to send off a sample of the old oil to Blackstone since that oil was added back in March after brand new rod bearings and then a HPDE in April.

[BL92]

I .

I think this started after a HPDE, so after the car spent a good amount of time at high rpm..

I believe the oil has broken down after all that high heat !

IMO If your behaves or sounds and differently after an oil change that is a very somber indicator that your oil change intervals are way too long.

I agree, Most Shops here Australia recommend an oil change ( 10,000ks ) 6200 miles or in 6 months, Which ever comes first

[Andratch]

I got my car back.......no dice on the second tensioner replacement. Noise persists.

The shop noticed that there is a little rattle between 2-3k rpm, almost exactly like THIS and suggested maybe it's Vanos related. My car already has the Beisan upgraded oil pump disc, so I'm not sure what else from the Vanos could be making that noise....

I ran a snake camera down by the timing chain to see if I could see any obvious signs of guide damage, nothing there either. Honestly, everything looks like it's in tip top shape.

I think this started after a HPDE, so after the car spent a good amount of time at high rpm. I haven't done a valve/lifter adjustment, so i'm going to do that as preventative maintenance and see if that helps. Other than that, everything looks to be in fantastic shape.

[ac427]

The factory CSL tune would do this 2-3 sec cold start rattle noise. The revs would pop up to near 2k before they immediately dropped back down to cold start idle. With the cold start map adjusted, it no longer does this rattle. Disabling cold start might be a good, easy test.

I wonder if they changed that on the later CSL tune. I have the CSL tune on mine and i'm pretty sure it doesn't raise initial revs to 2krpm.

[Slideways]

The factory CSL tune would do this 2-3 sec cold start rattle noise. The revs would pop up to near 2k before they immediately dropped back down to cold start idle. With the cold start map adjusted, it no longer does this rattle. Disabling cold start might be a good, easy test.

[Andratch]

IMO If your behaves or sounds and differently after an oil change that is a very somber indicator that your oil change intervals are way too long.

My oil is only about 200 miles / 3 months old, though there was a HPDE in there. It’s LiquiMoly synthetic 10W60

[lemoose]

IMO If your behaves or sounds and differently after an oil change that is a very somber indicator that your oil change intervals are way too long.

[Andratch]

Cool,

i found this a issue for me, with another car i owned in the past. Once the oil got a bit old, ( length of time ) ie, more than 6 months, I would get the rattle start, This was a car that sat 5 days a week, so the mileage on the oil was low. Once i changed the oil, the rattle would disappear again. I figured it was just the quality of oil at the time, now reading this post has me thinking otherwise

Interesting. I will say, my oil is only about 3 months old and only has a few hundred miles on it - but a few of those miles includes a HPDE event. I still wouldn't say that's my problem here, but if all else fails an oil change is cheaper than taking off the timing chain cover.

I did replace my timing chain tensioner with a new one back over the winter because I didn't yet understand that the S54 is just a noisy engine in general, and so I was trying to eliminate a 'normal' noise by swapping what I now believe was a good, working tensioner with another new one. The shop called me on Friday to say that they took out the one I bought from FCP and replaced it again, and didn't hear the sound after 24 hours of sitting.....so, fingers crossed all this fuss was a faulty replacement part. I'm not overly confident, but I can't really see what else it could be.

[ac427]

I just saw this title, and thought i would share

https://youtu.be/lqjVGhzDz2U

[BL92]

I just saw this title, and thought i would share

[BL92]

Cool,

i found this a issue for me, with another car i owned in the past. Once the oil got a bit old, ( length of time ) ie, more than 6 months, I would get the rattle start, This was a car that sat 5 days a week, so the mileage on the oil was low. Once i changed the oil, the rattle would disappear again. I figured it was just the quality of oil at the time, now reading this post has me thinking otherwise

[Andratch]

Any updates to this thread ? It's probably the brand of oil ?

No updates yet, car is still at the shop. It's a pain to diagnose because they only get 2 seconds with the sound before it has to be left for 6 hours to kill off the oil pressure.

I would say it's definitely NOT the brand of oil. It has Mobil 1 in it now, OEM weight.

[BL92]

Any updates to this thread ? It's probably the brand of oil ?

[sapote]

I did this as well. Didn't notice it at first and thought i'd have to grind the new housing, but then noticed i could gently persuade the 'nut' to proper clearance with a hammer.

FYI, the shop had three techs with ears on the car this week to identify where the sound is coming from, and they feel it's coming from "the tensioner level within the engine" - basically, not up top with vanos, and not bottom with bearings. They know my tensioner is new, and I gave them the spare that I purchased from FCP. I'm not sure where the next steps will be - my timing chain feels pretty taught from what I can tell by poking through the tensioner hole, perhaps there's a guide with a broken piece that the chain rattles against until it's fully taught? I don't really know.

My only other thought would be - maybe oil pump tensioner? That's on a separate chain...that tensioner isn't hydraulic though so I'm not sure why it would cause a problem.

with the alt ear supported on something it's safe to tap the nut rearward with a hammer. But I wouldn't use a hammer on the long bolt with the alt mounted on the car as this could break the alt ear, then it's a bigger headache.

Have the top right side chain guide ever replaced? At 70K miles and above this piece can break off the tip.