Uh oh, it's not the timing chain guides

**curtmcd** · 10-25-2018, 04:46 PM

Hi all,

I'm hoping to get some more opinions before I make a big mistake!

I arrived home one day and parked my 2000 540iA in my driveway. Later when I went to pull it into the garage, it was now making a loud, nasty rattle. I self-diagnosed it as timing chain guide, although it only has 75K miles. I had replaced the CC tensioner last year because of startup rattle, but it didn't really reduce the rattle.

I had it towed to an indy shop who listened to it. They quoted $5000 for a timing guide job, and another quoted $4000. I decided to tow it home and work on it myself for the "fun" of it. I ordered the ECS Tuning timing guide kit, VANOS timing kit, and a bunch of other tools and set out.

The whole thing is apart and ready for reassembly. The trouble is, the timing guides looked fine. There was no debris of any kind in the lower oil pan. The oil pump is tight and its chain is perfectly tensioned. Cam lobes look good. So at this point, I'm at a loss. Do I proceed to remove the heads for further diagnosis -- a major operation that exceeds my aspirations and may be for naught? Or do I put it back together and pray -- and maybe treat it with chemicals and high RPMs in case the lifters have not filled with oil? Can I examine the lifters without removing the heads?

I'm hoping someone experienced may recognize this noise as something specific that could save me a whole lot of headache! If you do then please let me know.

Disassembly status:

**1999 540i m** · 10-25-2018, 05:19 PM

Quite the disturbing sound! Did you try running it without the belts on? that could be one of the accessories failing, maybe an exhaust leak?

**edjack** · 10-25-2018, 06:35 PM

Sounds like one or more collapsed tappets. Might want to check valve clearance. This might identify the culprit.

At very least, you'll be able to renew the gaskets to forestall oil leaks.

**TerraPhantm** · 10-25-2018, 07:08 PM

Did the car ever run low on oil? Sounds kind of like rod knock to me

**philly98540** · 10-25-2018, 08:12 PM

Sounds too fast for tappet unless your idle was very high for some reason. Likely rod bearing.

**ChrisMelnyk** · 10-25-2018, 08:23 PM

+1 on the valve lifters.

I'm apparently one of the only people on the internet to have a valve lifter on a m54 engine go (was gone when I bought it at 70,000 miles), and it sounded very similar (if not the same -it was 5.5 years ago- to that)

As far as I know, the only was to diagnose is to use an automotive stethoscope.

**TheAngryBear** · 10-25-2018, 09:06 PM

It could be any of those but doesn’t the power steering sound like that when the bracket cracks or is failing?

2001 750iL DD74441
Stock

RIP: 2003 540iA Sport GS56111
H&R front springs, Ultimate Cup Holder, Euro Dash & Armrest, Grom, BavSound Stage1

**curtmcd** · 10-25-2018, 10:56 PM

This must be the loudest and fastest ticking noise on all of YouTube. Reading about rod knock is scary. If that's it, it seems to be Game Over anyway. The frequency does seem a bit fast for rod knock, and there are no traces of metal shavings in the oil or filter, and the onset was pretty sudden, so for these reasons I'll probably pretend it's not that for now.

The power steering pump was quite secure. The car has been used infrequently, which might account for the lifters draining and creating problems. If the concensus is the lifters, it seems the next step is to remove the camshafts and casings to inspect the lifters?

Here are all the additional data points I can think of:

It still made the noise with the fan blade removed, but I didn't try with the belts off.
The car has never run low on oil and does not burn oil.
With the engine open there is a bit of a burnt-oil smell.
It has received oil changes every 6000 to 8000 miles. Oil and filter were only ~6 months old when the noise started.
In the past few years, it has got less than 2000 miles/year since I ride a motorcycle most of the time.
Right when I landed in my driveway, I got a LOW OIL PRESSURE, STOP IMMEDIATELY warning on the dash (one time only, did not recur). It was knocking on the next start.
Indy shop said oil was maybe 1/2 qt low.
Indy shop reported oil found in the oil pressure switch connector.
Indy shop reported fault codes DME 00005D (FUNCTION, TANK VENTING SYSTEM), DME 000089C (ACTIVATION, MAP COOLING).

**1999 540i m** · 10-25-2018, 11:19 PM

Originally Posted by curtmcd

Right when I landed in my driveway, I got a LOW OIL PRESSURE, STOP IMMEDIATELY warning on the dash (one time only, did not recur). It was knocking on the next start.

You probably should have opened with this info,

How much oil did you remove from the engine? 1/2qt low won't cause that

**JimLev** · 10-26-2018, 12:21 AM

Oil pressure switch can leak at the connector, not a big deal.
Did you take the U guide off to look at the bottom? That part will wear the quickest.
Doesn't sound like a rod to me. The noise sounds like it's coming from the front of the engine.
Put it back together, take all the belts off and start it up. See if it still makes the noise.

**Santaclaus4** · 10-26-2018, 12:31 AM

That sound is way too fast and wrong pitch to be lifters or rod bearings. It doesn't sound like any of the accessory (water pump, alternator, power steering, A/C) bearings. It actually sounds like an air compressor. Hmmm... Could it have been coming from the back of the engine? That PVC diaphram?

**curtmcd** · 10-26-2018, 01:04 AM

Originally Posted by 1999 540i m

You probably should have opened with this info,
How much oil did you remove from the engine? 1/2qt low won't cause that

Yes, I forgot to mention the LOW PRESSURE warning until I went over the shop report again. Because oil was not low, my thought was that the oil pressure switch might really be defective, so I put in a new one.

I removed and examined all chains, tensioners and guides and found them all in good working condition (but will still replace them).

The noise certainly seems to be coming from front and center. Maybe the oil pump is making the noise and generating low pressure, even though it is installed tight and chain deflection is 10mm?

**TerraPhantm** · 10-26-2018, 01:06 AM

Well keep in mind the crank spins 2x as fast as the valvetrain. Might still be fast for rod knock, but I'm not 100% certain on that.

**Santaclaus4** · 10-26-2018, 02:42 AM

Originally Posted by curtmcd

The frequency does seem a bit fast for rod knock, and there are no traces of metal shavings in the oil or filter, and the onset was pretty sudden, so for these reasons I'll probably pretend it's not that for now.
Here are all the additional data points I can think of:

It still made the noise with the fan blade removed, but I didn't try with the belts off.
The car has never run low on oil and does not burn oil.
With the engine open there is a bit of a burnt-oil smell.
Right when I landed in my driveway, I got a LOW OIL PRESSURE, STOP IMMEDIATELY warning on the dash (one time only, did not recur). It was knocking on the next start.
Indy shop said oil was maybe 1/2 qt low.
Indy shop reported oil found in the oil pressure switch connector.

You said it was knocking on the next start. Was the LOW OIL PRESSURE... still lit up? How long did the engine run between the start of the noise and your taking it apart?

Did you rev the engine up? If so, did the "tone" change? Did the engine seem to labor?

I've listened to the sound over and over and I just can't quite place it.

**geargrinder** · 10-26-2018, 08:51 AM

Originally Posted by TerraPhantm

Did the car ever run low on oil? Sounds kind of like rod knock to me

Originally Posted by 1999 540i m

You probably should have opened with this info

Per the others here - I was hoping for something like loose PS pump or exhaust leak but...

I'm not optimistic. Way way too loud for a collapsed lifter.

I'm not sure where all the confidence that this isn't a rod is coming from. I've heard motors about to throw rods, hell I've OWNED a motor about to throw rods, and they sound pretty much just like this.

Couple that with the extreme low oil pressure alarm... mmmm. Yeah.

I mean you can try running it w/ no accessories just to be sure but, I'd prepare for the worst. Good news is M62 motors are relatively plentiful and not particularly in demand... although you'll be hard pressed to find a 75k one...

**JimLev** · 10-26-2018, 10:16 AM

After you get it all back together and confirm its not any of the accessory drive items and the noise is still present you can disconnect one coil at a time deactivate cylinders. If it's a rod knock the noise should diminish when you get to the one that's knocking.

**philly98540** · 10-26-2018, 11:26 AM

Maybe wiggle the rods bottoms you can reach with the lower pan off. Maybe it's one of the front ones and this can be done while it's apart now.

**jbwbhs** · 10-26-2018, 04:25 PM

subscribed

**vinyldude** · 10-27-2018, 04:13 AM

By audio analysis the knocking happens with about 12 Hz frequency, which corresponds to 720 rpm. Whatever it is, it is driven by something very close to (if not directly equal to) the crankshaft speed.

Could be a rod, something dropped inside one of the cylinders, etc.

If you are not ready to pull the heads yet, get a some kind of a borescope and try to see inside the cylinders if there's any evidence of a problem.

**geargrinder** · 10-27-2018, 08:19 AM

Nice job man! I have some of those audio tool apps on my iPhone didn't occur to me to listen to his vid with one!

**R Shaffner** · 10-27-2018, 10:23 AM

I'm curious too.

Once I had a similar puzzling sound from a head gasket that was leaking exhaust out the side when that valve opened. That frequency was at half the engine rpm, which led me to the top of the engine.

I'm surprised no one has mentioned the oil pump yet -- something loose or broken. (Spins off the crank. Near the front. Might explain the loss of pressure.) But it's geared and might have different rpm than the crank. Just a thought. (I have no experience with oil pumps on the M62.)

Is the sound any louder underneath the car?

(Sorry -- just re-read and saw the oil pump reference above.)

**BimmerBreaker** · 10-27-2018, 10:27 AM

My X5 4.6is engine developed rod knock and it sounded just like that...

My #1 and #2 were the worst, so philly's suggestion to try to tug on the rods on the front cylinders is a good one imo

Cylinder #1

**R Shaffner** · 10-27-2018, 11:40 AM

Would rod knock typically be at 1x engine speed or 2x (for play in both directions)?

**curtmcd** · 10-27-2018, 05:53 PM

Originally Posted by philly98540

Maybe wiggle the rods bottoms you can reach with the lower pan off. Maybe it's one of the front ones and this can be done while it's apart now.

Great idea. I tried to wiggle them with a large screwdriver and they do move back and forth a millimeter or two.
I took a video of it wiggling as best I could:

**Santaclaus4** · 10-27-2018, 05:57 PM

Some side to side play is normal except in the thrust bearing. You want to push and pull them (up and down for example). That'll be harder to do in situ.