M119 faint knocking sound after oil change

[Benzy Boy]

My 1997 M119 has a full service history with Mobil1 5w40 synthetic
When I bought it I switched to Castrol Edge 5w40 synthetic at my first oil change
Today 4000kms later I did an oil change and switched to Redline 5w40 synthetic and filled in 8.5 quarts, oil level is just above middle of min and max.
I started the car up with the hood open and immediatelyI could notice a faint knocking sound like someone is knocking on a door 15 knocks then silence for 10 seconds then knocking again and repeats. Oil pressure goes up to 3 bar immediately on start up and during idle so it's not an oil pressure problem. I turned the car off after 3 minutes and it's sitting in the garage now until I solve this.

What could be the culprit? My engine is a modestly driven 120,000km M119 with full service history and no problems whatsoever until now.
The car is an R129 SL500

Thank you M119 gods

 

[Benzy Boy]

Second half of this short clip: use headphones: it's like a door knock

 

[nocfn]

silly question but you didnt say - AC system turned off, first start up on a cold engine (meaning the cost iron manifolds are cold to the touch). What is the timeline of the "knock" on the video.... at 03 seconds in, 09 etc. Maybe a longer video.

Also have you replaced upper chain guides, do you have metal cam oiler tubes or plastic, did you replace oil separator if you have done this PM.

 

[gsxr]

Hard to tell in the video, but it sounds like it could be a popped oil tube. Try a stethoscope across both valve covers when you hear the ticking noise, should be able to tell if it's coming from under one of the valve covers... if so, remove the cover and check the oil tubes.

 

[Benzy Boy]

I haven't changed the upper guides and my oilers are plastic. Haven't replaced oil separator. The knock sounds very hollow and reverberated like someone hammering in a house next door or knocking on a door far away. Will try stethoscope tonight. The rapid ticking sound you're hearing is the MOT purge valve doing its thing.

AC off, first start after operating temperature oil change.

 

[Benzy Boy]

Hard to tell in the video, but it sounds like it could be a popped oil tube. Try a stethoscope across both valve covers when you hear the ticking noise, should be able to tell if it's coming from under one of the valve covers... if so, remove the cover and check the oil tubes.

I started the car up again today
No ticking on start up, but turning the ignition took maybe half a second longer to start the car than the usual instant start (this does happen on occasion in the past). After the RPM gauge settled down to idle for 30 seconds I could hear the knock again and it looked to be coming from the passenger side of the engine near the valve covers. Oil pressure jumped to 3 and stayed there immediately on start up, but I noticed it was a little higher than pre-oil change, like just above the 3 tick line. Oil level is still about 3 quarters of the way up the dip stick min/max. I'm going to check with a stethoscope tonight to try and narrow it down.

Question is this: Could the oil change have caused the problem or made it more pronounced? The change was from Castrol Edge 5w40 synthetic to RedLine 5w40 synthetic. My uncle says the oil is too thin for this engine and I'm sure he has a point since it's older and I don't winter drive the car, so next oil change I will try 10w40 or 15w40 but until then, I was wondering if he was right and somehow RedLine 5w40 is thinner or behaves differently than Castrol 5w40 and caused this sound to occur?

I checked the properties of the oils and RedLine 5w40 has higher kinematic viscosity across the board than Castrol 5w40 or Mobil1 5w40, so wouldn't that make it THICKER than what was in before technically speaking despite both being 5w40?

If my oiler tube popped, what gives? My engine isn't that old and is relatively low mileage. Is this normal?

gsxr, would you recommend I drain the brand new oil out and put in a 10w or 15w variant? Or stop using RedLine?

 

[gsxr]

The oil change could not have caused the problem, but it may have made it more pronounced.

5W-40 is not too thin, but is about the thinnest I'd recommend for warm climates. In Canada, 5W-40 would definitely be appropriate, especially if the car is driven in winter. You could use a 10W-40 or 15W-40 but if an oil tube is popped, changing viscosity won't fix it.

The plastic oil tubes failing is a common problem on these engines, it's likely more related to age than mileage. Unfortunately there's no way to confirm if it is an oil tube, without removing the valve cover on the side with the ticking noise. On the bright side, this also allows you to inspect the timing chain guide rails. If there is no record of rail replacement, you may find one or more damaged or broken... not expensive to fix yourself, but very time consuming as DIY. (And if paying a shop, it is expensive.)

 

[Benzy Boy]

The oil change could not have caused the problem, but it may have made it more pronounced.

5W-40 is not too thin, but is about the thinnest I'd recommend for warm climates. In Canada, 5W-40 would definitely be appropriate, especially if the car is driven in winter. You could use a 10W-40 or 15W-40 but if an oil tube is popped, changing viscosity won't fix it.

The plastic oil tubes failing is a common problem on these engines, it's likely more related to age than mileage. Unfortunately there's no way to confirm if it is an oil tube, without removing the valve cover on the side with the ticking noise. On the bright side, this also allows you to inspect the timing chain guide rails. If there is no record of rail replacement, you may find one or more damaged or broken... not expensive to fix yourself, but very time consuming as DIY. (And if paying a shop, it is expensive.)

Update: I used a stethoscope on the engine and I got nothing. The sound isn't coming from the valve covers or any area on the engine for that matter. I also tried the oil pan underneath and I hear nothing. If it was the bearings I would be able to hear it with the stethoscope from underneath right? The sound "comes and goes" every 30 seconds or so.

Here's a better video:

You can hear it near the end.

Should I flush with new oil again?

 

[gsxr]

I don't think it is oil related - changing the oil will likely only lighten your wallet.

Have you driven the car, to see if the noise goes away or gets louder at full operating temp? Note that you want to get the engine oil up to temp, which takes more driving / more load, you can't just let the engine idle up to 80C coolant temp. The oil temp will be much lower.

When the noise occurs, you should be able to tell SOMETHING via a stethoscope, to narrow down the location.

 

[Benzy Boy]

I don't think it is oil related - changing the oil will likely only lighten your wallet.

Have you driven the car, to see if the noise goes away or gets louder at full operating temp? Note that you want to get the engine oil up to temp, which takes more driving / more load, you can't just let the engine idle up to 80C coolant temp. The oil temp will be much lower.

When the noise occurs, you should be able to tell SOMETHING via a stethoscope, to narrow down the location.

Stethoscope didn't reveal any location of the sound. I check all over the engine including the oil pan and all I could hear was oil flowing sounds. The sound appears to come on less often or less loud as car approaches operating temperature. I'm not sure if you could hear it in the second video posted around 4 seconds in a tapping sound.

Any other potential locations to try the scope?

 

[yevgenievich]

Not likely, but another place to listen is the flex plate. If it cracks it will have a knocking type noise.

 

[Benzy Boy]

Not likely, but another place to listen is the flex plate. If it cracks it will have a knocking type noise.

This is seeming more likely now. I just cold started the car again and the sound is LOUDER but still the same, and remains on for longer periods of time (doesn't come and go as much, but rather it stays constant). Furthermore I put the stethoscope all over the entire engine anywhere I could reach from under and on top and the side and all I hear are loud smooth oil swooshing sounds and not the slightest problematic noise at all.

My car is too low to reach the transmission with the stethoscope in my ears but now I'm starting to think it might be flex plate or something else on the transmission.
It's oddly louder from behind/beside the car than in front of the open hood.

I hope I can solve this soon, not sure if I'm safe to drive and I need the car as it's my daily right now.

 

[gsxr]

I hope I can solve this soon, not sure if I'm safe to drive and I need the car as it's my daily right now.

From the video, I wouldn't worry about driving it. If there was a serious "don't drive it" knock, that would be VERY LOUD.

 

[yevgenievich]

If it is flexplate, it is usually fine to keep going for a while as both sides are bolted to something solid. But over long time can cause a pump issue on the transmission.

 

[Benzy Boy]

From the video, I wouldn't worry about driving it. If there was a serious "don't drive it" knock, that would be VERY LOUD.

Update today: Stethoscope finally narrowed it down to here where I marked with X is where I put the stethoscope needle:
This is the only area on the entire engine bay where I can hear the ticking through the stethoscope. It appears to be coming from underneath the vehicle as the sound is loudest at the side of the vehicle but I don't have a hoist or jack with me today to check. This this mean it's 100% transmission problem? What else can I do to narrow it down? What's the likely cause?

Just a coincidence this started right after an oil change?

 

[gsxr]

That is where the flexplate is located. Maybe @yevgenievich has more insight on what to do next...

 

[Benzy Boy]

I apologize for my stupidity
It’s a lifter on the drivers side near the back of the engine
I drove hard for an hour and hit 3000/4000 rpms and the sound is still present and louder at higher rpm.

That is where the flexplate is located. Maybe @yevgenievich has more insight on what to do next...

 

[Benzy Boy]

Next step is replace oiler tubes and timing chain guides? I hope I don't have to replace my lifters too like @grim 140 in Ticking after warmed up (Has metal Oilers) | M119 Engine

Any advice for me @grim 140 ? I'm going to do what you did this weekend probably.

Is there any chance @gsxr that flushing out my Redline 5W40 and using liquid moly 10w40 mos2 will fix it?

 

[gsxr]

If it's a lifter noise, it's almost guaranteed to be an oil tube. If so, it's a relatively easy fix! Make sure to only get OE/Genuine valve cover gaskets, and don't forget to buy new copper washers (18 total needed, get a few extra) for the bolts. Check all the chain rail guides, replace as needed.

Lifter failures are pretty rare. Now, if you pull the valve covers and find all 16 oil tubes intact, then we have a head-scratcher.

Changing the oil won't fix a popped oil tube. No way to avoid pulling the valve covers for inspection - gotta start there first.

 

[Benzy Boy]

If it's a lifter noise, it's almost guaranteed to be an oil tube. If so, it's a relatively easy fix! Make sure to only get OE/Genuine valve cover gaskets, and don't forget to buy new copper washers (18 total needed, get a few extra) for the bolts. Check all the chain rail guides, replace as needed.

Lifter failures are pretty rare. Now, if you pull the valve covers and find all 16 oil tubes intact, then we have a head-scratcher.

Changing the oil won't fix a popped oil tube. No way to avoid pulling the valve covers for inspection - gotta start there first.

I already changed my valve cover gaskets less than a year ago for preventative maintenance. Should I re-change them again?
I'm buying all the parts tomorrow including the copper washers and timing chain guides and I will tackle this job on the weekend or next week if they're on backorder. Anything else I should buy to do while I'm at it?

My real life car friends insist that the Redline oil is the reason this all happened. I don't see how that could be possible but they're insisting I'm wrong. From all the research I did, redline 5w40 is thicker than any of the group 3 5w40 oils my engine previously had in it. Is there any possible physical explanation as to why Redline 5W40 would cause cam oilers to suddenly pop or just simply cause my lifter to click all of a sudden?

Some guy on Quora says "It is possible the synthetic has a stronger detergent package.

It may break loose “gunk” in the engine. If the “gunk” gets to a hydraulic lifter, before being cleaned by the oil filter, the lifter can have its oil passage clogged.

This can cause the lifter to not “pump up”. It will rattle (make noise)."

Is this valid or just bullshit?

 

[yevgenievich]

Not much worth in guessing until opened up for inspection. Will be nice if just oilers. If oil change triggered it, it was ready to pop regardless

 

[gsxr]

If the valve cover gaskets are only 1 year old, they should be ok to re-use. Pretty likely you'll find other miscellaneous parts you'll need once it's apart.

yevgenievich is correct. If an oil change caused an oil tube to pop, it was going to pop no matter what oil you used. A different detergent package would not have any effect with only minutes of runtime. The Quora guy is grasping at straws.

Related anecdote: Years ago I changed the oil in a 1993 300D, drove down the road 2 miles, and it started billowing clouds of blue smoke. Turns out the head gasket failed between cylinder #1 and the timing chain cavity, and was sucking oil into #1. New oil vs old oil may have played a part in when the gasket was going to fail, but the gasket was going to fail regardless... just happened to coincide with the oil change.

 

[Benzy Boy]

Thanks gsxr.
I bought all the parts I need for the oil tube change and also the timing chain guides. Got a new breather hose assembly too.
Hopefully will do this by Friday and I HOPE it fixes the problem

 

[Benzy Boy]

We're back here again. None of the oil tubes were broken, in fact dare I say they were in excellent condition, including the timing chain guide plastics which I took off without breaking then threw them on the floor (they did not break still!). Not bad for a 120,000km 26 year old engine with no service done on those parts.

I installed all 16 aluminum oiler tubes and new timing chain guides on both sides.

I will install the hose tomorrow if I can find it available then I will start the car to see if it still ticks but now that we know it's not the oiler tubes, then what else could it be?

 

[Joncf]

We're back here again. None of the oil tubes were broken, in fact dare I say they were in excellent condition, including the timing chain guide plastics which I took off without breaking then threw them on the floor (they did not break still!). Not bad for a 120,000km 26 year old engine with no service done on those parts.

I installed all 16 aluminum oiler tubes and new timing chain guides on both sides.

I will install the hose tomorrow if I can find it available then I will start the car to see if it still ticks but now that we know it's not the oiler tubes, then what else could it be?

Did you install new o-rings on the tubes? The old ones would almost definitely be worn/flattened, and not seal as well.

 

[Benzy Boy]

Did you install new o-rings on the tubes? The old ones would almost definitely be worn/flattened, and not seal as well.

Yes

 

[gsxr]

I installed all 16 aluminum oiler tubes and new timing chain guides on both sides.

I will install the hose tomorrow if I can find it available then I will start the car to see if it still ticks but now that we know it's not the oiler tubes, then what else could it be?

If all the tubes are intact, it could be a lifter starting to make noise. This is more difficult to diagnose. For a rough check you can rotate the cams so the lobe is pointing up, and try pressing down on the lifter with a non-marring item (stick, pencil, whatever). The lifter shouldn't move. If it can be pressed down a few mm without a lot of effort, that lifter is suspect.

OTOH, if it's an intermittent lifter noise, I'd probably drive the snot out of the car for a few thousand miles and see if it goes away...

 

[Benzy Boy]

If all the tubes are intact, it could be a lifter starting to make noise. This is more difficult to diagnose. For a rough check you can rotate the cams so the lobe is pointing up, and try pressing down on the lifter with a non-marring item (stick, pencil, whatever). The lifter shouldn't move. If it can be pressed down a few mm without a lot of effort, that lifter is suspect.

OTOH, if it's an intermittent lifter noise, I'd probably drive the snot out of the car for a few thousand miles and see if it goes away...

Thank you I'll try this ASAP and get back to you. By the way, what's the socket size for the crank bolt and which way do you turn it?

Edit: I just pressed all the lifters on the side that ticked with a pencil and there’s no soft lifters. None of them depress even if I press really hard.

Maybe after all is said and done it really was the Redline 5w40 switch? Ester based oil might be conflicting with the previous stuff in there somehow? Might take some miles to transition till the sounds go away?

 

[gsxr]

Crank bolt is 27mm and only rotate it clockwise, as you face the engine (normal engine rotation). Don't turn it backwards.

There should be no conflict with a different oil, but it may take some time/miles to transition. The ester-based stuff may do some additional cleaning but it can take thousands of miles. I'd drive it and turn up the radio, unless the noise gets louder or more persistent.