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1990 500SL
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Sorry to revive an old thread but has there been any other success stories about re torquing cylinder head bolts on a m119?

I have an early 90' 500sl with only 60k kms. Doesnt get driven much and oil changed super regularly. Engine is clean and it has early metal oil tubes. No noises at all cold start or when cold. When engine comes up to temp it ticks a bit on idle only. Oil pressure is good. No loss of oil or coolant. Kind of want to try retorquing heads but also hesitant.

Thanks
 

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R129 500 SL 1991
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In the UK we have a magazine called ‘Mercedes Owner’. Back in 2001 a Swedish gentlemen wrote a small piece on the benefits of re-torquing the head bolts on his 300CE six cylinder engine. He professed that this practice, if undertaken around 80k, prolonged the life of the head gaskets, which were otherwise prone to failure around 100k.

This made sense to me. The integrity of the gasket relies on precompression. It’s called confinement, a principle we regularly use in engineering.

So, my 500SL was ticking when hot. I tried a less viscous motor oil 0w-40 and while this had some effect, the tick was still there.

So I took a closer look at the crankcase and there was very a slight mist of oil around No.1 cylinder. So when I checked the torque figures on the HD bolts they were all over the place. The bolts at the ends of the head were worse and had lost over half their prestress. This is why I re-torqued the head bolts. The benefit of doing this was the tick also went away.

It’s quite happy running on 10w-40 or 10w-50, BUT it does come back intermittently if I use 10w-60. So it’s not all about the HD bolt torque.

To be honest, if anyone is thinking of replicating what I have done, I would recommend using new head bolts and using the MB recommended torque specs.

In your case, low miles. Risk of head gasket failure low. I would try a slightly thinner base engine oil.
 

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I have an early 90' 500sl with only 60k kms. Doesnt get driven much and oil changed super regularly. Engine is clean and it has early metal oil tubes. No noises at all cold start or when cold. When engine comes up to temp it ticks a bit on idle only. Oil pressure is good. No loss of oil or coolant. Kind of want to try retorquing heads but also hesitant.
Ticking noises will not be related to head bolt torque. A short video where we could hear the ticking would help. It may or may not be the lifters / cam followers.

What viscosity and type of oil are you using?
 

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1990 500SL
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Robm.uk does your engine still tick or is it completely gone?

Gxsr i always use 15w40 oil from mercedes benz dealer. Usually shell rotella t4 or mobil delvac. Oil chnaged every year (1000kms give or take). The engine is very clean and low km. I know it doesn't help that i don't drive it often but when i do i try to drive spiritedly and keep the rpms up to get eeverything working.

Will try to take and upload a video soon
 

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15W-40 is the correct viscosity for the M119, so that's good. With such low km's, you probably don't need to change the oil annually, but that's a different discussion.

When you do drive it, keep in mind that extended idling isn't good... never let it "warm up" in the driveway. Fire it up and drive immediately, with light throttle until coolant is up to normal temp. Then drive it at least 20-30 mins to get the engine oil and ATF up to temp as well. Coolant comes up to temp very fast, but oil & ATF take far longer, especially in cool ambient temps. Lots of full throttle and high RPM isn't just fun, it can also help keep everything working properly.

Anyway - without hearing the ticking noise, it's nearly impossible to diagnose via keyboard. But it's extremely unlikely to be cured by re-torquing head bolts. If you have no other symptoms, I would leave the head bolts alone.
 

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Thanks for your feedback. I do sometimes let it idle but try to drive it right away and aware to get it to operating temp before going hard.

Here are some videos

Cold idle no noise

Warm idle ticking (only idle)
 

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Thats what i was worried to hear. Havent inspected the rails or even had the valve cover apart. Motor hasnt been apart before (low kms). I guess ill have to pull the right valve cover or lower oil pan and check.
 

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1996 SL500, 2000 E430
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Sorry to revive an old thread but has there been any other success stories about re torquing cylinder head bolts on a m119?

I have an early 90' 500sl with only 60k kms. Doesnt get driven much and oil changed super regularly. Engine is clean and it has early metal oil tubes. No noises at all cold start or when cold. When engine comes up to temp it ticks a bit on idle only. Oil pressure is good. No loss of oil or coolant. Kind of want to try retorquing heads but also hesitant.

Thanks
Honestly I would leave well enough alone. You could open up a bunch of problems retorquing the head (old bolts and head gasket) and what makes you think retorquing the old head would cure the ticking?

When I got my 96 in 2013, it was a one owner but had some neglect for the last few years. I started driving it and used Mobil 1. The ticking at warm up (which was pretty pronounced) disappeared. There is a slight tick at times in the motor is hot, but it doesn't bother me.

What oil viscosity do you use?
 

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R129 500 SL 1991
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... what makes you think retorquing the old head would cure the ticking?...
My fault I’m afraid, as a result of my post back in 2015. 😇 My context was gasket failure on high milers, particularly straight 5 and 6 cyl engines > 100k miles, and possible pre-emptive action on these but also 500s.

However, as I wrote in response to the OP “In your case, low miles. Risk of head gasket failure low. I would try a slightly thinner base engine oil”. I can see no benefit in checking the head bolt torques in this instance.

With regard to re-torquing, in around 2000/2001 an article in the Mercedes Owner magazine claimed that re-torquing the head bolts prolonged the life of the head gaskets on the M104. I had already gone through a somewhat painful experience with a failed head gasket on a 300CE, which I sold soon after it was repaired. This is why the article caught my attention.

This was followed 3 years later around 2003 by a failed head gasket on a 190d 2.5 five cylinder diesel, which was maintained by the main dealer. I had not re-torqued the head bolts on either the 300CE or 190d, but I did change the hydraulics lifters on the 190d to try to solve a ticking problem, but this turned out to be a waste of time.

With both the 300CE and 190d I noticed that the engines started to tick at the top within about 3 to 6 months of the gasket failure. My 190 died (actually I switched it off) while idling on my driveway while ticking (tapping) and then finally kicking out puffs of blue smoke. It had 75k miles on clock. The main dealer who did the repair took a photo of the head gasket, which had a tiny crack in the gasket cylinder ring seal to oilway. The ticking was caused by combustion pressure disrupting the oil flow in the oil way to no.1 cyl lifters.

So later with my 190e 2.6 six, 300SL R129, 320SL and my present 500SL v8 R129, armed with this knowledge I checked the torques of all the head bolts and typically found that the HD bolts at the ends of the heads had lost about 30-40% more torque compared to the bolts in the middle of the head!! On all three engines I noticed oil leaks (slight misting on the RH head on my 500) at the head gasket from the ends of the blocks. So I tightened the middle bolts by 1/8 of a turn (just a nip), and checked the torque, which was roughly 120Nm. I then torqued up the end bolts to the same torque, so that all the bolts matched. Since then I have had no further head gasket problems. I sold my 190e 2.6 in 2008 with around 225k miles and still on the original head gasket. I still have the 190d 2.5.

My 500SL suffered from the typical lifter ticking problem when hot and idling. This appears to be a common problem on the early 32 valve 500s. Now it may have something to do with the fact that when MB changed to plastic oilers, they also doubled the cross sectional area of the oilers. Could this be a reason to upgrade to plastic oilers! Ha ha. 😁

Anyway, after re-torquing the head bolts on my 500SL and also changing the oil to Mobil 10w-40 from 10w-60 the ticking stopped, and so far has not returned for 5 years.

We know that the integrity of the head gasket relies on the precompression provided by the head bolts, and we also know that head bolts (particularly at the ends) lose a significant amount of prestress over time.

Is it a coincidence that the worst loss of prestress typically occurs at the ends of the head, and this just happens to be where the gaskets leak?

Differential expansion of cast iron blocks and alloy heads are a factor, and also the long crankcase of the straight six, engine oil viscosity and the integrity of the hydraulic lifters. Any one of these factors can tip the balance. The first sign is ticking when hot and idling.
 

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R129 500 SL 1991
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Thanks for your feedback. I do sometimes let it idle but try to drive it right away and aware to get it to operating temp before going hard.

Here are some videos...
The noise does not sound like timing chain / guide wear to me, which is typically more prevalent when the engine is cold, but in your case its the other way round. In fact it sounds like my 500SL used to, and I have never heard of timing chain/guide problems on a 500SL with only 60k kms. So just to be sure, can you post another video of the engine starting up and running from cold.

The second video sounds like lifters to me, and as I wrote before, I suggest you try a less viscous engine oil. Perhaps Mobil 1 10w-40. What is the ambient temperature where you live at the moment?

Below is the recommended oil viscosity for your car.

2627818
 

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Chain rails are plastic and can get brittle over time, not just miles/km's.

It would be prudent to remove at least one valve cover for inspection; preferably both. If any guides are broken, the lower oil pan needs to be removed as well to clean out the chain rail debris.
 

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It can’t do any harm. 👍

For the OP, here is the test procedure for the lifters while you’re getting lathered up in engine oil 😉

2627822
 

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R129 500 SL 1991
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The video is a big help. That noise is almost certainly not from lifters. I can't tell for sure but it does sound timing-chain related...? Have the chain rails been inspected recently?
There is another post on BW here where the OP has posted a video of what appears to be a timing chain/guide and oiler issue. Useful comparison?
I would be interested in your thoughts.
 

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My fault I’m afraid, as a result of my post back in 2015. 😇 My context was gasket failure on high milers, particularly straight 5 and 6 cyl engines > 100k miles, and possible pre-emptive action on these but also 500s.

However, as I wrote in response to the OP “In your case, low miles. Risk of head gasket failure low. I would try a slightly thinner base engine oil”. I can see no benefit in checking the head bolt torques in this instance.

With regard to re-torquing, in around 2000/2001 an article in the Mercedes Owner magazine claimed that re-torquing the head bolts prolonged the life of the head gaskets on the M104. I had already gone through a somewhat painful experience with a failed head gasket on a 300CE, which I sold soon after it was repaired. This is why the article caught my attention...
I can't address all of the issues you presented but I am familiar with that head gasket issue with the M103/M104.

Just as the M119 used the SOHC block of the M117, the M104 used the SOHC block of the M103.

And that block had one major design flaw - the oil and coolant passages were too close together in the back of the block.

And over time that oil would mix with the coolant. When that happened, you needed a new HG.

In 370,000 miles on my 300E of driving, I had to replace the HG 3 times. When I sold the car, it needed yet another one.

That really wasn't the fault of the HG, although Daimler must have gone through multiple revisions of HG trying to keep that oil separate from the coolant. They kept trying to find ways of reinforcing the holes where that oil and coolant passed.

I tend the think the problem was the aluminum head and the cast iron block, and the different rates of expansion and contraction. But the main problem was that the 2 passages were too close together.
 

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Similar noise what should I look at first
Bob, that sounds like a classic case of a popped plastic oil tube. Assuming your engine has plastic oil tubes, remove the valve cover on the side where the noise is present, and inspect all the tubes... pretty likely you'll find 1 or 2 with the ends popped off. Replace the bad tubes and the noise should go away. If you never want to do the job again, replace all 8 on both sides (16 total) with aluminum tubes. There are sets on eBay for reasonable prices.
 

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To make a small update. I took a video a while ago from a cold start. Hard to tell from the video but honestly there is no noise on cold start up and running. I pulled the lower oil pan today because i noticed it was dented in slightly. At the bottom of the pan there was a small amount of debris. May be guide debris or from the oil pump pick up. I could not get a new rubber pick up so i removed the damaged rubber section and left it with the screen (clean). I then buttoned everything back and put a bottle of oil stabilizer in hopes to quiet it down. Initially it was much quieter but it seems like the noise is still there only on idle and a hot engine. No noises while driving or over 1000rpm. I really do not drive this car much (one or twice a month) but when i do i try to drive it good. May just try driving it some more and see before the next step of pulling right side valve cover. From beneath the oil cap i can see aluminum cam tubes so i assume they all aluminum but wont know until removal of valve cover.



 

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Outstanding Contributor
R129 500 SL 1991
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Debris in photo might be broken parts of chain guide, possibly top guide. Lifting cam covers would be only way to be sure. When I replaced the guides on my ‘91 500SL 5 years ago the original ones were a brown colour. The new MB ones that I obtained from MB dealer were black.
 

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I'm not sure which kind of lifter I have in my 1998 SL500, bought at 70,000 and now at about 110,000. I was worried about oil pressure fluctuations and pulled the valve covers to see that all plastic oiler tubes were intact. I decided to not replace them because there was a good chance that I would end up needing to replace the chain guides. In any case, some years later, one morning, the oil pressure suddenly started behaving exactly as it does on a real car. Varies with temp and RPM.

Now gentleman, I can't make out anything from the videos. I have a rod-type stethoscope and it gives me very accurate data about noises, always including some roar from various rotating items. When starting the engine from cold, everything is covered by the noise of the secondary air pump, still needing replacement, but I'll deal with that whenever I get a round tuit. As long as I don't get the code for that pump won't worry. (Used to get the code but after I washed the engine compartment, including that air pump, things are just fine down there.

Get a stethoscope and resolve the issue.
 
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