Hi everyone, I am new to this forum. I have a 2003 SL 500 (R230) with about 85k km. I was driving it the other day and suddenly the red abc warning light appeared on the dash. Following that I saw a bit of smoke coming from under the hood and lost my power steering as it became very stiff to steer, I managed to pull over safely, turned off the engine immediately, and popped the hood. I noticed my serpentine belt had torn apart and there were a lot of ripped-up pieces of the belt at the bottom of the engine bay. I also noticed a large amount of oil that was spilled all around the power steering pump area with a large sum dripping on the ground as I was pulled over on the side of the road. After putting the two and two together, I realized this is what must've happened: there was a heavy leak somewhere maybe from one of the pumps (either PS or ABC pump) or maybe the connecting hoses which spilled on the belt as I was driving and because it was hot it must have burnt the belt which caused it to tear up. Does this make sense? Has anyone ever experienced anything similar? Where could this leak be coming from? I checked the two hoses that come from the PS pump and the ABC pump and they seem to be solid with no cracks. Any help would be appreciated.

 

I would do it this way:

Clean everything up then check the idler pulley. They wear out. It should spin freely; if it binds or is noisy replace it. Then check that the tensioner, alternator, AC pump and tandem pump all spin freely, that nothing's binding.

Then top up the ABC tank, replace the belt and find the source of the leak. Probably the pump sprang a leak, or it's a hose which caused the belt to slip.

 

Unless I'm seeing things, your idler is completely destroyed and that is what took out the belt. Not sure where the fluid came from, but clean the pulleys, replace the idler and belt, check all fluid levels, and see if you have any leaks. d

 

Thank you Tom for your response! I spent yesterday taking out the pieces of the old belt and cleaning up. So much oil was managed to clean and used a degreaser to get rid of most of the oil. The PS pump and the tensioner were covered in oil, which I still couldn't completely get rid of. I have noticed that the idler pulley is smashed up and needs replacing. As far as all the other parts I tried to spin them by hand and test out whether they spin freely or not, which sort of got me confused and unsure. They seem to be spinning freely but one differently than the other and no squeaking noise either. For example, the idler pulley spins completely freely and fast when I tried with my hand but the rest for instance the tensioner and the PS pump do not spin so fast. Is there any other way to be able to tell if they have gone bad and need replacing or not? Also, are the PS pump and the ABC pump both operated by the same pulley?

 

Thanks Mike! yes, the idler pulley is destroyed and I have to order a new one. just trying to figure out if there is any other pulley I should replace while I'm at it. Found this kit on AutohausAZ https://www.autohausaz.com/pn/112113BELTKIT which includes a belt, idler pulley and tensioner and seems to be a complete kit for a good price. any thoughts on this?

 

Thanks Mike! yes, the idler pulley is destroyed and I have to order a new one. just trying to figure out if there is any other pulley I should replace while I'm at it. Found this kit on AutohausAZ https://www.autohausaz.com/pn/112113BELTKIT which includes a belt, idler pulley and tensioner and seems to be a complete kit for a good price. any thoughts on this?

 

Ah, yeah - it's the idler wot dun it. Many here change this as PM, the kit you selected looks good. Avoid the $20.00 idlers out there, as you've just found out it's a critical part.

Possibly your fluid leak is blown accumulator(s) in the ABC system - when they blow they force fluid out the top of the tank. Clean it all up and see. Almost certainly the PS pump, AC comp and alternator will be fine, I'd go ahead and fit it all.

 

Thank you, Tom! I will go ahead and order the kit from AutohauseAZ and take a look into the accumulators, assuming it's pretty obvious to tell if they are blown or not by just looking at them. If that's the case, and we have blown accumulators should the struts be changed as well?

 

You can't tell by looking at them. You have to interpolate by looking at how the level in the tank changes with the motor running or not. But don't worry about it for now, fix the belt and look for any obvious leaks first. There's no reason to change the struts - no connection there.

I was wondering if, when the belt breaks and the pump stops working, somehow the ABC system puts pressure back through the system and pushes fluid out the tank?

 

Hi Tom, the belt kit, the idler pulley, and the tensioner arrived today. So I will be changing them today by the end of the day. Do you think now that I have the new tensioner, I should replace it even if the old one is still okay?
Also regarding your theory, if that's true that can explain why all the fluid came out but it would also mean that the belt broke first which is not exactly what I thought. The other day when I was cleaning up the car I noticed the car was sagging a bit on the front left (driver's side). I wondered what caused that to happen or maybe it was like that since the beginning after the belt broke but I just noticed it the other day.

 

Check the bearing on the tensioner - if it's smooth and free then I'd leave it. But your choice. Look up the torque settings in WIS for the bolt torque spec on those torx bolts - it's less than you might guess. I use thread locker.

Sagging is a normal part of aging - talking about the car here of course. Even from new the manual says so; at this age they all drop a bit. Engine on, stick in neutral, park brake off and it will reach normal height.

Top up the tank and check level again in short order.

 

What is WIS? Sorry, I'm not so familiar with the terms. I used blue Loctite on the threads of the bolt for the idler pulley and did it by hand. When I was putting the new belt in, I noticed something odd about the crankshaft pulley which I am attaching pics below for you to see. It looks like the black rubber washer piece is not sitting properly all around. Not sure if it was like that before this happened or not or maybe even had something to do with the whole incident. I asked a friend of mine who is a mechanic and told me it's nothing to worry about but thought I should get a second opinion about it. Also when I was shopping for some ABC fluid I came across several forums that mentioned Pentosin CHF-11S is the hydraulic fluid to go with however, I do understand that it's not OEM and OEM is much more expensive for some reason. So was wondering if they are the same or if not is it safe to use the Pentosin fluid?

 

That crankshaft pulley, a.k.a. harmonic balancer, those do have a rubber piece in them that over 20 years and a zillion heat cycles, wears out and deforms. I thought it was specific to the SL55s with the supercharger, not sure having 2 belts or one, but anyhow mine was deformed and belt was tracking oddly. On the SL55 there is a double idler pulley that costs about $300 and the crank pulley costs about $700 (!!!!!!!) I got a new crank pulley for "only" $495 USD after shopping a while online, the best price I could get! My shop guyz had a friend with another shop somewhere who had the idler pulley and thankfully we got that for very cheap, all new Benz original parts of course. The way this came about was my alternator had been replaced by previous owner with a cheap junk one ($89 for a junk versus about $250-300 for a good new Bosch?) and that failed one day as I was motoring down the lane... so at the shop, they looked at all the pulleys and found these to be bad, as well as the water pump having gravel for bearings! Meaning, it was due to explode any moment. So, brand new Bosch water pump, and a new thermostat and all those pulleys and a new tensioner and new belt, and the car was all happy again. The car needed an owner like me who wasn't going to get rid of it or install chi-o-nese parts... It was a good thing the alternator failed because you do NOT want the water pump to explode while you are driving! Rick melting the engine. I'm hoping for your sake, the crank pulley for the SL500 doesn't cost as much as the one for the SL55, I'd think they are a different part. It is really great to know that all that stuff under the hood of my car is all brand new now and genuine parts as if it came from the factory new, should remain trouble free for a very long time! Never "cheap out" on these important parts on the R230!

 

Rockauto has the harmonic balancer for a 2003 SL500, for under $100 ! So does Autohausaz, although those are corteco parts not genuine MB. For mine, I got a genuine MBZ part. If you do remove that balancer to replace it, be sure to get a new front engine seal to put in there, it's only about $30 and makes sense since you'll have easy access.

 

The Pentosin is perfect. Once you get it all back together, watch how your belt tracks. If it doesn't track and ride perfectly where it's supposed to be, on the pulleys, then replace that harmonic balancer. That's what we did on mine, and the belt tracked funny, that's how we looked at the balancer and learned it had warped. The one for the SL500 is "almost free", comparted to the cost of the harmonic balancer for the SL55 AMG. Very different because it drives 2 belts...

 

I would absolutely replace that balancer, it is on the verge of failure.

 

There you go, lucky you found it...

WIS is MB's online workshop manual. Workshop Information System. It's free if you hunt for it or low cost on eBay.

Pentosin CHF-11S is the factory fluid, also repackaged by MB under their own badge but it's the same fluid.

 

Thank you so much for all the info Tony! Should I play it safe and order a new harmonic balancer? Or should I put the belt on, see how it goes, and then decide from there? Still not sure about what you mean by the new front engine seal.
Which part is that exactly? Were you able to see the condition of that in the pics I posted or it's just something that should be replaced often... I would appreciate more details on that thank you!

 

Is pentosin chf-11s also the same as what they use for the power steering fluid in the R230s?

 

I could tell it definitely did not look normal when I was putting in the new belt but thought I should check in with people with more experience before I go about replacing....thank you for letting me know!

 

Okay great thanks for the info. I will be looking for that hopefully can find it online. Regarding Pentosin fluid, is it also the same fluid for power steering? I was at the dealer the other day and he told me they use the same fluid which seemed kind of strange because I looked in the PS reservoir and could tell the color was kind of like gold/light brownish color and I know that pentosin is green so was wondering if that information is correct or not. Also is it safe to just fill up the ABC reservoir with the new oil and mix up with the old oil that's in the system or should I be doing a flush beforehand?

Thank you!

 

Yes it's the same fluid. You could well have a leak so don't get too fussed about replacing it for now. Top it up and see if you have leaks, no issue with mixing old and new fluid.

Fluid replacement and ABC maintenance is a separate dissertation, get your belt and pulleys and any leaks sorted then look at the maintenance.

 

A little update, after finally replacing the pulley, and the belt and topping up the ABC fluid, I started the car and let it run for a couple minutes and carefully looked for leaks but couldn't find anything. After I turned off the engine, I looked again and saw bubbles and a leak. I have attached a video I took down below to see. I have no idea where it is leaking from. I don't think it's the hose...