Going to tackle these two issues over the weekend. However, looking at the IC pump on my S65, it appears there's a hydraulic hose running right below it. For those of you that have changed theirs, any issues with that hose being in the way? I was only able to look while kneeling on the ground; haven't had the car on jack stands yet to get a better look.

Secondly, my slushbox is leaking from the pilot bushing. I have a replacement already. Is it just as simple as removing the TCM wire harness, unscrewing the pilot bushing center bolt and swapping? Am I going to expect a lot of oil to leak out? Any tips/tricks or anything else I should be mindful of when doing this?

TIA,
James

 

Was planning on doing this stuff on Saturday, but got called out to my house in PA by my security company saying that the sensors are going off. Had to leave my office before 10AM, pick up the Benz, and drive the 2 hours from Manhattan back to Pennsylvania... all the while hoping that there wasn't that much snow. Hahaha. Wishful thinking.

Got to PA, had 2 feet of snow in the driveway. My truck is in the garage. I'm sitting at the base of the hill dreading what I had to do next, but that's besides the point. To be safe, the alarm company sent out the PA State Police to check the house. They're obviously gone by the time I get there but they did a visual inspection of the property and found nothing amiss so left a note.

So back to the driveway, I had to leave the S65 in the middle of the street while it took me over 2 hours to snow blow just one side. It usually takes me 2 hours total to do the whole driveway including the part that wraps around to the other side of the house. I finally get the car in the garage so I'm no longer blocking the street just to find out that the power went out a day or two ago. I guess when the backup generator transfer switch kicked back over to mains, the circuit breaker on the line that feeds the alarm tripped, and the unit was running on batteries which was getting low causing the erratic readings being sent to the alarm company. Flipped the breaker, and all was well again.

After that ordeal, I decided I might as well start working on the car since I'm already here and it didn't make sense to drive back to NYC right away. I managed to replace the pilot bushing but oh man, that was a royal PITA. I only had the front of the car on stands but even then, the way the bushing is situated in the transmission, there's not a whole lot of room to fit your hand. Once I got it pulled out, the transmission barfed a lot of fluid out. I'd say at least half a liter. I had a catch pan underneath which got most of it but I'm surprised to see that much flow out. Looking at videos on Youtube, it didn't seem like that much.

Also, reorienting that plug was a pain. Took about 10 minutes trying to gently feel blindly how the damn thing was supposed to go back into the locking mechanism. Eventually got it in, filled the tranny with half a liter, drove it forwards, backwards. Seems OK. Will know more tomorrow.

As for the IC pump, I couldn't get the old one out. There's a rigid high pressure hose running directly underneath it. There's no room to clamp the tubes and pull the pump out. Only way is to drain the system or remove the front fascia. Too much hassle at this point. I'm going to have the dealer do it tomorrow and properly bleed the system.

But I digress - I thought the original IC pump was kaput hence the high IAT readings. Turns out it isn't. I removed the relay and jumped the power circuit pins and the pump came on. I could hear it easily with the engine off. So, either there's a ton of air in the system, or the pump isn't flowing as well as it used to, or there's a problem with the ECU telling the pump to come on. It isn't the relay because I replaced the original with a new one just to check. Again, will know more tomorrow.

 

Pop the cap and fill with distilled water, the intercooler radiator cap. I'm by Newark. I have a star system if you need anything

 

How much different is the 65 from the 55? The 55 has a hose running from one of the super chargers cooling lines to the coolant tank which would release any bubbles/air unless I guess it was huge. Everyone I've talked to said the 55 setup doesn't need to be bled if your just changing the IC pump.

 

The S65 doesn't have an expansion tank for the intercoolers like the S55. It's a closed circuit so when there's air in the system, it has no way to escape.

 

If I had known the tech was going to bleed the system the way he did, I would have done it myself. Basically he's using the funnel and two tubes from the Schrader valve method. When I asked him about the MB prescribed way of using a vacuum pump, he says it doesn't work as well as the method he uses. He's an old school tech who's actually German and worked at MB in Germany for many years.

 

Oh that's right, I read that somewhere also. Thanks! Is it better now that it was bled?

 

It's slightly better. Before, IC temps were around 110-120F when cruising in 25F weather. They're now down to around 87-90F in 45F weather.

What's interesting is that when I step on the gas, the IAT's actually go down, whereas if I release the gas and coast, IAT temps climb up.

What irks is me that I paid $400 to replace the pump and bleed. I chose to have the dealer replace the pump because I didn't have the right tools to clamp the inlet and outlet pipes and by the time I had attempted to do it, had just finished the pilot bushing and I was already knackered from snow clearing my driveway a few hours earlier. Anyway, the way the tech bled the system is the same method that we can do at home rather than the vacuum method. I asked why he was doing it this way, and he said he always got better results and the vacuum method didn't work properly.

If I knew in advance, I would have just bought the right tools to clamp the pipes, changed the pump myself and bled the way he did. I would have saved $400 bucks right there.

 

That is normal behavior, the IAT will be lowest at full throttle.

 

Ok, that confirms. ECU must be triggering the pump to run when it senses throttle input.

Question though - IAT's now hover about 40-45F over ambient. I hear that it should only be about 20-30F above ambient. I assume there's still pockets of trapped air in the system?

I recall also reading about a modification to have the pump always on when engine is running. Can't seem to find that thread now.

 

James, did you notice any performance changes after replacing the pump?

 

Vinny, the car gets heat soaked a bit less often. Before the pump swap and bleed, if I'd been driving it hard and then go full throttle again, it felt more like a 400 hp car than a 600 hp car if going by my seat of the pants feeling. I'd have to let it cool down for a few minutes before I'd get full power back.

After the swap and questionable bleeding process done by the dealership, the cool down times are far shorter, with full power being available for longer.

IATs went from 100-120F in 25F weather to 87-90F in 45F weather so things have certainly improved but still far from ideal. I'm wondering what IATs will be like once summer rolls around and brings with it 75-90F degree days.

Oh, and my tranny is still leaking even after pilot bushing replacement. No, I didn't over tighten the pilot bushing bolt. Can't seem to tell where the leak is coming from though.

 

Mine runs 40 to 50F over ambient after everything has warmed up and cruising at a constant speed like when driving on the freeway. Always has and I had the dealer check it a while back when it was in for something else and they said all was good with the system. Every now and then I plug in my reader and check just to make sure IAT's still good. When you hammer the throttle IAT's should drop significantly and then start climbing.

 

The pump turns on and stays on above 116f it won't turn off till you go below 90f iat

 

I feel like that is way to high for iat, with the 55k engine does 15*-30* above ambient normal driving similar heat x setup and coolers. With a higher flowing pump a second gear pull puts me at 45* above ambient.

I could be completely wrong though, mb some other s65 owners could chime in on iats to confirm.

 

Just to make sure we're all on the same page, F or C?

 

F

 

The pump doesn't run all the time, it's very load dependent.

You may still have air in the system, but this intercooler system isn't that efficient, 50-60 degrees over ambient is acceptable as per MB.

To get 20-30 over ambient you will need to go to aftermarket parts, bigger pump/intercoolers/heat exchanger. The system is just too small for the heat producing capacity of those tiny turbos being asked to deliver all that airflow.

 

Silly question, but what does the IC pump sound like when it starts? I was in line at the bank, window open. All of a sudden I hear what sounded like a mini hair dryer turning on. LOL Is this the IC pump or something else?

 

If the engine's running, you'd be hard pressed to actually hear the IC pump. It's really quiet. The only time I can hear it is if I jump the power circuit relay pins with the engine off.

If it's a hairdryer type sound, that can be heard while the engine's running, then it's probably the secondary air injection pump. It comes on initially after a cold start and should stop after the cats have warmed up. It could also be the electric cooling fan spinning up to a higher speed.

 

Thanks Joe. Curios as to where you saw the 50-60 degree specs? Is it in WIS somewhere?

 

No but the only issues that will set faults will be over 200 degrees. That tells me up to that point, they aren't worried about it. Obviously we aren't talking ideal for max power at those temps, but it can still be ok working at that level. The system is too small for the engine's output for sure, just like the 113k.