Pagoda SL Group
W113 Pagoda SL Group => General Discussion => Topic started by: FastWgn on August 01, 2023, 12:10:03
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I could use a little bit of help - have a couple of small oil leaks / collections of oil that I'm looking for some guidance on where they may have originated.
If the car sits for a few days there are two small oil collections on the floor. One is red and underneath the gearbox and the other is normal motor oil and under the engine and main subframe member up front.
I cleaned the engine and undercarriage to get a fresh start, drove the car for a bit and then rechecked and found the following:
1. ("Gear box" picture) From the gearbox, the red gearbox fluid is originating from the clutch linkage entrance (blue circle). Assume that gasket needs to be replaced to fix that problem? But a bit surprised there is gear box oil since I'd assume this would be connected to the clutch fork etc in the bell housing, and no gear box oil should be there? The red fluid is definitely NOT from the drain plug. Have also thought about the power steering fluid dripping down and then for some reasons collecting all the way back here, but that feels farfetched...
2. ("Bell housing" picture) From the bottom of the bell housing, the oil slowly collects in the two circles and then drips down. Now, it may be that it originated at the top, which is a soft foam like material that goes across (blue arrow). This foam is rather oil soaked. Anyone know what that foam does? Maybe it need to be replaced with a more robber like gasket?
3. ("Injection pump" picture) The weirdest one. Seems to be some oil collecting on the injection pump (top three circles), and then maybe drips down on the tip of the oil filter housing (at least that's what I think it is? - bottom circle). Have to admit I don't really understand why there would be motor oil coming out of the injection pump, assume it's cooled by the fuel, not the oil? So maybe that's just collecting there and originates somewhere else?
Any thoughts and pointers appreciated.
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Hi FastWgn,
1. The red fluid is possibly brake fluid leaking from the clutch slave cylinder in your photo. Could also be power steering fluid, blown there. Automatic transmissions normally use hydraulic fluid which is also red. Normal gear oil is very thick.
2.The foam is just a dust cover keeping water and road grime from entering the clutch housing, also called the bell housing. That cover is empty inside, except for the flywheel, clutch and clutch slave cylinder, etc. Oil leaking from there comes from the rear engine oil seal, front transmission oil seal or the slave cylinder, as mentioned before.
3. The fuel injection pump is cooled and lubed by engine oil. The pump has its own dipstick. It is therefor quite common for injection pumps to sweat or leak a little oil. The fuel arrives at injection pump( fuel distributor) under pressure and is distributed to the fuel injection nozzles under pressure. Fuel does not normally leak from this unit, but a little oil could.
Regards
Chris
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Hi FastWgn,
1. The red fluid is possibly brake fluid leaking from the clutch slave cylinder in your photo. Could also be power steering fluid, blown there. Automatic transmissions normally use hydraulic fluid which is also red. Normal gear oil is very thick.
Chris,
First - thank you very much for the comments!
The leaking oil is not brake fluid - unless there is leftover red version in the clutch circuit. The brake fluid in the car is the more normal light brownish type.
Power steering - yes agreed - but it will be an interesting path for it to land there!...
Great call on normal gear box oil - I'm used to the synthetic ones like Redline etc that are/can be more reddish in color.
2.The foam is just a dust cover keeping water and road grime from entering the clutch housing, also called the bell housing. That cover is empty inside, except for the flywheel, clutch and clutch slave cylinder, etc. Oil leaking from there comes from the rear engine oil seal, front transmission oil seal or the slave cylinder, as mentioned before.
Ugh - that's not great news. Both seals would be a challenge to replace.
The slave cylinder is on the outside - right? Else I got a bit confused from your comment above? Is there a second slave cylinder inside the bell housing as well?
3. The fuel injection pump is cooled and lubed by engine oil. The pump has its own dipstick. It is therefore quite common for injection pumps to sweat or leak a little oil. The fuel arrives at injection pump( fuel distributor) under pressure and is distributed to the fuel injection nozzles under pressure. Fuel does not normally leak from this unit, but a little oil could.
Regards
Chris
That is interesting news on the injection pump - appreciate the info!
Since the car is running great, I think we will live with that small leakage then. Don't want to mess with a healthy injection pump!
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FastWgn,
I am sure others more knowledgable than me will chime in. Keep in mind at 50 or 60 mph, oil and fluids could be blown all over the show and drip from their next new position.
Good luck.
Chris
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The pump has its own dipstick.
I thought this was only true for the earlier pumps used on the 230SL. The R11? Someone with more trivia skills will know when this changed over to recirculating oil instead of the FI Pump' having its own personal reservoir.
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FastWgn,
I am sure others more knowledgable than me will chime in. Keep in mind at 50 or 60 mph, oil and fluids could be blown all over the show and drip from their next new position.
Good luck.
Chris
Really appreciate your thoughts and pointers above. Hope my response did not come across as anything else? If so - apologies!
Agreed on the flying around part..I think I will clean the power steering fluid container and all the affiliated lines extra carefully and see if that provides any hints.
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Rodd,
Jep, I believe you are correct. Early ones were plumbed into the engine oil system and the later ones had their own oil and little dipstick.
Apologies
Chris
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FastWgn,
First, is "FastWgn" your screen name because you have an AMG station wagon? Or, maybe M5 or RS6 wagon?
Second, you must share your engine cleaning techniques! Looks great!
Third, it is the earlier (older) cars that have the FI pumps with their own oil reservoir and dip stick. I have it on my 230SL.
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FastWgn,
First, is "FastWgn" your screen name because you have an AMG station wagon? Or, maybe M5 or RS6 wagon?
Yes, guilty as charged....
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Tks Rodd,
Chris😔
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If it’s red oil, our manual gearboxes run Dexron A/T oil.
I would hazard a guess the input shaft seal is leaking on the gearbox and dripping down inside the bell housing.
You could remove the plate you mentioned that you can see the leak on and shine a light in to have a look.
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Rodd,
Jep, I believe you are correct. Early ones were plumbed into the engine oil system and the later ones had their own oil and little dipstick.
Apologies
Chris
Sorry: I think it was a bit vice-versa.
FastWgn - you have the detailed description of how the fuel injection pumps are lubricated in our Technical Manual.
If you look, again, at the Technical Manual under Maintenance, you will see that the ATF goes to manual gear box - it will produce a red leak.
What I learned from this Forum (not being technically educated) - if anything is dripping from under the plate between engine and gear box - if it is red, most likely it is the gear box shaft seal, if it is engine oil color, it is that famous old fashioned string-like rear crank shaft seal that is leaking very often. The repair is about dismantling the engine - I learned how to live with a small leak there (the only leak in my car, I can proudly say).
P.S. About using the www.sl113.org resources - they are absolutely fantastic! I printed the maintenance schedules and I use them all the time. For instance: I do the maintenance myself, but If I had a regular (not classic Mercedes specialist) mechanic do them for me, I would give them a list of maintenance items, fluids, etc. and made sure they follow it. I think there are very few mechanics who would know e.g. they need to lubricate the drive shaft front flange assembly and would know how to do it...
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If it’s red oil, our manual gearboxes run Dexron A/T oil.
I would hazard a guess the input shaft seal is leaking on the gearbox and dripping down inside the bell housing.
You could remove the plate you mentioned that you can see the leak on and shine a light in to have a look.
Thank you - did re-read the Technical manual section and I must have missed it the first time.
Will definitely remove the plate and take a look.
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What I learned from this Forum (not being technically educated) - if anything is dripping from under the plate between engine and gear box - if it is red, most likely it is the gear box shaft seal, if it is engine oil color, it is that famous old fashioned string-like rear crank shaft seal that is leaking very often. The repair is about dismantling the engine - I learned how to live with a small leak there (the only leak in my car, I can proudly say).
Either scenario is not great - most likely I will then live with the small leak.
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..3. ("Injection pump" picture) The weirdest one. Seems to be some oil collecting on the injection pump (top three circles), and then maybe drips down on the tip of the oil pump (at least that's what I think it is? - bottom circle). Have to admit I don't really understand why there would be motor oil coming out of the injection pump, assume it's cooled by the fuel, not the oil? So maybe that's just collecting there and originates somewhere else? Any thoughts and pointers appreciated.
hello FastWgn, I had oil seeping from these same two bolts (circled in blue) on my fuel injection pump and a little bit of thread sealer on each bolt resolved the leaks. Appears these bolts run through the governor housing and into the oil reservoir. It was a quick simple fix. BTW, that's the tip of your oil filter canister that the oil is collecting on.
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hello FastWgn, I had oil seeping from these same two bolts (circled in blue) on my fuel injection pump and a little bit of thread sealer on each bolt resolved the leaks. Appears these bolts run through the governor housing and into the oil reservoir. It was a quick simple fix. BTW, that's the tip of your oil filter canister that the oil is collecting on.
Very helpful advise - I will try that! Do you recall the specific torque spec for those bolts?
And thank you for correcting me - I meant to write oil FILTER, not oil pump... :)
(now corrected in the original message)
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..Do you recall the specific torque spec for those bolts?..
I didn't use a torque wrench - I applied thread sealer to each bolt and carefully tightened them by hand. I've attached some torque specs I found for the Bosch R11 pump but I'm not so sure they'll help (I can't translate them). When you re-tighten the 2 bolts just remember the governor casing is aluminum and it's thin. Note that the bolts are flush on the inside of the aluminum casing.
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Again - thank you!
I do speak decent German and that seems to be more of a calibration table based on the lengths (mm).
Not a lot of torque specs in it.
But the second picture is very helpful. I will try that.
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If it’s red oil, our manual gearboxes run Dexron A/T oil.
I would hazard a guess the input shaft seal is leaking on the gearbox and dripping down inside the bell housing.
You could remove the plate you mentioned that you can see the leak on and shine a light in to have a look.
Had a chance to remove the cover plate for the bell housing. Good news is that it was dry inside, no motor oil, no Dextron red gearbox fluid.
So that is good news, but still looking for the source of the oil that ends up there.