Author Topic: Engine Oil Leak from Fuel Injector Pump (Read 25742 times)

rjmarco · « **on:** October 09, 2014, 04:01:01 »

I have a 1965 230 SL and have recently seen oil in my garage floor drip pan. My mechanic added dye to my engine oil and it shows oil leaking from the injector pump. Any remedies for this short of having the injector pump pulled and rebuilt? I understand this is a major job with a total price tag around $5k including the shop rebuild and installation.

My leak is not so large such that I'd tackle this now but interested in whether there are any fixes with the pump in place? The car has what I believe are 53 thousand original miles.

Regards,

wwheeler · « **Reply #1 on:** October 10, 2014, 05:20:15 »

There are several places where it can leak. Did the mechanic specify where? That is where I would start and pin point the exact location. Most oil leaks can be fixed w/o removing the pump.

rjmarco · « **Reply #2 on:** October 10, 2014, 11:15:57 »

Hi, Wallace. Thanks for the reply. My mechanic has the car and we're still checking. Speculation is that we have an issue with an old seal and hopefully nothing worse than that.

scoot · « **Reply #3 on:** October 10, 2014, 14:01:34 »

Is your injection pump the kind that has the red cap for adding oil? If so, there is a dipstick also that unscrews. Check the oil level in the pump and see if it is high. Check to see if oil is leaking from the red cap of the injection pump. If so, you have gas leaking into the injection pump and it is over-filling the oil and coming out the top. Probably not the situation though since I think those pumps have an isolated oil reservoir and the mechanic added dye to the engine oil.

jameshoward · « **Reply #4 on:** October 10, 2014, 17:49:05 »

My money is on Scoot's reply. If you undo the dipstick on the injection pump and oil pours out, that's the cause. The dipstick is at the back of the pump and has two lugs on the side so you can undo it. Use a domestic household sprayer to get the oil out (from the filler cap) and replace it with - from memory - something like 185ml of fresh engine oil. Then monitor.

wwheeler · « **Reply #5 on:** October 10, 2014, 19:58:11 »

Scoot has a point about the dye. On those pumps, the back half has its own reservoir and dye in the engine oil wouldn't get to that. The front half with the pistons and camshaft, uses engine oil feed. So dye in the engine oil would show up there. In the later pumps, the entire pump is engine oil fed and they got rid of the dipstick. Notice the position of the oil line on the pump changes with the different pumps.

So if it is leaking from the dipstick (overfilled) or the back half, dye won't show up. Checking the oil level is easy in the older pumps. Since you do see dye, it should be from the front half. Could be the gaskets where the pumps mounts. Or maybe the oil feed line where it goes into the pump or onto the engine block. Could also be the side or bottom gaskets.

I never understood why if the two parts have sepearte lubrication areas on the early pumps (as was told to me), where does the gas come from when it contaiminates the oil in the rear self contained area?

scoot · « **Reply #6 on:** October 10, 2014, 20:03:31 »

I tend to agree with WWheeler. The oil supply in the injection pump is isolated from the engine oil. What goes horribly wrong is that gas leaks in the injection pump into the oil area and the result is it overflows. That requires a pump rebuild. But if the oil leaking is the dyed engine oil, then I don't think it's from the pump itself leaking but rather from some other lubricated point where the pump connects (is driven) by the engine. That sounds easier to me anyway.

If however the oil leak is NOT dyed, then I would suspect the injection pump, particularly if the oil in the injection pump has some gasoline in it.

scoot · « **Reply #7 on:** October 10, 2014, 20:11:14 »

Here's a picture of an injection pump from a 2.5 L engine. I think the ones from a 230 are similar. There is no passageway of oil between engine and pump. The only place where I can imagine oil leaking would be the seal where the pump is driven, which is the far left of the picture which is the front of the car. The red cap you see on the right side of the photo is where you add oil. The little metal t-handle dipstick is not visible in this photo, but it is lower on the back side, lower than the oil fill red cap.

The other inlets are water in/out and fuel in/out. No oil in/out.

66andBlue · « **Reply #8 on:** October 10, 2014, 22:41:37 »

Quote from: scoot on October 10, 2014, 20:11:14

... I think the ones from a 230 are similar. There is no passageway of oil between engine and pump. ...

You got fooled again!
The R11 injection pump is indeed connected to the cylinder crankcase with a thin metal oil "leak line" indicated by red arrows in the photo. Sometimes this line does indeed leak!

Rich, check the connection in the back and on the crankcase.

andyburns · « **Reply #9 on:** October 11, 2014, 00:31:39 »

Hey Alfred, is the pipe a return for overflow in the event the pump is overfilled? Also I have noticed that your pipe is clamped to standoff with a small saddle at its halfway point. I have just been back through my photos and cant see this on my car. Do you know if it is definitely suppose to be there. Will engineer up something if I can confirm it. The bolt the standoff is hanging from on my car is now very crowded. It not only takes the clamp for the main dip stick but now also handles the clamp for the power steer reservoir mounting. If I also now need to cater for a new standoff for this overflow pipe I will probably need a longer bolt. From memory its on off the three bolts that hold in the injection pump.

Any help on this will be very well received.

Also Alfred, I see you have a special tool for the main injector pipe fitting. I would love to see a pic of this an know where you got it from. Is it a crow foot type of tool?

RonB · « **Reply #10 on:** October 11, 2014, 01:14:34 »

I will be receiving my injector pump back after 10 months in the shop for rebuild. It was leaking gas into crankcase oil. They found that all 6 injectors to be malfunctioning.

The injector replacement is $140.00 ea. The old babe ran, so it will be interesting what it will be like with the new injectors.

The cost for the pump was $2483 which included cleaning and replanting the injector lines for $300.00.

The part the is a sore spot is estimate of time was about 3 months - it took 10 months. Sent the pump, lines and injectors in on January 6 2014 - will have them back on

October 16th.

66andBlue · « **Reply #11 on:** October 11, 2014, 03:42:10 »

Quote from: andyburns on October 11, 2014, 00:31:39

.... Do you know if it is definitely suppose to be there. Will engineer up something if I can confirm it. The bolt the standoff is hanging from on my car is now very crowded. It not only takes the clamp for the main dip stick but now also handles the clamp for the power steer reservoir mounting. If I also now need to cater for a new standoff for this overflow pipe I will probably need a longer bolt. From memory its on off the three bolts that hold in the injection pump.
Any help on this will be very well received. ....

Heya Andy,
before I answer I should ask you to promise not to lift the pump up from the ground until you are fully healed!

I am absolutely sure that all 230SL (LHD & RHD) have this line (nr 198). Here is a copy of the entry in the spare parts list. The pipe with fittings was p/n 1270700135 replaced by A1270700235 and still available from Daimler at EU 32 or US$52 - quite expensive IMO.
The hollow screw (nr 200) was p/n 007623 002102 replaced by 915011 002102 but I am not sure whether it is still available.
I am also attaching another photo showing the lines going into the IP (different car but same R11 pump) on the back. I have a spare R11 IP and when I have a chance will shoot a photo of the backside.

66andBlue · « **Reply #12 on:** October 11, 2014, 04:05:33 »

Quote from: andyburns on October 11, 2014, 00:31:39

Also Alfred, I see you have a special tool for the main injector pipe fitting. I would love to see a pic of this an know where you got it from. Is it a crow foot type of tool?

And heya again.
Yes it is a 17mm crowfoot tool made by Hazet. There are two part numbers for it "2745" and "4550", I have both of them, but I cannot detect much of a difference between the two except the first is polished chrome and about 2 mm shorter and the second is matte chrome. On eBay you find them with p/n 4550-1 (4550-2 is a 19mm wrench) or 2745-1.

andyburns · « **Reply #13 on:** October 11, 2014, 05:04:07 »

Hey Alfred thanks for your reply, really appreciate the time and effort.

I am going to go and buy myself one of those claw foots when I get myself back on my feet the only one I have is for adjusting the camshaft rocker pillars. I think it will be a different size. Will check

I 100% agree the pipe between the IP and the block should be there. Mine also has this. I was asking about the bracket that held it in place Take a look of the modified photo I have posted for a better idea of what I am prattling on about.

The picture from epc you have posted doesn't show it but from experience this doesn't mean it wont be shown in another section.

66andBlue · « **Reply #14 on:** October 11, 2014, 06:02:45 »

Hi Andy,
now I got it what you were searching for. I did not think about the bracket because the good news is that your car/engine does not need it.
That bracket came later, see attachment. However, if you really want one I am sure that it can be found.
BTW, the pictures are not from the EPC but the actual printed spare parts list; the one without the bracket is from the Edition B and the one showing the bracket is Edition C.
The EPC is a lot less accurate than the old books.

mbzse · « **Reply #15 on:** October 11, 2014, 08:37:29 »

Quote from: andyburns

....a special tool for the main injector pipe fitting. I would love to see a pic of this...

See attached. For Hazet ref number see Alfreds reply #12.
/Hans in Sweden
.

scoot · « **Reply #16 on:** October 11, 2014, 12:51:45 »

Cool tool.

mbzse · « **Reply #17 on:** October 11, 2014, 13:05:34 »

Quote from: scoot

Cool tool.

It is useful for the fittings on top of the Injection pump, these are spaced quite narrow. Somewhat hard to get to, especially when the pump is in situ in the engine compartment.
As you may be aware, the spec for the torque is 25Nm [19 lb/ft] for the nuts attaching the injection lines. Tool is too weak for higher torque use, though.
/Hans in Sweden

scoot · « **Reply #18 on:** October 11, 2014, 13:16:24 »

Quote from: mbzse on October 11, 2014, 13:05:34

It is useful for the fittings on top of the Injection pump, these are spaced quite narrow. Somewhat hard to get to, especially when the pump is in situ in the engine compartment.
As you may be aware, the spec for the torque is 25Nm [19 lb/ft] for the nuts attaching the injection lines. Tool is too weak for higher torque use, though.
/Hans in Sweden

I would somewhat prefer it to be a flare-nut design (5 sides) rather than a 12-point (minus however much necessary design...

nahuston · « **Reply #19 on:** October 11, 2014, 18:23:56 »

I too am having an oil leak issue from my injection pump, good info here - mine overflows the dipstick but I'm pretty sure its not because of fuel. The oil that comes out is very thick and black so I assume it is crankcase oil getting into the reservoir.

mbzse · « **Reply #20 on:** October 11, 2014, 19:23:05 »

Quote from: nahuston

.../...my injection pump ../...overflows the dipstick

This is because of internal seals in your unit that do not seal any more. Time for a rebuild. See also Scott's reply #6
/Hans in Sweden

wwheeler · « **Reply #21 on:** October 12, 2014, 19:15:40 »

I have that 17mm tool and it works very well. Allows you to torque the fittings with confidence.

The metal oil line feeds engine oil into the pump. There is also a special fitting on the pump where the oil line connects to. It is similar in purpose to the fuel fitting on the rear pump as discussed on another thread recently. The oil drain back into the engine is simply on the front where the splined gear is. If you take you pump off and tilt it forward, you'll find the oil drain.

66andBlue · « **Reply #22 on:** October 12, 2014, 19:20:29 »

Quote from: rjmarco on October 10, 2014, 11:15:57

... My mechanic has the car and we're still checking. Speculation is that we have an issue with an old seal and hopefully nothing worse than that.

Have you figured by now where the colored oil is coming from?

ja17 · « **Reply #23 on:** October 13, 2014, 02:57:08 »

In a W113 gasoline engine the clearance between the engine pistons and its cylinder walls is around 0.04 mm. In order to keep engine fuel and combustion gasses from slipping by the pistons and into the oil sump, piston rings are fitted. With an injection pump, you have the same concerns. Engineers had to figure how to keep the fuel under pressure from leaking down past the IP pistons (plungers) and into the sump of the IP or even back into the engine sump. In injection pump, the clearances between it's pistons (plungers) and cylinders are measured in millionths of an inch. A simple oil groove in the side of the IP cylinders is supplied with oil under pressure from the engine to form a seal (like a piston ring). This "oil seal" feature is common to both the early and late IPs. This feature keeps gasoline from slipping by the IP pistons (plungers) and into the IP sump or into the engine sump (later IPs). You should make sure your injection pump is supplied with oil under pressure. The metal oil feed line must be clear and if it has a check valve built in, it must be free and functioning. This will keep gasoline from mixing with IP oil and raising the oil level in the early IPs. In the later IPs it keeps fuel contaminated oil from leaking back into the engine sump. As engine oil becomes more contaminated with fuel, then the "oil seal" in the IP degrades as does engine oil pressure. So as the oil supply degrades, the rate of fuel contamination increases.

Now if you determine that you do not have a fuel/oil mix happening in the IP sump , and it is an oil only problem, then it can be the rubber o-ring seals, under the IP cylinders, deep within the IP. When these seals fail the oil feed escapes into the IP sump without ever going to plungers.

rjmarco · « **Reply #24 on:** October 13, 2014, 03:24:09 »

Hi, Alfred. I'll get to see the car up on a lift tomorrow after having the whole are cleaned-up. Should know more then. Thanks for everyone's assistance!

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Author Topic: Engine Oil Leak from Fuel Injector Pump (Read 25742 times)

nahuston