Injection Pump internal leak - what is it damaging?

[scoot]

My 250 SL injection pump seems to be leaking gasoline into the oil in the pump.  The oil in the pump doesn't circulate with the enjine oil so it isn't contaminating the engine oil with gasoline.  It doesn't happen overnight.   I also don't want to spend the $2000 (?) to have the pump rebuilt right now.  So my question is whether or not I am damaging anything by driving the car still, or is it going to cost me the cost of a rebuild regardless and I don't need to worry about it...

I previously (a month ago) pumped all of the oil/gas out of the pump twice and refilled it to the proper level with oil.  The car runs seemingly just fine.   Now it's at the point where the injection pump oil level is at the level of the dipstick threads.

thanks
Scott

[Benz Dr.]

I take it you have a 230SL? All of these old pumps leak eventually. Yours sounds like it's leaking a lot. It shouldn't cost that much to do a pump. Figure on more than half that much but not 2K.
The biggest problem with high oil level in the pump is that it affects the fly weight governors somewhat. Apparently, they don't like spinning in all that oil and it slows their functions a bit. Other than that, your pump is worn out so figure on a rebuild. It's inevitable.

[scoot]

I take it you have a 230SL? All of these old pumps leak eventually. Yours sounds like it's leaking a lot. It shouldn't cost that much to do a pump. Figure on more than half that much but not 2K.
The biggest problem with high oil level in the pump is that it affects the fly weight governors somewhat. Apparently, they don't like spinning in all that oil and it slows their functions a bit. Other than that, your pump is worn out so figure on a rebuild. It's inevitable.

It's an early 250 SL.  The pump has its own dipstick and filler and the oil is separate from the rest of the engine oil.  I plan to get it rebuilt but financially it's better if I don't do it right now.  Still I want to be able to drive it for a few months or so until I get it rebuilt...

[jameshoward]

Scoot,

I had the same problem. For a while I drove it with the issue but just monitored the oil levels (we have the same sort of pump). I emptied it using a syringe and thin tube when it became overfull. I did notice a significant change in MPG once the pump was redone. I had my pump modified by an old chap in Holland who has done these things for a while. He also recalibrated it. It cost me about 500 euros and it's been perfect since then. I realise the costing doesn't help you much as you're in the US, but it might serve to give you an idea that a rebuild doesn't have to cost $0000's.

JH

[scoot]

I emptied it using a syringe and thin tube when it became overfull.

I may try the syringe and thin tube method.  Previously I had been using a spray bottle top from Windex, shoving the tube down the fill opening and pump-pump-pumping it out.  Rather tedious.

[hauser]

A syringe woks great.  One time the shop I use filled the brake reservoir too high and I used it to remove the excess fluid.  The bad thing is that I didn't catch it before the overflow had eaten part of engine bay paint directly below the master cylinder!

[scoot]

Where do I buy a syringe?

[jameshoward]

Report sick to hospital and request an examination using a false name. When the nurse isn't looking stuff your pockets full of medical supplies and run out.

Hey presto, free syringes.

[hands_aus]

The oil level in my early 250sl injection pump slowly increases over the 6 months between engine oil changes.
I make sure I change the inj pump oil at the same time.
So I only half fill it on the dip stick and constantly monitor the oil level.

[scoot]

The oil level in my early 250sl injection pump slowly increases over the 6 months between engine oil changes.
I make sure I change the inj pump oil at the same time.
So I only half fill it on the dip stick and constantly monitor the oil level.

Right, and from what I understand this isn't an increase in oil - it's gas mixing in with the oil and causing the oil level to rise.  I discovered this at the point when it was dripping/leaking from the FILL cap and I opened it and some came dripping out.  From what I understand, later pumps intergrate the oil in the pump with the oil in the car and don't have a little dipstick.  The result is that if the same thing goes wrong with that kind of pump, you end up integrating gasoline into the engine oil and don't notice it nearly as quickly.

From what I have read, I can get away with pumping the old oil (and gas) out of the injector pump and replacing it with new oil every so often and limp along like ths for a while until I have the $$ to send it to Palo Alto or some other good rebuilder...