The engine of my 1950 Chervrolet Fleetline is mixing oil with water and leaking water from the fuel pump. The engine is running well but the leak is substantial. Can anyone help with finding the source of this leak? If the head gasket is defective, can the engine be running this well? All help is welcome :-) Here is a video of the engine running: https://photos.app.goo.gl/9B4JimyyaFcboFpG9 here is a video of the leak: https://photos.app.goo.gl/kFWxrePvHZdwydx89
What is going on inside the crank case / oil pan? If it is really water coming through the vent hole of the fuel pump its coming from the crank case??? Could be a head gasket or a crack in the head or block. Make sure your oil is not being contaminated with water if you are running the engine. Do a cylinder compression test, see if there are signs of water or significant compression differences. Good luck.
PULL OUT THE OIL DIP STICK. IS THE OIL OVER FULL, CLOUDY AND LIGHT DRAY, SMELL LIKE Gas? If it is you may have coolant leaking into the oil or a lot of condensation water in the oil. First I WOULD REMOVE THE FUEL PUMP AND-OR CHANGE THE OIL,
The oil on top of the head has a LOT of water in it. From the color, I'm thinking you don't have antifreeze in it as it doesn't appear gray. That's good in that antifreeze will QUICKLY destroy a running engine. It may be bad, because if you have pure water in the cooling system, that may be what has happened here. Frost.
Are you sure it's water leaking from the fuel pump? Not gasoline? If it IS water, that's really strange, and probably not at all good. Only thing I can think of that would do that is a crack right above the fuel pump dumping water into the crankcase.
I can't think of any situation where water would be leaking from a fuel pump while an engine is running. If the crankcase is overfull, as a result of coolant leaking into it, it would be a water and oil mix that is coming from the vent hole, not water. You have water in your oil, for sure, but anything that is clear and leaking from the fuel pump has to be fuel.
It is definitely water coming out of the vent hole of the fuel pump! Water is getting into the crack case, mixing with oil but some/most of the water is getting out through the vent hole before it has a chance to mix. The main question is where could this substantial leak be coming from? (with the engine running well on even compression)?
I also noticed that there is no oil going to the rear half of the rocker arm assembly. And there is definitely water mixed in the oil. I would be very cautious about running the engine much more under these conditions.
If that is truly just water coming out the fuel pump vent hole expect that there is a crack in #2 cylinder wall but below where the rings travel. The head gasket is intact. That is why you have good compression and the engine runs as well as it does. The water is coming from the water jacket into that lower cylinder area and into the pan. Some of it is being splashed by the camshaft towards the fuel pump. That water never gets into the crankcase to mix with the oil.
I assume that you are currently running just water.
If my guess is correct you should be able to see the damaged area if you remove the oil pan.
That was my first guess above. Water is running down the inside of the crankcase from right above the fuel pump, and pooling in the fuel pump housing before it mixes with much oil, and running from there down into the oil pan. But doesn't that ALSO mean he has to have a leaky seal on the stem of the diaphragm in the fuel pump to let the water out of the hole in the fuel pump? I don't know how else the water coming out of the fuel pump can be NOT milky. A highly coincidental combination of ailments if this is what's happening.
update: I have pressurized the radiator with 1.7 bar of pressure and there is no water coming from the vent hole of the fuel pump. The leak only occurs with running engine. I have taken the fuel pump of and looked inside the crack case with an endoscope but I can find no traces of water leak or cracks (but view is limited). The oil level is normal which would indicate that not a lot of water is coming into the crack case. I'm a bit stuck here. Any ideas?
Please confirm that you are running water only in the cooling system. That will help us confirm that the cooling system is the source of the water.
Ole,
This is a strange scenario. That fact that there is no pressure leak-down when the system is pressurized is really interesting.
I wonder if the crack was covered by the piston skirt when he ran that test. I suggest that he pressurize the system again and turn the engine over by hand to see what happens.
It appears that you must have several problems here.
I'm thinking you must have a LOT of water in your gas.
You also have a bad DIAPHRAGM in the fuel pump letting the water down into the area in the pump with the vent hole. You also have a bad SEAL on the diaphragm stem in the pump letting water from there down into the crankcase. In short, you need to clean up your gas and replace the fuel pump.
You also have no oil going to the rear half of the rocker arms as Rusty pointed out above. You MUST find that problem and fix it. Possibly the rear rocker arm shaft has been installed backwards.
You also have a lot of rust in the rocker arm area suggesting the ventilation system isn't working.
Got side tracked in the middle of typing the above and you posted while I was away.
I'm beginning to think the source of the water has to be in the gasoline. But here again it seems highly unlikely. That much water would have to put enough water into the carburetor to stop running at some point. And the water and gas should be pretty mixed in the diaphragm area so the leak at the pump should have both water and gas in it. And I don't see obvious water in the glass bowl.
I think your idea of turning the engine while pressure testing is a good one.
Hi guys, thanks for your help. Some backstory: this is a Belgian (Antwerp) built Chevrolet Fleetline from 1950 with 100000km and completely original with full history. The car has been sitting for 25 years and I would like to get it back to running condition. I will take the head of and fix the oil supply to the rocker arms, but for now I'm trying to find the cause of the leak. I will follow your suggestions and turn the engine with the cooling system pressurized. The cooling system has mostly water but also some anti freeze in it. I will also check the gasoline for water and switch fuel pumps. I'll report back with the results. Thanks for the help. Eric
It is a 216 engine and the oil does not come up throgh the head, The oil LINE comes from thr left lower side of the block, passes through the block between #3 and #4 cylinders, The oil line comes out the right side of the center of the block goes and the the line goes through an opening in the head and blcok and then attached to the oiler between the the rocker arm shafts. Yu can begin by blowing out the oil line from either end.
here is another update. I have pressurized the cooling system and it holds pressure for a long time (more than half an hour at 1,7 bar). After a while I noticed some water seeping out from the thread of the oil line (see video https://photos.app.goo.gl/zsUVjZXmZuWFzswU7) but that stops as soon as I release the pressure. I have taken the rocker arm of for cleaning but the oil line seems very tight at the bottom. Does this line go through the water jacket? thanks, Eric
You have water in your oil... Do you have oil in your water?
If no oil in the water, you can probably fix your leak by soldering right where the leak is. If there IS oil in the water, you will need to replace the complete line, from the left side of the block up through the water jacket and up to the rocker arm connection.
That still doesn't explain the water coming out of the fuel pump though. Strange that.
Yes, f you read my post it passes through the block between number 3 and number 4 cylindera. It passes through the coolant that is between the cylinders and can leak watr into the push rod area.
Thanks for your input. Is there a procedure I should follow te replace the oil line? Since it is leaking I'm inclined to change the whole line but the fitting at the bottom is very solid and I'm afraid of breaking things. Any suggestions on ho to get it loose? thanks Eric
IF you do NOT have oil in the water in the cooling system...
I would be inclined to try cleaning up the area where the oil line comes through the fitting (where it is leaking), applying flux, and re soldering just the way it is.
Make sure you drain the water from the system first, including draining the block from the drain on the left side of the block, towards the rear and down low. Blow everything dry with compressed air to make sure there is no water where you will be soldering. Apply the heat to the fitting and the area around the fitting. Don't apply heat directly to the oil line until the fitting is hot enough to melt your solder, and then only if necessary for the solder to flow and bond to the line.
Use an acid core solder.
Looking at your original video again... It looks like the water is running FORWARD from the leak at the oil line, and before mixing much with the oil, it is draining down the small drain hole which happens to be DIRECTLY above the fuel pump. I would have said it was impossible for that water to make it's way into the fuel pump and come out the hole in the fuel pump still looking like pure water if I didn't actually see it happening in your videos.
The water flows BACK from the leak at the oil line (due to a small inclination of the engine). Normally the water would reach the drain hole at the back first so I'm still wandering about the leak at the fuel pump....
After reading the most recent posts in this thread I was thinking about the same thing. Normally the engines in these classic Chevy's have a slight slant to the rear. That is to make sure that any oil lying on the head does drain and to the rear. Plus that inclination helps to slightly reduce the angle in the u-joint.
Unless you know that the oil line through the head is defective I would encourage you to try to solder it as is. If you read other posts about replacing that line you will learn that it can challenging. One issue is trying to get it bent properly after it is inserted through the head. And you still have to seal the new line to the head.
I just watched the video again. I focused on the first 15 seconds or so. Here are some observations. I do see the both plain water stream plus the watery oil drain into that hole right above the cam shaft. Plus it is appears that your engine is inclined forward. The watery oil mix coming out the rocker arm weep holes is not flowing to the rear of the block.
Possibly that water is working its way forward along the camshaft to the fuel pump.
Here is an interesting simple test. Drain the cooling system completely and run the engine for a couple of minutes. If there is no water at the fuel pump hole then pour some water into that drain hole in the middle of the block. Then check the fuel pump hole.
I think that the line that goes through the fitting is kinked a bit... So the fitting is not sealing around the line. As Chev Nut says, That line that goes through the water jacket and it's leaking.... Something happened to that line to cause this problem...... Maybe the line has been damaged also ..... so a source of an oil leak.....
I dont know how you could repair the leak using shoulder. I dont know if you can heat the joint up hot enough with a soldering iron with that block acting as a heat sink..... Using an open flame..... Prob something that should be only done on independence day here in the states.....
I would vote for replacing the line... they are available from the usual suppliers
I may be wrong, but I think when you install a new line, you still have to solder the new line to the fitting when you are done. If this isn't true, someone please correct me.
Regarding heat, I've almost always used a propane torch for soldering, except when working on really small stuff. I'm still here so far. 🙂
update! I have repaired the leaking oil line and the engine now holds water. I have cleaned the rocker assembly and changed the oil. I have attached an external fuel supply to run the engine. As soon as I start the engine, you can see water droplets flying out of the fuel pump mounting hole: https://photos.app.goo.gl/9eLng8dqoytxbgS86. As before the engine runs fine except for the water flying out. Where can the water be coming from? Do I have a crack in the block? Where?
Back to the earlier posts on this thread. If that's water, there almost certainly has to be a crack/leak directly above the fuel pump eccentric on the camshaft. That lines up with the center of number 2 cylinder bore.
I think you now have no choice but to remove the oil pan, lightly pressurize your cooling system and look for leaks in that area.
I agree with Ole. There is a crack or leak in the block in the area of the fuel pump eccentric. If the head gasket was bad I would expect that you would see steam in the exhaust.
Did you pressurize the cooling system with the #2 piston at Top Dead Center? Or as I suggested manually rotate the engine with the system pressurized. The crack could be associated with #1 or #3. When I look at Figure 117 in the '49-'53 shop manual it looks like the fuel pump is centered between cylinder #1 and #2.
It's hard to tell from here, but it looks like the fuel pump eccentric on the camshaft is actually throwing the water out the hole. Can you verify that?
The running engine is throwing out water out of the hole. I have pressure tested the cooling system but it shows no leaks and holds pressure well. I have investigated with an endoscope the inside of the engine but I can't see any leaks with a stationary engine. The water only shows up with a running engine but how can this happen when the pressure test is good?
I’m late to the discussion but will offer different theory for all to consider. Initially water leaked from the fuel pump weep hole and around the threads of the fitting where the oil line goes through the block. When the engine is shut off the water goes away. These factors might indicate excessive crankcase pressure. When the fuel pump was removed the droplets come out the path of least resistance, the fuel pump hole in the block. The coolant system hold pressure. Could the road draft tube be completely plugged and the water is actually condensation from combustion blow by? How about reinstalling the fuel pump, remove the draft tube and seeing if there is any loss of coolant or accumulation of water in the oil after short run?
Hi Eric, It just pushes into the hole in the block with an interference fit. There is usually a circular clamp around the body that has a tab held in place by one of the oil pan bolts. Once the clamp is unbolted, I use a rubber mallet striking it back and forth from above while pulling out at the same time. Mike
Running the engine a couple of minutes (on an external fuel supply) with no water in the cooling system revealed no leaks.
After adding water and running the engine again I noticed a lot less water droplets coming from the fuel pump hole. I collected the droplets on a piece of paper and after a few minutes there seemed to be no more water droplets, only oil.
I investigated the issue further by sucking fuel through the original fuel pump (again attached to the engine) with an external electric pump but with the engine not running. Fuel was coming through to the electric pump, but at the same time the original fuel pump started leaking from the vent hole. I collected the leaking fluid which was mostly water but had a smell of gasoline.
I suspected water in the gasoline so I drained the fuel tank. First it was proper gasoline but at the bottom I found about 2 liters of water. I suspect that somehow the fuel pump was pushing out water through the vent hole while still pushing enough gasoline to the carburetor. I took the original fuel pump apart and the diaphragm was still intact but felt a bit grainy and looked suspect.
Since the oil is still in good condition since I repaired the oil line I suspect that the source of fuel pump leak is no longer coming from inside the engine but was coming from water contamination in the gas tank. I had a new fuel pump I wanted to install but it seems to be the wrong model (shorter arm).
I'll report back as soon as I have a new fuel pump but I now think there were 2 simultaneous problems: The leaking oil line and excessive water in the gasoline both contaminating the oil with water.
I originally thought the source of the water coming from the fuel pump vent hole had to be water in the gasoline. But the likelihood of the water separating from the gas in the fuel pump and coming out the bottom... and not pumping enough water up to the carburetor to cause obvious trouble there... did seem rather slim.
Hope you've found all your trouble spots. Good luck! 🙂
I have a new fuel pump that doesn't work. When I compare the operating lever with that of the old pump there is a difference (38mm for the old pump and 33mm for the new). The old pump has a glass bowl, the new one doesn't. Can anyone help? Where can I get the correct pump?
Unfortunately this is not an unusual problem with today's replacement/reproduction fuel pumps. No one is making a glass bowl fuel pump. The suppliers try to cover as many applications as they can by cheating on the specs such as stroke/arm length. Check valves are often not well seated and staked. The die cast bodies are warped so the top and bottom will not seal.
Based on my personal experiences and conversations with many others your best solution is to rebuild the pump you have. Or find an original core to rebuild.
Most of the classic car vehicle parts houses sell them. You might also search for a fuel pump rebuilder who will sell the kit they use. There seems to a better chance of getting a good kit from them.
here is a new update: I have rebuild my glass bowl fuel pump and fitted it back on the car. It have run the engine for 15 minutes now and there is no more leaking from the pump. Also there is no mixing of water and oil so it seems my first soldering job was a succes :-) Fingers crossed but it seems that the problem has been solved.
