Lift pump diaphragm leak help

[loggin350]

Hey everyone, I have a concern about my lift pump pumping fuel into my crankcase. I have been reading as many old threads as I could find but could not find a definitive answer. My question is how long would it be safe or unsafe to run it with this problem in question to be able to check my oil level to see if it rises? What brought this up in the first place was when I got home from work a couple days ago I noticed my starter looked wet and I looked closer and it had very small bubbles at the starter to bell housing connection it didn't appear to be leaking from anywhere I could see so I wiped everything surrounding clean and have checked it again multiple times to find nothing. I'm a worrier by nature and started reading and jumping to conclusions and now am worried I may be putting fuel in my oil it doesn't seem thin but I changed it less than a week ago. Any input would be great as I'm supposed to drive to Florida from north Carolina Friday. Thanks in advance everyone!

 

[oldmisterbill]

!st if you suspect a bad lift pump don't drive it till you know. Check your oil is the level getting higher? Can you smell diesel fuel on the dipstick. They aren't real eexpensive and fairly easy to chane. On the other hand if you dilute your oil with fuel ,your engine is hard to change and expensive as well.

 

[loggin350]

I ordered a new pump that should be here Friday or Saturday because the local parts stores don't have anything in stock, but in the mean time being without a vehicle is tough and I just wanted to know if I can drive it to and from work tomorrow (30 miles round trip) to be able to check the level and look for any change. Are there any other tell tale signs that it is definitely shot? I ran it for about 20 minutes tonight and checked oil level with zero change, however when I pulled out the dipstick imediatly after shutting down there were a few small bubbles on it in the oil, then checking level again after letting it sit for 10 minutes no bubbles at all. I've never noticed bubbles before, but I also wasn't looking for a problem so it could have slipped my vision. I'm going to change the pump regardless because I've got almost 250k on the ticker and it looks original but just wanted to know as much as possible about it and the signs for future reference. Thanks again - Matt

 

[redneckaggie]

if the oil level isnt rising and the oil doesnt smell like fuel drive it like you stole it

 

[gandalf]

I'd tend to side with OldMrBill on this. If fuel IS mixing with the oil, don't drive it. Fuel is not a good lubricant, and will eventually, sooner rather than later, ruin the bearings. Engines are expensive and difficult to replace. You're safer to arrange for a ride tomorrow and leave the truck to sit. 30-60 miles can be a long way for compromised oil.

What it comes down to is your confidence in your diagnosis of a leaking fuel pump diaphragm. If you think it might be something else, weigh the possibilities. Do you feel lucky today? How about tomorrow?

 

[79jasper]

But what if it's draining out the valley, and getting slung over there by the flywheel?

Or even the filter dripping and running back there.
Them fuel heaters and restriction sensors love to leak...

 

[loggin350]

Thank you for all the opinions I ended up carpooling with my wife today luckily her schedule matched mine. Anyway I'm going to take it to the store tonight which is about a 10 mile round trip to be able to check the oil level. Are there any other signs that would indicate a harmful situation? It has been running as far as I can tell exactly the same as far as power, idle and smoke. My new pump is supposed to get here tomorrow sometime and as long as it gets here with enough time to change it out before I need to leave for Florida I'll change it to be on the safe side. If it doesn't arrive when it's supposed to I would like to be able to determine if my pump is still working properly and this was just some random liquid that got me worried for nothing.

 

[riotwarrior]

Unless the the weep hole on the LIFT pump is puking fluid, then it's likely not leaking OUT of the pump ONTO the engine, it could however be LEAKING INTO the engine.

Your description of a wet starter does not lead me to think LP but something else, like return lines and that leaking down the back of the block onto the starter.

If OIL level is NOT increasing and NOT smelling like Diesel it's likely NOT the pump and you would be throwing parts at this truck without adequate diagnosis.

JM2CW

Al

 

[loggin350]

I know my return lines are leaking I haven't checked the whole system but I know they leak from the caps so maybe somehow it ran down the back of the block I just drove bout 10 miles with a few minutes idling at 2 stop lights and let it sit for about 15 minutes after shutdown and it looks like it rose but just barely. How much would it rise in how much time if it were pumping fuel into the crankcase?

 

[loggin350]

And also I can't smell any diesel on the dipstick but my nose isn't very good

 

[gandalf]

What RiotWarrior says is very true. My first reply was assuming that the gasket was allowing a leak into the engine, fuel leaking into the oil. If that is the case, my opinion stands. 20 miles might not be far enough to really see an appreciable increase in oil level, unless you've got a steady stream into the oil.

You mention that your starter is soaking. Is it covered with oil, fuel, or water? If it's either oil or water, that brings up another possibility, one you really don't want to contemplate. That would be the head gasket. The starter is right below one of the more common areas for blown head gaskets. The two rear cylinders, 7&8, give the most trouble for head gaskets. Check that possibility also.

 

[loggin350]

The starter actually hasn't been wet since I noticed it the first time cleaned everything surrounding the area and then drove normally for a few days it stayed bone dry and as far as I can tell there isn't any leakage at the head gasket. A little oil from the corner of the valve cover but nothing note worthy.

 

[loggin350]

Also would there be a change in oil pressure if I'm getting fuel in there? On cold startup I show 40 psi like always and hot idle about 19-20 psi like always

 

[riotwarrior]

Sounds to me like your issue is the return caps leaking and then slowly working down the valley drain hole and down back of block.

Not sure what else to say, if you were pouring fuel into your oil it would smell of diesel and likely raise level fairly quickly

Al

 

[loggin350]

Thank you for all your help i think I just over reacted when there was wetness down there the once but I've got a new pump coming so at least Ill be ready in case I see it get iffy. Thanks again!