Blowby at fuel pump

[vegas39]

My new to me truck, the 89, developed its first oil leak a few days ago. I crawled underneath it this morning and it appears to have an oil leak around the fuel pump but I also noticed that while the engine is running, there is a little bit of blowby coming out in the same area.
One bolt on the pump was a little loose but tightening did not help. I have to assume the gasket it bad but would it be normal to have blowby in an area like this?
I pulled the hose off the cdr valve while it was running and even then, still get the blowby down by the fuel pump. This engine seems to have quite a bit of blowby but doesnt hardly use any oil and runs great.

 

[metalminded]

what are you defining "blow by" as? if you are going to replace that gasket on the fuel pump i would replace the pump as well. i am about to replace my pump, i'll take some pictures when i do.

 

[OLDBULL8]

Blowby causes crankcase pressure, all diesel engines have blowby due to high compression. By pulling off the CDR, which means "Crankcase Depression Regulator" you increased the crankcase pressure, any oil leak of that nature will let out the crankcase pressure, if oil can get out, surely air can. The reason you see "Smoke" is that there is an oil squirter for each cylinder, the oil squirted on the hot cylinder wall causes an oil vapor, the blowby air and vapor mix, that is what your seeing. Normal crankcase pressure is only about ~2-3 PSI. To high of crankcase pressure will cause front and/or rear main seals to leak.

 

[rockbender]

I've got a leak on my recent fuel pump install too and am planning on pulling it tonight and replacing the gasket. What kind of torque on the bolts and are you just using the gasket or also silicone on the gasket as well?

 

[riotwarrior]

I've got a leak on my recent fuel pump install too and am planning on pulling it tonight and replacing the gasket. What kind of torque on the bolts and are you just using the gasket or also silicone on the gasket as well?

First always use a gasket, second my personal choice is Permatex Aviation Form A Gasket on both gasket surfaces and thread sealant on the bolts.

Remember that engines cannot heal themselves like we can from a cut or scrape, thus when you take stuff apart and replace parts, the two surfaces must be better than surgically clean especially of oil residue. Can of brake clean is yer friend here!

Any oil residue on the block surface or fuel pump surface can impair any RTV or other sealant from making proper seal to surface and subsequently leak!

My methods are tried and tested 100's of times with not one leak so far. There is an electric fuel pump conversion in the tech section that shows the pump area well. Just imagine that block off plate is the pump and the rest is the same!

Leaks are most always attributed to poor cleaning and or oil residue more than any other issue in my experience.

JM2CW

Al

 

[vegas39]

When I say blowby around the fuel pump, I could see vapor coming out from somewhere in that area. I could also see little tiny bubbles where the pump mounts to the block.
I guess somebody probably didn't mount the pump properly but is it normal for this to happen?
I'll just go electric pump like my other truck.

 

[vegas39]

Does it sound like my crankase might be under too much pressure? If so, what do I need to do about it?

 

[icanfixall]

Kenny you will see blowby escaping from any gasket area on the block like that. As for installing an electric lift pump be careful installing the block off plate. At the top of the machined area the mechanical lift pump gasket seals there is a step in the machining. Sometimes the plate hangs up on that lip and then theres a heck of a oil leak. As for using a gasket like Al said I feel its not warranted that much because we don't use a gasket for the oil pan. Why is this small area critical. But to be sure use what makes you feel right. I also really don't see why we need a gasket on the rear main seal cover either. Same rtv seal can be used there as the rtv used on the oil pan. Now the front timing gear cover has two completely differant looking gaskets sealing it to the block. I did use a gasket up there and rtv on both sides of said gasket. Because we change water pumps and the sandwich may loosen between the plate and block I errored on the siade of caution and rtv and gasket went there. Still no leaks and I'm happy for that.

 

[rockbender]

Hmmm... any idea on why mine was leaking?

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FYI, I was also seeing smoke vapor / blow by coming out of this area.

 

[riotwarrior]

Hmmm... any idea on why mine was leaking?

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FYI, I was also seeing smoke vapor / blow by coming out of this area.

ya it leaks cause yer muffler bearing rotator cuff is miss aligned...it is clear as bitumen crude from Alberta oil sands lol.

ya I would say someone boo bood when they did that install.

 

[vegas39]

ya it leaks cause yer muffler bearing rotator cuff is miss aligned...it is clear as bitumen crude from Alberta oil sands lol.

ya I would say someone boo bood when they did that install.

Just add more headlight fluid, that fixes everything.

 

[vegas39]

So before this thread fades into the sunset, one last question. Can some kind of engine problem cause excessive crankcase pressure?
I plan on permanently removing the fuel pump and installing a block off plate but am dumfounded how all of a sudden this thing could spring such a bad leak. This engine didnt leak a drop of oil until recently and it really burns me up.

 

[riotwarrior]

So before this thread fades into the sunset, one last question. Can some kind of engine problem cause excessive crankcase pressure?
I plan on permanently removing the fuel pump and installing a block off plate but am dumfounded how all of a sudden this thing could spring such a bad leak. This engine didnt leak a drop of oil until recently and it really burns me up.

Bad or broken rings, or carboned/coked rings, hole in piston, maybe CDR may have some affect on it.

Pressure is from combustion/compression pressures getting past rings into the crankcase thus it has to go somewhere...

Try a dose or two of Auto-RX that has been known to help out cleaning up rings and so forth.

JM2CW

Al

 

[vegas39]

Bad or broken rings, or carboned/coked rings, hole in piston, maybe CDR may have some affect on it.

Pressure is from combustion/compression pressures getting past rings into the crankcase thus it has to go somewhere...

Try a dose or two of Auto-RX that has been known to help out cleaning up rings and so forth.

JM2CW

Al

Ok thanks. I think I'm going to see if someone around here has a compression tester I can use when we get back from vacation. I think everything is ok with it but want to be sure.

 

[icanfixall]

Sounds like a good idea just for the knowing what you have. It can be used as a baseline for later tests too. Are you taking this rig on vacation or another rig.