Engine/Transmission (1994 - 1998) Oil Blowby - Causing Major Leak

[Dave M]

Oil leak started this way:



Checked oil on Sat and 6 quarts low- Yes I said 6 QUARTS! Added oil and went to coast (150 miles) checking oil on the way. Picked up a 4 horse stock trailer and drove back home. By the time I got there and back I had lost another 6 quarts in 300 miles. Thats 3 GALLONS oil I added on Sat. I'm really bummbed cause I was getting ready to add the #10 plate and 3K GSK from Piers thats sitting on the bench. I bought this truck 2 years ago so don't know how abused it was. My first diesel... . I love this truck but can't afford the cost of engine work, so I'll try to do all I can myself.



Kept checking for leaks on the way and looked like no engine leaks. I did KDP back in November. Oil was spraying from the blowby tube across the front diff (4 WD) and under truck and spraying on rear bumper and tailgate :{ . Truck seemed to run fine. Oil pressure at 40 PSI, Radiator fluid looked clean, overflow bottle clean, never overheated, water temp normal, no extra noises from engine... . Whats going on?



I haven't yet checked out the truck... its sitting till this Friday when I'm off to work on it. After adding a quart about 80 miles from home it didn't seem to leak much after that . The dipstick is now maybe 1/2 quart low. I noticed some oil spray around that dipstick tube and on top of the brake master cylinder... just a light film. . its not dripping there.



I will check turbo lines for oil and blowby tube for restrictions on Friday.



I have access to a compression gage from our auto shop at work and just wondered if someone could give me an idea of how to check compression. I've done it on a gasser but this is a whole new ballgame for me. Looks like I may have a head gasket or ring problem. :{



I'm a novice at this so I'd appreciate anyones help on what other things I can do. I'll have the compression gage for Friday so I need to get it done. I have read that to check compression the fuel start solenoid is disconnected and injectors pulled. Is that alll there is to it? What has to be done to purge air out of injectors when done to get truck started again?



Thanks in advance for any help.



Dave

 

[Jeff H]

Almost sounds like its being spit out the exhaust side of turbo? Does she smoke a little? That could be why your bumper is oily?

Check intake also maybe sucking it in. If oil is in the intake stop driving it. Your engine could do a run away.

Is your dipstick up where you pull it out oily? If not thats good no exessive blowby.

If yer losing that much it will show some where. You'll find it.

 

[Dave M]

Almost sounds like its being spit out the exhaust side of turbo? Does she smoke a little? That could be why your bumper is oily?

Check intake also maybe sucking it in. If oil is in the intake stop driving it. Your engine could do a run away.

Is your dipstick up where you pull it out oily? If not thats good no exessive blowby.

If yer losing that much it will show some where. You'll find it.

Jeff,



Yeah there was oil on the dipstick but not sure if it was oily all the way up the dipstick above the full mark if thats what you mean. It looks like the oil is leaking from the front diff towards the back of truck. Its a dually so I never noticed it smoking but it would be hard to see around the dually fenders with the stock mirrors. Truck seemed to run OK on flat but lack of power pulling that trailer in the hills... . 3rd gear 35 MPH on grades pulling about 3,000 lbs I guess.



Thanks for the reply. I'll check the turbo intake and exhaust for oil. The exhaust tip was black sooty inside but thats normal I believe. Didn't notice oil in it. The rear diff was dripping oil from the blowby when I stopped truck.



Thanks guys... keep em coming.



Dave

 

[Smokey96]

My truck is doing the same thing. I went on a 250 mile round trip a couple weeks ago and filled the truck up with oil before I left. When I arrived there was no oil on the dipstick! It was dripping off the tailgate and undercarrige so I filled it back up. When I got back to my house it was dry again. My truck always used a little but now it has gotten worse. It only blows it out when I run over 60 mph. I also noticed that when I open the oil fill cap while the truck is running I can hear a whistle/rattle, kinda sounds like a bearing but not sure.

 

[bmoeller]

I have access to a compression gage from our auto shop at work

How high does it go? If it is for a gasser, it probably doesn't go high enough. Not 100% sure, but I think the compression on the engines is in the neighborhood of 4-500 PSI. The ones for diesels generally get threaded into the hole, so they don't get blown out of your hand.

I have read that to check compression the fuel start solenoid is disconnected and injectors pulled. Is that alll there is to it?

Pretty much.

What has to be done to purge air out of injectors when done to get truck started again?

All I ever do, is once everything is tightened up, is to keep pushing the primer button 'til the OF valve starts to squeak/chatter. Then give the primer another 30 pumps. Then try to start it. If it doesn't hit, do it again. I've never had to break the injector lines loose, to bleed mine.

 

[Hammer]

Sounds like a headgasket is blown to me. There is no other logical reason to disperse that amount of oil out of the crankcase vent tube under the truck... ... ... . Andy

 

[Dave M]

Quote:

Originally Posted by Dave M

I have access to a compression gage from our auto shop at work



How high does it go? If it is for a gasser, it probably doesn't go high enough. Not 100% sure, but I think the compression on the engines is in the neighborhood of 4-500 PSI. The ones for diesels generally get threaded into the hole, so they don't get blown out of your hand.

bmoeller:

The compression gage is for diesels. The mechanic knows me and my truck and works on Ferd diesels, althought... he owns a Ferd ... but I think I can still trust him :-laf. He's aware the compression is 400-500psi and I told him also. He started off telling me to remove glow plug... but I told him there is none and then he got on track when I told him its a mechanical inj pump and to stop the engine starting to disconnect the wires to it... I told him that was probably the fuel solenoid. bmoeller, thanks for insight on restarting after testing compression.

My truck is doing the same thing. I went on a 250 mile round trip a couple weeks ago and filled the truck up with oil before I left. When I arrived there was no oil on the dipstick! It was dripping off the tailgate and undercarrige so I filled it back up. When I got back to my house it was dry again. My truck always used a little but now it has gotten worse. It only blows it out when I run over 60 mph. I also noticed that when I open the oil fill cap while the truck is running I can hear a whistle/rattle, kinda sounds like a bearing but not sure.

smokey96:

Sounds like we have similar troubles. :{ I'll check the oil fill to see if it whistles. Can't imagine what that is... maybe inj pump?

Sounds like a headgasket is blown to me. There is no other logical reason to disperse that amount of oil out of the crankcase vent tube under the truck... ... ... . Andy

Andy,

Headgasket is what I'm thinking too... hope I'm wrong :{ ! I'd prefer a bad turbo... Then I could get a better turbo!



How difficult is taking the head off? I think I could try it (I have done it on gassers. . but rings and valves are not something I'd try alone . Head gasket I could do... I think. Any wise advice along that line and on compression testing would de helpful. I'm just a backyard mechanic but ready to learn.



Please be a bad turbo... . please be a bad turbo. There's a Piers HX35 in the classifieds I'd like to get! Oo. Oo.



Thanks all... anymore insight. . please chime in. I'm sitting here waiting for the best Cummins advice on the web... . I love this site.



Dave

 

[mechanic]

One quick check is to open the oil filler while idling and see how much blowby there is, and if it is a constant stream/ flow, or if it is "puffing". If it is "puffing", is it making a "puff" in time with the firing of a cylinder or cylinders? If so, you most likely have a leak on one or so cylinders, rings, headgasket, piston ect. If a constant stream, it is more then likely several or all cylinders leaking. In this case would most likely be rings. Just a thought one narrowing the possable cause.

 

[Hammer]

Dave. .

If it was a turbo problem you would not find the oil blowing out of the crankcase breather at all. The oiling down of the rear differential should tell you its a compression leak and it will be easily visible as Mechanic said above or just by you looking underneath while the truck is at a high idle by the amount of vapors blowing out of the vent tube. I'd like to tell you its a turbo deal,but,realistically,I would have to say not with what symptoms you are giving us here. Plus,your description of where the oil is at underneath and not on the rear lower quarter panel by the exhaust exit is also a good indication of whats up.



To do the headgasket is about like a gasser job and if you have done them its something you can handle. Approach like one of those and allow plenty of time for anything that may pop up and you will be fine. Just make sure you have a good repair manual on hand to help you through some of your questions and you know the rest of us here can help are only a finger walk away... ... . Andy

 

[mechanic]

Dave. .

If it was a turbo problem you would not find the oil blowing out of the crankcase breather at all. The oiling down of the rear differential should tell you its a compression leak and it will be easily visible as Mechanic said above or just by you looking underneath while the truck is at a high idle by the amount of vapors blowing out of the vent tube. I'd like to tell you its a turbo deal,but,realistically,I would have to say not with what symptoms you are giving us here. Plus,your description of where the oil is at underneath and not on the rear lower quarter panel by the exhaust exit is also a good indication of whats up.



To do the headgasket is about like a gasser job and if you have done them its something you can handle. Approach like one of those and allow plenty of time for anything that may pop up and you will be fine. Just make sure you have a good repair manual on hand to help you through some of your questions and you know the rest of us here can help are only a finger walk away... ... . Andy

I agree with Hammer on the job, and the manual. The best source I have found is either Mitchell or Alldata. I don't know if Mitchell offers an online service for the DIY'er but Alldata does. I used it in my business for a good while untill I got the subscription version on C/D. You can get it at www.alldatadiy.com the cost is $24. 95 for the first vehicle and $14. 95 for each additional. That pays for one year of use any time 24 hrs a day, or all-day, all-year.

Not a bad deal and it is the manufactures shop manuals, not a wanta-be afterthought.

 

[Dave M]

One quick check is to open the oil filler while idling and see how much blowby there is, and if it is a constant stream/ flow, or if it is "puffing". If it is "puffing", is it making a "puff" in time with the firing of a cylinder or cylinders? If so, you most likely have a leak on one or so cylinders, rings, headgasket, piston ect. If a constant stream, it is more then likely several or all cylinders leaking. In this case would most likely be rings. Just a thought one narrowing the possable cause.

mechanic:

Thanks for that tip. I'll sure try it.

Originally Posted by by hammer

Dave. .

If it was a turbo problem you would not find the oil blowing out of the crankcase breather at all. The oiling down of the rear differential should tell you its a compression leak .....

Ok. But if the turbo was leaking on the intake side could that not only cause oil to burn... . but also pressurize the crankcase and contribute to the blowby... I may be wrong. . and probably am. . but am I thinking wrong on that? I really feel your right and it looks like its not a turbo... . dang! If it was a turbo intake leak would that big of a leak cause a runaway condition and therefore rule the turbo intake leak out based on that not happening too?

Originally Posted by hammer:

To do the headgasket is about like a gasser job and if you have done them its something you can handle... . have a good repair manual on hand

I do have the Dodge dealer manual, but if this turns into more than a head gasket job... like rings, pistons, etc... (lower end)... then I'm stuck towing it 50 miles from out in the boonies away from the nearest diesel shop in Fresno. Kinda scares me ... I got no backup on this. . its just me... but I sure like to give it a try myself and learn more about this beast.

Originally Posted by Hammer

... . and you know the rest of us here can help are only a finger walk away... ... . Andy

Thats greatly appreciated by me guys... and why I'm willing to go for it !

Originally Posted By Mechanic:

I agree with Hammer on the job, and the manual. The best source I have found is either Mitchell or Alldata. I don't know if Mitchell offers an online service for the DIY'er but Alldata does. I used it in my business for a good while untill I got the subscription version on C/D. You can get it at www.alldatadiy.com the cost is $24. 95 for the first vehicle and $14. 95 for each additional. That pays for one year of use any time 24 hrs a day, or all-day, all-year.

Not a bad deal and it is the manufactures shop manuals, not a wanta-be afterthought.

Hammer:

I had never heard of the Alldata manuals. I'll check them out. I like to have as much info as I can get, since I don't do this all the time. Thanks for the info. I check out the web site.



I appreciate all the great help so far. I'm feeling a little apprehensive about tackling this beast but a little better than before.



Do I need a hoist to get the head off or can me and my son get it off? Any other details on the removal would be helpful. I haven't checked the Dodge manual yet but they always say to use tools only Dodge has. There is a Cummins West shop in Fresno, so I may get an estimate from them too. Any special tools to remove the injectors? I haven't seen the compression gage I'm going to borrow yet... it may be snapon and have everything with it.



Thanks again for all the advice... . Any more please jump in. I'll be tackling this on Friday April 1... . at least its not supposed to rain .



Hey... Wait a minite! Geez... Friday is April Fools Day... . Man I guess thats a good day for a fool like me to tackle this :-laf



Dave

 

[Vaughn MacKenzie]

Check the vacuum pump before tearing things apart! I heard a bad or leaking vacuum pump will cause tons of blowby and significant oil loss.



My truck did a weird thing where it suddenly started drinking a lot of oil, but no more than a quart every 2-300 miles. It has since subsided and only used about 1. 5 quarts in 2500 miles.



I did a compression test on mine not long ago, I had 520psi on all but #1 which was 500. This was at 366,000 miles and . 010" over head gasket.



Vaughn

 

[41jay]

Whats going on ?

My truck is using oil purtty good too I know the oil pan is leaking but a-lot of oil is coming out that black hose I mean a-lot what is that and why is it leaking so much oil? I wish I could put a check valve on another hose and run it into my exhaust pipe could I doo that that way my truck won't get so oily underneath and I can really tell where the real oil leak is coming from. But why is it leaking so much I have to watch my oil I've caught it a Qt or two low before I check it twice a week. could exses oil leaking cause my clutch to slip or is it closed off to outside elements?

 

[Dave M]

Check the vacuum pump before tearing things apart! I heard a bad or leaking vacuum pump will cause tons of blowby and significant oil loss... ...

Vaughn

How can the vacuum pump cause blowby? Hmmm... Are there oil lines going to the vacuum pump and if that seal blew then it would pump vacuuum pressure into the oil return? Obviously an external oil leak would not cause blowby. Just trying to understand this. I don't think there are any external leaks at the vacuum pump/power steering pump area. I'll check better tomorrow for leak paths again.



I borrowed an OTC (a division of SPX) 5020 Compression Test Kit today from work for tomorrows testing. Has an adapter for the Cummins B injector and it says for glow plug... . Huh... there is no glow plugs... so figure its a typo.



Compression Testing Questions for Ya:



1. ) Should ALL the injectors get removed in the beginning or one at a

time as I test each cylinder or does it matter?

2. ) Will a simple wrench work to remove the injectors... Injectors are

threaded into block... Right? Just Remove line and remove Injector?

3. ) If Fuel shutoff solenoid is disconnected will any fuel come out of

the injection lines when I crank the engine? I'm thinking... NO!

4. ) Shoulds 3 or 4 cranks be enough to get a good psi reading?

5. ) Am I missing anything else?

6. ) Is the compression test worth doing?



I talked to a Cummins shop today and they said the compression test is not necessary and recommended the "Manometer" blowby test as it will more accurately point to the problem. They do it under load and with turbo disconnected. Also didn't think it would be a head gasket either but more a compression leak thru the cylinder (rings or sleeve) into the crankcase.



They said if the turbo was bad it would be due (in my case) to the turbo blowing into the oil return and pressurizing the crankcase... and therefore would not show up as oil in the intake or exhaust lines to the turbo. They also said my low boost (9 psi max) problem is causing damage to the engine especially if I "Get on It". I'll probably call them tomorrow (after I snoop around my engine) and make an appointment for the "Manometer" test ($125) Monday. They were really noncommittal on diagnosing the problem until the results of the "Manometer" test are known.



Anyone have a suggestion for a better "Diesel Shop" in the Fresno area let me know. I hate to get into the head and just have it towed to a shop for rings or something :{ . Would you guys just pull the engine if the rings or cylinders were bad and take it to a engine shop ?



Kinda pulling my hair out here on whats best to do! How much would I save by pulling the engine over letting Cummins or a Diesel Shop do it... I don't know yet... but money is tight right now.



I'm starting to get a painfull feeling in my wallet right now! :-laf

 

[Vaughn MacKenzie]

DaveM, I don't really understand the vacuum pump thing either, but it exhausts into the crankcase, so if it's sucking lots of air through a leak it blows all that air into the crankcase which blows more oil vapor and oil out and/or causes leaks. I just remember reading 3-4 posts of guys having high oil consumption and when they found out it was the vacuum pump, the problem went away.



Compression test:



Only remove injector to cylinder you are testing (keeps cranking RPM consistent and aviods sucking junk into cylinder)

Yes no fuel will flow with shutdown solenoid plug disconnected.

It takes a 19mm wrench to unscrew injector, also need to disconnect return rail (small line joining all injectors)

If injector won't come out easy, use lug nut off wheel to screw on the end and pry with a wrench or large screwdriver



Taking reading:



Record reading at 3rd compression hit, but keep cranking until it maxes out (5-6 hits). So record 2 numbers for each cylinder. If it takes quite a few hits to max out and your reading after 3 is weak then you have a weak hole. I would practice a couple times before recording your numbers.



On mine I always had 300 on the second hit and 520 peak. I learned afterwards to take reading on 3rd hit.



My cylinder #1 was weaker coming up, it was only around 150 on the second hit as I recall, but it still maxed at 500.



Good luck and tell us what you find. Vaughn

 

[JBrookshire]

I feel your pain

My 1996 is doing the same thing with 240,000 miles. I had it looked at last weekend He thought it was a turbo. so he put a rebuilt one on and I went for a test drive soon as I hit the road I mash the go peddle hit 3 and it was all over with, poped the turbo. So he thought it was the turbo so he put a new one on and I babyed it down the road turned around and jumpend on the fuel and popped it. He said I more than likle have a scuffed cylender or rings And the new turbo seals wernt blown and it was pressuring the oil return line and not letting the turbo get oil. so be careful on putting a turbo on... . I am getting ready to tear the head off to make sure and then do a rebuild. hope this helps. The guy that works on my truck was a engineer for cummins and is real knowlageable too. But I feel your grief. Justin

 

[Dave M]

Vaughn,



Im still not sure on how to tell if its the vacuum pump. Not sure how to test for it other than take a vacuum gage and measure it. I'll keep it in mind though... . maybe ask Cummins if I go there.



Thanks for clearing up the questions I had on the compression tests. Lotsa good advice there. I'll try taking the 3rd and highest reading for each cylinder. I assume the return line is only disconnected one at a time on each injector... . need to look at it again to see how its plumbed.



Jbrookshire,



Man!... You had bad luck with the turbos. Sounds like you said the turbo oil return line was pressurized but not sure by what? A leaky turbo will pressurize the return line but sounds like your saying the bad rings were pressurizing the oil return to the turbo and starving it for oil. . Geeez. . Thats sounds weird! Good luck with your problem. Sounds like new rings at least.



Tomorrow I'll take a closer look at the leaks, check turbo lines, and test compression. Any more ideas. . let me hear it.



Thanks,



Dave

 

[mechanic]

How can the vacuum pump cause blowby? Hmmm... Are there oil lines going to the vacuum pump and if that seal blew then it would pump vacuuum pressure into the oil return? Obviously an external oil leak would not cause blowby. Just trying to understand this. I don't think there are any external leaks at the vacuum pump/power steering pump area. I'll check better tomorrow for leak paths again.



I borrowed an OTC (a division of SPX) 5020 Compression Test Kit today from work for tomorrows testing. Has an adapter for the Cummins B injector and it says for glow plug... . Huh... there is no glow plugs... so figure its a typo.



Compression Testing Questions for Ya:



1. ) Should ALL the injectors get removed in the beginning or one at a

time as I test each cylinder or does it matter?

2. ) Will a simple wrench work to remove the injectors... Injectors are

threaded into block... Right? Just Remove line and remove Injector?

3. ) If Fuel shutoff solenoid is disconnected will any fuel come out of

the injection lines when I crank the engine? I'm thinking... NO!

4. ) Shoulds 3 or 4 cranks be enough to get a good psi reading?

5. ) Am I missing anything else?

6. ) Is the compression test worth doing?



I talked to a Cummins shop today and they said the compression test is not necessary and recommended the "Manometer" blowby test as it will more accurately point to the problem. They do it under load and with turbo disconnected. Also didn't think it would be a head gasket either but more a compression leak thru the cylinder (rings or sleeve) into the crankcase.



They said if the turbo was bad it would be due (in my case) to the turbo blowing into the oil return and pressurizing the crankcase... and therefore would not show up as oil in the intake or exhaust lines to the turbo. They also said my low boost (9 psi max) problem is causing damage to the engine especially if I "Get on It". I'll probably call them tomorrow (after I snoop around my engine) and make an appointment for the "Manometer" test ($125) Monday. They were really noncommittal on diagnosing the problem until the results of the "Manometer" test are known.



Anyone have a suggestion for a better "Diesel Shop" in the Fresno area let me know. I hate to get into the head and just have it towed to a shop for rings or something :{ . Would you guys just pull the engine if the rings or cylinders were bad and take it to a engine shop ?



Kinda pulling my hair out here on whats best to do! How much would I save by pulling the engine over letting Cummins or a Diesel Shop do it... I don't know yet... but money is tight right now.



I'm starting to get a painfull feeling in my wallet right now! :-laf

Hi Dave,

Just a thought or two. I would be cautious about pulling the head if you don't have a place to get in out of the weather / dust. While not as bad a problem in your area as in mine, a little dust will go a long way to damage cylinders.

I have heard that the best way to pull that engine is to unbolt the cab and lift it a few inches and block it up. This allows engine to be lifted up far enough for the oil pan to come forward over the crossmember with out the bellhousing hitting the floor pan.

Oh well, maby you won't have to go there.

That vac pump possibility? Since the vacuum pump routes the air it evacuates from the brake booster, cruise control and ect. into the crankcase then a leak in a vac hose or the pump could add pressure in the crankcase. I just remembered that the 92< VW diesels which have a vane type pump much like the 94> Cummins, if run with the hose off the pump will cause oil to spray from the crankcase vent on the valve cover. The oil ejected increases with engine speed, non at idle and low speed increasing to a bunch at 4000 RPM. However the turbo pressurizing the oil return line sounds also sounds plausable since you have low boost. This is getting interesting and educational.

Keep us posted.

 

[Dave M]

Originally Posted By Mechanic:

Just a thought or two. I would be cautious about pulling the head if you don't have a place to get in out of the weather / dust.

Well. . You got me there... This would be done in a gravel driveway and I live off a 1/2 mile of dirt road... sounds bad for this job HuH? Oh well. . I'll see what testing reveals at least before passing judgement on the next step.

Originally Posted By Mechanic:

That vac pump possibility? Does the vacuum pump exhaust the air it evacuates from the brake booster, cruise control and ect. into the crankcase? If

Well. . I just replaced the brake booster. The power steering pump lines go to the booster to supply hydraulic boost to the brakes. Still can't see how it could pressurize the oil but if a seal goes it could pump pressure into the oil causing the pressure in crankcase... . Hmmmm... I suppose its possible. Kinda makes my head hurt trying to imagine how it would happen though. . :-laf Hope its isn't true. . but it would be cheaper that a rebuilt engine .

Originally Posted By Mechanic:

I just remembered that the 92< VW diesels which have a vane type pump much like the 94> Cummins, if run with the hose off the pump will cause oil to spray from the crankcase vent on the valve cover.

Thats very interesting... Hmm. . I'll sure check the vacuum pump lines closely since I was working around there when bleeding and refilling the power steering pump a few weeks ago when I replaced the Hydroboost unit.

Originally Posted By Mechanic:

However the turbo pressurizing the oil return line sounds plausable. If you don't have much blowby at idle, that idea would fit that senerio.

Keep us posted.

This sceanario would be more possible and easier to fix than the engine, but diffucult to prove without another turbo. I'll let Cummins do the "Manometer" test on the blowby and that should prove if the turbo is at fault. . at least thats what I think they said



Thanks guys. Tomorrow should be interesting. Hope I find a cheap solution... . Come on Income Tax Return... I need some cash! Oo. :-laf



Dave

 

[mechanic]

I didn't realize that your's has the Hydraboost brake booster. It is by far the more desirable system as far as I am concerned, but it would have nothing to do with vacuum leaks. However anything else that lets air into the suction side of the vacuum pump could be the culpert. I be interested to hear what the test shows.