I have an 04 ram 4x4 1500 with the 5.7L Just looking for advice on diagnosing where my oil is going ??? i am using about 1 litre of oil per tank or tank and half of gas and have no engine oil leaking externally.the truck has 80000km on it i bought it used so i have no history and i have no record of maintenance so i am out of luck with warranty if i need motor work unless the truck was maintained at chrysler and they have records. I have noticed a blue puff of smoke once or twice on startup so i know i am burning it. I want to fix it before it destroys my cat which will destroy the motor if it gets plugged up.
i was thinking of starting with compression test for all cylinders does anyone know the minimum pressure and the maximum difference between cyl pressures on these motors ?(usually 100psi and 30-40 psi difference on other motors)
if compression is all good then where to look ?
does this motor have a plenum gasket like the 2nd gen motor ?
or would this be leaking valve guides ?
i also have a small tapping noise and vibration at idle could this be a bent push rod in the valvetrain or a bad lifter?
does this motor have hydraulic lifters or solid type ?
does anyone have technical service bulletins on this procedure ?
thanks for any info or help ?

 

the tapping noise you are hearing is the hemi tick...every hemi has it, it's normal...heres a test you can try doing:
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
² Exhaust and intake valve leaks (improper seating).
² Leaks between adjacent cylinders or into water
jacket.
² Any causes for combustion/compression pressure
loss.
(1) Check the coolant level and fill as required. DO
NOT install the radiator cap.
(2) Start and operate the engine until it attains
normal operating temperature, then turn the engine
OFF.
(3) Remove the spark plugs.
(4) Remove the oil filler cap.
(5) Remove the air cleaner hose.
(6) Calibrate the tester according to the manufacturer’s
instructions. The shop air source for testing
should maintain 483 kPa (70 psi) minimum, 1,379
kPa (200 psi) maximum and 552 kPa (80 psi) recommended.
(7) Perform the test procedures on each cylinder
according to the tester manufacturer’s instructions.
Set piston of cylinder to be tested at TDC compression,
While testing, listen for pressurized air escaping
through the throttle body, tailpipe and oil filler cap
opening. Check for bubbles in the radiator coolant.
All gauge pressure indications should be equal,
with no more than 25% leakage.
FOR EXAMPLE: At 552 kPa (80 psi) input pressure,
a minimum of 414 kPa (60 psi) should be maintained
in the cylinder

I also have a chart that would be of more help to you, but you'll have to PM me your e-mail addy so i can send it to you...can't post it on here

 

is this procedure using a special compression testing tool ? I have a compression tester but does not have an air inlet on it for compressed air. what is the tester ur using called and best place to get one this seems like a very thorough way to test for all types of leaks !!! thanks for the help my e-mail is riddjo@gmail.com i appreciate the help and the charts if possible !
nice trucks by the way !
do you have a body lift kit on the tall one ? are they easy to install ?

 

Try having a local shop test the compression, some of the smaller non-mainstream ones will do it on the cheap.

I have no idea if it's safe to do on a Hemi, but the way I was taught to test compression was to just hook up the compression meter and crank the engine over with the distributor cap removed while someone watches the gauge.
(Repeat for each cylinder)

Just as an afterthought, does you compression tester use a quick disconnect system? (like air tools)

If it does, just use a Valved "Y" Coupling with it and you can air it up with a compressor.

 

ok i sent ya that chart that i made for ya...yeah i have a 3" body lift on my 4x4....they are fairly easy to install if you have access to a lift...otherwise they kind of a PIA

basically just rig something up that will let you hold a steady 80PSI in the cylinder and then walk around the truck and listen for air coming from someplace...

 

ok, first off, a cheap compression tester from your parts store is used to test for the cylinder MAKING compression...not holding compression. every cylinder is going to leak air past the rings hence the need for a pcv system. your compression tester should have a threaded fitting on the end that you put in place of the spark plug for your cylinder of choice. then you pull the fuel pump relay and crank the engine over. turn it over 3 or 4 times and then go check your tester. your compression tester should also have a one way check valve so that when maximum pressure is read, it wont drop in pressure. this is to keep you from having to haul #$% to the tester to see what the pressure is before it drops. you can type in a search for specs for your engine. eventually you should find what the pressure reading should be and what the pressure difference tolerances are. secondly, a pressure check isnt going to tell you much except what the cylinder pressure is. its not going to tell you where the leak is. if your burning as much oil as you say you are, i would seriously doubt that much oil is defying gravity by moving that far UP past the rings. i would check the easy stuff first like checking for oil in the radiator(blown head gasket), checking for oil in the air filter housing and throttle body(screwed up pcv system). im not sure if it has a plenum style like the 2nd gen, but if it does, i would suspect the plenum gasket first (a simple look in the intake should tell you). if everything so far seems ok, then i would definitly say 1 or more valve stem seals are leaking. in your case i would focus on the more part of that previous sentence. you can check your valve stem seals by taking off the intake manifold and looking at the back side of the valve face. if its completely covered in oil and probably a little gritty, theres the culprit. By the way, if you run a compression test and one or more of the cylinders is making extremely low pressure, i would bring really bad piston rings into the equation at that time, but thats the only time i would concider that. I hope i've helped. if anyone sees any flaws in my statements, please feel free to correct me.

 

Sounds like a bad valve guide

 

Bang on!
Good help and info here.
Al.

 

Just performed a compresion on 5.7 this past weekend.
Did it just as posted above. Pulled the fuel pump fuse and cranked it for a few seconds. Most of my cylinders where 175-185# with the exeption of the #6 which was 130#. Haven't sent it to dealer yet.
Best of luck.

 

130psi on one cylinder isnt good, but i also wouldnt suspect a bad ring on that one cylinder to be burning that much oil. i would honestly say a bad valve stem seal. you could do the combustion leak down test as stated earlier to find out if it is a bad ring or valve causing the bad compression. as far as the oil consumption, you could take off the intake manifold and look at the back of the valve faces and see if any are really dirty and oily. exhaust valves are a little bit more difficult since there are extreme pressures going out of the cylinder, so oil isnt going to just sit on the valve, it would go from the valve stem to the exaust pipe, completely skipping the back side of the valve face. you could take off the exhaust manifold and look inside of it and see if any of the holes are dirtier than the rest. you can check your plugs and see if any of them are dirtier than usual(look like they have burned oil on em). if any of the plugs are really dirty, i would lean towards a bad intake valve stem seal. if all the plugs pass inspection, then you could go to the exhaust manifold. i should warn you though, exhaust manifolds arent fun to deal with. since they get hot and cool off all the time, the manifold likes to warp. the only thing that keeps everything straight on there is the bolts...as soon as you remove them the manifold likes to stress relieve itself, hence the warping. getting it back on can be a b#!&h.

I am assuming that you checked the coolant and air box for oil before doing all of this.

BTW, if your truck is under warranty or you have the money to spend on it, i would just take it to a dealer or independent shop and let it be their problem. now days, its alot cheaper for a shop to replace the entire motor than to put new piston rings in, do a head gasket, or valve stem seals.