| From | Message |
Brewstar
Dodge Dakota
JOIN HERE
12/04/2009
22:33:12
|
 Subject: Oil idle pressure zero?
IP: Logged
Message:
Hey, so I recently bought a 2000 dakota with an
automatic and 4.7 v-8 with 155,000 miles on it now
and it drives smooth. I just found out that my
idle oil pressure is zero. My gauge reads normal
at cold, warm and idle, but the shop I took it to
did a manual pressure test and showed 40psi at
cold 2,200rpm, 25psi at warmed up 2,200 rpm.
The reason why they did the test was because the
truck has a ticking sound that is more pronounced
when the engine is cold, and because the passenger
side valve cover gasket was leaking. When they
took off the valve cover they said the valves
looked fine and didn't think the ticking sound was
from the valves, so thats when the manual pressure
test was done.
So I have narrowed it down to being either the oil
pump is clogged/broken, or the barrings are too
worn. It will cost me $660 to remove the oil pan
and find out what the problem is (includes re-
installation), and another $330ish to replace the
pump/filter if that is the problem, but about
$2,000 to replace all the barrings (if there is no
damage to the crankshaft).
I can't afford to replace the barrings, and I
don't want to pay to remove the oil pan if I can't
fix the problem. Also I don't want to replace the
oil pump if the zero idle oil pressure damaged the
cylinders or pistons enough that the engine will
die soon anyway. So, I don't know what to do. I
could save all that money and just drive it till
it dies, then replace the engine (i would have to
finance it), or I could just take the risk to
repair it now and hope the repair will last me a
while.
The timing chain cover has also been replaced, if
that is a sign of a past broken timing belt, it
might mean that when the chain broke it caused
debris to fall into the oil pan and clogged the
screen.
But my question to anyone is: With what I know
about the truck (not much), is lack of oil
pressure at idle most likely caused by a
clogged/damaged pump or something else?
The truck drives well, it doesn't feel like the
engine is vibrating (if that happens with bad
barrings), and the valves look great, and it seems
like the maintenance has been kept up on the
vehicle. I don't think it is burning oil yet and
the transmission shifts smoothly. There is only
no pressure at idle and it is at 40psi cold and
25psi warmed-up, so it is getting oil flow
sometimes and is not totally dry. If it were a
clogged screen the pressure should increase when
it is warmed-up because of easier flow of oil when
warm. But if it were worn barrings the thinner
warm oil would flow too freely and the pressure
would drop. So the signs are pointing to barrings
in my opinion, unless oil pumps can partially fail
in which case a partially failed fan might be able
to pump the thicker cold oil to a higher pressure
while not being able to do the same to the thin
sloppy warm oil; can oil pumps partially fail and
am I right about how they work?
Where is the dash oil pressure sensor? Because it
is still reading normal and depending on where it
is located and where they took the manual oil
pressure test from I might be able to tell more
about the problem.
If it looks like it is the pump, should I replace
it with OEM or after-market? I've read that sludge
can easily clog stock oil screens and pumps. Is
there anything else I should check/replace/clean
when everything is out from under the truck, when
I get the oil pan removed?
Come-on, I have a white quad cab with a 3 inch
body lift sitting on 33s, and I really want to
keep it.
|
mister
Dodge Dakota
JOIN HERE
12/05/2009
08:42:57
| RE: Oil idle pressure zero?
IP: Logged
Message:
You should of stuck with a 318 V8!!
|
stevedak
Dodge Dakota
JOIN HERE
12/05/2009
09:11:44
| RE: Oil idle pressure zero?
IP: Logged
Message:
These engines are prone to building up sludge and crap in the oil pan and around the inside of the block, it can clog the oil pickup screen. All of your oil pressure readings are low for the conditions you describe. If you wait for it to die, it won't be long. A new timing cover may mean the oil pump has been replaced. Even if the pump has been replaced, it doesn't mean the pickup screen was cleaned or replaced, gotta remove the oil pan for this. Did you just buy this truck?? If so, you may have found the reason the previous owner sold it.
My 2002 dakota with 4.7 had the sludge/crud problem. After dropping the oil pan, I found the pickup tube totally blocked. WIth the pan removed it was easy to remove and clean the pickup tube. But I also had to use a decreaser and rinse with a lot of water to clean the crud from the block and cylinder walls to prevent the same problem from happening again. I also changed the oil pump. I was surprised but its run great ever since, no bearing issues. The bearing are held in by a cradle, I didn't want to take it out and have the entire crankshaft unsupported.
If you have to have a mechanic do all the work, have the pan dropped, clean the pickup tube and install a new oil pump.
If you are adventurous and feel like you have nothing to lose, you might try backflushing. Drain the oil, leave the drain plug out. Remove the oil filter and use a water hose (yes I said water) to flush as much water as possible into the engine. You want to flush water thru the hole in the center of oil filter fitting, the hole is threaded. This should get water thru the oil pump and out of the pickup tube to remove any crud blocking the screen. Check the water that drains out the oil pan, is it just oily or filled with crud? Catch the water in a pan so you can check. After flushing, install old oil filter, fill with the cheapest oil you can find. Run this oil for a few minutes and check the pressure. Drain the oil (will have water residue), install NEW oil filter and refill with good oil. IF you get good results but not good enough, repeat the procedure. THis is unconventional but I don't think you have anything to lose.
|
02dak4x4
Dodge Dakota
JOIN HERE
12/05/2009
22:00:31
| RE: Oil idle pressure zero?
IP: Logged
Message:
You can also try something else to help remove sludge and free up some junk but nothing is completely safe from causing problems.
One thing you may try is adding a quart of ATF tranny fluid (any type) to the engine oil and let that sit and run in there for a while before changing the oil. The additives in the ATF should remove some junk. (you can also do this with a quart or so of diesel for more cleaning)
From the sound of what you have said I doubt your pump is a problem and I doubt you have a bearing problem. I think you may have some debris on the screen of the pump and within the oil passages.
There are also some off the shelf engine flushes you may try to remove debris. Seafoam works wonders and you can use it in the engine oil, gas and dump right into the intake.
As with any of these change oil and filter after doing them. Good luck and keep posting.
Fyi don't have them "repair" it. They don't know what it is and bearings, well if they are bad let em go because you will need to machine the crank anyway. The oil pump is a geroter style which is basically two gears...the only thing to go wrong is the pressure relief valve can stick open but you would have 0 oil pressure at idle with that...so you dont have that problem.
|
mac
GenI
12/05/2009
22:09:43
| RE: Oil idle pressure zero?
IP: Logged
Message:
I've never seen anything like what Steve suggests...interesting. And certainly worth pursuing before signing a big credit card slip.
Before that, though, I think I'd go a little wilder than 02dak4x4 suggests, try half and half ATF and cheap 5-30 for about 50 miles or so (enough to get it all warm) then drain and try again with the same stuff if the drain looks really nasty. Try not to work the engien hard during this time, but drive it and not just idle to temp.
I like Sea Foam, but I think the ATF trick will work better in this case. Seafoam in gas...yessireee...every oil change<G>
|
Brewstar
Dodge Dakota
JOIN HERE
12/05/2009
23:16:46
| RE: Oil idle pressure zero?
IP: Logged
Message:
So, you guys think that I should try and flush
everything first? Will that actually cure the
problem of a clogged screen? I agree that I should
do everything I can before paying a mechanic, but
I don't want to spend money trying to flush the
engine and then pay to drop the pan. Would it be
better to put the ATF in first then have the pan
cleaned or clean the pan then flush? I'd like the
longest term cure here without replacing the
engine.
Anyone know what the ticking might come from? The
mechanic I talked to said that it is probably a
result of the lack of oil flow, but he agrees that
he doesn't really know whats wrong, but says he
should be able to figure it out if he removes the
oil pan though.
|
Brewstar
Dodge Dakota
JOIN HERE
12/06/2009
06:28:48
| RE: Oil idle pressure zero?
IP: Logged
Message:
Alright, I think I'm going to do the 50-50 ATF-oil
and see how it turns out, hopefully Ill get it to
the point where I can drive it to my parents and
drop the pan myself.
Is there any other way to get the reverse flow
stevedak was talking about to clean out the pump
screen without flushing it with a water hose?
Anyone think the ticking I have is from a bad
hydrolic lifter? Or you think once I unclog the
pump it should right itself?
Also, 02dak4x4, the manual oil pressure test said
i DO have 0 pressure at idle.
Anyone know where in the engine the oil pressure
sensor is that goes to the dash? Because the dash
gauge does not drop to 0 when I idle but the shop
said they got a manual reading that said it is at
0 psi while idling...
|
Brewstar
Dodge Dakota
JOIN HERE
12/06/2009
06:30:58
| RE: Oil idle pressure zero?
IP: Logged
Message:
Oh, and I bought the truck from a small used car
salesman who bought it at auction from a bank who
repossessed it. I assume the guy didnt want to give
up his truck, but he could have also let the
maintenance slide because he knew it was going to
get repoed.
|
stevedak
Dodge Dakota
JOIN HERE
12/06/2009
13:45:49
| RE: Oil idle pressure zero?
IP: Logged
Message:
Everything you've been told is in hopes you don't have to drop your pan. If you try these remedies and get good pressure, don't drop the pan. If you do drop the pan yourself, you'll have to lift the engine til the intake manifold hits the firewall or whatever max height you can get. Once the pan is lose and down, you'll have to disconnect the pickup tube before the pan can be totally removed ( clear the crossmember). If the mechanic told you the pressure and you don't have your own manual oil pressure guage, get one. As you try these remedies, you'll need to see what improvements you get. Get a pressure reading before and after each remedy you try.
Your pressure is low, you should minimize (stop if possible) driving until you fix it. If its not dead, you don't want to kill it.
Good luck and keep us posted.
|
02dak4x4
Dodge Dakota
JOIN HERE
12/07/2009
19:08:23
| RE: Oil idle pressure zero?
IP: Logged
Message:
Sorry, I mis-read your original post about 40 psi cold and 25 warm. I would try flushing everything as best as possible before removing the pan. Once you flush you may want to drop the pan anyway to clean out any sludge that gets loosened and doesn't come out. I still doubt you have a bad pump, but I could be incorrect. A sticking by-pass valve would create 0 at idle but I would still expect to see near 75 psi at around 2000 rpm. The bypass valve opens at 75 psi which should be the upper bar on your dash gauge.
I would lean toward a clogged pickup on the pump as we have mentioned. Also the lack of oil to the top end of the engine would create a ticking. my 02 4.7 ticks a little until warm and I am pretty sure its due to the lack of oil in the valve train upon start up.
I have also heard of people putting all ATF instead of oil but DO NOT drive it that way, just idle it if you do that for a while to warm it up and loosen the material. Don't be afraid to overfill the pan either, the sloshing from the oil hitting the crank could help loosen sludge.
Good luck, let us know how it goes.
|
huh
Dodge Dakota
JOIN HERE
12/07/2009
22:49:44
| RE: Oil idle pressure zero?
IP: Logged
Message:
"I can't afford to replace the barrings"
WTF is barrings?
|
steve.v
Dodge Dakota
JOIN HERE
12/18/2009
20:03:55
| RE: Oil idle pressure zero?
IP: Logged
Message:
My 2001 with a 4.7 developed a low oil pressure issue, then it would completly drop to zero. I tried flushing the engine with no improvment. I pulled the pan and found major sludge in the pan and the pickup tube screen blocked except for a 1/4 inch area. after cleaning the pickup screen and removing the crud from the pan, the truck is showing pressure like it was new again. If you decide to do the job yourself, it will only cost you about $60 in gaskets and a refill of oil. one item to note is that the intake manifold will have to be removed to allow the engine to be jacked up high enough to get the pan off.
|
Ken montg
Dodge Dakota
JOIN HERE
7/19/2012
20:25:21
| RE: Oil idle pressure zero?
IP: Logged
Message:
I have a 2001in Durango 4.7 engine and runs perfect,doesn't
have a misfire,sounds good,except that it sounds as if it has a
rod knocking in the engine.But this engine has over head
cams and no hpush rods.So I replaced the lifters on both
sides and the noise is still there!can anyone tell me where
this knocking is coming from? And what I need to do to fix
the problem.How can a engine knock that way without rods?
Someone suggested that I should change the oil
pump.(HELP)!!!!
|
daddio
Dodge Dakota
JOIN HERE
7/19/2012
22:05:35
| RE: Oil idle pressure zero?
IP: Logged
Message:
Probably too late to change the oil pump. Rod knock
is from connecting rods not push rods.
|
ant
Dodge Dakota
JOIN HERE
12/11/2012
21:54:46
|  RE: Oil idle pressure zero?
IP: Logged
Message:
How does the oil pan come off I got it a inch
down but it won't come off all the way on a
2003 dodge 4.7
|
harold
Dodge Dakota
JOIN HERE
12/13/2012
13:44:12
| RE: Oil idle pressure zero?
IP: Logged
Message:
why don't you just replace the exhaust manifold studs on the back of the manifold. they always break and cause exhaust leaks and you idiots think its a rod knock. fix your exhaust leak first before you waste your money on a pointless engine rebuild.
|
KJ
Dodge Dakota
JOIN HERE
2/01/2013
14:18:25
| RE: Oil idle pressure zero?
IP: Logged
Message:
Pretty much all 4.7 high-mileage engines have that cold start ticking. Mine has been meticulously maintained and it cold ticks too. If its not knocking I would forget the ATF and engine flushes and try an oil change with Pennzoil 5w-30. It's a high-detergent oil that will work on sludge without cleaning too much at one time. Just change the filter a few times while the oil is cleaning the inside of the engine. I think you pretty much have to lift the engine on a 4x4 to take the oil pan off.
|
markwelb
Dodge Dakota
JOIN HERE
12/22/2013
16:45:23
| lifters keep running dry
IP: Logged
Message:
2001 dodge Dakota 4.7 lifters keep running dry oil
pressure seems to be normal,flushed the engine
twice ,oil just doesn't seem to be getting to the
lifters . Bad pump? Blocked ports? Blocked oil
pick up?
|
Navy HeloGuy
Dodge Dakota
JOIN HERE
5/15/2016
20:08:40
| RE: Oil idle pressure zero?
IP: Logged
Message:
Late add to this older thread. My 2001 Dakota 3.9L had a "low oil pressure" event when my daughter was driving it. Dash light came on and gauge was at zero.
I drained the oil and then took a round nylon brush like a big pipe cleaner that I had in a pack of various size round brushes bought at Harbor Freight. I inserted the approx. 1/2" diameter brush up through the drain plug in the oil pan, put several 90 deg bends in the wire stem of the brush so the bristles would scrub the bottom of the oil pump intake tube screen as I worked the brush from outside the oil pan drain plug. It was unbelievable how much hard black carbon came out. Little chunks about 1/16" - 1/8" in size. I flushed the pan with fresh oil a couple of times, refilled again and put on new filter, ran it, drained, scrubbed the oil pump intake tube screen again, etc.
I kept getting stuff out, but finally had to wrap it up and see how it was doing. Oil pressure was back up to normal range. It was a PITA, but much better than jacking the engine and dropping the pan. I have no doubt dropping the oil pan would be the best solution, but that was more work than I was up for. (Standing by for the haters!)
Anyway, just wanted to put it out there that there is another way to clean the debris off of your oil pump intake tube screen without jacking up the engine and dropping the oil pan if you think that exceeds your capabilities/pain threshold. I expect I will need to do this again at each oil change for a while until I stop finding the hard carbon chunks when I scrub the screen. You do this "in the blind" since you can't actually see the screen, but it is in the sump/lowest point of the pan and you can definitely tell when the brush is under the screen. Work it around a bit and you can remove a lot of crud.
The last time I did this (this weekend) I also modified a new oil filter in an attempt to backflush the screen. I removed the "anti-drain" rubber gasket inside the oil filter, drilled a 1/2" hole in the top of the oil filter (kept metal out of the filter using a strong hard drive magnet), glued in a hose/tube, screwed on the modified filter and ran fresh oil into the filter. Thought was this would let fresh oil run back down the passage to the pump and out through the pickup tube and screen, carrying away the debris clogging the screen that I has loosened up by scrubbing with the brush. While the oil would slowly drain down through the tube and modified filter, it was a VERY slow drain. I didn't get the flushing action I was hoping for. Just wanted to put that out there. My understanding of filters in general, and engine oil filters in particular is that the oil comes from the oil pump, enters the filter through the multiple holes around the outer circumference of the filter, goes through the filter media and into the center of the filter and out through the spin on fitting to the lubrication points in the engine. That is why I fed the oil into the outer portion of the filter. I don't think forcing a flushing solution into the engine through the center spin on filter fitting will send oil back to the pump and out through the intake tube & screen. I could be wrong, but I think the center spin on fitting routes oil down stream from the pump, not up stream back toward the pump.
I have never had a vehicle engine produce so much crud/carbon deposits in the oil system. Something about this dodge 3.9L engine I guess, although it doesn't sound like the issue is confined to just the 3.9L.
I do not profess any expertise in engine maintenance/repair or anything else. I've benefitted greatly from these type forums and just wanted to return the favor.
|
| | P 1 |
|
Post a reply to this message:
Username Registration: Optional
All visitors are allowed to post messages
|
