replace 93 oil pump?
#1
03-12-2011, 08:15 PM
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replace 93 oil pump?
I have a 93 dakota 3.9 2wd automatic.It started rattling on the way to work. The oil pressure guage went to zero. But if i accerlerate the oil pressure would rise until the tranny shifted and then fall back to zero and stayed at zero while idling.Mechanic thinks the only way to replace oil pump is to pull the engine. Maybe drop tranny and rack and pinion possibly.Is there a way to tell if the pump is bad before doing all of that or is a rod knocking?The truck has 171,000 miles on it.Really cant afford to replace truck right now and kind of like the old girl even with her flaws. thanks in advance!
#2
03-12-2011, 09:36 PM
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Welcome to DF. I will move this to the 1st Generation Dakota Sub-Forum.
The low oil pressure is a common problem. It usually is the oil presser switch/sensor. The fail quite often, even some new ones can be bad. I say replace it and see what happens. Also do a good oil change if possible use an oil treatment like Sea Foam to clean the oil passages.
If then it still is low get a mechanical oil pressure gauge to see what exact the number is.
The oil pump is at the bottom the engine. It is possible to remove the oil pan and change it. But getting the oil pan off can be very intensive.
Also lower pressure is a normal side effect of an older engine.
The low oil pressure is a common problem. It usually is the oil presser switch/sensor. The fail quite often, even some new ones can be bad. I say replace it and see what happens. Also do a good oil change if possible use an oil treatment like Sea Foam to clean the oil passages.
If then it still is low get a mechanical oil pressure gauge to see what exact the number is.
The oil pump is at the bottom the engine. It is possible to remove the oil pan and change it. But getting the oil pan off can be very intensive.
Also lower pressure is a normal side effect of an older engine.
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03-12-2011, 11:32 PM
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#6
03-13-2011, 08:51 PM
Have you been able to identify exactly where the rattle/knock is coming from? Does it speed up and change with rpm?
To get to oil pump would be easier to pull engine in my opinion, getting oil pan off is tricky at best. And unless you can be certain the noise is from there it is time to pull engine anyway.
To get to oil pump would be easier to pull engine in my opinion, getting oil pan off is tricky at best. And unless you can be certain the noise is from there it is time to pull engine anyway.
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03-13-2011, 09:09 PM
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#9
03-19-2011, 06:05 PM
Had the same problem twice and fixed it myself twice.
Hey guys and gals.
I have a 2001 Dakota sport with the 3.9.
one day I noticed the oil pressure gauge went to zero and you could tell there was no pressure because of the noise and rattlin'.
I investigated the problem on line and learned that alot of these motors with the 3.9, (including Durangos and others) have too small of a oil return jet hole and they get plugged because the oil in the engine will start to burn creating sludge. Mine was all full of sludge under the oil cap. I learned that there were (and probably still are) many owners who were told their engines were junk and either purchased new engines or junked the vehicles.
So the solution that worked for me:
Yes, you do have to unbolt the motor and tranny from the motor mounts and the tranny mount. (not hard to do). Next, take the two bolts off where the exhaust connects to the exhaust manifold (don't take the manifolds off, just unbolt the exhaust pipe). Now drain and remove the oil pan. This is what mine looked like.
The bottom of the pan was loaded with what looked like very small chunks of coal. It was the oil sludge that burned and made its way to the pan via the return jets. The oil pump filter was full of this stuff as it tried sucking the oil back through. There was only a hole the size of maybe a dime that would allow the oil through, so it really wasn't getting through the screen. I did buy a new oil pump as well since it was such a deal to get the pan off.
I cleaned the old gasket material from the pan and where it bolts on, took the screen off and was able to scrape and clean the screen which was fairly thick, so it was fairly easy to remove the baked on sludge and clean the screen with a wire brush.
I put the old screen onto the new oil pump and bolted in place.
Install new gasket and bolt on oil pan.
Lower engine making sure to carefully align the bolts as you lower the engine back onto the engine mounts (fairly easy).
Now just Re-bolt the exhaust back onto manifold; Re-bolt the transmission to the cross over mount and finally bolt the engine back onto the mounts.
Fill with required amount of oil and with alot of luck, maybe it will last another couple years before happening again, like mine did.
Second go around was completely different.
If you decide to try this and find yourself unsuccessful, U can email me and I can explain what worked on the second go around after the two years it took to go bad again (and not the oil pump, hell for all I know there might not have been anything wrong with it to begin with.
I really scraped and cleaned all the parts I could get to when the oil pan was removed (that might have been a big mistake because I loosened up alot of that crud and after the pan was reinstalled, I'm thinking alot of that crud came off and went back to the bottom of the pan. The pan was full of crud again on the second go around.
Anyway, if you want to learn how I managed to get lucky on the second go, send me a message at:
RTLetvinchuck@hotmail.com and I will try to help out the best I can.
Just don't expect a reply right away as I only check my emails maybe once a day, sometimes every three days.
Thanks and I hope I am able to help out a few of you with the same problem and save you a ton of money or save your engine. Don't trust any mechanic that says you have to remove the engine and transmission and a whole bunch of other stuff. Yes you do have to unbolt everything and just jack the motor up.
Also, if someone tells you your motor is shot and say they offer you a lowballer price on your vehicle because supposedly it is junk, take my advice and at least try doing what I explained, it can't hurt to potentially save you a grand or three (or more).
Robert T. Letvinchuck
North Fond du Lac, Wi
I have a 2001 Dakota sport with the 3.9.
one day I noticed the oil pressure gauge went to zero and you could tell there was no pressure because of the noise and rattlin'.
I investigated the problem on line and learned that alot of these motors with the 3.9, (including Durangos and others) have too small of a oil return jet hole and they get plugged because the oil in the engine will start to burn creating sludge. Mine was all full of sludge under the oil cap. I learned that there were (and probably still are) many owners who were told their engines were junk and either purchased new engines or junked the vehicles.
So the solution that worked for me:
Yes, you do have to unbolt the motor and tranny from the motor mounts and the tranny mount. (not hard to do). Next, take the two bolts off where the exhaust connects to the exhaust manifold (don't take the manifolds off, just unbolt the exhaust pipe). Now drain and remove the oil pan. This is what mine looked like.
The bottom of the pan was loaded with what looked like very small chunks of coal. It was the oil sludge that burned and made its way to the pan via the return jets. The oil pump filter was full of this stuff as it tried sucking the oil back through. There was only a hole the size of maybe a dime that would allow the oil through, so it really wasn't getting through the screen. I did buy a new oil pump as well since it was such a deal to get the pan off.
I cleaned the old gasket material from the pan and where it bolts on, took the screen off and was able to scrape and clean the screen which was fairly thick, so it was fairly easy to remove the baked on sludge and clean the screen with a wire brush.
I put the old screen onto the new oil pump and bolted in place.
Install new gasket and bolt on oil pan.
Lower engine making sure to carefully align the bolts as you lower the engine back onto the engine mounts (fairly easy).
Now just Re-bolt the exhaust back onto manifold; Re-bolt the transmission to the cross over mount and finally bolt the engine back onto the mounts.
Fill with required amount of oil and with alot of luck, maybe it will last another couple years before happening again, like mine did.
Second go around was completely different.
If you decide to try this and find yourself unsuccessful, U can email me and I can explain what worked on the second go around after the two years it took to go bad again (and not the oil pump, hell for all I know there might not have been anything wrong with it to begin with.
I really scraped and cleaned all the parts I could get to when the oil pan was removed (that might have been a big mistake because I loosened up alot of that crud and after the pan was reinstalled, I'm thinking alot of that crud came off and went back to the bottom of the pan. The pan was full of crud again on the second go around.
Anyway, if you want to learn how I managed to get lucky on the second go, send me a message at:
RTLetvinchuck@hotmail.com and I will try to help out the best I can.
Just don't expect a reply right away as I only check my emails maybe once a day, sometimes every three days.
Thanks and I hope I am able to help out a few of you with the same problem and save you a ton of money or save your engine. Don't trust any mechanic that says you have to remove the engine and transmission and a whole bunch of other stuff. Yes you do have to unbolt everything and just jack the motor up.
Also, if someone tells you your motor is shot and say they offer you a lowballer price on your vehicle because supposedly it is junk, take my advice and at least try doing what I explained, it can't hurt to potentially save you a grand or three (or more).
Robert T. Letvinchuck
North Fond du Lac, Wi