Oil pressure drops at idle [Archive] - Dodge Durango Forum and Dodge Dakota Forums

: Oil pressure drops at idle


FullboreDakota
03-13-2008, 01:32 AM
I have my truck running and idleing now after I put on some ported heads, 4bbl intake, 4bbl throttle body, fuel injectors, and some roller rockers. The truck idles decent at around 800rpms. When I start it up, the oil pressure goes up like normal, but after about 5 seconds, it drops to zero and the "check gauge" light comes on. I can rev it up and the oil pressure will go back up to where it should be, but when it goes back to idle, it drops again. The oil is at the normal level, but I am getting ready to change it again, along with the filter. What are some things that would cause this?

Also, I dont have my valve covers completely bolted down, only 3 or 4 bolts on each cover. Would this cause the oil pressure to drop at idle?

Dakudaman
03-13-2008, 01:37 AM
Valve covers are not the problem here! I am thinking maybe the valve train somewhere isn't correct something loose or missing in an oil gally??? What year truck is it?

FullboreDakota
03-13-2008, 01:38 AM
Its a 1999

TurboBlew
03-13-2008, 01:42 AM
Look at your sending unit first.

FullboreDakota
03-13-2008, 01:45 AM
Should I take it out to see if its clogged or what? I have a "T" on it for the paxton oil line and its flowing oil pretty good. The sensor is plugged in and everything , could it possibly be going out?

Dakudaman
03-13-2008, 01:48 AM
Yes it could be that simple too! Slap a new one in there for $15 and and then you know for sure before a bigger teardown!

slammedR/T
03-13-2008, 03:41 AM
I don't see where you messed with the cam or lifters so I'll assume they are the way they were before other stated parts were installed.I had this happen on mine and I checked the oil pressure with a mechanical oil pressure gauge,oil pressure was fine.So I replaced the sending unit and oil filter at same time and the problem was solved.So I would try the filter since you need an oil change anyway and replace the sedning unit since yours is prolly the factory unit anyway.


DEPUTY

FullboreDakota
03-13-2008, 03:50 AM
Yeah the cam and lifters are the same. I will change the sending unit and the oil/filter and see if the problem goes away. Thanks

FullboreDakota
03-13-2008, 11:14 PM
Well i went to change the oil filter and it is pretty much stuck on there. The filter just crushes instead of turning loose. Its a mobil-1 filter and I just put it on about 300 miles earlier. Anybody have any tricks to getting a stuck oil filter off?

ColoDak
03-14-2008, 12:16 AM
Usually, you just have to wrench on the filter to get it off, sounds like you may have overtightened it when installing or didn't lube the gasket. I've had the samething happen in the past, and it was a bithc to remove it.

FullboreDakota
03-14-2008, 12:29 AM
Yeah i probably overtightened it, I guess I will just have to keep trying.

R/T Durango R/T
03-14-2008, 04:05 AM
a trick for removing really badly stuck oil filters is to take a screwdriver and hammer it through the side of the filter and use it as a handle to turn the filter, gives you a lot more leverage then a normal filter wrench and who cares about the filter when yer replacing it anyway..

mlobitz
03-14-2008, 12:25 PM
Or just hand tighten it instead being fucking He-Man when you put it on...

FullboreDakota
03-14-2008, 05:07 PM
Yeah I was on my daily roid rage, so maybe next time I will lay off the steroids for the day.

R/T Durango R/T
03-14-2008, 07:44 PM
haha, i always hated that when i would do someone a favor by changing their oil for them and they had gone to the local jiffy lube last time where they seem to import the largest gorillas they can get their hands on just to install oil filters.

FullboreDakota
03-22-2008, 11:10 PM
The filter is still stuck in there. Is it possible to just cut it out? I really dont want to do that, but I might have to resort to it.

NXNLINE
03-23-2008, 01:31 AM
go down to autozone and buy a strap oil filter removal tool, that way you can use an extension and a ratchet to remove it big guy!!!:bump:

FullboreDakota
03-28-2008, 01:51 AM
Finally got the old oil filter off and I put the new one on. I only got the new oil filter hand tight and when I started it, oil poured out of it. So I tightened it alittle bit more with a oil filter band clamp and it still leaked. I dont want to tighten it down anymore and get it stuck like last time, so what could be the problem? There was a small cut in the oil filter ring, but not big enough for this much oil to pour out of it. I did notice that when I was using the air chisel the entire piece that the oil filter bolts to was turning (about 1/4" total).

Black5.9R/T
03-28-2008, 02:14 AM
the old gasket from the old oil filter is still on there

it is double gasketed

just take it back off and make sure you only have the gasket on the new filter there

FullboreDakota
03-28-2008, 02:19 AM
The old gasket came off with the old filter. What else could it possibly be?

Black5.9R/T
03-28-2008, 03:35 AM
filter spindle could have backed off

Black5.9R/T
03-28-2008, 03:35 AM
take it off and grab the filter spindle and make sure it is tight

FullboreDakota
03-28-2008, 03:52 AM
I will try that tomorrow. Now that I think about it, the filter doesnt look like it fits up as close to the block as the other one did.

mlobitz
03-28-2008, 12:40 PM
Did you cross thread it? Start it by moving it counter clockwise until it catches the threads and then turn clockwise until tight...

buzzbass
03-28-2008, 02:10 PM
I have my truck running and idleing now after I put on some ported heads, 4bbl intake, 4bbl throttle body, fuel injectors, and some roller rockers. The truck idles decent at around 800rpms. When I start it up, the oil pressure goes up like normal, but after about 5 seconds, it drops to zero and the "check gauge" light comes on. I can rev it up and the oil pressure will go back up to where it should be, but when it goes back to idle, it drops again. The oil is at the normal level, but I am getting ready to change it again, along with the filter. What are some things that would cause this?

Also, I dont have my valve covers completely bolted down, only 3 or 4 bolts on each cover. Would this cause the oil pressure to drop at idle?

bad oil pressure sender, it's somewhat of a common issue.

buzzbass
03-28-2008, 02:15 PM
The filter is still stuck in there. Is it possible to just cut it out? I really dont want to do that, but I might have to resort to it.

Is it crushed at all yet ? If not, but a socket style filter wrench that fits over the end. I don't use the band type anymore, for reasons like this. I also don't like the screwdriver method, as I've wound up just tearing the case to shit and making a bigger mess. In the future, warm the engine up, before you try and take the filter off. That usually prevents this problem altogether, no matter how tight it's on there :banana2:

Bad_banana
03-28-2008, 06:49 PM
Mine did this when I broke some rings and chunked a piston, lol. At idle oil pressure would drop to 0 for a few seconds and then bounce back up:)

FullboreDakota
03-28-2008, 10:57 PM
I already have the stuck filter off.

The filter is leaking between where the oil filter screws on and the plate. I went out and bought a new K&N filter to make sure that it wasnt a faulty oil filter, but it still leaks. Also, the plate spins off with the oil filter when I take the filter off. I am going to go back out and try to torque the screw/bolt that the filter goes onto back into the block, maybe that will stop it from leaking.

FullboreDakota
03-28-2008, 11:20 PM
I went out and tried tightening down the plate and it still leaks.

Is there suppose to be a gasket on the bolt that the oil filter screws onto? Thats the only thing that I can think that it would be.

Bad_banana
03-30-2008, 01:23 AM
I think there is a gasket on the end of the bolt, like an o-ring. Put the old filter back on and see if it still leaks.

FullboreDakota
03-30-2008, 06:04 PM
I am going to have to buy a new o-ring, because the old one probably got destroyed when I was removing the oil filter.

Bad_banana
03-31-2008, 01:25 AM
updates?

FullboreDakota
03-31-2008, 02:27 AM
I went to advanced auto to see if there was some type of o-ring that goes on the end of the bolt/stud, but theres not one. I am going to put in a new adaptor plate gasket to see if that will some how stop the leak. If that doesnt work then Im just going to order a new adaptor plate and bolt/stud. Maybe my plate is warped or something.

FullboreDakota
04-09-2008, 12:56 AM
I ended up buying the adaptor plate, bolt, and gasket. Its stopped leaking, but my oil pressure still does the same thing. I even replaced the pressure sensor/sender. Could having an almost drained battery mess with the gauge and have it read low oil pressure?

crow318
04-10-2008, 01:13 PM
I have the same problem. Once my truck is warm, I have low oil pressure at idle. Down near 5 psi. Every once and a while the check gauges light came on and the factory gauge read 0. I installed a mechanical and found the 5 psi. Adding an oil stabilizer like Lucas brought it up to 10 psi and stopped the fatory gauge from dropping to 0.

After installing the mechanical gauge, I replaced the pump figuring that was the problem. It is a huge PITA to pull the pan on a 4x4. After all of that work, the screen was clean and the new pump didn't change the pressure.

My truck has 150k on it. I've been told that the low pressure is most likely due to worn cam bearings. Luckily for me, I just got my work truck so I can pull to motor and get it built up.

Keep in mind, low pressure does not mean no flow.

Five9Dak
04-10-2008, 06:17 PM
You need feed oil pressure to overcome even the low pressure section of the hydrodynamic film in the journal bearing. 5psi is not gonna cut it.

FullboreDakota
04-10-2008, 07:18 PM
I can start mine up and at idle the "check gauge" light comes on, but my battery is also almost all the way down.

My oil pressure was fine before I installed the new heads and the engine itself has less then 70,000 miles.

FullboreDakota
05-01-2008, 08:31 PM
I went out and checked and I have enough oil pressure to send oil to my paxton. I dont know if it takes very much pressure to do that, but im getting oil to it. I havent hooked up an oil pressure gauge yet.

FullboreDakota
05-03-2008, 08:04 PM
Well i hooked up a cheap oil pressure gauge today and it barely shows any oil pressure. I show around 40psi on my factory gauge, but only around 5 on the mechanical gauge. I installed it in the pressure sender spot and on the end of the hose that goes to the supercharger, both showed the same amount of pressure.

FullboreDakota
05-06-2008, 10:38 PM
I went out and drove the truck down the road today and when its idleing it still loses oil pressure. But if I drive with the rpms up around 3000rpms, then the oil pressure stays up around 40psi. What could be causing this?

If I have to tear down the engine again, then im either parting out this truck or im just going to part out the engine and buy a stroked long block. So does anybody know where I can get a good 408 or preferably bigger long block?

txlen
05-06-2008, 11:24 PM
ok..i got a question for you...do you have the oil line for the blower tapped off of the same fitting as the sender??.. if so do this, take the blower belt off and the oil lines, hook it back up as original and start it back up... see what the oil pressure is now...

FullboreDakota
05-07-2008, 02:31 AM
Yes I have it T-ed off of where the sender is. I will try what you said tomorrow. I did re-route the oil drain line from the supercharger, as before i did this it would get kinked really bad.

WiCKeD 5.9L
05-07-2008, 03:21 AM
Also having low oil pressure at idle after replacing heads, so I went to install a new oil pump, pickup and sensor. Turned out I had about a quart and a half of oil, so it's a safe bet that clears up my low oil pressure mystery...

It could be a dirty pickup or a sludged engine. What was the color of the oil? If it's sludge buildup, Auto-RX is supposed to work miracles clearing gunk out, but the 408 might be the only answer. Think the rings are blown on mine.

...and yes, replacing the pump was a PITA on a 4x4.

FullboreDakota
05-07-2008, 03:33 AM
It was running good before I changed heads and the oil pressure was fine. I hope i figure this out soon, i want to drive my own vehicle for once.

FullboreDakota
05-07-2008, 06:54 PM
I took the oil lines off and at first the oil pressure went straight up to where it should be. My idle is off right now and it idles at around 2200rpms, but the oil pressure still stayed up. But then i got out to adjust the idle and when i got back in, the oil pressure was back down to ZERO. The idle was still around 2000rpms, so i dont think it was that. I dont have to rev it as high to get the oil pressure back up from zero, but it still drops back down when i let off.

FullboreDakota
05-10-2008, 09:53 PM
I messed with the truck again today and it seems that when the truck is cold, the oil pressure will go up to normal. But as soon as it starts to barely even warm up, the oil pressure drops.

crow318
05-12-2008, 01:59 PM
Well, I hope you figure out what it is, because I have the same issue. I still think it is your cam bearings, but if you find something else, please let me know.

Fluffy
05-12-2008, 03:10 PM
I didn't read the whole bunch of posts, so forgive me if I repeat anything.


Have you dropped the oil pan to make sure the pick-up isn't partially if not fully plugged? Mine was doing it.



Well, I hope you figure out what it is, because I have the same issue. I still think it is your cam bearings, but if you find something else, please let me know.


If the cam bearings are bad?


The timing should start going bad then.


.02

FullboreDakota
05-12-2008, 10:09 PM
I havent checked the pickup yet, i guess that is the next thing on the list to do.

FullboreDakota
05-13-2008, 03:46 AM
I changed the oil with some 20w-50 to see what would happen and the pressure would stay up at idle, even with the supercharger hooked up. But if I didnt keep the rev's up going down the road, the pressure would drop back down like it would always do.

mtlcafan79
05-13-2008, 01:47 PM
My 408 had oil pressure issues at idle when hot. Turns out it had bad main and cam bearings. Good luck with yours.

360 xrt
05-13-2008, 03:10 PM
try using synthetic oil.Hot or cold this oil doesn't change as much as conventional oil.And maybe stick with the 20-50 for synthetic also.

crow318
05-14-2008, 01:36 PM
Throw a bottle of Lucas Oil Treatment in the oil. That brought my pressure up a little. At my next oil change, I left out the Lucas, and I was back at no pressure at idle. That reinforced the thought of bad bearings for me.

FullboreDakota
05-18-2008, 09:41 PM
I tried the oil treatment stuff and it really didnt help. I dont have any knocking or anything coming from the engine yet, so i guess im going to have to check out the oil pump.

FullboreDakota
05-19-2010, 11:25 PM
I forgot to give an updated to this. I found a huge crack down the center of the entire block. I guess I should have looked better when I took the stock heads off.

Kingst3r
05-20-2010, 03:15 AM
I forgot to give an updated to this. I found a huge crack down the center of the entire block. I guess I should have looked better when I took the stock heads off.

That could be the problem haha. My pressure actually went down the other day too, except it would go down, then i would shut it off and start it again and it was fine sometimes. or i would wait a few seconds and it would go back up. I check me oil and i was down about half a quart, so i added it and it was fine.

Misfit
05-20-2010, 07:57 PM
I forgot to give an updated to this. I found a huge crack down the center of the entire block. I guess I should have looked better when I took the stock heads off.


Time to break out the welder..lol