What's up guys, I've got a 79 Dodge D100 with the slant six. My problem is that my oil pressure gauge is reading 1 psi at all times and frankly its freaking me out. I've been told best way to determine if its the gauge or the pump is to ground the wire for the switch to see if the gauge sweeps. I haven't done it yet, but hopefully its part of the problem. I did notice upon pulling the oil cap and breather filter that there is not much in the way of oil under the valve cover, another bad sign, however, I'm curious if this is a familiar problem with slant sixes and any usual problems such as blockage or bad pumps. Any ideas would surely help!
-Grant
RAM MAN
04-02-2008, 11:07 PM
how well do you know the service / maint on this truck
(no offense), but when was the last time you changed out the oil for some quality stuff, new oil fitler etc ?
the reason I asked is: I used to have an old Ford Ranger with like 184,000 miles that drank oil like it was going out of style, and I was just buying cheap no name oil (Meijer to be exact) and then I heard about free refills at Jiffy Lube, and noticed immediately that my oil pressure was better with a name brand oil (I think JL used Quaker State) instead of some cheapo oil
I know Jiffy Lube doesn't have the best reputation in the industry, but I can tell you that once a week, I could go into the bay with my oil burnin Ford, and they put in 2 quarts, no questions asked
I have used engine flush in the past to clean out old gunky engines, but you have to take the chance that it may dislodge something else and cl;og things up real bad ... or worse
keep us posted
acton mike
04-02-2008, 11:12 PM
one way to be sure is to pull out the oil pressure sender and screw in an oil pressure test gauge
this will tell you what your actual pressure is within the following parameters
engine cold idle
engine hot idle
oil pressure at various engine speeds, cold or hot
this will give you some solid numbers
slant sixes are as tough as old boots and will tolerate, in my experience, very low oil levels but I am not sure how forgiving they are with low oil pressure
I suspect if you engine is not making funny sounds or behaving badly, then the gauge or the sender are faulty
But check the actual pressure first
the senders are cheap and so if you actually have good pressure, then stick in a new sender and see what happens.
engine
bherder
04-02-2008, 11:31 PM
+1 with what Acton Mike says.....
I would think with (Gauge showing) 1 PSI, something not-very-good would have happened by now.....
Just so happens, I had a recent scare on my 360... Gauge was showing VERY low oil PSI... Like 10-15 PSI. But no funny noises, no valve clatter, no nothing. Scared the hell out of me, though....
Swaped the cheap-o oil pressure sender I had put in a year or two earlier, for a quality unit (Standard Ignition) and gauge now reads 40 at idle and 60 at anything above idle.... (Whew!)
But it could be that... Or bad gauge.... Or bad instrument cluster voltage regulator... or could be your engine really does have a prob.
But again, as Acton says, you really need to screw in a mechanical oil PSI gauge and see what that says and go from there.... and yeah, if you ground the connector for the oil sending unit, it should peg out.....
Megunticook
04-02-2008, 11:54 PM
I would think if the gauge were reading correctly your motor would be talking to you...the kind of sounds you hear for a few seconds right when you fire her up after an oil change, or on a super-cold morning when the oil's sitting down in the pan like a bunch of frosted molasses.
A mechanical gauge screwed into the sending unit hole is definitely the accurate test, as AM suggested.
You will want to get that gauge fixed, too, or at least put a light in (some people say a light grabs your attention better--I installed both after my light quit on me last summer).
And if you plan on keeping that motor for a while (and with a /6 "a while" is measured in decades, not years!), definitely change that oil religiously and use quality stuff of the right viscosity for your climate. Biggest thing you can do to preserve that motor.
Speed Dragon
04-03-2008, 08:28 PM
If it ain't knocking or ticking, it's good :D
old rat
04-04-2008, 12:30 PM
Had similar problem with my 86 /6 and on the third NEW sending unit everything was fine. Check pressure for sure like people said. One nice thing about oil pump is that its external and esy to replace. 186K miles and going strong. Just getting broke in good. :D Alan G
6cylofpurefury
04-15-2008, 11:34 AM
alright, double checked and definitely not getting oil pressure, decided to change out the pump. Went down to pep boys where they were discontinuing the pump and I got it for only $2 and some change. My problem is when I went to pull it out the shaft for the pump is so long that the pump hits the crossmember and I'm stuck between the block and the crossmember. Anyone have any ideas or tricks on how to get it out? I was going to borrow a crane and move the motor a little to free up some extra space.
Delray Dude
04-15-2008, 12:34 PM
You can undo the motor mount and use a floor jack to raise the motor - just be careful - use jackstands to protect the vitals (like you) - you should be able to raise the motor 3-5 inches - keep in mind that the body will come up some as you are jacking up the engine - till the weight is off the torsion bars.
Speed Dragon
04-15-2008, 05:20 PM
Or you can use a hoist to raise the engine, if you have one.
Megunticook
04-15-2008, 06:02 PM
Went down to pep boys where they were discontinuing the pump and I got it for only $2 and some change
Uh, you sure you want to stake your motor's life on a two-buck pump made for pennies on the dollar in some subpar Chinese foundry? Just my opinion (well, I know others on this forum agree), but you get what you pay for, and cheap parts at discount stores are not always reliable. If I were you'd I'd think twice about slapping that thing in there--it might be OK, then again it might not.
bherder
04-16-2008, 02:27 AM
Well, now, Ed... Depends on what he got. There may have been a nice Mellings pump sitting on the shelf, with a thick layer of dust on it, taking up space where they could use the space for a fast turn-over rice-burner part.
Most parts stores now days will not generally carry parts for an engine that hasn't even been made for 20+ years. They can GET it for you, but shelf space = $$ space.
It was probably cheaper for Pep Boys to practically give him the part, than it was for them to send the part back to 'wherever' and possibly get nothing for it. Funny game, this retail biz is... ;)
Anyway, 6cylofpurefury, may have just lucked out. Right time in the right place wanting a part that was gonna be sent back anyway. It happens from time to time :D
But like I say, it all depends on what he got... If it was a Melling or McQuay Norris part.. THUMBS UP!! If it was a Chin-Ho-Hyuk part. Then you're right.. ;)
Megunticook
04-16-2008, 06:19 AM
You're right, I should've qualified my warning. If it's a quality piece just deeply discounted, then congratulations on a good find!
Delray Dude
04-16-2008, 03:16 PM
but then again we are talking about a /6....these things run with little or no oil pressure!!!!
most likely is a nice oil pump and it's not like that slant six is gonna see 8,000 rpm (I think).
most of the oil pumps out there that I've seen are melling anyways...I think it'll be allright on this application - heck it'll be better than it is right now!!!
If it does take a crapper on it, then he has the learning curve down - but i suspect that new pump will last the life of the engine (tell it really needs a rebuild)
acton mike
04-16-2008, 04:46 PM
i believe that after Armageddon all that will be left are cockroaches and slant sixes
bherder
04-16-2008, 10:47 PM
i believe that after Armageddon all that will be left are cockroaches and slant sixes
