Hello all,

Had a little problem this morning and I came here looking for some words of wisdom. First, it's a 4.7 2003 4WD with 140k on the motor. I've had it since 60k and done regular maintenance on it. A few months ago I stumbled across this board when I had an overheat problem and replaced the drivers side head due to a crack. During the rebuild everything went smooth, the chains / gears / guides all measured up good so everything was re-used. (Maybe a big mistake). I never removed the primary chain or tensioner (no need to) and the secondary tensionors checked out good as well. Been running for 4500 miles now with no problems (other than a 4WD issue last week which is now solved).

Now the problem. This morning I start the truck and notice that the check guages light comes on. The oil pressure stays real low for a couple seconds, then comes up to normal. There is some clicking going on (sounds like lifters to me) but that also goes away after a minute or so. I check the oil & it looks fine (was changed first at 500 miles after head work and then again about 700 miles ago). I restart with no problem so I head off to work. After a fulld day outside (25 degrees today) I start it up and find the same thing. This time, however, there is a definate noise coming from the front of the motor, sounds like maybe a timing chain slap. I let it idle for a few minutes, the noise subsides, so I drive it home.

I had already planned on making the Durango a project truck for myself & two 7yo boys this spring and have been shopping for a 4.7 core to rebuild, but there's no way to do that right now. Besides, it's supposed to be a "fun" family project along with a lift kit & some "bling".

I obviously need to do something about this now before the motor toasts on me. Pulling the timing cover / front of the motor is probably the best start, but I really didn't want to get into pulling the pan, oil pump, etc. unless i have to. Besides, it seems kinda funny that this would start all of a sudden. Do the primary / secondary tensioners have anything to do with oil pressure buildup? If a tensioner failed (or is failing), could the oil pressure be affected like this?

Any ideas for a reasonably short term (until springtime anyways!) fix until we can get going on a real rebuild? I have a large garage to work in, but it's not heated (other than my torpedo heater). I can take the car down for a couple weeks if needed, but it really is my "winter mode" of transportation. (the 65 'Stang *never* sees snow!!!!)

Thanks for any and all advice, it's much appreciated.

Bob

 

Sounds like the oil pump to me. You can always verify that your oil pressure sending unit is giving you the right output by hooking up a mechanical gauge.

As for a quick fix, in this case, I don't think there is one. These oil pumps don't like oil weights other than 5W-30 for the most part. I don't think the tensioners have anything to do with the oil pressure.

You could try an oil pan heater, keep the oil warm for startup, but it really isn't a fix, if the pump is going it probably just needs to be changed. Will be an expensive fix if you toast it, sounds like you already know that though.

 

That is incorrect analogy. The motor calles for 10W-30 oil for normal use and 5W-30 in extreme cold (nothing over 32 degrees F).

Now if you run Fully Synthetic oil like what I run (Mobil One 10W-30 Fully Synthetic) then even at -58 F it STILL flows like water. This takes care of both low and high temps hands down along with better ware protection.

With you motor acting up then I seriously think that the sending unit is fine and you idea have an issue with the motor. There is an oil pressure regulation with the timing chain but nothing that would do what you are talking about. If it sprung then it would not just go away. It sounds like oil is not making its way to the top of the motor. I would replace the pump. First I would replace the oil filter, you could have a bad one.

 

Like hydra said I would replace the filter first and foremost.

The first diagnosis I would give it is your filter failed. What it sounds like is there's a clogage in your filter (hence the low pressure start) and something got thru the filter and was clanking around your engine (hence the clicking).

Before you go replacing the sender unit or pump I would drain all the oil (let it sit for half an hour so all the junk comes out), and replace the oil with full synthetic Mobil1 10W-30 and replace the filter with a premium filter such as Mobil1 or K&N.

 

Thanks guys, the garage is warming up right now and I just pulled the truck in to work on it. When I started it up the pressure stayed real low for 3 seconds or so, then went to 1/3 gauge for another 3 seconds before going to its normal 1/2 gauge and staying there. There was a definate lifter click going on from the right side of the motor, as well as what sounded like a timing chain slap which subsided after 30 seconds of running. I let the truck warmup fully (sounds and runs perfectly normal) then pulled it into the garage & opened up the drain plug.

I'm going to let it sit that way for an hour or so while the garage warms up some then will change filter / oil as recommended. I've always run non-synthetic 10w30 in it and normally use a Fram filter, no oil additives or anything else thru it.

Here's hoping that it's a bad / clogged filter. If not then I guess I'm going to start tearing it down today. I'll update later on when I find out some more....

Thanks!
Bob

 

I normally have mine run a Fram Tough Guard filter in it as that's the only thing I trust from Fram, and they're cheap. I've read way too many bad things about every other Fram brand filters and I would stay away from those, just my .02

 

yea i would stay away from fram altogether but thats just me loving my truck too much . . .

 

Like I said earlier, if I was having problems like that I would have put a Mobil1 or K&N filter in. I do like to put Mobil1 oil filters in on a regular basis. I have just recently been puting Fram Tough Guard filters in a have not yet had a problem.

[knock on wood...]

 

yea thats the thing with lubrication, if you have a problem w/ the oil filter ONCE and have insufficient lubrication its often new engine time

 

Now that you say that I feel like I've neglected my truck, and brings back memories of all those bad reviews I've read on Fram filters. I can say I do like the Mobil1 filters a lot.

And Bobman, me think that if it's a problem with the Fram filter that Bobman stop using Fram in his truck and give it what it deserves, not an el cheapo $2 filter.

I'm not sure if you're using the base line orange filter or if it's a Extra Guard or Tough Guard, but it you're using the cheap orange filter, I would recommend even just forking out the extra $4 to upgrade to the Tough Guard.