For what it's worth, I would check out the oil pressure for sure.
I just spent a full week working on a chevy that had an oil pump starting to fail...
ended up being main bearings, rod bearings, timing chain, and a few other items.
Monitor that pressure and if it falls, fix it quick!
The bill.... won't be nice.

 

just got done testing some things on the truck but unfortuanatley there was not much noise today and i'm not sure why but I think i should have done it earlier in the morning instead of waitin until this afternoon. It is quite warm here today at 46 degrees. i also put an oil pressure gauge on and monitored the oil pressure while a friend and I probed around with our sethescopes. my pressure started out around 85 and then settled down to 80 while it was running. it never came down much and after about 10 minutes or so it was reading 79 when i noticed a few drips of oil and decided to shut it down to minimize the mess. My pressure seems to high for idle.

 

I was looking in the service manual and they don't mention much about high oil pressure - all I saw there was that at idle, the min pressure was 3 psi and at around 3K rpm, it could go up to 80 psi, so that sort of tells me that they pressure bypass valve is set at 80, so if that's what you're reading at idle, I'd say that's high. Have you considered changing the filter? Were you able to make any headway with the stethoscope? Did you mention earlier what viscosity your oil is? What type of pressure gauge are you using? What does your dash gauge read?

If you don't have any manual, download the Factory Service Manual that's in the sticky on this forum, the 4.7 Liter lubrication system is described in chapter 9 (volume 1) around page 974. If I can find my Haynes, I'll also check that for you.

 

I'm running mobile 1 5w30 and a Bosch oil filter, all are new as of about 5 or 6 days ago. I really couldn't make much headway with the stethoscope. a friend and i each had a scope but there wasn't much noise that i could hear today. I think it might have been to warm out when we did the test although the truck sat all night it was still in the mid 40s when we scoped it. All i can say is that the loudest most prominent noise is coming from the fuel rail and i don't know if some of the other faint noise i was hearing on the top of the engine is also just transmitting off the fuel rail too.

under engine specs it says:
OIL PRESSURE
SPECIFICATION SPECIFICATION
At Curb Idle Speed (MIN)* 48 kPa (7 psi)
@ 3000 rpm 240 - 725 kPa (35 - 105 psi)

under diagnostic testing engine oil it says:
1. Remove oil pressure sending unit and install gauge
assembly C-3292.
2. Run engine until thermostat opens.
3. Oil Pressure:
² Curb Idle—25 Kpa (4 psi) minimum
² 3000 rpm—170 - 550 KPa (25 - 80 psi)
4. If oil pressure is 0 at idle, shut off engine. Check
for a clogged oil pick-up screen or a pressure relief
valve stuck open.

so depending on which section you read the idle oil pressure is different, but at least the diagnostic test values assume that your thermostat is open so engine would be hot. I never let the engine get that hot in the 10 or so minutes that it idled before i shut down. At any rate i'm assuming that my idle pressure could have been a significant amound lower at idle after 10 minutes at idle, if not 7psi maybe 20 and as the engine got fully warmed up then settle down toward 7.

 

This would leave me to believe that the lifters are making the noise. You can get ticking from fuel injectors, but it is very faint. If you can hear the noise from inside the truck, I would rule out the injectors ticking.

Are you still on a factory intake system pre-throttle body?

 

Thanks skybox, if those specs were in that manual I guess I don't read well these days

A colder day/morning should magnify the ticking problem, but at 80 psi, it appears that you have a ways to go to get to the max of 105 - I'm assuming that you did a rev up test. I would leave that mechanical gauge attached (a few drops of oil coming out won't hurt anything) and let the engine get warm, then check the pressure.

I still think that 80 psi at idle is somewhat high but there's no mention of any nominal idle pressure, did you manage to get a reading from the dash gauge?

A restriction around the filter would increase the pressure and could also explain the brief ticking period. Personally, I would probably try another filter to see how that might affect the situation - you only loose less than a liter of oil and the cost of a filter. New doesn't mean good, and Bosch doesn't mean perfect, I've had more than 1 instance of new & good brand name items that didn't operate properly.

 

everything is still stock on the truck. I can defintely hear it in the cab of the truck so i agree that its to loud to be injectors, although I believe I can hear the injectors also when i put my head under the hood.

I didn't have enough time to use the scope this morning but will have to get out of the house an extra 5 minutes early one of these mornings and keep listening.

 

Just a few quick questions. How long do you run the oil when you do quick multiple oil changes. a couple days, weeks, hours? Do you give it an engine flush before draining and filling with new oil? I don't have a pressure gauge on the dash, so i don't know what it reads. I have the idiot light that did come on when i had the sensor disconnected for the pressure test. I was using a cheap harbor freight oil pressure test gauge. it comes with an assortment of fittings and the gauge all for 24$. I revved the motor a small amount right before shut down and i did notice the gauge climb but i couldn't see it well enough and i was working alone at that point, so i don't know exactly what RPM i was at and I don't know what my max pressure was either. I don't think i was anywhere near 3000 rpm and no where near the max oil pressure either.

 

On engine lubrication system flushing, it's kind of hard to give you a direct answer, cleaning anything you can't see always tends towards a black art and everyone you talk with will have a slightly different approach. There are generally 3 approaches to this, first, you can use a flushing oil, second, you can use a cleaning additive, or third, you can use a high detergent oil and each one has a different method of use. The first 2 will usually have the recommended procedure on the label, and the last, which is probably the least intrusive, is used as normal oil once everything looks clean. Overcleaning an engine is not recommended. Before you make any determination, I'd suggest that you read over this article, I find it's a really good summary of facts even though it is slightly biased towards a product. In your position, I would get a new filter and a quart of oil, change the filter, add some oil if you wish (it shouldn't show below the add line with just the filter amount gone, but if it does, add some to get to about mid range). Then, I'd start it up, watch the pressure, look for the tick if it comes up, and let the engine warm up. When it's warm, you should be able to rev it to around 3K and see how the pressure increases. If it's acting reasonable, button it all up and run it that way for a while & before you decide to change oil, add something like Sea Foam, run it for the recommended time period & again change oil & filter.