3.0 engine noise

[reborn55]

Neighbor friend has a 89 Dodge Dynasty with 3.0 liter in it and less than 100,000 miles on it.. Has only been used for short trips lately. Started it up Sunday, engine rattled for a couple of seconds and went away. Drove fine after that. Sat for a couple of more days. Tuesday the same thing. Oil is good and clean--pressure is good by gauge standards--does drop off somewhat after fully warm. Went out last night started it quiet as can be. Was a bit cooler than the last 2 times starting. Would inactivity on this engine cause some oiling problems. She said she never noticed anything in the past but I really don't think she understood what I was trying to ask. Am goin to put mechanical gauge on it this weekend to check pressure hot. Had recent oil cahnge at WalMart. Thanks

[theFREAKnasty82]

unfortunately, this is a common thing w/ the 3.0 V6 engine. The hydraulic valve lash adjusters that actuate the valves (acting in conjunction with the rocker arms) are not getting enough oil in them thus causing the ticking sound you hear when the engine first starts up. There is a shadetree mechanic way of quieting those "tickers" as I call them, put in about a pint of transmission fluid into the engine and let it run. The tranny fluid will not only clean things up inside the engine it will also help seat those hydraulic adjusters somewhat so that they don't tick as loud, though it will be there slightly.

[neon_rt]

The cause for the ticking is low oil pressure on startup, one of the causes the "anti drain-back" valve in the oil filters is leaky. It allows the oil drain backwards through the passages. When you start up, it takes a few seconds for the oil to fill up the passages and gain pressure, hence the rattling/ticking for a few seconds. The quick fix (if this is the problem) is..... drum roll please....change the oil filter.

[reborn55]

Thanks--any recommendations on the oil filter to try. Last oil change she had was at WalMart Quick update. Started the last 2 evenings--relatively cooler than last Sunday and there was no noise at all. Will try the oil filter and oil gauge this weekend. thanks again.

[reborn55]

Ok--I put mechanical oil pressure gauge on it this morning, started it up --no noise. Oil pressure is great at higher rpm fully warmed up--in drive it is right around 10-15 psi on 4 different gauges averaged out. Is this bad for this engine. All the specs I find are for a higher rpm reading. Thanks.

[neon_rt]

10-15psi is OK for warm idle.
The pressure should rise to 40-50 psi at highway speed.

[reborn55]

That is what it does---Thanks for your help. Appreciate it.