2.5 Clattering and Pinging

[MrGiggles]

My 98 2.5 has made some noise since I bought it a couple months ago.

If you start it after sitting for a few hours, it clatters pretty loudly, like a lifter is not pumping up. After warming up, it's smooth and quiet as can be.

Should I maybe try a thinner oil? Not sure what's in it now, the PO said he changed it a couple weeks before I bought it.

 

[RonD]

Almost all oil filters have a back flow preventer valve inside, almost being the key word.

This valve is just a rubber flap that prevents oil from the upper engine passages from draining back into the filter when pump/engine is off.

2.5l has over head cam(OHC), but does have hydraulic lifters, they are actually pivots for the rockers not "lifters", if oil passages are drained it can take a few seconds to get oil back up to the top end of the engine, so you get valve train noise at startup.

Shouldn't cost too much to swap filters, and add a bit of oil, just to see if that is the problem.

 

[Marty'70]

Possibly "nature of the beast" I have had a 90 and also now have an 01 with the 2.5. Both rattle when cold.

Sent from my QMV7B using Tapatalk

 

[tomw]

The 'lifters' or supports have a check valve in them that 'traps' a small quantity of oil in a chamber when the follower is on a cam lobe opening a valve. If a speck of something gets into the lifter, and allows the check valve to seep, it will allow the lifter to 'collapse' a bit and clatter on start up until the oil pressure pumps more oil into the chamber.
The check valve may have a speck, or have a seating problem allowing the leakdown. Two choices come to mind, 1) leave it alone and it may stop if the 'speck' travels to the filter and is caught, or 2) figure out which lifter is noisy and replace it.
If it is the 'start - count one thousand .... to about ten thousand and it is quiet' then I'd leave it alone. If it is the one or two minutes of tapping before quiet, I would investigate further, determine the source, remove the cam cover(after upper intake, plug wires, etc), swerve out the cam follower, and pull the suspect. Take it apart and inspect the check valve surfaces. If blemished, replace. If not, punt.
tom

add What's with this 'pinging' no mention...

 

[MrGiggles]

The clattering does go away after a minute or so.

Sorry, I forgot to mention the pinging in my first post.

It pings sometimes under hard acceleration. Temperature and humidity have no effect. Some days it won't do it at all.

I ran a healthy dose of seafoam through the brake booster line and it didn't help either.

The truck has a significant vacuum leak somewhere that I haven't been able to find. I sprayed carb cleaner all over the intake and hoses with no luck. I think it may be under the dash. It sets a P0171 code and the fuel trims are very high

Oddly enough, I first started noticing it after I changed the air filter. Everything there is fine though.

 

[tomw]

Is the clatter from one or multiple lifters? If one, try an Italian tune-up. Run it up to higher rpms before shifting, or keep in a lower gear longer. That may also help the pinging if there are carbon deposits that are causing the noise. Carbon can 'glow' and pre-ignite the fuel:air mix causing pinging. The 'tune-up' might just cause the deposits to burn or break loose and clog the converter(unlikely as there are probably a pebbles worth of carbon total and I have never heard of it happening). I think the converter gets hot enough to 'eat' the carbon anyway.
Make sure your EGR is working as it may cause pinging if it hangs or does not open properly. There should be no EGR flow at idle. Opening the EGR valve manually should cause a warmed up engine at idle to stumble or die. If not, the passage, the valve, or the tube may be plugged. If you have DPFE, the orifice may be plugged, but that should cause the SES or MIL to shine on the dash.
tom

 

[MrGiggles]

I'm not sure if it's just one or a couple lifters. It sounds like more than one though.

I drive it pretty spirited, and the Seafoam should have taken care of any carbon.

It was very hot and humid today, and it didn't ping at all even with a 400lb tractor tire in the bed. Being intermittent like that makes me think the knock sensor may not be working. Does anyone know off hand where it's at on these engines?

 

[MrGiggles]

I think I found a solution to the pinging.

I've been having trouble getting this thing to warm up all the way. Lack of heater flow was causing it.

With the engine finally getting hot like it's supposed to it hasn't been pinging.

As for the clatter, I added most of a quart of MMO last week and have been driving it.. It hasn't made any difference yet.