Start-up rattle?

[wolfehunter]

I have some questions regarding this rattle as I have noticed it on my 98 Chevy Truck 5.7 with 116K on it. This vehicle might be driven 1 time a week and sometimes sits for 2 weeks. It gets conventional 10-30 oil (whatever is on sale) and I have never been filter specific. Have used Wix, AC Delco and Fram. Not sure what filter is on it right now but will check. I change oil every 7,500 or 1 yr since it doesn't see much use unless hunting season.

The noise I hear is a rattle but not immediately at start up. All sounds good when it starts but after about 7 or 8 seconds it will rattle for 5 to 10 seconds and then get quiet. So is this a filter issue or is it my valve train knocking until oil gets up on it? What filters may eliminate the noise if it is a filter problem? I am assuming it is not a filter issue since it would most likely rattle at initial start up.....correct? If it is not hurting anything I am not too worried about it. My cousin brought it to my attention in hunting season.......he's a Ford guy and ribbed me about my "Chevy rattling apart"!!

If it is the filter......what causes the noise? Please explain. thanks

 

[KCJeep]

You are correct filter issues usually are present immediately at start up from a faulty ADBV. In your case if it's the filter you could have a bypass valve that is not working right.

Most here believe bypass valves rarely open, however I experimented with a non-spec filter on my Jeep that happened to have a bypass rating double that of the factory spec. The result was exactly what you just described. Rattle AFTER start up which would dissapate after a little run time. I had to take it off after about 500 miles. Problem gone. And this was during warm months, so I tend to believe bypass valves at least crack open at start up more often than you'd think.

Anyway, cheap and easy attempt at fixing would be a new filter so I'd try that first.

Are you using and AC Delco ecore? I am not convinced the combo valves (ADBV and Bypass Valve) in the ecore works well.

 

[ZeeOSix]

Originally Posted By: wolfehunter
I have some questions regarding this rattle as I have noticed it on my 98 Chevy Truck 5.7 with 116K on it. This vehicle might be driven 1 time a week and sometimes sits for 2 weeks.


So if the truck sits for only a day or two, does it have the same start-up noise? If not, then the filter and oil galleries are draining down if it sits a very long time. Use a filter with a silicone ADBV to ensure good ADBV operation.

 

[ZeeOSix]

Originally Posted By: KCJeep
You are correct filter issues usually are present immediately at start up from a faulty ADBV. In your case if it's the filter you could have a bypass valve that is not working right.


GM engines usually have the filter bypass valve built into the engine block, which means the filters have no bypass valve built into the filter.

 

[Boomer]

ZeeOSix is correct about the bypass valve. It does sound like a momentary oil "starvation" to the valves or lifters. Is there any evidence of sludge in the engine? Could the oil screen have some dirt on it that slows cold flow of the oil?

Has the truck done this since you owned it or is this a recent thing? Could it be a piston slap issue?

 

[Wilhelm_D]

Originally Posted By: wolfehunter
I have some questions regarding this rattle as I have noticed it on my 98 Chevy Truck 5.7 with 116K on it. This vehicle might be driven 1 time a week and sometimes sits for 2 weeks. It gets conventional 10-30 oil (whatever is on sale) and I have never been filter specific. Have used Wix, AC Delco and Fram. Not sure what filter is on it right now but will check. I change oil every 7,500 or 1 yr since it doesn't see much use unless hunting season.

The noise I hear is a rattle but not immediately at start up. All sounds good when it starts but after about 7 or 8 seconds it will rattle for 5 to 10 seconds and then get quiet. So is this a filter issue or is it my valve train knocking until oil gets up on it? What filters may eliminate the noise if it is a filter problem? I am assuming it is not a filter issue since it would most likely rattle at initial start up.....correct? If it is not hurting anything I am not too worried about it. My cousin brought it to my attention in hunting season.......he's a Ford guy and ribbed me about my "Chevy rattling apart"!!

If it is the filter......what causes the noise? Please explain. thanks


10W-30 is a mite heavy for Pennsylvania in winter in a vehicle for which the manufacturer recommended 5w30 16 years ago. Personally I'd be using a 0W-30.

You could be hearing piston slap. It could be the oil filter. If it is going away it is probably not a rod bearing or other part that's about to exit the engine.

Since it is not filter specific, I'd go with either piston slap or the oil. Try 0W-30 on your next change and see what happens.




.

 

[KCJeep]

Originally Posted By: ZeeOSix
Originally Posted By: KCJeep
You are correct filter issues usually are present immediately at start up from a faulty ADBV. In your case if it's the filter you could have a bypass valve that is not working right.


GM engines usually have the filter bypass valve built into the engine block, which means the filters have no bypass valve built into the filter.


True I have owned a bunch and still own one totally forgot about that when I posted. I still suggest you change the filter first and see if it helps.

 

[ZeeOSix]

Originally Posted By: KCJeep
Originally Posted By: ZeeOSix
Originally Posted By: KCJeep
You are correct filter issues usually are present immediately at start up from a faulty ADBV. In your case if it's the filter you could have a bypass valve that is not working right.


GM engines usually have the filter bypass valve built into the engine block, which means the filters have no bypass valve built into the filter.


True I have owned a bunch and still own one totally forgot about that when I posted. I still suggest you change the filter first and see if it helps.


He needs to give more info ... like does this noise happen if the truck just sits over night, or does it take a week of sitting to happen. Some filters and oiling systems may not drain back over night, but could over a week of sitting.

And is this start up noise temperature dependent? Need more clues.

 

[wolfehunter]

So I last had truck running 3 days ago. I started it when I got home from work today and it did the "rattle" and went away after 5 to 10 seconds. It has a Wix filter on it currently. Owners manual says 5-30 is preferred but 10-30 is fine for temps over 0 degrees Farenheit. I am due for an oil change and am looking for suggestions on filter and oil. 0-30 was suggested by Wilhelm above. I have only noticed the rattle since fall when it was brought to my attention. If the truck is warm or if I take it to work it will not rattle at the end of the day when I start it to go home. Zee is on to something as it seems to do it after prolonged sitting. What can I do to prevent it or what should I be looking for?

 

[ZeeOSix]

Whatever oil filter you buy, get one with a silicone ADBV. They seem to do a better job of keeping oil in the filter and oil galleries after shutdown.

What are your oil change intervals (OCIs)?

 

[dailydriver]

Originally Posted By: Wilhelm_D
10W-30 is a mite heavy for Pennsylvania in winter in a vehicle for which the manufacturer recommended 5w30 16 years ago. Personally I'd be using a 0W-30.


Agreed, especially since THIS winter here (in Pennsyltuckey) has bordered on an average year northern tier midwestern state's winter ambient temps.

 

[dlundblad]

I bought a WIX filter for my moms 3.8 Wrangler and it rattles compared to the M1 equivalent.. Makes me wonder if it is the ADBV. I've thought about giving the Fram Ultra a try next.

 

[wolfehunter]

I change the oil once a year or 7,500 miles. It doesn't get driven much. Is that OCI too long? I've got another Wix and just bought two Napa Silvers but maybe I should take the Silvers back and get Gold for the silicone ADBV? Is a gold ok for that OCI?

 

[ZeeOSix]

Originally Posted By: wolfehunter
Is a gold ok for that OCI?


Yes