Lifters are rattling. They have been replaced and are still rattling.
Has the oil pressure been checked? Is the oil pressure light on?
has good oil pressure. quiet when first started, rattles when warm. Just put in a new oil sending unit. oil light is not on.
Do they rattle all the time or just on cold startup? If it is just on startup, my 2002 was doing that and it was cured by using a Motorcraft filter.
Who changed the lifters and what do they have to say about it?
it doesn’t rattle until it warms up. wondering if it could be the rocker arms or the push rods
How many miles on the engine, and what makes you think the lifters are rattling?
147000, can hear a clicking sound
You might want to have someone check and see if the timing chain is stretched.
A stretched timing can become more loose as it heats up from the engine heat and the hot oil. This can then allow the timing chain to start hitting against the timing chain cover, and it sounds like noisy lifters.
Thank You! Will have it checked.
Does it rattle at idle when warmed up or only during acceleration?
Just trying to weed out a pre-ignition rattle which can be mistaken for valve lifter rattle and which may not be present on a cold engine but will surface on a warm one.
This could go hand in hand with distributor timing which I assume may have been altered during engine work. An EGR system or knock sensor fault can also cause a spark knock.
+1 for ok4450. Spark knock is certainly a good possibility.
+2 for OK4450.
I also agree with Tester’s suggestion that it could be the T-chain and/or wear on its guides. Generally they’ll make a racket when cold too, but they do sound exactly like lifters.
I would add that if the OP replaced the lifters him/herself, it would help to know how he/she adjusted them. Hydraulic lifters need to be adjusted to their proper place, such that they have the ability to expand properly when pumped up without maxing out.
Thanks everyone. It was the T-chain
And @Tester is the grand prize winner today. Your trophy and all expense paid trip to work monday will be arriving any minute.
How did you zero in so quickly on the cause @Tester? The timing chain was off my radar completely when considering that there was no noise until the engine was warmed up.
All my suggestions are based on what I’ve seen and experienced in the past.
I have to congratulate Tester as well, as I forgot about the same noise in my 1984 Chevy Impala which started to make the similar lifter noise, at 200,000 miles. It also was the timing chain which my mechanic picked up readily.
A tip of the hat to Tester!
The chain was replaced already and verified to be the problem? Someone working overnight?