My wife's 1996 2.4L Cavalier has about 105k miles on it. It runs fine but (unlike my 1996 2.4L Cavalier, hers sounds like a diesel engine when it idles. (Kinda clackety.)
1) Should I have the timing chain, timing gears, tensioner, etc. replaced based on mileage (and regardless of the sound)?
2) Any idea what causes that sound? (Is it likely the timing chain system?)
I've heard that it's a good idea to replace the timing chain, gears, tensioner, etc. at 100k miles because the timing chain is at risk of failure, and if it breaks it destroys the valves and causes an expensive repair job. Our Cavs are convertibles (which we still really love) and so it's worth it to me to spend some money (if necessary) to keep them running a good long time.
That is how mine has been since I bought it a 120,000 miles. It has 150,000 now. Every one I heard sounded like that. I have no idea if that is what they sounded like new or not. All I know is all gm 4 cyl seem noisy. If you replace it I would love to hear the before and after sound.
On the inside my car looks like a fighter jet.
Mine does the same and that's after 3000 or 4000 thousand miles on the new timing kit from PCI. It has new cam sprockets, chain, chain guides, chain tensioner and water pump. I don't remember if it sounded like that before those components were replaced. But I've been driving it like that everyday with no problem. Once in awhile there will be a brief half second rattle on cold start up as well. It doesn't have the start up rattle as much anymore because I went with a genuine ac delco pf46 oil filter the last time I changed the oil.
The original pf46 ac delco oil filter has an anti drain back valve to prevent dry starts, which also helps keep tension on the timing chain at start up. The chain tensioner is hydraulic and operates off oil pressure. Ford had issues with their mod engines and people not using the proper oil filter and oil which in turn caused the timing chain tensioners to fail. Ford issued a TSB for the tensioner problems on the mod engines and the problems could be prevented by using the proper OEM oil filter and 5w20 synthetic blend oil instead of 5w30 since the thinner oil flows faster, etc...
The 2.4 ld9 in our cars is in fact an interference design engine and if the chain breaks it will in fact bend and or break valves and possibly damage pistions. Do a compression test and if your engine still has good, healthy, and even compression and doesn't leak or burn any oil, go ahead and replace the timing chain, chain guides, chain tensioner, cam sprockets and water pump. Flus the cooling system, replace the thermostat and change the oil and filter as well.
Remember to use the proper ac delco pf46 oil filter and don't fall for the knock off/ fake/ imitation ac delco filters at walmart that are completely different and have plastic internals. The pf46 is the correct and proper oil filter for the 2.4 ld9, NOT the pf46e. The ac delco oil filters with an "e" at the end are cheap junk like fram and are not original ac delco filters.
I'm wondering if this diesel sound at idle is possibly being cause by a malfuntioning check valve in the cylinder head. I've heard that the 2.4 ld9 has a check valve in the cylinder head for oil flow and they can malfunction and decrease oil flow to the cylinder head, which could possibly explain why the diesel like ticking noise only happens at low rpm when the oil pressure is low. Maybe ???
Sounds like the timing chain tensioner is not holding pressure...
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
