My wife's 1996 2.4L Cavalier convertible has 115k miles. It has the original timing chain. The head gasket has had a slight oil leak for many years but many years ago my mechanic said that I shouldn't bother fixing the head gasket until I replaced the timing chain at 100k miles. I never replaced the timing chain, but based on his comments long ago, maybe I should have? The car runs well (jinx) but for several years, the engine makes a "clackety" sound like a diesel engine. (It is much more "clackety" than my 1996 2.4L Cavalier convertible which only has 78k miles.)
1) Should I have the timing chain (tensioners, guides, sprockets, gasket, etc.) replaced now as preventative maintenance? Do I risk destroying the engine if I don't replace the timing chain?
If the answer to #1 is "yes" & "yes":
2) Should I also replace have the water pump, thermostat and associated gaskets while it's torn apart? (I guess so.) They were replaced at 38k miles.
3) Is there anything else that I should have replaced at that time?
4) Does anyone have any recommendation on brands or models to buy our not-buy?
Thanks in advance for any help.
it just so happens i also have a 96 2.4, and i have just replaced the timing set although in my case it failed and destroyed the valves so a head was also in that job. to answer your question, if the clackety noise your hearing is coming from the timing, then yes replace the timing set, crank and cam gears, tensioner, guides and might as well do the water pump while your in there. for me i went with a cloyes timing set and victor reinz gasket set through rockauto. the gears had the wrong offset right out of the box so i picked up a set from o'rielys.
The clacky noise you speak of is more than likely the chain slapping because of a bad tensioner. At some point it will give out completely.
Chain doesn't really need to be replaced, but tensioner for sure, and maybe the guides. This is a good time to do the water pump also.
FU Tuning
FYI: I just took my wife's car into my (trusted) mechanic. He listened to it and said that is sounds fine. (It's a little louder than my Cavalier 2.4L but not much.) He said that I shouldn't have him replace the timing chain until it starts to make noise. He said that I'd know for certain when it started making repair-worthy noise. He said that the chain won't just break all at once. I'm going to heed his advice unless somebody here tells me differently based on their experience.
i have a '96 sunfire with the 2.4L twin cam. 213K miles and the timing chain clacks something fierce. its on the second or third one (cant remember if the guy before me replaced it or not) but i make it a habit to check or replace every 50k-80k. ( i also beat the hell out of my motors tho so my stuff fails much more often)
The Chain truly never needs replaced. It is the tensioner that goes back allowing slack and the noise.
If tensioner needs replaced and is not it can lead to the chain jumping time and even messing up the motor.
I have 148k on my original chain and guides, but my tensioner was replaced around 40k when I did a cam swap with a tensioner I trust.
FU Tuning
Thanks Addicted, et al.
As a follow-up to my original post, in case it helps anyone else...
My wife's 1996 Cavalier LS Convertible 2.4L needed a new water pump again at 116k miles. (The first one failed at about 40k miles.) Since the water pump is powered by the timing chain and you have to remove the timing chain cover in order to replace the water pump, I told my trusted mechanic to feel free to change the timing chain if needed. He said that the chain and gears were fine and will probably last for 200k miles or more. However, he did replace the timing-chain tensioners.
And of course he replaced the thermostat, & timing-chain-cover-gasket).
$650 in labor to replace a $45 water pump. What a terrible engine design. GM designed it for cheap manufacturing and expensive (out-of-warranty) repairs. The water pump should be outside the engine and run from a belt.
My Chrysler 300M is built the same way.
At least when I purchased my 2001 Z24 with 2.4L engine, the timing chain and water pump had recently been replaced.
The PO showed me his repair to the Z.
The bill for my 300M was similar, around $1k.
