When my daughter's car sits a few days, when it is started it has a
fairly pronounced "rap" for about half a minute. I haven't had a
listen to it yet - just her description. Is lifter noise common on
these 24 valve engines, or is it likely to be piston slap? Not sure of
the mileage, but I think about 170,000km. I'm leaning towards lifters,
because it is apparently intermittent - and doesn't USUALLY happen
after just sitting all day or overnight (which would be cold enough
for piston slap) - thinking lifter bleed-down if the particular
lifter(s) in question stop with the valve open.
That could be anything from a wrist pin,piston slap, or rod bearing. (all
uncommon for this vehicle) Yes it could be lifter noise, also uncommon. Of
course this all depends on how well the vehicle has been maintained.
The noise could be excessive carbon build up on the head/piston. The noise
could also be a cheap oil filter withe the check valve allowing all the oil
to drain back to the oil pan.
I would start off with doing an oil change and using a Mopar filter to see
if the problem goes away.
My thoughts only
On Thu, 18 May 2006 06:15:40 -0400, "damnnickname"
Vehicle has been well maintained - but it could very well have a cheap
filter on it at this point (daughter's car - I didn't have time to do
the oil change, so she had it done.)
Carbon on the head would not gradually quiet down after starting and
only show up after a long rest - and it gets driven hard enough I
doubt there is any appreciable carbon build-up.
I'm going to put some additive in the oil and see if it gets better
(clean up the lifter hydraulics)
If its ticking then its the lifters:goto Pep boys or autozone or somethin and
get some Mystery Oil and put it in where u put the oil in!! this is comin wit
these cars, but I still love them and I still have mine!! nothin to worry
about with this problem just get some Mystery Oil and u will be good!!!
If its Knockin and its real loud and annoying like someone is knockin on a
door then that would be the Rod Bearing. Engine is bout gone!!! only reason
why that would happen is no constent oil changes or no oil in motor!!!
Well, you have all the answers for everyone else. Why the hell can't you
answer this one? Your the mechanical genious that has worked on a million
cars, and dispense your diagnosis to everyone else, figure it out on your
On Sat, 20 May 2006 22:45:31 GMT, "Rome97neon via CarKB.com"
Sorry - my bad - 4 valve per cyl = 16 valve. The Wife's car is a 24
valve (V6 ford). I have put some MMO in and ran the car for a few
hours. It was significantly quieter all round than it has been. We
will see if the knock is gone in the morning.
She's been running 87 octane fuel in it too - which is a no-no on this
engine. On 89 it is marginal - it really likes 91 Octane fuel.
On Sat, 20 May 2006 23:09:01 -0400, clare at snyder.on.ca wrote:
Well, I fired it up this afternoon, and it was MUCH quieter. The
engine sounded like it had a piston slap before I put the MMO in - my
STRONG suspicion is that the wrist pins were sticky, causing the
pistons to tip in the bores, giving the classic double rap. When
warmed up, the pistons expanded enough to free up the pin (assuming
the pins are free to rotate(float) in the piston) and the engine
quieted down. The MMO would disolve any varnish in the pin bush area,
stopping the stiction. I'll have the car for a few more days as my
daughter is spending some time travelling in Europe with her older
sister. We'll see how it behaves.
On Sun, 21 May 2006 17:45:47 -0400, clare at snyder.on.ca wrote:
Well, the engine is still quiet. Had a bit of a missfire when started
cold - I had washed the engine and #1 plug well got some water in it-
dried it up and it ran perfectly. I think the engine is quieter now
than it was when my daughter bought it 50,000KM or more ago. For a 2
liter 4 cyl, it pulls pretty good, too.
No lifters? Really?! Man my automotive knowledge must be waning badly.
Although it'd be nice to see the day that lifters are somehow no longer
needed. I've become convinced that regardless of maintenance you're
eventually going to have at least one lifter start tapping. Just a matter
But I see lifters for sale (turboneonstore.com) for the SRT4 to replace the
"factory and aftermarket hydraulic units"
And on www.neons.org I see reference to lifters as well. "The 2.0L OEM
lifters trap this aerated oil and fail to pump up properly negatively
affecting engine performance at high RPM usage."
Yes, I see even the 4.7L V8 in my two Durangos refers to "hydraulic lash
adjusters". I guess that's the term to use for OHC engines but it really
looks like it's pretty close to the same thing? I imagine you still can get
the same ticking noise when a lash adjuster eventually wears out, too.
I read somewhere that if the knock sensor picks up the ticking then you
could lose some power and efficiency from the engine.
The problem may be the injectors when the engine is cold. I had the
same problem on a couple of my vehicles and got a good injector
cleaner(at the injectors themselves), changed the fuel filter and my
troubles went away.
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