yet another issue with the '96 Caravan...

I swear I'm gonna blow this thing up... Same 1996 3.3L caravan that I
replaced the fuel pump on and mysterious tensioner issues.

Last night while coming home from work I noticed the engine started
making a knocking sound. I'm not sure what rod knock sounds like, or
even what causes it, but this may be it.

I only hear the "knocking" sound when I accellerate. If I'm idling, or
if I'm cruising under 1500-2000rpm, I don't hear it. If I have to
accellerate even mildly from a light, I hear it.


I know thie description is vague, but if anyone can help with this it
would be appreciated.

 

Could be "spark knock".. pre-detonation/ignition.

 

High mileage 3.3's had a problem with rocker tower cracking that would
cause noise. I believe that this problem was corrected before the 1996
model year.

-Kirk Matheson

 

What is mileage?

Rod knocks are caused (usually) by oil problems, A-1 cause
is letting the oil level go too low for too long, too many times.

It sounds like someone's taking a ball peen hammer and slamming
it into the side of the engine block, the sound definitely sounds like
it's coming from inside the engine. And it's loud and all the time.

Ted

 

Does it match the engine rpm or the output shaft (wheel) rpm? If it
is the latter it might be an inside CV joint that has gone bad.

 

May be nothing more than an exhaust leak.
Larry

 

Welp... The van died. I'm assuming that the engine seized up on me, and
I'm also going to assume that it was, in fact, rod knock. It did sound
like a ballpeen hammer banging against the inside of the engine.


Tuesday afternoon, the oil light came on, which was odd because I had
just dropped a couple of quarts of oil in there over the weekend. I
checked my oil level and it appeared to show that all was fine. Not
being one to chance it, I added 2 more quarts of oil and the light went
off. I get off work and headed home. About half way there, the light
came on again. This time, it was accompanied by sluggish response when
accellerating (I did try to keep my rpm's between 1500 and 2000
though). I stopped, checked the oil, which, again showed plenty of oil.
I added 1 more quart and the light went off. I drove about two miles
and the van was barely moving. I decided to pull off the road and just
as I tried to make my way over, I heard a "POP" and the engine stopped
running. Right now, it won't even attempt to turn over.

129K on the ticker, I'm selling it for $1500...

 

Why do people equate oil volume and oil pressure? They are two
different things. Why do you add oil if the level is correct? (1) if
the level is in fact correct, but there are other problems, overfilling
is not going to fix anything, and (2) Overfilling can in fact create a
new problem that the engine won't survive even if the original problem
is survivable. Not saying that your original problem did it in, but you
didn't help by continuing to add oil.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

Adding two quarts above the full mark is a sure way to kill an engine
even if it didn't have a problem before.


Matt

 

That was a sad story, wasn't it? You know how it is, most people don't
think, and they're happy that way. Instead of just putting "oil" on that
light they should put "oil pressure not volume"

 

Sad, but true.

 

If the alert had stated "oil pressure low", there would have been no
confusion over what the problem was. All you get is a little light of
an oil can, that's it, and you're left to your own devices to figure
out what the issue is. Now the really odd part of this whole story, is
that even after adding oil, the level NEVER changed. It always read the
same on the dipstick.

It kind of doesn't matter anymore, there's a guy coming to pay for the
van tonight.

 

Glad you're able to get something out of it.

In your second post you described adding 5 quarts over a period of just
a few days. At one point, the dispstick showed the level as, in your
word, "fine", and you immediately added two quarts. As a believer in
the conservation of mass in everyday physics, I seriously doubt that the
level did not change on the dipstick when two quarts were added after
getting a reading between 'add' and 'full'. At that point (after adding
two quarts), it was by definition grossly over-filled (and a definite
change would have registered on the dipstick).

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

Well, that isn't physically possible unless you had a large puddle under
the van with the exact amount of oil that you just added. I guess the
question really is, why did you put the extra oil in the radiator?


Matt