I own a 96 Collector Edition LT4/6 speed. I bought it new and have only
16,000 miles on
it.It is kept in a locked garage when not in use. I have religiously
had this car serviced by Chevrolet and have used only Mobil 1 synthetic
oil. About one month ago, I started hearing noise from the left valve
conver. I brought the car in for service and the mechanic replaced 3
rocker arms and three pushrods. The oil had been freshly changed.
Within 100 miles I experienced an engine failure.The same noise started
from the valve train and within a few miles the motor stopped. The
engine temp at the time it stopped was 198F and the oil temp was 210F
but the oil pressure had dropped to nearly 0 psi The failure was due to
the fact that the engine oil had turned to a thick sludge and the
mechanic says that the engine is ruined. Unfortunately, up to now, the
dealership insists that they have no responsibility for fixing (or
replacing) the engine. I have taken a sample of the sludge and sent it
to a lab for analysis to try to find out why it turned to sludge.
I have several questions for the group:
1. Has anyone ever heard of such a thing happening?
2. Since the LT4 engine was a limited edition motor and seems not to be
available anymore, if Ido have to make an engine swap, can anyone
recommend an aftermarket or crate engine that will fit this car without
Any advice from the group on how to proceed? Please reply off list to
me at email@example.com.
Such a sad story of another neglected Corvette, I do like the "locked
garage" bit. A number of things come to mind like, "If you rest you
rust" or, "Use it or lose it". This car has been available to use for
10 years and has 19,000 wonderful miles of use. That's about 37 miles
a week. In other words it has been driven such short times that the
engine has never been up to running temperature enough. Never hot
enough to move any "sludge" that may accumulate. Probably never warmed
up to change the oil because it would put on to many miles.
My guess would be that the rockers going out on an un-used engine
should have told you and your "mechanic" something. Like why did they
fail, maybe sludge build up? When you disturbed the sludge buildup in
the valley it moved on to more important destruction, your bearings
and the oil pump. It should be rebuildable, but if you don't use it
any more than that, just push it around.
05 C6 Silver/Red 6spd Z51- with 16,000 miles
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Very true, if you don't drive it each time long enough
to evaporate or boil off the condensation that is in all engines
you will end up with sludge after 10 years.....
Many people think that just starting up the engine for a few minutes,
every month or so while it's being stored is the thing to do...
Which is actually very very bad for it.
I have a 1970 Dodge Challenger with the original engine and 32,000 miles on
it. No sludge problem, and its also a garage queen for most of the time.
Nice to blame the user when its probably something else. The challenger runs
OK, so the user was not at fault and the engine broke its self, I
understand now. Did you assume that he took it out for a 100 mile
drive when it's possible that it was 20, 5 mile trips after the sludge
was broken lose during the repair 2 years ago? Good to see you're able
to diagnose that it wasn't the "users" fault on a nearly bullet proof
engine, I'm not. I have seen cars with less miles than that with the
entire valley full of ash for 5 or 6 block trips every day for 2 or 3
years. I've also had a rocker fail in less than a year with no further
damage to the engine in the next 90,000 miles. Based on my experience
and not seeing the engine I offered an opinion, your opinion was based
Great impute on how your challenger is treated, like maybe warmed up a
bit more before the oil is dumped. I have a '50 Chevy with 123,000
miles on it and it runs fine with the original babbited rod bearings.
What does that mean, that it's 5 times better than your challenger?
Give us a hint of what "something else" might be. Keep in mind that
this post was to be answered off line so he can keep the help to
himself like he may be doing with other reasons his machine failed.
Pretty low opinion of me, eh? Well, the car was repaired one month ago
and the oil was changed. The old oil was 6 month old and came out of
the bottom looking nearly new.
The sludge formed in the 100 miles since the repair (1 month). I drove
the car 3 times
during that period...two trips of 50 miles each...plenty of time for it
to warm up properly).
On line answers are perfectly fine....I just didn't want to take up too
much bandwidth hence the comment about answering off line. What could
have happened to make the oil sludge
up? Certainly neglect except I have the service record to prove that it
wasn't neglected. Fuel in the oil from an improperly repaired
rocker/pushrod? Coolant in the oil from a blown head gasket or other
gasket installed during the repair. I did tell the mechanic
that the low coolant light had come on during the 100 miles of driving
since the repair.
My note to the group was an honest effort to try to figure out what
went wrong. I should have know that it would bring the trolls out.
Oh quit your whining, I never said I had a low opinion of you, and you
never said how long ago the repair was made. I do have an opinon of
how you treat your Corvette or lack of it's use, but that's your
You watched it being changed but you can't check your cars oil?
How many times did you shut it off and restart to make those 3 or 2
trips? What about the other 723 times you drove it before that at 3
miles a pop? Plenty of time to warm up? One or two times not getting
to running temperature don't make ash form.
Yeah, right, you would be the first.
I thought you sent it off to be tested but you want us to guess?
That only proves it was serviced, not how it was maintained or driven
which can be where it was neglected if it was neglect. My statement
had nothing to do with that kind of neglect, get over it.
None of these relate to changing a rocker arm or push rod.
You told him but didn't check it? How odd.
There you go with the name calling, try to tell us what really
happened or what you're trying to accomplish and the troll will go
Did you check the oil at anytime after it was fixed?
Was that new oil dark?
Did they pull the lifters when they changed the rockers and push rods?
Did they pull the manifold and clean the valley?
Was it their, Chevrolet's, mechanic that did the work?
Did you get a look at the parts that were replaced?
If so, were they dirty with ash or just stained?
What was the reason they were replaced?
What did the roller look like?
Was the end of the push rod broken?
If so, did it damage the rocker socket?
If so why didn't they change the lifter?
Did you keep the parts?
When you started hearing the "noise again", did you check the oil?
Was it the same" It shouldn't have been.
Where in the 100 miles did the oil pressure start to drop?
Did you check the oil when it did drop?
I would never rule out the job may have been screwed up but with what
you've told me you are the suspect. You seem to know very little about
your car and want to share less, just blame someone else for its
Now the group troll, Dad
The man's out 10 grand and we dog pile on him?
Sounds like the lab analysis will be the key. Don't see that you have any
recourse no matter what they find unless the Mobil 1 is at fault.
Hopefully, you can have the motor rebuilt. Maybe a slight bore job and
maybe a new crank. And a new..................................
Good luck, Ed
Not sure why you think that unless you read some more information on
it than was given. I raised two sons, when they were young they told
how things went bad in the same manner. Just enough so they wouldn't
get their ass kicked, this story reminds me of that same tactic. The
answer will be simple when all of the truth is told. Even the
paragraph you left has no true statements in it, or maybe you
understand how you drive it 3 times 100 miles, 2 trips, 50 mile
each??????? It's a lot easier to make sense when you're telling the
The old troll-Dad
First, don't let the barbs get under your skin (you seem to be shrugging
off the hostility well). I offered some free wallpaper of Ferrari pix,
because I know quite a few Vette lovers who appreciate Ferraris, and the
only response I got was an extremely rude one. That's usenet for ya.
Second, I can relate to the comments about the bad things which happen to
collector cars. I was shopping for a real-low-miles C4 (and finally found
one). i had the help of an all-Corvette mechanic and he sniffed and poked
around a long parade of prospects. I could tell you horror
stories...bottom line is, aside from bad gas and dried-out rubber parts,
many bad things do indeed happen to cars that are "just started up" on a
regular basis. I looked at a few high-compression cars which hadn't been
driven enough for the simple reason that it was a hassle to prepare cars
that didn't like pump gas--in order to really drive them, I mean. And then
there's the horse thing. You know: "rode hard and put away wet"? It's
funny how many people will gladly detail the body and interior before
replacing the car cover, but don't prepare the mechanical part of the
beast for a long sleep.
I once did photography for a guy who restored Ferraris. ***Those who can't
stand this OT stuff can move on to the next paragraph.*** He gave me some
very good advice about sports cars: never even start the engine if you're
not going to warm it up to operating temperature, and never work it hard
until it reaches operating temperature. Operating temperature he defined
as normal operating range on the OIL temp gauge, not the water temp.
As to your sludge thing, I'm not familiar with fuel in the oil, but
coolant in the oil looks light brown and opaque; pretty distinctive, like
chocolate milk almost. If yours is nearly black, and some parts are coated
with a lacquer-like substance, I'd have to go along with the theory of too
many short trips or running it too much without "blowing out the carbon,"
as mold man used to say...
Sorry for inconvenience. Pulled my post after finding out that he saw
the car being drained rather than extracted.
Whole thing doesn't make much sense but 16K miles in 10 years would give
a proper change interval of about 500 miles.
Would like to find out what the oil analysis shows.
I have heard that even if you don't drive a car very often you should change
the oil periodically, especially synthetic, don't know why or how often.
Have you asked mobil one folks? I think, Two Guys had
a show on this very problem.
personally i would rebuild your engine, how bad could it be?
(sleek '96 vette bonb)
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