What the hell was that noise????

Hey all, I have a 1992 S-10 Blazer 4x4 with the 4.3 litre and auto tranny. This evening I was changing the front brake pads and decided to spray some carb cleaner in the intake and let it soak while I changed the pads. When I
went to start the truck it ran rough (no suprise there since I sprayed about a half can of carb cleaner in the tbi unit) I goosed the throttle to clear the cleaner. When I goosed it, it started to rattle like I dropped a rod. The rattle/ thunk/thump was consitent with a blown rod bearing, It would rise up with the revs and go down with the revs. Now for the wierd stuff. According to the HIGHLY ACCURATE oil pressure gauge that is in the dash I never lost any oil pressure ( a nice 40 lbs) and once the truck warmed up the sound went away. What the hell was that noise. The truck runs fine and it has no noise now so I am VERY CONFUSED here Thanks Steve
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Fuel knock due to the carb cleaner dripping into the cylinders that had open valves? Or maybe some of the oil was washed away from the cylinder walls perhaps resulting in some piston slap.
Just my guess.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Steve,
With half a can of carb cleaner in there you likely washed all the oil off the cylinder walls the first crank of the starter. Took the engine a few minutes to replace it, hence the knock. Just your pistons stretching their legs in your cylinders!
Doc

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I
about
Ever hear of hydro-lock? That's what it was trying to do. VERY hard on everything. H
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Most likely when you sprayed carb cleaner of that amount and you let it soak it probably broke loose some carbon. Carbon knock can and will sound likes rods beating around. Hence after running a few minutes the carbon made it's way out of the combustion chamber.
Alan

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

what you heard was probably the engine running with no oil in the sleeves, as Doc said, and maybe a big-assed chunk of carbon rattling around... lol Good thing you didn't do that to a ferd.. you'd be sweeping up pieces of engine..
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
LOL!
Sweeping up pieces and putting them in shoe boxes!
Refinish King

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Well this a.m. I changed the plugs and all of them looked ok. No oil residue and with the new plugs the engine runs smoother then it ever did. Thanks to all the replies Steve

tranny.
some
When
clear
rod.
would
stuff.
I
up
and
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
severe preignition caused by thr highly flammable carb cleaner flooding the cylinders............................... Don't do that again.
--
Mad-Dog
'79 Chevy K-10
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
holy smokers....the things you don't think of when trying to do yourself a favour. man its a good thing that relative mechanical rookies like myself read these posts!!!
its great when someone (and it never fails) has to learn the hard way....we can all benefit from the information. i'm glad it wasn't me this time!! ;)
bmoney

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.