Just had my favorite mechanic change the intake gasket on my 91 suburban
(350). Specifically asked him not to use a scotchbrite pad to clean the
heads but he did anyway. I am concerned that there may be debris in the
oil. I have heard of stories of these pads leaving particles that have
destroyed the bearings. He ran if for two hours after finishing it up and
then changed the oil before he gave it back to me. The question, should I
change the oil again in a few hundred miles to make sure there is nothing in
the oil or not worry about it. He is a good mechanic so I trust he was
clean about what he did but I just wanted to see what the Olympic wisdom was
about this.. As a side note he did check all of the things suggested here
(timing chain, crank seals ect) and did not find a problem, in fact he said
it was in amazingly good shape for 150k on the clock. Thanks for the help.
You favorite mechanic should know better here, but in his defense he may
have covered up all the areas around where he was doing work to prevent
entry into the engine, if there is any in there the damage would be done
quickly, what did he say about this?
Scotch Brite, huh...? I would never use one on an assembled engine...or even
on any component after hot-tanking!
Him not doing what you requested isn't being a 'trusted Mechanic' now is
it? I think I would have a long talk with your 'trusted Mechanic' about this
issue. I will say this though, its amazing how clean something can be kept
with balled up paper towels and a small shop vac.
For the particles to get to the bearings they would have to go through the
oil filter...not likely. Now cylinder walls...THAT would be far more
likely. That and oil pump impellers. Neither of which are near as soft as
bearing surfaces. If there was gonna be any damage, it would have happened
"Shades" <shades_1970(at)netins(dot)net> wrote in message
I don't know if he used a scotch brite pad but at least a wire brush was
used to clean the heads. I don't completely understand why... All of the
intakes I have ever done nothing more was required then 5 min with a single
edge razor and some carb cleaner to clean the gasket surfaces...
Well... I checked the oil today and it turning dark. Which was a shock as
it was a clean as a bell before I left his shop. I went ahead and drove it
around for 20 miles and then changed the oil as hot as I could get it
(wanted to get it all in suspension). What came out was dirty but it
appeared to be soot, no metal at all and nothing was stuck to the magnetic
drain plug. The oil filter actually had a very fine black sludge in it but
also nothing that was metallic. I ran my fingers though the oil and oil
filter spoils and I could not feel any grit what so ever, so the material
was fine enough I could not feel it. I will keep an eye on it and change
it in a hundred miles or if it starts to get dirty before then, I will
change it again and again if necessary. Everything else is ok, oil pressure
is as before, temp is ok and it runs smooth. No unusual sounds or smells...
Thank you to all who offered advice it was appreciated.
I wish, I did not see him do the job so I am still giving him the benefit of
the doubt. Since I did not find any metal particles I am hoping that it was
a wire brush. When I asked him not to us the scotch brite he responded, "we
always do it that way and have never had any problems" so I assumed when I
saw the scratches on the heads... But I am willing to go with your
suggestion....that one is cheaper. :)
The issue is with Rol-Lock disks, not with Scotch-Brite pads.
Both 3M products, Both come in Red/Maroon Medium Grit. Yet Both are
Rol-Lock disks have a compressed Media, which is placed in a press,
with a natural(1 inch thick) Rubber disk. The Press heats to 450 to 700
Degrees Fahrenheit(232 to 370 C). Then with 55 to 70 TONS of pressure
presses the disk to the backing, the heat adheres the disk to the
rubber, the die in the press shapes the rubber, and the heat turns the
rubber in to a hard plastic like material.
Scotch-Brite Pads on the other hand come in 6 foot tall by 4 foot wide
1000 pound rolls. Then are cut in to 4 inch by 8 inch pads in rotary
If you ask someone not to use Scotch-Brite, they will not think you
mean Rol-Lock disks.
Anyone Cleaning a head sealing surface should seal the ports with rags.
Then blow the area off or vacuum the area.
So it probably is just soot/dirt as suggested. I am going to stay on top of
it and see what happens. Thank you all for all your help, I just need to
get somebody else's opinion.
Your help was appreciated.
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