Motor flush

Bob Dunahugh

New member
Sep 17, 2012
2,784
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Dave. I too am interested in. What criteria was met to determine that you=
had great success with that motor flush? I had heard of people using this=
type of produce. Sludge build up was very common prior to 1963. As crank=
case ventilation was done by of a road draft tube. This tube generally we=
nt down next to the bottom of the oil pan. To be in the air stream under th=
e engine. Was cut at an angle to help create a low pressure area at the end=
of the tube. This angle cut helped to pull fresh air in the oil fill cap =
that had a crude filter media in it. In 1963. The Fed mandated that a Posit=
ive Crankcase Ventilation ( PCV ) system be put on all cars/trucks sold in=
the US. Calif preceded this Fed action. The PCV system used that vacuum i=
n the intake manifold to remove these contaminates from the crankcase. Prio=
r to 1963. Few engine ever made it to 100,000 miles. The main contaminant t=
hat shortened engine life was carbon. The PCV system was a great move forwa=
rd for extended engine life. EFI has also moved engine life farther out. B=
y way of decreasing crankcase contamination/carbon. This is how synthetic =
oils started to be more viable with engine produced in resent years. Thus a=
llowing longer oil change cycles. Our 403/455 will NEVER get to the point =
of the engines that are produced in recent years. PIRIOD. Thus we will stil=
l need more frequent oil/filter changes to remove the contamination that do=
n't get picked up by the oil filter. We see a lot of engine hitting over 25=
0,000 miles on mineral oils. Remember that our oil filters ONLY remove the =
larger pieces of carbon that slowly eat up YOUR engine.. Frequent oil chang=
es remove the rest. Thus back too. Your monkeys. Your circus to do to do =
as you wish. I change all my lubes more often then recommended by GM. Oils =
cheep. Part/labor aren't. Bob Dunahugh With an over maintained 78 Royale=
 
My motivation for asking: I don't have any immediate need to use one as of yet, but I wondered if anyone was using such a flushing product in their GMC.

I had a 70's Chevy that I used the '5 minute motor flush' on for years. I could pull the valve covers and adjust the rockers and never even get my hands dirty. It always looked spotless inside.

When I got my '59 DeSoto, the sludge was so thick under the valve covers that you couldn't see the rockers -- and that was with regular oil changes by the previous owner. Got about a coffee can of sludge out with a spoon, and then did a few oil/filter changes with the same flush product, and it got to be as clean as the Chevy inside.

That's my history with flushes. Now, on the GMC, I will be doing my first oil change shortly. So far, no one has said that they use a flush product, so I will probably skip it for now. Was looking at it simply as a preventative/cleaning measure.

Thanks, All.

-Dave
1978 Transmode near Pittsburgh
 
John L. I've got turned around on some of those engine produce it seems that GM put out. What was the one that poured like STP?. Bob Dunahugh