1997 Chevrolet Blazer - 4-Door 4WD
Vin #1GNDT13W0VK134606
221,500 miles

I am in the process of doing my upper and lower intake gaskets
and decided to purchase new Valve covers.
They are the original valve covers and after nearly 20 years
of use I thought I might give the vehicle a fresh look.
I followed my ALLDATA info for my vehicle for both valve covers.
The passenger side - GM OEM-Engine Valve Cover 12554256.
Looks fine, just like the one I have on there. No problem.

But the drivers side valve cover that I ordered according to ALLDATA
was GM OEM-Engine Valve Cover 93441317. I even verified the info
from the Chevy parts dealer with my Vin number and he said this was the correct
valve cover. When I received it I found out it has a permanent PVC valve/orifice. My old
valve cover has the rubber grommet and removable PVC valve.

My research shows that indeed GM started to make valve covers with permanent
PVC valves/orifices starting I believe in 2004/2005. I am pretty sure the valve cover will fit just fine.
I am just a little confused /concerned about the permanent PVC valve/orifice. Does anybody have any
experience or feed back on this kind of setup. Not sure why GM did this. Not sure
if I can consider this an upgrade with no future problems. Any feedback from any body
who might have this kind of PVC valve/cover would be appreciated.

Thanks - Mark

 

I used the newer style cover when i rebuild the engine in my last truck. Ran it for ~30K with no issues before i sold it.

I believe the change from a valve to orifice was to reduce oil consumption issues sometime caused by PCV valves. Never heard much about our 4.3's but I know this was a big issue on some of the early 5.3/6.0 engines.

 

my 05 has the permanent style on it

 

Thanks for the input. Tomorrow I will be doing the upper and lower intakes
along with a the new Spyder injection system. I'll be using the new valve cover style
with the orifice. I'll update for anyone interested.
Thanks.

 

i'm interested...why are you changing the injection system? upgrade or old one went bad?

 

Well after almost 17-18 years on this vehicle I decided that I was going to keep it as long as possible, which means extra maintenance and changing things before they go out.

Yesterday I changed out the upper/lower intake gaskets,
new upgraded fuel injectors ACDELCO Part # 2173028.
Also put in a new water pump and power steering pump.
Everything that was taken out were the original OEM parts.

A buddy of mine helped me do the work. Everything took
about 10-12 hours and a six pack of beer.

The old fuel injectors basically fell apart when we removed them.
They were very brittle. The new injectors are more beefy looking
and took a little persuading to get them all popped in.

The changeover from old to new is quite noticeable.
More responsive and it idles much nicer. I also put in
a new EGR valve and Idle air control valve.

The lower intake was caked with carbon. I took my time cleaning
it all out. The throttle bottle was all caked up too. For a nearly 20 year old
vehicle I think it has served me well over the years. I am very happy with
the money I have put into it for the future. I plan to keep it for another
20 years. It drives really nice now. On the highway at 70mph it felt smooth.
The new injectors really make a difference. A good investment.

Very Happy,
Mark

 

That's good to hear!


I'm planning to do fuel injector upgrade soon. This a pretty straight forward job?

 

Looking at RockAuto at those gaskets, it's recommended to replaced the manifold bolts. Did you do that too?

 

Yes I replaced the lower manifold bolts with Felpro ES72224. Got them from Rockauto.
I used the Felpro Gasket Set MS98002T
Torqued them down with a good torque wrench according to spec.
From what i researched those torque specs are important.

You could probably just clean off the ones that come out but I played it safe and used new bolts.
Having 2 people do the entire job helps out a lot. One person taking things apart and another gathering
all the bolts and labeling them to make sure things don't get lost. Things go quicker. One person doing the work
and another being the gopher for the correct tools. One person can do this job but it makes life
easier with 2 people if you want to get it done in 1 day.

Mark