Can Smog check results point to actual problem?

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

volkswag@sbcglobal.net - 17 Dec 2007 20:28 GMT

My 1977 half ton 2wd 350ci 350 turbo automatic Chevy pickup failed smog
check as Gross Polluter. Could the numbers on the smog test point to actual
problem such as air/fuel mixture, unburnt fuel, oil consumption, bad
compression, bad cat? Or wrong timing, unburnt fuel, oil consumption around
value stem seals, worn guides, valve seating, piston rings frozen to piston,
EGR plugged, carburetor adjustment, etc or are they vague? Of course,
check of spark plugs is the first check. Check of compression is good and
within 5% on all eight cylinders. If the cat is the problem, is that caused
by the wear or mileage of engine? This engine does not have the hardened
valve seats. In need of head overhaul or complete engine overhaul?

I'm ready for a newer vehicle but hate to part with it if repairable.
Registration and insurance is cheaper than a new vehicle. A major safety
concern is the fuel tank outside of frame rails.

Mr Goodwrench is not old enough today to know what a carburetor is. I took
my 1975 Van with maximum speed problem of 20 mph, he wanted to rebuild (no
parts) or replace (no replacement available) the carburetor. I returned
home and replaced the $1 fuel filter. I can still get rebuild kits at any
local auto parts store.

Should I take it for mechanic diagnostics since there is no computer in this
vehicle?

Gary

Reply to this Message

Shep - 17 Dec 2007 20:57 GMT

What were the exact results of the test? How can anyone point you in the
right direction without knowing what part of the test failed?

> My 1977 half ton 2wd 350ci 350 turbo automatic Chevy pickup failed smog
> check as Gross Polluter. Could the numbers on the smog test point to
[quoted text clipped - 22 lines]
>
> Gary

---- Posted via Pronews.com - Premium Corporate Usenet News Provider ----
http://www.pronews.com offers corporate packages that have access to 100,000+ newsgroups

Reply to this Message

aarcuda69062 - 18 Dec 2007 01:53 GMT

> My 1977 half ton 2wd 350ci 350 turbo automatic Chevy pickup failed smog
> check as Gross Polluter. Could the numbers on the smog test point to actual
> problem such as air/fuel mixture, unburnt fuel, oil consumption, bad
> compression, bad cat?

Yes.

> Or wrong timing, unburnt fuel, oil consumption around
> value stem seals, worn guides, valve seating, piston rings frozen to piston,
> EGR plugged, carburetor adjustment, etc

Yes.

> or are they vague?

There is no such thing as a silver bullet.

> Of course,
> check of spark plugs is the first check.

Depends on which gas(es) were out of spec.

> Check of compression is good and
> within 5% on all eight cylinders. If the cat is the problem, is that caused
> by the wear or mileage of engine?

They don't last indefinitely and excess engine oil will tend to
poison them.

> This engine does not have the hardened
> valve seats. In need of head overhaul or complete engine overhaul?

A cylinder leak down test would provide more conclusive .

> I'm ready for a newer vehicle but hate to part with it if repairable.
> Registration and insurance is cheaper than a new vehicle. A major safety
> concern is the fuel tank outside of frame rails.

Well then, sounds like you want a new vehicle.

> Mr Goodwrench is not old enough today to know what a carburetor is.

Not necessarily true.

> I took
> my 1975 Van with maximum speed problem of 20 mph, he wanted to rebuild (no
> parts) or replace (no replacement available) the carburetor. I returned
> home and replaced the $1 fuel filter. I can still get rebuild kits at any
> local auto parts store.

Point?

> Should I take it for mechanic diagnostics since there is no computer in this
> vehicle?

If you can't diagnose it yourself, yes.
Just because there is no on-board computer doesn't mean that
diagnostics can't be done.

Reply to this Message