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Smog check HC question



 
 
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  #1  
Old August 9th 06, 01:51 AM posted to rec.autos.tech
nutso fasst
external usenet poster
 
Posts: 97
Default Smog check HC question

Hello.

I replaced cat converter 2 yrs ago to bring down HC in wife's 81 VW
Scirocco. Now the car's failing due to high HC again, with only about 2800
miles since last test! Results:

15mph, 1807rpm
HC max: 162 - HC meas: 149
CO max: 1.09 - CO meas: 0.27
NO max: 1227 - NO meas: 983

25mph, 1938rpm
HC max: 132 - HC meas: 172 FAIL
CO max: 1.09 - CO meas: 0.27
NO max: 1227 - NO meas: 791

The car is driven every few days for short trips except was driven about
15-20 miles on the freeway before the test. Also, tester ran it for 2
minutes at 2K or so before starting the test. It has over 250K miles and
does pass some oil - about 1qt every 200 miles or so I think. It doesn't
smoke in normal driving though, and near-new plugs look toasty-good.

Question: I put a bottle of Techron in the tank. Is there a chance running
that out on the freeway would clean up the test results, or is a new cat the
answer? (Can a cat go bad in 2800 miles?!)

Also: what effect does Techron have on a smog test? Does it all have to be
run out and refueled before testing?

thx,
nf




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  #2  
Old August 9th 06, 02:01 AM posted to rec.autos.tech
Nate Nagel
external usenet poster
 
Posts: 1,010
Default Smog check HC question

nutso fasst wrote:
> Hello.
>
> I replaced cat converter 2 yrs ago to bring down HC in wife's 81 VW
> Scirocco. Now the car's failing due to high HC again, with only about 2800
> miles since last test! Results:
>
> 15mph, 1807rpm
> HC max: 162 - HC meas: 149
> CO max: 1.09 - CO meas: 0.27
> NO max: 1227 - NO meas: 983
>
> 25mph, 1938rpm
> HC max: 132 - HC meas: 172 FAIL
> CO max: 1.09 - CO meas: 0.27
> NO max: 1227 - NO meas: 791
>
> The car is driven every few days for short trips except was driven about
> 15-20 miles on the freeway before the test. Also, tester ran it for 2
> minutes at 2K or so before starting the test. It has over 250K miles and
> does pass some oil - about 1qt every 200 miles or so I think. It doesn't
> smoke in normal driving though, and near-new plugs look toasty-good.
>
> Question: I put a bottle of Techron in the tank. Is there a chance running
> that out on the freeway would clean up the test results, or is a new cat the
> answer? (Can a cat go bad in 2800 miles?!)
>
> Also: what effect does Techron have on a smog test? Does it all have to be
> run out and refueled before testing?
>
> thx,
> nf


Have you replaced the O2 sensor? Or had someone tweak the mixture
adjustment on the fuel distributor? (techron is a good idea tho, dirty
injectors are another possibility) A VW shouldn't NEED a catcon to pass
emissions, I know lots of people with gutted and/or known failed cats
(myself included) who have passed smog tests with flying colors.

If you are anywhere near DC I advise you to just give the car to me,
because early body Sciroccos are utterly worthless and certainly not any
good for monster 1.8 turbo swaps

Seriously, though, a quart in 200 miles is not good, engine might just
be getting tired if a real tune-up doesn't get it to pass. Your cat
might well be dead already if all that oil is being burned and not
leaking out. Good news is that vee-dub 4-cyls are near unbreakable so
it should be ready for another good 250K after a rebuild.

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel
  #3  
Old August 9th 06, 05:09 AM posted to rec.autos.tech
nutso fasst
external usenet poster
 
Posts: 97
Default Smog check HC question


"Nate Nagel" > wrote in message
...
> Have you replaced the O2 sensor? Or had someone tweak the mixture
> adjustment on the fuel distributor? (techron is a good idea tho, dirty
> injectors are another possibility) A VW shouldn't NEED a catcon to pass
> emissions, I know lots of people with gutted and/or known failed cats
> (myself included) who have passed smog tests with flying colors.


The car invariably passed smog checks w/o cat replacement until 239K miles
('98). Then the HC numbers were way out, and a new cat brought them way
down. The car passed in 2000 and just barely in 2002. In 2004 needed another
cat to pass. So we get one cat going 238K, next 10K, and next...2.8K? I
don't think it's been using THAT much more oil. It's been tuned, CO adjusted
and O2 sensor replaced a while ago - symptoms don't indicate O2 sensor, do
they?

Any idea what effect Techron will have on the test if tested with it still
in the tank?

> If you are anywhere near DC I advise you to just give the car to me,
> because early body Sciroccos are utterly worthless and certainly not any
> good for monster 1.8 turbo swaps


That sounds perfectly unreasonable. Hmm, maybe I should be asking what's
involved in a 1.8 turbo swap! Anyway, I'm on the best coast.

> Seriously, though, a quart in 200 miles is not good, engine might just
> be getting tired if a real tune-up doesn't get it to pass. Your cat
> might well be dead already if all that oil is being burned and not
> leaking out. Good news is that vee-dub 4-cyls are near unbreakable so
> it should be ready for another good 250K after a rebuild.


Maybe so, but also needs a fender, weatherstrip, upholstery, headliner,
paint, dashboard, wiring, CV joints...and who knows what else. It sure has
been the best car I've ever had though. Only 2 sets of tires, 2 brake jobs,
2 timing belts, and IIRC only one clutch in 252K miles. In its youth it got
36 mpg hwy, 29 city.

nf


  #4  
Old August 9th 06, 04:57 PM posted to rec.autos.tech
N8N
external usenet poster
 
Posts: 3,477
Default Smog check HC question


nutso fasst wrote:
> "Nate Nagel" > wrote in message
> ...
> > Have you replaced the O2 sensor? Or had someone tweak the mixture
> > adjustment on the fuel distributor? (techron is a good idea tho, dirty
> > injectors are another possibility) A VW shouldn't NEED a catcon to pass
> > emissions, I know lots of people with gutted and/or known failed cats
> > (myself included) who have passed smog tests with flying colors.

>
> The car invariably passed smog checks w/o cat replacement until 239K miles
> ('98). Then the HC numbers were way out, and a new cat brought them way
> down. The car passed in 2000 and just barely in 2002. In 2004 needed another
> cat to pass. So we get one cat going 238K, next 10K, and next...2.8K? I
> don't think it's been using THAT much more oil. It's been tuned, CO adjusted
> and O2 sensor replaced a while ago - symptoms don't indicate O2 sensor, do
> they?
>
> Any idea what effect Techron will have on the test if tested with it still
> in the tank?
>
> > If you are anywhere near DC I advise you to just give the car to me,
> > because early body Sciroccos are utterly worthless and certainly not any
> > good for monster 1.8 turbo swaps

>
> That sounds perfectly unreasonable. Hmm, maybe I should be asking what's
> involved in a 1.8 turbo swap! Anyway, I'm on the best coast.
>
> > Seriously, though, a quart in 200 miles is not good, engine might just
> > be getting tired if a real tune-up doesn't get it to pass. Your cat
> > might well be dead already if all that oil is being burned and not
> > leaking out. Good news is that vee-dub 4-cyls are near unbreakable so
> > it should be ready for another good 250K after a rebuild.

>
> Maybe so, but also needs a fender, weatherstrip, upholstery, headliner,
> paint, dashboard, wiring, CV joints...and who knows what else. It sure has
> been the best car I've ever had though. Only 2 sets of tires, 2 brake jobs,
> 2 timing belts, and IIRC only one clutch in 252K miles. In its youth it got
> 36 mpg hwy, 29 city.
>
> nf


I just don't like your oil consumption... I would suggest just dropping
in a junkyard engine (hell, I sold an '84 with similar mileage for $600
a while back that *didn't* burn oil) but I'm not 100% familiar with the
earlier cars, I don't know what would and wouldn't bolt in without any
mods at all. High oil consumption can cause failures of both the O2
sensor and the cat well before their time, and on a car with a cat you
won't see any smoke until the cat is well and truly trashed.

nate

  #5  
Old August 9th 06, 07:45 PM posted to rec.autos.tech
nutso fasst
external usenet poster
 
Posts: 97
Default Smog check HC question


"N8N" > wrote in message
oups.com...
> I just don't like your oil consumption... I would suggest just dropping
> in a junkyard engine (hell, I sold an '84 with similar mileage for $600
> a while back that *didn't* burn oil) but I'm not 100% familiar with the
> earlier cars, I don't know what would and wouldn't bolt in without any
> mods at all. High oil consumption can cause failures of both the O2
> sensor and the cat well before their time, and on a car with a cat you
> won't see any smoke until the cat is well and truly trashed.


Yeah, the oil consumption seems pretty high. The amount is an estimate,
don't really track exactly when I add because I'm not the driver. I'm
thinking I'll give this tank of Techron a long run today and see how quickly
oil level goes down.

No $ to do major work right now but wife needs this car badly.

Any idea how Techron-treated gas will affect smog check?

Thanks for taking the time to reply.

nf


  #6  
Old August 10th 06, 03:02 AM posted to rec.autos.tech
Steve Walker[_1_]
external usenet poster
 
Posts: 62
Default Smog check HC question

nutso fasst wrote:
> Hello.
>
> I replaced cat converter 2 yrs ago to bring down HC in wife's 81 VW
> Scirocco. Now the car's failing due to high HC again, with only about 2800
> miles since last test! Results:
>
> 15mph, 1807rpm
> HC max: 162 - HC meas: 149
> CO max: 1.09 - CO meas: 0.27
> NO max: 1227 - NO meas: 983
>
> 25mph, 1938rpm
> HC max: 132 - HC meas: 172 FAIL
> CO max: 1.09 - CO meas: 0.27
> NO max: 1227 - NO meas: 791
>
> The car is driven every few days for short trips except was driven about
> 15-20 miles on the freeway before the test. Also, tester ran it for 2
> minutes at 2K or so before starting the test. It has over 250K miles and
> does pass some oil - about 1qt every 200 miles or so I think. It doesn't
> smoke in normal driving though, and near-new plugs look toasty-good.
>
> Question: I put a bottle of Techron in the tank. Is there a chance running
> that out on the freeway would clean up the test results, or is a new cat the
> answer? (Can a cat go bad in 2800 miles?!)
>
> Also: what effect does Techron have on a smog test? Does it all have to be
> run out and refueled before testing?
>
> thx,
> nf
>
>
>
>


If you really want to keep the car,and keep it cheap, put in some
Restore(?), engine rebuild in a can, put a few hundred miles on it, put
in a new cat & get tested again. If you pass(you should), go home,
remove cat, replace with old one, & drive it until next test. Repeat
process as needed.

--
Steve Walker
(remove wallet to reply)
  #7  
Old August 10th 06, 04:02 PM posted to rec.autos.tech
nutso fasst
external usenet poster
 
Posts: 97
Default Smog check HC question


"Steve Walker" > wrote in message
news:1twCg.14176$rd1.9396@trnddc01...
> If you really want to keep the car,and keep it cheap, put in some
> Restore(?), engine rebuild in a can, put a few hundred miles on it, put
> in a new cat & get tested again. If you pass(you should), go home,
> remove cat, replace with old one, & drive it until next test. Repeat
> process as needed.


Brilliant! Thanks.

nf


  #8  
Old August 10th 06, 07:02 PM posted to rec.autos.tech
E Frank Ball III[_1_]
external usenet poster
 
Posts: 1
Default Smog check HC question

nutso fasst > wrote:
> Hello.
>
> I replaced cat converter 2 yrs ago to bring down HC in wife's 81 VW
> Scirocco. Now the car's failing due to high HC again, with only about 2800
> miles since last test! Results:
>
> 15mph, 1807rpm
> HC max: 162 - HC meas: 149
> CO max: 1.09 - CO meas: 0.27
> NO max: 1227 - NO meas: 983
>
> 25mph, 1938rpm
> HC max: 132 - HC meas: 172 FAIL
> CO max: 1.09 - CO meas: 0.27
> NO max: 1227 - NO meas: 791
>
> The car is driven every few days for short trips except was driven about
> 15-20 miles on the freeway before the test. Also, tester ran it for 2
> minutes at 2K or so before starting the test. It has over 250K miles and
> does pass some oil - about 1qt every 200 miles or so I think. It doesn't
> smoke in normal driving though, and near-new plugs look toasty-good.
>
> Question: I put a bottle of Techron in the tank. Is there a chance running
> that out on the freeway would clean up the test results, or is a new cat the
> answer? (Can a cat go bad in 2800 miles?!)
>
> Also: what effect does Techron have on a smog test? Does it all have to be
> run out and refueled before testing?


The Techron is good, but you need more than that. With that level of
oil consumption and all the short trips you have a lot of carbon
build-up. Get a can of Berryman B12 Total Combustion Cleaner Kit.
Get the engine well warmed up then follow the directions. Then go out
and drive and FLOOR IT until smoke stops billowing out the tailpipe.
Depending on how much buildup you have this will take a couple blocks to
a couple of miles.

Run the techron in the gas tank too. After both of these change the
oil, it will be black.

--

E Frank Ball
  #9  
Old August 10th 06, 07:33 PM posted to rec.autos.tech
[email protected]
external usenet poster
 
Posts: 86
Default Smog check HC question


nutso fasst wrote:
> I replaced cat converter 2 yrs ago to bring down HC in wife's 81 VW
> Scirocco. Now the car's failing due to high HC again, with only about 2800
> miles since last test! Results:
>
> 15mph, 1807rpm
> HC max: 162 - HC meas: 149
> CO max: 1.09 - CO meas: 0.27
> NO max: 1227 - NO meas: 983
>
> 25mph, 1938rpm
> HC max: 132 - HC meas: 172 FAIL
> CO max: 1.09 - CO meas: 0.27
> NO max: 1227 - NO meas: 791
>
> The car is driven every few days for short trips except was driven about
> 15-20 miles on the freeway before the test. Also, tester ran it for 2
> minutes at 2K or so before starting the test. It has over 250K miles and
> does pass some oil - about 1qt every 200 miles or so I think. It doesn't
> smoke in normal driving though, and near-new plugs look toasty-good.


I doubt the Techron helped with this. What may let you pass emissions
are using the hottest spark plugs allowed and changing the oil to
20W-50. Were 1981 Sciroccos part of a recall for high hydrocarbons?
VWs made until some time in the early 1980s had valve stem seals that
would wear out and cause a quart of oil to be burned every 100-200
miles. VW initially said this was normal, but they were later forced
by the EPA to fix this, and a recall was issued that included new valve
seals, valve adjustment, and, for some model years, elimination of the
EGR valve and replacement of it with just an ignition vacuum advance
time delay. I think the recall was called MK or KQ. The valve seals
on this engine can be replaced without removing the head if you pump
air into the spark plug hole or stuff non-fraying rope through the hole
and turn the engine by hand slightly to compress it.

  #10  
Old August 11th 06, 02:46 AM posted to rec.autos.tech
nutso fasst
external usenet poster
 
Posts: 97
Default Smog check HC question


> wrote in message
ups.com...
> I doubt the Techron helped with this. What may let you pass emissions
> are using the hottest spark plugs allowed and changing the oil to
> 20W-50.


Exclusively Castrol 20W-50 since I bought the car w/10,000 miles on it.

> Were 1981 Sciroccos part of a recall for high hydrocarbons?


Interesting...would a recall fix still be available if I never received a
notification? I seem to recall, though, problems with Rabbits made in USA,
not Sciroccos made in Germany. Anyway, the car passed all checks until 1998
(239,000 miles), when it failed HC miserably and got its CAT replaced for
the first time. And I know it wasn't using a lot of oil when I was driving
the car a lot prior to 1994.

Valve seal failure does seem a logical explanation for seeing smoke after
the engine is started cold, and why it would use more oil per mile on short
trips.

> The valve seals
> on this engine can be replaced without removing the head if you pump
> air into the spark plug hole or stuff non-fraying rope through the hole
> and turn the engine by hand slightly to compress it.


Good tip. Thanks!

nf


 




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