Jgarlock

Hi guys,

I just failed an emissions test due to burning some oil, I have just redone the head gasket, valve cover gasket, valve stem seals, exhaust manifold, vacuum lines, plugs/wires ext.

I did a compression test on the engine dry/wet and below are the results
1. 135/145
2. 140/150
3. 140/150
4. 135/145
5. 140/150
6. 135/150

As far as I can see it looks like the rings are not a major issue, having the <10% variance between the dry/wet is acceptable correct?

I am wondering if the new valve stem seals I put on got messed up somehow? I have never replaced the seals before, but it seemed very straight forward and hard to mess up unless I mixed an exhaust/intake seal..

My current plan is to replace the valve stem seals again with compressed air to hold the valves in place, does anyone have any other suggestions to troubleshoot/fix the oil burn? Or any suggestions as to mistakes that can be made while installing the valve stem seals?

tjwalker

Curious, how exactly fail you for "burning oil". Is that something that is just visually observed? Or do the exhaust analyzers come up with that conclusion? If there is a technical diagnosis for you failing, please post the exact wording so we can try to help you.

Jgarlock

I failed for being a Gross Polluter, the specs are below

Measured/Max
CO- 0.9/1.0 Idle 2.56/1.0 @2500/rpm
HC- 151/120 Idle 82/180 @2500/rpm

O2 was 1.0 at idle .1 @2500/rpm
CO2 was 13.9 idle, 13.5@2500/RPM

I was told by the guy running the station that the slight smoking was caused by oil burning and that had also caused the high numbers

tjwalker

Don't you get another free retest with a failure?

Here are some general tips to passing emissions screenings. I would be sure you are up to snuff on all of these before digging into your valve seals.

1. When was last oil change? Want to have clean oil.

2. Tuneup. Secondary ignition parts can play a pretty big part. Fresh Champion plugs, quality plug wires, cap and rotor.

3. Use oxygenated (10% alcohol) gas when testing. Can produce slightly better results

4. Be sure engine is fully HOT before testing. Take it for a long drive before pulling into test station.

5. Be sure your CCV system is intact, all hoses, etc. and clean.

6. Go to the test lane whene they are not busy and you don't have to spend time idling, waiting which can hurt your results a bit.

Jgarlock

Sorry for the slow reply.
1. Oil was just changed
2. Plugs/wires/cap/rotor/coil have all been replaced
3. I will definitely try that on the next go
4. Test station is a half hour drive away
5. CCV is all intact, i just repaired it all
6. The shop sets appointments and has no wait.

Also, I just realized that I did not mention there is a low amount of white smoke coming out of the exhaust, it seems somewhat intermittent, but more prevalent at idle after it warms up. I was told this was also due to oil leaking into the chamber.

Is there any chance that the white smoke and the failed test could be to faulty injectors? I imagine if you had injectors sticking open you wouldn't burn all of the fuel, and would have some smoke coming out...

Sorry if i'm all over the place here. Just trying to figure out what would cause the low amount of white smoke and the failed test.

tjwalker

White smoke is more often caused by burning coolant rather than oil. However, if you are living in a cold climate it can be easy to be fooled by what you think is smoke, but rather is simply exhaust hitting the cold air.

If you are truly burning coolant, the level in the coolant reservoir should be down and you should have to be adding coolant. Are you having to do that?

I don't believe injectors are involved with this at all. How much oil is your XJ consuming per a certain amount of miles?

Jgarlock

I'm currently in northern California, it's been hitting around 80 here.

There is no coolant loss, it's been driven roughly 200 miles and the recovery tank/radiator are both at the same level as when i started, also the shop checked for exhaust gases in the cooling system and didn't find any.

Fixmy59bug

Hydrocarbons (HC) is unburned fuel. When I had a car that burned oil, I was told that burning oil is not a factor in the tailpipe test. Though, that was over 10 years ago, I still believe it to be true because fairly modern Vw's and hondas have problem burning oil and they are still on the road.

HC is from running too rich, be it from sticking injectors, poor atomization of fuel, or a bad O2 sensor giving false readings.

And high CO is burned fuel. So you are definitely dumping fuel.

If you have $150, I would recommend the 4 hole injectors from ksuspension and a new O2 sensor.

Also, Blue smoke is oil. White smoke is water/coolant (think steam), and black smoke is fuel (think forest fire)

Jgarlock

Update-

So it does look like i'm dealing with two separate issues here,

1st- I did find oil in the CCV line to the intake, and in the intake. All the vacuum lines are unplugged, any idea what might be causing it to pull oil in?

2nd- Fuel issues causing it to fail emissions, I have ordered the Injectors as suggested from Ksuspsension "thank you!" and am going to grab a O2 sensor. I'll update you guys on that part of things come tuesday or so when the injectors arrive.