Mercedes 300E High hydrocarbon

Bingo! there's part of your problem. Platinum plugs. Throw them away and replace with the Bosch H9DC (or any other copper plug for that matter). The platinums have resistance build in. Older engines have the resistance in the distributor and the plug connector. This extra resistance can change the quality and/or timing of the spark significantly, as you found out.

you can do even better, go to Parts Source on Weber near University.

Neil, MOST important is that after you change your plugs, you get the engine good and hot (ie the catalysts) and get the measurement done 'immediately' after you stop driving. Go for a run out to St.Jacob and make sure the testing station will take you immediately after (possibly leave car in 3rd gear :-)

good luck, guenter

Guenter, Thanks. I will try what you said, change the plugs and take it for a long drive, then go for emission at a different place this time, most probablly at Econo Oil at University and Weber. Will let you know what happens. Canadian Tire owns Parts Source and have the same outfit. Thanks anyway.

Neil

Area, or rather distance.

When I heard this, and it was a few years back, all of tornoto and environ was 416. Now that they've moved a bunch of things into 905 it may not be true any more. But I don't relaly know.

Fair enough. I pay $18/mo to Bell and get virtually unlimited North America wide long distance free.

Run a tank of premium mixed with some gas line antifreze through the car. That helps.

If it hasn't already been said, change the air filter too.

Thanks Richard, I will try that too. Could not get Bosch H9DC spark plugs so bought Champion eqvivalent copper ones. I had put platinum plugs and may be thats why HC went up as Guenter suggested.

no question, just make sure for your re-test that they take you 'right away' after you get the cat good and hot..... NO! lolligagging for coffe or what have you :-)

cheers and good luck

guenter

Richard Sexton, Guenter, Thanks for the help. I changed plugs and air filter, took it for emission at Econo Lube on University and Regina.. It FAILED at HC 81. Then the guy changed oil and put in thick synthatic oil (PZ26) instead of regular oil and did retest. It just PASSED at HC 52. Allowable limit is 52. At least I dont have to worry for 2 more years. Just for information, I have learnt that synthatic oil burns much less than regular oil, so HC is reduced. It cost $50.00 more, but saves the other hassels of adjustments. Cheers.

glad to hear it. Interesting about the synthetic oil, it does make sense. However, do tell what the oil was. Pz26 is the filter for the syn oil I will likely need to do this for my next emission test.

cheers, guenter

Check out this site:

Neil, interesting compared to your findings. big difference of course is the age of the engine and, possible/probable oil leaking into the cylinders via the valve stem/seals. Because the syn oil remains more viscous it appears to make a significant difference in HC levels on old engines

thanks for that, guenter

I think this is measuring the oil leaking into the combustion chamber... You can try running mobile 1 instead of regular oil, if you aren't doing that yet. I have heard that reduces HC emissions (don't know for sure).

Let us know...