Trying to get my 1988 2.3 190e to pass emissions,,, Am running out of ideas, other then replacing the cat,,,

On the 25 MPH test this car registered 2856 (1313 max) NOx and 225 (181 max) HC,, CO passed with 0.40 (1.16 max) CO2 was 14.35%

So I'm wondering, if the ticking I hear might be the cause of the high readings for NOx and HC.

On another note,,, I took off the oil filler cap (while car idling) and there was quite a bit of blowby,,, the car doesn't appear to be burning any oil (through exhaust) I've only put 100 miles on the car so I don't know if there is any oil consumption,,, but from the looks of it, the answer would be no.

The car runs good, a little vibration at idle, but no where near as bad as a domestic with 1/2 the miles,,, 247K miles on it.

Any input is appreciated.-

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anyone with knowledge wanna chime in???

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I'll take a shot, others can give their comments.

I read some of your previous posts and I think you mentioned some blowby and idle vibration. Probably caused by loose piston rings/valve guides or burnt valves which is not creating enough compression/combustion therefore the high HC. Shot at the moon tells me that the good cylinders are leaned out because of the unburnt O2 in the bad cylinder.

Did you do a compression test yet?

Valve lifter noise won't cause that emission problem..sticking valves (R burnt valves can..ie: low compression.

To start with the CO is high for that car..how old is the O2 sensor? Has the duty cycle been adjusted? How old are the plugs & were they gapped to 0.040"

IF all of that is OK...try a OLD remedy..a water tune-up

About 10oz thru the engine will make most cars that close to PASS.

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MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

OK Ran a compression test,,,

#1 = 105 PSI
#2 = 150 PSI
#3 = 150 PSI
#4 = 135 PSI

So #1 seems a little low,,, is this enough to cause the O2 sensor to over compensate?

I, just recently put a quart of Tranny fluid in the Crankcase to help clean out any sticking valves (Only have driven about 50 miles since I put it in,,,) also put a can of Guaranteed to Pass in the Gas, in hopes of cleaning up the valves.

Shy of rebuilding the top end, what can I do to reduce emissions by 30% to get a waiver?

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That low compression is MOST likely the cause...now why is the compression low?

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MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Hoping it's the sticking valve. I'm sure it's on the intake because I hear no noise from the exhaust side,,,

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I know that the Guaranteed to Pass directions told me to burn the whole tank of fuel and refill, but this little 190e is getting way too good a mileage for me to burn up a whole tank in the few days left on the temp tags. SO, I decided to get an emissions test after burning 1/2 tank.
Amazingly the NOx increased to 3274.2 (1313.0 limit) while HC increase to 286.5 (181.0 limit) C)=0.39% (limit = 1.16%) nad finally CO2= 13.92% (limit is N/A)

I had just changed the oil (the stuff with ATF in it) and put some fresh Castrol with a new oil filter, so dirty oil isn't causing me to be an execesive polluter, but I didn't think it was.

The ticking sound remains, gonna do another compression test tomorrow to see if the GTP has increased compression any by cleaning the vlaves. I just hope compression hasn't gone down.

My daughter's been driving it as she finally passed the manuverability driving test. First time she failed driving a 1992 olds 88 (big car) she managed to pass driving this baby benz. So I'll be getting my second and last 30 day tag so she can drive off the rest of the GTP - provided the compression stays the same or increased.

I should also look at the lifters, what should I look for,,, besides the obvious - that they are there?

The brakes (don't know if you read a previous post or not) are really good, since I replaced both rotors, pads and RF caliper.

Off to play some poker, I'll update after I test in the morning,,, after I reread my post so that I am reminded what I wanna test for,,,

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I was trying to figure out the same thing. I was thinking that bad lifters can't hold their oil. Since we suspect #1, after leaving the car overnight without starting, try turning engine from crank shaft pulley manually so that the cams on #1 are at the lowest. If you have a bad lifter the rocker between cam and valve spring should rock. If all rocks, probably #1 should rock worse than the others.

I forgot but have you replaced all electricals from distributor to plugs? If yes, how about your injectors. Because if you did all these, probably you have a burnt valve.

Rechecked compression, close to, or same as before
1 2 3 4
105 155 155 135

So the compression hasn't gone down (after 200 miles), and the GTP hasn't cleaned any crud that might be causing my issues.

Also the ATF in the Crankcase didn't help either, that was changed out before my eCheck test yesterday. (Good thing eChecks are free in Ohio,,, this was my 4th one in a month) - Thank you Ohio smokers for footing the bill,,, atleast I get something back in return for the $4.00 pack of cigarettes.

But on the optimistic side,,, the GTP hasn't been completly used up, still have little less then 1/2 tank. And I'm only $35 away from a waiver. But I don't like the idea that there is a bad cylinder,,,

Almost all the rocker had some lateral play. I didn't notice any more play on the number one cylider, they all moved about the same, as long as the valve was closed.

Also didn't notice any up/down play when the valve was closed. Pressing down on the rocker I was able to open the valve slightly,,, all about the same pressure to open.

The cam looks fine, I didn't see and excessive groves or pits or strange wear.

And finally,,, placed 3rd (out of 45) in the tourney last night,,, +$7.00

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I've heard of this being done on old Chevy's that were carb equipped. In some cases the engine hydro-locked.

How does one feed water to a CIS system?

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Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

There must be a vacuum line somewhere, that feeds into the intake manifold.
Restrict ( pinch the feeder hose a little ) the waterintake.
Run the engine at @ 2 000 rpm while doing this.

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2007 C 230 Sport.

If it's an automatic, use the manifold connection where the vacuum line from the vacuum modulator connects.

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1993 190E 2.3
2001 SLK230
1971 LS5 (454) Corvette Convertible

so let me get this right,,, I take a vacuum line off, stick the open end in some water,, with the hose pinched, I slowly let the engine suck in the water from the vacuum line,,, doing this at 2000RPM,,,

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sorry for the delay in answering these questions,,, O2 sensor replaced with one that fits a ford,,, I adjusted the duty cycle, but I should look at it again,,, Plugs (gapped .032" I think) I am getting low compression on 1 cylinder (105 PSI engine cold) the car runs good, but the idle isn't becoming to a Mercedes.

So you think the water treatment might work? you state 10 oz, how many minutes should it take to go through the 10 oz?

What does the "water treatment" do?

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