Everyone please chime in on these exhaust pictures...

[scarfie]

I'm feeling like there is way too much oil in the exhaust. Check out the pictures and let me know if this is normal or not. I spent yesterday changing out the oil because I didn't know what the previous owner was using. I then changed the fuel/water seperator filter. I finished off by launching the boat and running 2 gallons of Sea Foam treated gas through it to decarbonize. Plugs are 3 weeks old and properly gapped.

It still doesn't look right to me. What do you think? It's a Merc 240 EFI BTW.

Thanks!

 

[seadoosnipe]

Smoke?

It does seem a bit much to me also. Have you done a compression test? With all that you've done, it seems that you could have a ring sticking on a cylinder or two.
I looked at your oil system. There is a slight chance that your pumping to much oil into your engine through your injection system. The output of your oil pump should be 15cc after running at 1000rpm for 3 minutes, the pump full open. Of course, this isn't with it on the boat. You'd have to remove it and control the rates as described.
Hope you can find a solution, but I would check the compression and see that all 6 cylinders are within a few pounds of each other. I think at this point, a compression test is key to finding out if your problem is major or minor.

 

[kustomkarl]

I agree taking a compression test will tell what is going on in the engine... check as per the manual instructions.

 

[scarfie]

Thanks...

Compression test sounds like my next course of action.

 

[seadoosnipe]

curious?

Please post your results, I'll be curious to know what they are!..

 

[scarfie]

After looking through the repair manual, I think i'll try testing the oil pump first then move on to the compression. It's a pretty quick thing to do and I've been wanting to see what the exhaust from a 50:1 oil/gas mix looks like.

I'll move on to the compression test after that and report my findings.

 

[seadoosnipe]

Gas mix?

O.K.....but I think I may be a bit confused as to what your doing. Are you running premix in those pictures along with your oil injection system? ...and unless you made adjustments to your injector system, your oil pump should be o.k., but your right, it isn't that hard to check.

 

[scarfie]

No, it's straight gas in the pictures. Ill use the premix when disconnecting the oil pump.

Electronic Fuel Injection doesn't leave much room for adjusting, however there is a section in the repair manual about adjusting the oil pump flow when the motor is at idle. I was basicly just going to check to see if that is out of whack and then see how much oil it's pumping into a graduated cylinder.

This past weekend I kept a close eye on the exhaust through the no wake zones. Sometimes the exhaust was fine when bringing it down to idle speed and sometimes it was just really excessive. If it was really bad, I could throttle up to 4 or 5000 RPMs for a few seconds until it cleared out. Most of the time when I idled back down, the exhaust would be fine.

More info for you to chew on. Oil pump and compression tests will happen sometime this week.

BTW - when you said there may be a ring sticking, the only remedy for this is new rings, right? I looked up the parts...a set of 12 rings is somewhere around $350. Ouch. Just hoping there was a different way to solve the ring issue.

 

[seadoosnipe]

Pump sticking?

From what you describe, it sounds like there could be an oil injection issue then. If your onplane and things are looking good and you slow down, then you start building smoke, maybe your oil injection pump is sticking allowing to much oil to pass into the engine. You said you could throttle up sometime and then slow back down and it would clear up.
Yeah, I agree.......I'd check the oil pump.
Cross the bridge about a sticking piston ring when you get to it. I'd go with the minor issue first. But since you there was a previous owner, I'd still want to do the compression test just to give the cylinders a clean bill of health. That test will say alot about your engine, along with reading the spark plugs.

 

[JoeZ]

I think just about everyone knows my opinion on the oil injection system by now...

I'm going to be watching this thread to see if it was compression or the oil injection system. Hopefully the compression is nice an high

 

[kustomkarl]

Visualy check the cable operation for sticking when applying the throttle. Make sure it returns, and not sticking open when it shouldn't

 

[GailRV]

Our 2002 Challenger has always done this and we consider it normal for sart up and idle speeds

 

[seadoosnipe]

Excessive...

It's a bit excessive Gail. If the oil injection pump is working right, you may have a light hazing of oil smoke/vapor, but not enough to look like your spraying for mosquitoes...........
In his thread, it seems that he's only smoking during times of deceleration and can make it clear up by goosing the throttle.
Still looking at the possibility that the oil pump isn't sticking in the full open position as he's slowing down.

 

[scarfie]

you may have a light hazing of oil smoke/vapor, but not enough to look like your spraying for mosquitoes...........

good one! We pulled up to a dockside restaurant the other day with the exhaust just rolling out...the diners did not look too happy.

Won't have time to do the diagnostics until this weekend. I have a new head temperature sensor on the way. The old one was diagnosed as bad and I'm thinking this has a lot to do with the exhaust problem because the ECM controls the mixture according to engine temp (or so I understand).

I'll have some updates by the end of the weekend.

 

[scarfie]

Results from the compression test first:

Starboard side from top to bottom: 130 psi, 130 psi, 130 psi

Port side from top to bottom: 115 psi, 111 psi, 114 psi

The repair manual says that if they are within 15 psi everything is OK.

That port side has me worried. Since they all seem low compared to the starboard side, could it mean a leaky head gasket? Cracked head?

Or is it OK to have everything on the port side lower than the starboard. Seems to me they should all be 130 psi.

Thoughts? On to the oil flow test next.

 

[seadoosnipe]

Temp sensor!

I made this nice reply to your post and being at work, this junky T1 connection dropped me before I could post, so I'll make this short and simple.
Yes, the ECU (electronic control unit) and the mpem (multi purpose eletronic module) work hand in hand to run your engine at optimum efficiency and make the necessary adjustments in oil, fuel and ignition as needed by way of information sent to it via all the sensors. So in short, your right about the temp sensor capable of causing inaccurate adjustments in the engine. I didn't read this but I'd also think there is a redundancy for this system to err to the richer side than the leaner side in the event something is faulted so there is no major engine damage. But I'd also think you'd get some kind of signal to let you know something was wrong. I know if the sensor was registering a high temp, you'd be getting a steady beep.
The compression on the other hand could be a problem. I dont' think you have a cracked head or a blown head gasket. Because your drop in compression is equal on that one bank, it would lead me to believe your reed block is out of spec. This part is not repairable. It has to be replaced and in the manual, it doesn't look like it's to hard to do. I think the open stop on it was .20 thousandths. If the compression on that bank had one cylinder low and the other two good, I'd say you may have piston rings that were going to need to be replaced soon. Or if you had one cylinder good and two bad (the two sitting side by side) then your gasket could be blown at the weakest point between the two. But this is all three on the one side. I think it's your reed block or even yet, could be a bleed line problem. One of them with a hole in it, etc....There is a test to check your bleed lines.
Go to your manual and read the chapter on your powerhead, specifically page 4A-40. This may shed a little light on your compression test. Also, if the oil smoke is caused by your reed block out of spec, it's a lot easier to replace than re-building an engine. Don't let this problem go on to long without finding the root cause of your problem. This can lead to a major failure.

 

[scarfie]

Thanks snipe. Question...aren't there 6 reed blocks? If so, what are the chances of 3 of them being bad on one side? If one is bad on one side, does that mean it affects compression on all 3 cylinders on that side?

The reed blocks are on the induction manifold, right? We're starting to get into uncharted territory here. Suppose this is the only way to learn.

 

[scarfie]

results from the oil flow test are in...

I think I screwed this up. The manual said to connect an external premix tank to the fuel line. I did that.

Next it said to disconnect the output of the oil pump so it can drain into a graduated cylinder. Did that too.

Next it said to crank it up and run it for 15 minutes. Did that, too.

It said I should end up with 75 cc (ml) of oil. I got 30.

The problem is the output of the oil filter did not run to the same place on the motor as in the picture in the manual. I'll double check the serialon the motor to make sure i'm using the correct manual.

BTW - the exhaust was still smoking like a fiend the whole 15 minutes the external pre mix tank was hooked up. Maybe there is a second uotput hose on the fuel pump I missed. gotta take a look.

This is discouraging.

 

[scarfie]

Disregard the oil pump test for now. I think the first thing I need to do is to get to the root of the compression problem on the port side first. It may or may not solve the exhaust problem but I believe this is a much more serious problem that I need to address first.

My question from the previous post still stands...what are the chances of 3 reed blocks being bad on one side? Or, ifone is bad on one side, does that mean it affects compression on all 3 cylinders on that side?

 

[seadoosnipe]

Reed blocks?

Your so very right. I've been at work over the weekend and looking over your manual in between doing my work. I must re-think the idea on the reed valves because at first, I thought there was one set per side. Put in vertically, now I see that they are horizontal and 3 sets. It seems strange that all 3 cylinders would be so close in compression at 115, without there being a common link between them. The cylinder rings all wearing at the same time to create the same compression.....that's strange. That's why I think it's caused by something else.
I was looking at the exhaust ports to see how each cylinder is linked by the exhaust system and from first glance, it doesn't seem that there can be anything there that would cause it. What about your bleed lines. Have you checked them to see if any got hot and dry rotted/ cracked?
I'm working off the week-end shift and will be off most of this following week. I've bookmarked this post and will do further research on it to see if I can come up with something a little more concrete. Just bear with me. I don't know how many times you checked your compression and mean no offense, but can you do it a second time? If you've already done it several times and this is the average you came up with, then that's o.k....Also, did you do the compression with the engine hot or cold?
BTW, you used the word "discouraging" in a post above. I'm not to sure about that word yet. For some reason, I think there may be simple solution to this or one that doesn't require a motor overhaul anyway......this engine has a lot of sensors and engine controls, so I'm going to remain optimistic that it's pretty simple.....we just got to find it.

 

[scarfie]

The oil flow test was discouraging. I'm actually enjoying getting to know the motor so well. It's been a long time since I worked on anything mechanical like this. With this boat, it's becoming quite the hobby.

You're right, I need to do the compressin test again. I was alreadt thinking about that. I did the test with the engine cold. Should I warm it up first? Or be consistent with another cold test. Hell, maybe i'll do another cold one then take it out and do a third after it has warmed up.

I need to locate the bleed lines and check them. I saw them in the manual. I'm completely ignorant as to what they bleed. Are they are bleeding air from the cylinders? Bleeding fuel? Please set me straight on this.

I, too have the feeling it is something simple only because the motor works great except for the exhaust issue that started this thread. It does not hesitate through any of the throttle and i get full RPM and speed out of it.

I'm doing more digging on the problem as well. I'm going to hit up a couple mercury repair shops to see if i can pick some brains there as well. I'm just trying to avoid the shops and do it myself. Thanks again for the help.

 

[seadoosnipe]

Open Wallet!

Believe me, I want you to avoid the shops if at all possible. Unless you just hit the lottery!...
I want to do some more research on this system before I give you any kind of definite answer. It seems the bleed lines equalize the system pressure across the heads. There's a check valve in each. I hope to do a good bit of reading tomorrow, so look for me then.

 

[seadoosnipe]

Oil pump...

I didn't want you to think I forgot about ya, but I'm still reading through the manual on the M2, looking for a solution to the compression and smoking.
I did find somthing pretty interesting. The oil pump is shafted to the crank and the oil is kept seperated from the engine side by an "O" ring so I've been looking into the effects of what the oil would do if the oil ring went bad and allowed to much oil into the crankcase area.
Also, I was wondering about your oil consumption. Are you using a lot of oil? How does the oil in the remote oil tank level off when the reservoir tank is full. Does it seem to always run a little low?
I'm going to send Don a PM and see what he thinks about your compression results.

 

[scarfie]

Didn't think you forgot...you said you'd be looking through the manual. I've been reading it until my eyes bleed.

It's hard to say if I'm using a lot of oil. I've had the boat two months now and don't have anything to base it on. It was probably a gallon and a half below the fill line on the reserve tank before I decided it was time to add another gallon. I'm estimating we went through 40 or 50 gallons of fuel in this time. I'm just estimating so we can't use these figures as fact.

Not sure what you mean by the remote tank oil leveling off. Do you mean when I'm adding oil to the remote tank?

I need to get outside to do the compression test again...I'll set aside an hour to do it tomorrow.

Do you think there is a chance that the cooling hoses were blocked at some point on that side of the motor and it heated up enough to fry the rings only on that side? Or does the cooling flow around the both sides meaning a blockage would heat up the whole motor.

 

[scarfie]

BTW - I'm still waiting on the head temperature sensor...the more I read into what's going on in the manual, the more I think that the ECM still thinks the motor is cold when it is not and is pumping a heavy mix of oil to fuel all the time. We'll see.