How much smoke is too much?

So I've read the forums on Volvos. I accept they are smoky, especially at startup. Yesterday was a sunny beautiful day in Seattle so we headed out onto Lake Washington to take advantage. The boat is still new to us and I'm still coming to terms with all of the systems in the engine room.

After warming up for 15 minutes at the doc the exhaust had reduced down to what I've seen and come to expect of the engines at this point. But maybe it was because it was so crisp and sunny I noticed that there was always a discernible grey exhaust with a slight blue tinge, even after several hours of running between 1800-2000 rpm.

Is that to be expected?

Also, on our way home I thought I'd bring up the rpms to exercise the turbos. So far I've only cruised at 2300 rpm, but slowly nudged the throttles up to over 3000. The amount of visible exhaust increase hugely! It was a little alarming to me. So after only a minute or so I backed back down to 2000. I checked the engine and transmission temps in the engine room. Everything seemed happy down there.

A couple photos at aprox 1500 rpm.

I run Detroit's so I am not an expert on yours. However when mine experience this it is usually a sign of a stuck injector. Is it both engines doing this or just the one?

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Thanks mbevins. Both engines have identical exhaust.

Tegdesign,
I will be interested in what the engine guys have to say about this. I run a TAMD60 of similar vintage and was out on the Sound yesterday as well.
Yesterday the conditions were such that the water vapor in the exhaust was more visible than some days but my experience with my green monster is not with the blue tinge that seems apparent in the pictures of your exhaust. Always hard to tell from pictures and the background plays a role.
I smoke a little on a cold startup but more greyish black than blue, and once up to temperature and powered up, seems like only a little water vapor in the exhaust. I would be asking this same question as you are if blue under those conditions.

tegdesign said:

Thanks mbevins. Both engines have identical exhaust.

Click to expand...

Then I'm out. Can't see both having bad injectors

Sent from my Nexus 4 using Trawler

Blue smoke is oil smoke. Not injectors. Smoke is caused by valves rings or turbos. First of all, there is no emission control, so they will smoke. Think dump truck, not Audi. Next, warm your engines with a load. Running them wot will clean out the soot etc so you will get more smoke, it also is an excellent way to check the entire engine, especially the cooling system. Go for the easy stuff first: change the oil and filters, change the air filters, adjust the valves and then go cruising. When the oil consumption gets excessive, overhaul time. But until it does, long time from now, just go cruising.

If engines have been putting along at low power setting for a long time, then exhaust is all gunked up with oily slime. When you went to 3000, it started to cook off, and that makes LOTS of smoke. Usually bluish, not coal black. You backed off after a minute, that is not long enough for the process to complete. Go back out and do it again, might take ten minute of 3000+ to clean em up.

If smoke is coal black, then that is a different issue, overload or lack of boost.

I suspect what you experienced is pretty normal for these engines. I don't know the year of your boat, but it would appear to be older. Some exhaust haze is usually the norm for older generation diesels. Blue smoke is oil as Xsbank states and it could be as basic as somewhat worn valve guides, or more likely, worn out valve guide seals if the engine uses these seals.

If the engines start promptly, idle smoothly, and run well at normal temperatures I'd suggest simply using and enjoying the boat instead of inviting a whole lot of solutions that are in search of a problem.

Since the boat is new to you, i suggest using what you've observed as your baseline normal, and then seeing if things change as time goes on or suddenly. At that point it may be worth getting a qualified diesel shop involved. But right now what you're seeing is no different than what I see with a whole lot of boats of all kinds as they enter or leave our harbor past our slip.

PS- I should add that my limited experience operating and being around equipment with turbocharged engines (all petrol, IIRC) has taught me only one thing really, and that is that turbochargers are absolutely brilliant for increasing performance and efficiency as long as they're on somebody else's engine. So I cannot offer any insight or speculation regarding any potential link to what you are seeing to the fact your engines are turbocharged.

Its been my experience (maybe I'm just not lucky) that blue smoke is due to worn out rings. If you ARE lucky it could be turbos leaking, gunked up exhaust, valve guide seals, or just simply need to be "blown out". I would suggest cranking it up to max and watch the temp gauge. If it doesnt overheat keep running it. If it gets hot back off incramentally until it cools down.

Warm up in unnecessary and perhaps even harmful. Start them and go.

You don't tell us what WOT is supposed to be and what you can hit. An overloaded engine will smoke a lot. If you can hit rated WOT run them at 80% load for a while and see if it clears up

"Overloaded" produces black smoke.

Other than on sea trial, I've not run the boat anywhere near WOT. I believe the engines are rated at 3800.

Pretty much what Marin stated here, including the barb about turbos being great devices best enjoyed on others boats. I got a laugh from that, but having owned high hp Volvo diesels, it was no mistake I moved to naturally aspirated 3208s.

As far as being worn out, possible but not probable. You might very well be the first boater in the history of pleasure diesels to wear out a set of rings, but again that's not all that probable.

You could be overloaded. Heck that's even probable in pleasure craft, especially if your bottom has some growth, but that's not what we are seeing here. You have blue smoke. Very clearly blue smoke. That's not from overload or poor turbo speeds. Overloading and turbo issues mess with the air/fuel and that results in incomplete combustion, or in another word soot and lots of it. You would very clearly be seeing black smoke. It's very noticeable if you have ever seen it. Turbos are easy to diagnose for this reason as you don't need them at idle-ish speeds, so your exhaust suddenly turns coal black after getting above idle and into boost speeds. That's not what you have. Likewise on these cold winter days with cold surface water temps, it's pretty common to develop steam plumes behind your boat. Those are distinctively white and again, not really what we see here.

Your blue smoke is simply burning excess oil. Others have mentioned a number of causes, but it's most likely just a buildup over time. It can take awhile to really burn it out. You can run at wot if you are confident your bottom is clean and your cooling system is up to snuff, but just throttling up to the point you see a nice cloud is perfectly sufficient too. Expect if you have not run over trawler speeds for awhile that you will start to see a clearing in as little as 5 minutes, but might not truly burn through it all for closer to 20. So the comment about not running them hard enough, long enough is very very likely spot on. You will also note that once you get them to clear at a pm that was smoky, pushing them a little harder might produce a little smoke again. Pretty classic behavior, and usually another couple minutes at that higher rmp will again clear.

Go do that and only pursue further if they never clear at all. Even then, it would not be likely that these engines are getting ready to have their way with you. It just means that at low loads the rings get a little sloppy, but very unlikely that you are varnishing your cylinders are anything like that. This is a pretty normal thing for many engines.

My naturally aspirated cats have fewer rings than the turbo versions. I run around at 8 knots without ever increasing speed much. IIt does not take much buildup on my engines to start seeing a bit of smoke. You should see the smoke signals I send up if I suddenly bump up to 15 knots to get across a shipping lane. They will then run perfectly clear and we start the process over again. If it makes you feel better, bump up your engines to 200 off wot for 10 minutes every time you take them out. Or don't. Honestly the dogmatic vocal may praise you, but your engines won't really care much either way. Might make you look better coming in to Roche.

Remember diesels like their oil like a sailor likes his rum. Why is that Captain Ron? Nobody knows!

Warning, some thread drift here but musing about Ski's comment about putting along at low power output and build up.
When cruising in my 55000# full displacement hull, everything about the sound of the Volvo TAMD60C engine and feel of the boat tells me that something around 1650-1750 rpms is the sweet spot. This is around 8.1-8.4 knots with LWL around 44 feet.
When I look at the data sheets for this engine on BD, this is almost off the left side of the HP/fuel use curves for this engine. I have only seen the comment in manuals that long period below 1400 rpm are not so good.
What about this? Is 1700 rpm too low cruise? Also, can someone tell me what to expect to burn for fuel here in this range given the above data? The data sheets referred to above give me too high a number based on what my usage estimates are. Maybe I am reading them wrong. Anyone with experience or sound theory here? Chart reads 7 gph? and usage feels more like mid-high 3 ish.

I love this forum SO much! Thank you all!

Nordvind solve the problem one step at a time. do the full sea trial first if you don't know what that is look it up. If your boat passes sea trial do what Ski says you get free professional advice there. Run it at 80% plus load for 15-20 min and you should be doing a high load run toward the end of every use if possible. I keep my boat in Portage bay and take it out on the lake for engine exercise about every two weeks in the winter and that always includes a wot run for a few min and a relatively high load run for 10 min. My engines have terbos and full common rail electronic controls. My personal experience with turbo diesel engines autos-trucks and several boats now is very positive maybe those having trouble are not managing them well. Good equipment poorly managed soon becomes bad equipment.

tegdesign said:

So I've read the forums on Volvos. I accept they are smoky, especially at startup. Yesterday was a sunny beautiful day in Seattle so we headed out onto Lake Washington to take advantage. The boat is still new to us and I'm still coming to terms with all of the systems in the engine room.

After warming up for 15 minutes at the doc the exhaust had reduced down to what I've seen and come to expect of the engines at this point. But maybe it was because it was so crisp and sunny I noticed that there was always a discernible grey exhaust with a slight blue tinge, even after several hours of running between 1800-2000 rpm.

Is that to be expected?

Also, on our way home I thought I'd bring up the rpms to exercise the turbos. So far I've only cruised at 2300 rpm, but slowly nudged the throttles up to over 3000. The amount of visible exhaust increase hugely! It was a little alarming to me. So after only a minute or so I backed back down to 2000. I checked the engine and transmission temps in the engine room. Everything seemed happy down there.

Click to expand...

I have a green monster in the bilge also...smokes like a ww2 destroyer when cold, the smoke drops way down to a acceptable level when warm..but there is still a hint of color (whitish grey) even when warm. I had the injectors done, timing checked, and the thing looked at by a pro who knows the volvos well and he proclamed all is normal. I am working on a pre heat system to lessen the embarassment associated with a cold start in the marina. On a side note the mosquito population is now non existent within 3 miles of the marina.

The mechanic I use holds the basic volvo engine is a really stout platform..I had the injectors derated by the shop and plan to remove the intercooler to eliminate the possibility of sea water ingestion and to raise the intake temp to help lessen the smoke. Volvo built these series motors in many variations so I hope this will help my smoke issues. I also run the motor at about 1700 as it really purrs and feels right at that speed. The boat is doing 8-8.3 kts at that rpm and seems to sip fuel..my yet to be installed floscan should confirm this.

Do what I plan to do..run it and enjoy it!
Hollywood

ghost said:

Pretty much what Marin stated here, including the barb about turbos being great devices best enjoyed on others boats. ...

Click to expand...

I intentionally avoided a turbo-charged engine. Didn't need the added power and expense, or maintenance (more working parts) issues.

Sounds like a job for Marvel Mystery Oil.

hmason said:

Sounds like a job for Marvel Mystery Oil.

Click to expand...

I already have smoke..... I don't need smoke and mirrors!

Hollywood

Have absolutely no smoke after nearly four years and 400 engine-hours, starting with a new engine. ... Is it just a matter of time?

markpierce said:

Have absolutely no smoke after nearly four years and 400 engine-hours, starting with a new engine. ... Is it just a matter of time?

Click to expand...

I'll bet your engine is much newer technology than my old 1987 lump. However, I've only got a little over 1000 hrs.

41A's in my girl as well teg. They do smoke at startup but quickly drops off once warm. I cruise at around 2k rpm if running on both or about 27-29k rpm if cruising on one (~7knts).

I had all my injectors removed and serviced early on, but what really made a difference was new air filters. The old ones looked clean, so I left them on for the first 8 months - but found them to be pretty dirty when I actually removed them from the housing. Replaced them and made a big difference.

shufti said:

41A's in my girl as well teg. They do smoke at startup but quickly drops off once warm. I cruise at around 2k rpm if running on both or about 27-29k rpm if cruising on one (~7knts).

I had all my injectors removed and serviced early on, but what really made a difference was new air filters. The old ones looked clean, so I left them on for the first 8 months - but found them to be pretty dirty when I actually removed them from the housing. Replaced them and made a big difference.

Click to expand...

That's next on my hit list. Breather, Air Filter, and Oil Filter. Then it looks like I need to let the engines run hard (3000-3200) for 20 min or so while monitoring my cooling until the crud build-up is burned off.

If anyone sees what looks like a forest fire coming from the North end of Lake Washington next weekend, no worries, it's just me.

hollywood8118 said:

I already have smoke..... I don't need smoke and mirrors!

Hollywood

Click to expand...

I love your Ocean Alexander 40. We looked at one, the one that got away, when we were just starting to look at boats, but not ready to pull the trigger yet.

Teg, keep in mind the 41A's have a sustained high cruise of 3600RPM and redline (5minutes only) of 3800. Don't be scared to give her a jolly good run at 3600rpm for a few hours if you can. Obviously keeping an eye on temps/pressures. We do a 3 1/2 hr fast run home from Lady Musgrave Island (~55nm) regularly at 3600RPM and she loves it.

When you are out next and running the engine harder to cook off the internal crap, also do a careful check of you wide-open throttle (WOT) RPMS. It's really important that the boat be able to easily reach about 200 rpm OVER the rated rpm. Check you engine manual to see what the rated RPM is. This is the max rpm, not the max cruise or anything like that. We are talking balls to the wall. So if the rated rpm is 3800 as someone here suggested, at WOT you should be able to reach 4000. I'll bet you don't come anywhere close, which is indicative of an over-propped boat. That would contribute to your smoke level, and general accumulation of crud over time.

Xsbank said:

Blue smoke is oil smoke. Not injectors. Smoke is caused by valves rings or turbos. First of all, there is no emission control, so they will smoke. Think dump truck, not Audi. Next, warm your engines with a load. Running them wot will clean out the soot etc so you will get more smoke, it also is an excellent way to check the entire engine, especially the cooling system. Go for the easy stuff first: change the oil and filters, change the air filters, adjust the valves and then go cruising. When the oil consumption gets excessive, overhaul time. But until it does, long time from now, just go cruising.

Click to expand...

exactly correct. Oil is cheap.