volvo 2002, white smoke

[jam1]

Have volvo 2002 (unfortunately came with boat) which is emitting a fair amount of white smoke from the exhaust. Ok at very low revs but anything further the smokin starts. No real loss of power although tend to drive engine, at times, at fairly high revs 2500 as its small, 18hp, compaired to boat which is 32 feet. Any ideas of the cause?

John

 

[VicS]

White smoke is due to water vapour. Not necessarily due to a defect because you are injecting water into the exhaust anyway. If it starts and runs Ok there no reason to suspect anything sinister like a head gasket.

However there may not be an adequate water flow. Check inlet strainer, all the hoses etc the exhaust injection point and the water pump. When was the impeller last changed?

 

[jam1]

Impellor removed yearly and reinstalled as was in good condition. Engine did smoke a little but this season noticed increase as weeks progressed.

John

 

[KREW2]

Not wishing to hijack but, is 2500 revs excessive, I motored for six hours the other day at between 23/2600 rpm.

 

[jonathankent]

Most boats I've sailed on they tend to only motor at approx 2,000 revs.... but whether thats just personal preference of something behind it I don't know. I don't think you really get much noticeable benefit once you start to get into the higher rev range.

 

[jam1]

Only high rev when pushing into mod seas, otherwise boat tends to stop. If i go behond this just notice and cavitatation from prop therefore tend to keep below this say 2000 to 2225.....but still more white smoke than usual!

John

 

[jb2006]

I don't think 2500 rpm is at all unusual - max revs for small diesels seems to be around 3400 rpm, cruising 2500 to 2800 should be normal I think. Above that all you will do is burn diesel for little benefit. Our new Volvo smokes a little when started but quickly clears - advised this is normal by the Volvo agent.

White "smoke" is unlikely to be water - water vapour will disperse quickly after leaving the exhaust - if the smoke drifts you are possibly burning something you shouldnt be.

Another engine question just added in a new thread ... /forums/images/graemlins/confused.gif

 

[jam1]

In does linger at the stern for a short time, although there is no long plume....what elso could i be burning, could it be a problem with the injectors, timing or water in the fuel? Also noticed increase in the fumes i.e smell off the stern

 

[mrpvb]

Steam shows as white but vaporizes quickly.
Black smoke is over rich combustion ( to much diesel OR excessive load) White smoke lingering could be fuel to lean.

 

[oldharry]

White smoke (as opposed to steam) has a pungent smell, and is fairly normal with an older engine at cold start, but should disappear within 30 seconds or so. It is actually unused atomised diesel fuel as sprayed from the injectors passing straight through the engine. Usual cause is fuel starvation: the injectors are not getting enough fuel to burn properly. It can be caused by air leaks, clogged filters, injection pump fault, clogged injector(s), faulty air filter or low compression (valve or head problems)

Exhaust steam smells bad, but not excessively so. White smoke - one sniff and you will have had enough!

Sorting it: on a multi cylinder engine crack each injector pipe in turn to see if it is just one cylinder or if all are producing smoke.

If it is just one, and the compresssion is good, then almost certainly the injector is faulty. If all cylinders are smoking then check for restrictions in the fuel line. Also check carefully for tiny leaks. A very slight leak can admit a stream of micro bubbles which are not enough to kill the engine altogether but will change the burn characteristic and produce the smoke.

The injector pump itself may be faulty and not delivering the correct charge to each injector. retarded injection timing may produce smoke, but it would not be getting worse unless the pump is loose and the timing is slipping.

Whatever the cause, if it is getting worse, then it needs to be sorted as the engine will stop if it is not getting enough fuel.

Good luck, as it can be quite a tricky one to sort.

If OTOH it is steam, then the problem will almost certainly be coolant flow. Check the exhaust elbow for clogging which may be preventing water from being discharged into the exhaust. check any thermostat arrangement which may reduce water flow, and check that the waterways are not blocked reducing the flow through the engine - which may also be suffering local overheating.

 

[jam1]

Thanks for all info, last reply very comprehensive. Will attempt to look this weekend.....pehaps one for engineer as engine hasn't had servine since purchase of boat 6 years ago except normal oil,filter and impeller change. One last question, have not checked the filter on fuel pump, perhaps cause of fuel starvation? All other filters changed yearly

John

 

[pvb]

Smoking isn\'t unusual...

The 2001/2/3 series engines often smoke - especially older ones. My 2003 certainly smokes. It's worth getting the injectors serviced. Otherwise, if it motors happily at 2500rpm without overheating, I'd be tempted not to worry about it.

 

[cpedw]

The volvo 2000s are notorious for overheating. This is known to be exacerbated by scale deposits in the water channels (narrow and tortuous) of the exhaust elbow.
On my boat, with an indirect cooled 2003, after a season limited to 2000rpm (any quicker and the overheat alarm would go off), during which I cleaned out the elbow (it was a bit clogged but didn't cure my problem) and inspected, cleaned and/or replaced every other part of the cooling system that I could find, the problem was eventually located - an abundant growth of shellfish in the cooling water inlet skin fitting.
CLearing them out last winter has made all the difference.

Derek.

 

[oldharry]

<<One last question, have not checked the filter on fuel pump, >>

Then thats almost certain to be the trouble.

The main weakness of diesel is the fuel system must be 100%. Any compromise will cause problems.

 

[davidfox]

Try tracing back towards the engine, took off oil cooler cover where water pipe enters and took out a handfull of stripped impellor blades from old incidents (before my time) now no steam comes out

 

[chrishelen]

Hi John, when you say the engine came with the boat "unfortunately"have you had previous probs with Volvos?The 2000 series, yours is the 18hp twin are proper marine engines, built to last.when they go wrong its usualy the fault of the owner,lack of proper servicing etc.when did you last sevice the engine?direct injection diesels like yours do tend to smoke on tickover and at low revs it being the nature of the beast,but at high revs it should clear,it sounds like overheating IMHO.try the easy things first like the impellor its right at the front of the engine,best of luck Chris.

 

[jam1]

Used to own a Beta Chris and thought it was a better engine generally. The 2002 series has problems with the splines stripping and a complete loss of drive which is a design fault. Most now have a cushion plate fitted or have a new drive/hex made by engineering company (not volvo). Volvo fail to admit there is a fault even where it happens on low hour engines. Otherwise you are right perhaps it is time for a more detailed look/service I have only changed oil,filters ect and the impellor yearly, have changed the impellor recently, even though it looked ok. This w/end will start at the inlet side off sea water side and work my way round, perhaps the exhaust elbow is choked.
Cheers John ps will need all the luck

 

[chrishelen]

Hi john,best of luck,you will get there in the end its all part of boat ownership,i wasnt aware of that problem with volvo 2000 series stripping their splines must be the weak link in the engine,they all use a common final drive so perhaps its the bigger engines that break.best wishes Chris.