Best way to avoid engine issues when using at low speeds

P

philipm

Well-Known Member
Joined
4 Feb 2008
Messages
116
Location
Staffordshire
Visit site
Slight newbie question. I have 2 x 200hp D3 Volvo pentas and have been given three different theories by different engineers about how to avoid creating engine problems by running at normal river speed limits (which can be reached by running the engines at just above tickover!) . I think this is about avoiding the turbos getting coked up so as to avoid an expensive stripping down of the turbos.

One engineer said to me that running engines for say 20 seconds at 2,000 rpm would suffice. Another said just "blipping" each engine in turn to 2,000 rpm would suffice. A third said I should turn one engine off and run for an extended period (hour or two) on the other engine (swapping to the other engine from time to time).

I'd be interested to hear views from others on this potentially expensive issue.
 
Doesn't sound like you spoke to any engineers at all judging by that advice :)
Loads of silly myths about this sort of thing and no doubt there will be some more posted here shortly, my advice would be just to get on and use it for now. There is no definitive way to prevent these things except a good blast out to sea whenever you can.
Just blipping it to 2000rpm will be pointless as without any load there will in sufficent load and boost, did they mean whilst underway?
You could remove the air filter reguarly and check the turbo spins freely if you want to some reassurance, early D3's are notiorius for turbo issues regardless of use, latest ones better I understand.
 
Chris_d said:
Just blipping it to 2000rpm will be pointless as without any load there will in sufficent load and boost, did they mean whilst underway?
Click to expand...

They meant blipping whilst underway. Engineer who recommended that was with me on the boat at the time and said it was sufficient to blow out any crud.
 
philipm said:
They meant blipping whilst underway. Engineer who recommended that was with me on the boat at the time and said it was sufficient to blow out any crud.
Click to expand...
Ok, more sensible. I used to do this a couple of times a year on a quiet bit of river, just one engine at a time until I heard the turbos whistle. Not sure it really does any good but you feel like you have done something, I don't bother anymore and the turbos are fine.
 
Yes there is a kind of whistle at around 2,000 rpm.

Funnily enough after I did that last time, an engine which had been producing some exhaust smoke, stopped producing any smoke at all so I concluded there had been some benefit.
 
Chris_d said:
my advice would be just to get on and use it for now. There is no definitive way to prevent these things except a good blast out to sea whenever you can.
Click to expand...


+1.
It really would benefit from a good hard hot run at some point in the season
Join one of the many clubs and come out down through Teddington to Burnham/ Ramsgate/ Rochester for a weekend.
Will achieve everything the engines need.
Chum had a Brava 37 based in Bray, opened it up in Sea Reach, the black smoke that came out for about half a mile was impressive to say the least.
 
Last edited:
Thanks. I'm based on the Severn. My marina did have one trip out to sea organised for June but was cancelled by the floods.
 
Last edited:
philipm said:
Thanks. I'm based on the Severn. My marina did have one trip out to sea organised for June but was cancelled by the floods.
Click to expand...

Sorry mea culpa...assumed you boated in the La La Land above Teddington, did not realise you boated in the real world. :)
 
No idea if it really helps but we have had various motor cruisers with twin 250 to 300 hp engines, all based on Upper Thames.
Always used one engine in between locks.
At end of cruise did two circles, one left and other right. Wheel hard over and shove each throttle in turn to max’.
Tight circle.
No wash.
Wait for Turbo whine.
Never had smoke and no problems when in tidal waters.
 
The answer is to buy sea going boats for use at sea and river going boats for use on the river. The upper Thames is full of white boats that will never go anywhere near salt water all with massive engines they will never fully use.
Horses for courses.
 
AuntyRinum said:
The answer is to buy sea going boats for use at sea and river going boats for use on the river. The upper Thames is full of white boats that will never go anywhere near salt water all with massive engines they will never fully use.
Horses for courses.
Click to expand...

Our plan is to move the boat to the coast but wanted to have a season or two getting to know the boat on the river which is relatively near where we live. Hence needed a boat that can do one job (river) followed by another job (sea).
 
miket said:
No idea if it really helps but we have had various motor cruisers with twin 250 to 300 hp engines, all based on Upper Thames.
Always used one engine in between locks.
At end of cruise did two circles, one left and other right. Wheel hard over and shove each throttle in turn to max’.
Tight circle.
No wash.
Wait for Turbo whine.
Never had smoke and no problems when in tidal waters.
Click to expand...

Thanks. Good info. One of our engines works the power steering so I guess would have to have it running at all times although would be in neutral for half of that time when it's not its "turn".
 
philipm said:
Thanks. Good info. One of our engines works the power steering so I guess would have to have it running at all times although would be in neutral for half of that time when it's not its "turn".
Click to expand...

I assume you have an outdrive boat and the above advice for the blipping at full lock was really for a shaft driven boat, so I'd be a bit wary of giving it full throttle at full lock, the UJ's might not like it and you may get a bit of a wild ride :)
 
I'm glad you mentioned that Chris because I was having the same thoughts - albeit I've never hit full throttle when on full lock! Yes, mine are outdrives.
 
Not tried this with outdrives but perhaps temper the helm hard over bit and def’ leave other engine in neutral for power steering.
 
AuntyRinum said:
The answer is to buy sea going boats for use at sea and river going boats for use on the river. The upper Thames is full of white boats that will never go anywhere near salt water all with massive engines they will never fully use.
Horses for courses.
Click to expand...

+1 And don't forget the radar cans and GPS antenna. They are a must for the non tidal Thames.
 
Last edited:
AuntyRinum said:
The answer is to buy sea going boats for use at sea and river going boats for use on the river. The upper Thames is full of white boats that will never go anywhere near salt water all with massive engines they will never fully use.
Horses for courses.
Click to expand...

What a lot of twaddle. Just cos you dont see them offshore don't mean they don't go.
Total over generalisation...
 
You must log in or register to reply here.

Share this page

Top