Overhauling turbos would you bother?

A

Adrianwool

Well-Known Member
Joined
3 Dec 2008
Messages
213
Location
Algarve Portugal
Visit site
My dear old girl (boat not the 'boss') is now 20 years old with about 1650 hours on her engines (TAM41b) engines, always been a bit of a 'smoker' on start up , but now I am getting some black smoke at cruising speeds, oil, filters et. al. all recently replaced, good oil pressure, no percevable oil usage, normal temps, all fuel recently polished, boats botty resonably clean. So in the minds eye I start to think about the turbos (KKK K26 3262 MGA/10.71's), now in the forums opinion am I suffering from that famed boaters ailment 'fiddlitis' or would these now benefit from a visit to the workshop for a bit of fettling?. Opinions welcomed

Adrian
 
Our Fords (a bit older) were black smoking, went through the usual suspects, could not find the cause, then went to turbo and lost the tip of my right ring finger in it. When I was mobile again I tackled the problem again, going through the intake air side, dismantling and cleaning the intercooler, still black. Almost at the end of my tether by now, then I checked the valve clearances, and found one of the rocker shaft pillar bolts had sheered, and cylinder No. five was not working. Moral of this story is, even though it sounds daft, check each cylinder in turn, by cracking the fuel pipe at the pump or injector, and note any differences in engine. If you find one that makes no difference then that's likely your problem. The answer maybe just valve clearance, or injector. Whatever keep your hands clear of the turbo inlet.
 
Black smoke usually takes me straight to the injectors, I have seen smoke from turbos and its not normally black, a bit of a mixture ie greyish. Injectors would be my first option to get checked, then go from there if not.
 
Black smoke seems to suggest being short of air due to unburnt fuel.
Turbo's don't last forever and it is often the turbine blades that wear down.
If you remove the injection elbow off the turbo and check the clearance between the turbine blades and the housing, there should only be about 1 to 2mm gap.

You could fit boost pressure guages to determine if you are down on boost pressure.

Check also the pipe between the turbo and the intercooler. The o-rings can go hard over the years and lose their airtightness.

The intercooler too can become clogged with oil which reduces air flow to the induction manifold. The insert can be cleaned with gunk or perhaps a steam cleaner - don't forget to do an air test on rebuild.

Thats a start from a keen amateur, I'm sure Volvopaul and Spannerman will come along and give you some profesional advise.

Eddie
 
Adrianwool said:
My dear old girl (boat not the 'boss') is now 20 years old with about 1650 hours on her engines (TAM41b) engines, always been a bit of a 'smoker' on start up , but now I am getting some black smoke at cruising speeds, oil, filters et. al. all recently replaced, good oil pressure, no percevable oil usage, normal temps, all fuel recently polished, boats botty resonably clean. So in the minds eye I start to think about the turbos (KKK K26 3262 MGA/10.71's), now in the forums opinion am I suffering from that famed boaters ailment 'fiddlitis' or would these now benefit from a visit to the workshop for a bit of fettling?. Opinions welcomed

Adrian
Click to expand...

The only thing turbos ever need is new bearings and seals nowt else to go wrong, unless something on the rotating bits is burnt away (PT) or broken.
 
Adrian
You have had some good advice already
Injectors first Mate
If the engines are revving to normal at WOT , like 3500 ish the turbo is performing
If the turbos were poorly it would seriously effect the revs the engine would make
Plus
Can you hear them 'whistle'?
 
Thanks to all for input, I will 'sort' the injectors at the end of the season, engines do rev to 3,500 and whistle, so it is likely I have been looking in the wrong directon. One lives and learns (hopefully).

Regards to all and happy boating

Adrian
 
Over time both turbines wear especially the exhaust ones due to salt corrosion, this reduces the diameter of the wheel so gas escapes by it reducing the rpm and boost pressure.

Id also go down the pump and injector route after all those years as, springs, cam plates and governors all wear to a degree.

Id also strip and clean the intercoolers, rid them of oil mist build up and replace EVERY o ring in the air train from the turbo to the inlet manifold.
 
You must log in or register to reply here.

Share this page

Top