Mercruise 3.6D down on power

Very nature of boating involves a basic knowledge of your vessel.

Low power trouble shooting should always involve fitting new filters as first step, no exeptions.

I would not promote screwing around and making any adjustments, however basic self sufficient troubleshooting should be within the hands of owners, the most basic is knowing how far 'off' tachos are. Around £20 off Ebay for a digital hand held tacho.

Having audited main dealers I can assure you that many give you a blank look when you ask for their test gauges, as for calibration certificates, doh!

Hands up who has something as simple as restriction gauges in their fuel system.
 
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Here you go....

FF105c around £15, Racor version of same filter £22 ish. Auto factors can supply FF105c but not normally on the shelf, however far superior FS1000 is £13.40 each, box of 6 and price comes down a bit. Plus FS1000 is normally stock item, not next day.

Both filters have the same thread Size 1-14 UNS-2B
 
Closure at last

Well its finally solved.

After floating around in Cardiff Bay with the diesel lines dangling in a clean container and having, by this time dismissed the filters, we finally noticed the turbo was not spinning.

We freed it off and up went the engine revs.

Its obviously dodgy because the turbo had been checked and dismissed but at last I can draw this thread to rest!!!!!!!

Thanks to everyone on the forum for their help and support.

Anyone got a cheap turbo??
 
Does your motor have the screwy Mercruiser 'snail' riser?

Designed to dump sea water into turbo housing causing it to rust.

New turbo costs $$, however do not dispair if your cast iron housing is corroded. Housing can be machined out and a 316 stainless sleeve intalled and TIG welded in place. Good and permanent fix.
 
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Converging said:
Well its finally solved.

After floating around in Cardiff Bay with the diesel lines dangling in a clean container and having, by this time dismissed the filters, we finally noticed the turbo was not spinning.

We freed it off and up went the engine revs.

Its obviously dodgy because the turbo had been checked and dismissed but at last I can draw this thread to rest!!!!!!!

Thanks to everyone on the forum for their help and support.

Anyone got a cheap turbo??
Click to expand...

When the engine was down on power due to lack of boost, did it not smoke? I ask because one of my mercs is a little down on power, not enough for no turbo, but the lack of smoke made me dismiss airsupply problems. I will be changing the filters next though.
 
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With the two engineers on board they had dismissed the turbo through lack of smoke. I also made the same assumption.

One of the engineers had been suspicious because he had found a trace of oil in the intercooler and thats really what made him check again.

Both them and I, had witnessed the turbo was spinning during initial checks.

They sprayed WD40 in and its not stopped spinning since.

(Before the advice starts I know this is not the fix!!!:))
 
For ages now my Mercruiser 3.6d have not managed to rev beyond 3k on one engine and 3.2k on the other.

I have checked the turbos

Changed the fuel filters

Checked the lift pump

Replaced the props

But still the problem persisted.

I decided today to have the turbos re-built.

As we started to strip the engine down it was going to make the job easier if we took off the exhaust manifold.

Once the exhust was off it was immediatly apparent what the problem was. The exhust had completly carboised itself. Best way of describing it is what should have been a 70mm hole was 50mm hole.

The carbon was removed and a two year headache has been resolved.

I hope this post may help others who have this issue.
 
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