Mercruiser 6.2 engine fail (again!!)

telcowilliam · 08 October 2015, 14:10

Not rib related but I'm after some advice and thought somebody on here may be able to help. I have a maxum 2700scr, I had a brand new engine, bravo III leg and props fitted by abc marine in 2007. I have had it serviced by them every year since then as well. A couple of weeks ago I went to take it for a run, (it is moored in Victoria dock Caernarfon) started up ok as normal, I left engine running as I removed ropes and fenders. Got back on boat ready to go and the engine cut out. Tried to start it and it wouldn't have it. Tied it all back up and left batteries in charge overnight, came back next day and tried to start it again. Still wouldn't have it, anyway after abc coming out I towed it to their yard in Beaumaris, they have since removed the engine and have said that it is frost damage. I find this hard to believe because I have used the boat quite a lot over the summer approximately 50 hours and it has been fine. Abc rebuilt the engine in 2013 because they said it was water damage caused by washing the decks and it going on to engine and it not drying out properly. I feel as though abc are having me over a barrel here and want advice on what I should do next. They are advising me that it now needs a new engine. This engine has done 268 hours from new and that includes being rebuilt once!!

kerny · 08 October 2015, 14:25

P.M. Sent

matt h · 08 October 2015, 16:18

What a load of bull! If it turns over fine i would say its fuel/filter or dodgy wire on ign side as an initial thought!

Xk59D · 08 October 2015, 16:34

Frost damage on a mercruiser normally means a cracked block fyi.

Tbh there is not enough info to really help you here. I can only assume as the engine is out the block has cracked. Whilst I don't know temps where you are, it has not been cold enough to cause frost here yet. Google can give you the answer on lowest temps where you are for this month as proof (maybe) it can't be frost.

Did you always empty the drain plugs in the block after each use? It was a ritual on a 5.7 I had years ago.

I guess it is possible if you have never drained it the crack was done over winter and got worse to the point you are at now.....this is assuming there is a crack of course.

Need more info as I said, what exactly do they say is wrong?

telcowilliam · 08 October 2015, 17:18

I dont think that it has been cold enough to freeze this last winter, It is in a tidal lock which has fresh water running into it. I have never emptied any drain plugs and I didnt know there was any on this engine? The crack is on the exhaust manifold apparently, although I couldnt see it myself. The plugs on one side are a little rusty, especially the rear plug. I have a couple of pictures I will upload now

telcowilliam · 08 October 2015, 17:21

matt h · 08 October 2015, 17:37

hmmmm.Im assuming the pics are before the re build or have you stripped down the engine for the second time?... looks like there has been piston damage on that one.. head gasket failure poss. TBH its looks in poor condition really. lack of use is an engines enemy!
Can I see milky oil by the cam carrier?
Did you do a compression test? or have you?
The piston rings/scraper rings look jammed it looks like.
More detailed pics could help a bit more. if the block has broken on the outside it will still run Will.

telcowilliam · 08 October 2015, 17:49

it is definitely not head gasket failure, they have also been used quite a bit this season, at least once a week

Xk59D · 08 October 2015, 18:30

Assumption again....the manifold cracked due to freezing over winter and here you are.

I am no mercruiser expert but I'll be surprised if you don't have drain plugs on the block and manifold which probably would have prevented this.

If the engine was fitted new then perhaps the owners manual recommends to empty it? If none were supplied then perhaps the installer should have showed you??? I.e they need to take some of the blame and hence costs.

EDIT- according to Google there are 4 on the engine, one on each manifold and one on each side of the block it looks like at a quick glance on most new v8's....ymmv.

telcowilliam · 08 October 2015, 18:45

I have never been told of any drain plugs at all for this engine, I have definitely never drained it down after each use. I will be going back in to see them next week and will report back with what they say

Xk59D · 08 October 2015, 18:59

Each use probably is overkill but it should 100% be drained in winter and some suggest putting antifreeze in just to be safe. Again, your manual will tell you the correct procedure.

I know with our 5.7 it was drained after every trip as this issue is pretty common.

Good luck with it though.

Mollers · 08 October 2015, 19:52

'Kin 'eck! This boat is a proper 'Cold shower/£50 notes'.

Been down the V8 frost f'ked road myself, it's not uncommon or that simple to avoid.
As mentioned, you may've had a hairline crack in the block due to frost, which has held out for most of the summer, but has finally let go. Emulsified oil somewhere would be the giveaway. Mine blew mousse out of the airfilter.

For future reference, getting all of the water (fresh or sea) out of a vee engine is close to impossible. I used to remove the thermostat and run antifreeze through until it blew blue out of the exhaust and then switch off. The added bonus being, antifreeze has corrosion inhibitors in. The job is a total faff, but at least you can relax and not study the temp forecasts all winter.

Have the repairers explained exactly what the frost incurred damage is?

willk · 08 October 2015, 19:55

Quote:

Originally Posted by Mollers

Have the reapairers explained exactly what the frost incurred damage is?

Those will be the Grim Reapairers then?

Mollers · 08 October 2015, 20:17

Quote:

Originally Posted by willk

Those will be the Grim Reapairers then?

It does appear that way.

Nightfisher · 13 October 2015, 06:40

Frost plugs are on them all in strategic places. The idea being as frozen water expands the frost plugs will be the first to burst saving the block from potential crack-damage. The tell tale sign, that I don't believe you mentioned when you first started the engine while unmooring the lines and is crucial to the above, was there clouds of white smoke while in warmed before shutting down? White smoke (steam) means two things..cracked head/block or blown head gasket through the water journals..with water entering one or more cylinders. Don't fool yourself rip-off engine overhaul places have a backyard full of junk heads/blocks you could be shown. As I mentioned the key is if any white smoke (steam) clouded around the stern on startup. Good luck.

Nightfisher · 13 October 2015, 06:44

One more thing. The pictures of the block-cylinder bores are not new. That much rust, depending how long you waited before the engine was (apparently) dismantled is the key.

Last Tango · 13 October 2015, 07:09

"Tried to start it and it wouldn't have it."

Did it spin or was it "hydro-locked". I've had exactly the same issue with a failed manifold on a V6 Merc.

Were the manifolds/risers replaced with the new engine ?

paintman · 13 October 2015, 08:49

What are commonly referred to as 'frost plugs' or 'freeze plugs' - more correctly called 'core plugs' or 'welch washers' - are simply plugs used to fill the holes resulting from when the part is sand cast & were the locations of the sand forms used to form the internal passageways/cavities of the part.
That they sometimes pop out if coolant freezes led to the belief that they were designed in to prevent damage to the block.
They can be a PITA if no corrosion inhibitor is used as they corrode from the inside & sod's law & my own experience says that the least accessible will be the one that starts to leak!

telcowilliam · 13 October 2015, 09:34

I didn't notice any white smoke when engine started but to be honest I wasn't looking either. The engine was still in boat for a fortnight after the initial non start. The risers where replaced when engine was new in 2008

beamishken · 13 October 2015, 11:44

It looks to me like the risers/ manifolds were the problem have you confirmed the block is cracked?
If frost damage they either crack on the outside & leak water into the boat or they crack inside the valley under the inlet manifold & fill the sump with water
The block might be ok & if your lucky you might get away with 1 or more pistons & a hone & re ring
That piston has been run for a while with water gettingo n top of it to cause the pitting
5 years out of a set of manifolds isn't unusual if not flushed or drained
If the block isn't cracked the water in the oil could just be from what has seeped past the piston over a period when stood idle