Merc 470 coolant bypass filter?

[NWVintage]

So, with all of the cooling issues with these, has anyone ever considered/tried adding a coolant bypass filter? I know they're generally used on diesel engines, but you can get filters without the diesel coolant additive, so why not?

Discuss...

 

[Bondo]

Re: Merc 470 coolant bypass filter?

So, with all of the cooling issues with these, has anyone ever considered/tried adding a coolant bypass filter? I know they're generally used on diesel engines, but you can get filters without the diesel coolant additive, so why not?

Discuss...

Ayuh,... That won't help, nor fix, Any of the 470's Issues....

Sorta like treatin' a bullet wound with chemotherapy,...

 

[NWVintage]

Re: Merc 470 coolant bypass filter?

Ayuh,... That won't help, nor fix, Any of the 470's Issues....

But isn't dirty coolant a big part of the cause of failed crankshaft seals, scoring of the crank and the whole redi-sleeve/double-seal fix that just about everyone has to do at some point? Dirty 3" heat exchangers will also be less effective than they already are. Hence the numerous discussions on here about the importance of changing 470 coolant extra-often...

I'm more interested in logistical issues...

 

[stonyloam]

Re: Merc 470 coolant bypass filter?

But isn't dirty coolant a big part of the cause of failed crankshaft seals, scoring of the crank and the whole redi-sleeve/double-seal fix that just about everyone has to do at some point? Dirty 3" heat exchangers will also be less effective than they already are. Hence the numerous discussions on here about the importance of changing 470 coolant extra-often...

I'm more interested in logistical issues...

It is the camshaft seals that ware out, and it is not like they ware out quickly, my engine is an 87 that I have qwned since 91 and have changed the seals once about 10 years ago (without Spedi Sleeves) and it is holding just fine. Mercruiser recommends changing the coolant every two years, but I will bet almost nobody does that. The main recommendation for proper cooling is to change the impeller every two years at least, to maintain a maximum raw water flow through the exchanger.

 

[NWVintage]

Re: Merc 470 coolant bypass filter?

It is the camshaft seals that ware out, and it is not like they ware out quickly, my engine is an 87 that I have qwned since 91 and have changed the seals once about 10 years ago (without Spedi Sleeves) and it is holding just fine. Mercruiser recommends changing the coolant every two years, but I will bet almost nobody does that. The main recommendation for proper cooling is to change the impeller every two years at least, to maintain a maximum raw water flow through the exchanger.

Ok excuse me. I suppose that does make more sense... But the point is still the same. The difference between your situation and mine is that you got your motor more-or-less new, while I just got a 1978 this year - that's 34 years old. The coolant in the system was clean and the motor appears to have been fairly well taken care of in the recent past but the drain at the front of the block, under the water pump was totally clogged - as in it took me probably an hour of jabbing at the crud with various implements (screw, screwdriver, small punch) to get it unclogged. I have to assume that this is an indicator that the cooling system was not well taken care of for some period in the past. I just want to makes sure that I get everything out of the system. We have 4-month old and are working on having another in the next 1-1.5 years, so this is probably only a 3-5 year boat (we'll need to upsize a bit), but I'd like to make the motor last for that period without having to do major surgery. Even if I have to rebuild, it's not the end of the world - I'll do it - I would just prefer to avoid it.

Anyway, now that we're clear on the motivation, a filter base is $40, filter is $9, and I'd need some hose. This will not only protect my camshaft seals but everything in my cooling system (heat exchanger, water pump, manifold). So we're talking $60 to prevent damage to components that would cost at least $1,000 - in a best-case scenario - to replace. Is there any substantive reason that I can't or shouldn't do this? My question is whether there is a significant possibility of some negative effect that I am not thinking of.

 

[Howard Sterndrive]

Re: Merc 470 coolant bypass filter?

I have cut open some of those coolant filters and all that was in there was a big puck of additive (like an air-wick). I know you could buy a no-additive can from Fleetguard and it was empty.
Maybe some have filter media in them, but not the ones I am familiar with (Cat mainly). So if you are looking to filter your coolant, make sure the filter is really a filter.

The reason for the empty can was for the scenario where you rebuilt somones engine, installed new coolant with all new additives and didn't want to overtreat with a new element. We used to install the customer's old element back and that was always met with a frown. So the shiny new empty can was a great solution.
Now with long life coolants in diesels, I suppose all those additives are history.

 

[stonyloam]

Re: Merc 470 coolant bypass filter?

Anyway, now that we're clear on the motivation, a filter base is $40, filter is $9, and I'd need some hose. This will not only protect my camshaft seals but everything in my cooling system (heat exchanger, water pump, manifold). So we're talking $60 to prevent damage to components that would cost at least $1,000 - in a best-case scenario - to replace. Is there any substantive reason that I can't or shouldn't do this? My question is whether there is a significant possibility of some negative effect that I am not thinking of.

IMHO you are not going to gain much. My suggestion id drain it, flush it throughly, put in new high quality coolant and forget it. If the camshaft seals start to leak, replace them, cost about $100. I do not see any significant benefit of a filter for the exchanger or manifold. If you really want to keep it running, change that impeller every year. As for ill effects, where are you going to splice it in?

 

[NWVintage]

Re: Merc 470 coolant bypass filter?

IMHO you are not going to gain much. My suggestion id drain it, flush it throughly, put in new high quality coolant and forget it. If the camshaft seals start to leak, replace them, cost about $100. I do not see any significant benefit of a filter for the exchanger or manifold. If you really want to keep it running, change that impeller every year. As for ill effects, where are you going to splice it in?

Yeah, I've decided that I'm probably over-thinking this. I was planning to put it between the hoses that go to my heater - that's what I did on my truck and it's worked out nicely.

So if you are looking to filter your coolant, make sure the filter is really a filter.

I'm running a Napa filter on my truck and it definitely has medium - don't know what to make of the empty canister deal...