loosing coolant

[lilgervais]

i have a 1983 mercruiser 470.when i bought this boat was told it was ready to go but found out the water pump in the lower was gone fix that..then it went threw a little coolant now its getting worse and starting to smoke more and more..sometimes when i start it now it seems like the starter is getting bad and just makes noises does not turn the engine over not sure if the probloms go together..thinking my head gasket is gone??

 

[Bondo]

Re: loosing coolant

Ayuh,... Is the coolant gettin' into the Oil,..??

 

[nola mike]

Re: loosing coolant

sounds like you're leaking coolant back into the cylinder, usually from a bad riser or gasket. Next time it's hard to start, pull the plugs and then turn the engine over--see if you get coolant shooting through the plug holes.

 

[guyaverage]

Re: loosing coolant

Welcome to the 470 club.....

When the headgasket gave up on mine, the only symptoms I had was the coolant very slowly disappearing, and progressively getting more and more difficult to start. Once it started, it ran great. The gasket was blown in 3 different places. Luckily the thin section between the water jacket and the lifter galley was still good, so no water in the oil.

Pressurize the cooling system and see where the water ends up. Check the #4 cylinder, thats a pretty popular problem area on 470's. If you have the room around the engine compartment and dont mind doing some teardown, this is a pretty easy engine to work on. Hate to send you in that direction right off the bat, but thats probably where this is headed anyway.

Good luck and let us know what you find. Unfortunately a lot of these 470 stories dont end happily.

 

[stonyloam]

Re: loosing coolant

Time for a compression test and cooling system pressure check. You can borrow the tools for both from Autozone (free)

 

[lilgervais]

Re: loosing coolant

Time for a compression test and cooling system pressure check. You can borrow the tools for both from Autozone (free)

i did do a compression test over 120 in all 4 cylinders..last year i did a cooling system pressure test and found a hose that was leaking and thought that was the problom fix the hose and this year took it out a few times and i guess that hose wasnt the only problom..

 

[lilgervais]

Re: loosing coolant

sounds like you're leaking coolant back into the cylinder, usually from a bad riser or gasket. Next time it's hard to start, pull the plugs and then turn the engine over--see if you get coolant shooting through the plug holes.

i already pulled the head off the boat thinking that was the problom but i guess now im not sure..the boat didnt start hard just once in awhile it was like the starter bendixs wernt comming out like the starter was just turning and not touching the flywheel..after removing the cylinder head i found no noticiable cracks in it but also the gasket didnt seem to be ripped in any place..i am bring the cylinder head up to the machine shop tomorrow to have it pressure tested and plained just not sure if i am heading in the right direction anymore..maybe the starter is also getting bad along with whatever this problom may be just hate to get it back together and have the same problom..there is no visiable coolant or anything in the engine oil..i changed the oil at the beginning of the year and is still at the same level and looks okay

 

[lilgervais]

Re: loosing coolant

no coolant in the engine oil that i can see..i do have a parts boat with the smaller 4 cylinder 120 hp i beleive..that motor has a lot of white white milkey stuff in the engine guessing it was water so not sure if the head or riser is any good to even try on mine..anyone know if there is a way to get the riser tested??really like to get the problom fixed before putting the engine back together..i guess it is kind of a guessing game now but thats gonna get exspensive very quick even with the parts boat and i dont know if the boat is really worth it..thats why i researched and found this sight to try and get a little help...thanks to eveyone

 

[lilgervais]

Re: loosing coolant

early when talking about my boat i forgot to mention that the last time i had it it sometimes it seem to go perfect then others it seemed like it didnt have the power it ussually does and took much longer to plain out with about the same amount of weight that i ussually carry in it

 

[stonyloam]

Re: loosing coolant

the gasket didnt seem to be ripped in any place..

Neither was mine, but it was still leaking. Look for pitting in the head chambers, and look at the sparkplug insulators, white clean insulator is an indication of coolant getting in the cylinder. Your machinist should be able to tell you a lot. BTW the head (nor any of the other major parts) off the 120 will not fit on your engine.

 

[lilgervais]

Re: loosing coolant

the spark plugs do look pretty white..as i said im taking it to the machine shop the morning hopefully i get some good news..what do the mean by the head chambers?im not really that familiar with boats this is my first one

 

[lilgervais]

Re: loosing coolant

sounds like you're leaking coolant back into the cylinder, usually from a bad riser or gasket. Next time it's hard to start, pull the plugs and then turn the engine over--see if you get coolant shooting through the plug holes.

which part is the riser? the part you pour the antifreeze into or the parts that bolts to? should these parts and gaskets be changed when redoing the head?

 

[Don S]

Re: loosing coolant

i do have a parts boat with the smaller 4 cylinder 120 hp i beleive.

Those are two completely different engines. The 120 is a GM engine, your 470 is a Mercruiser designed aluminum block with a Ford 460 head on it.
Here is a link to the OEM service manual that covers your engine.
http://www.4shared.com/document/M35B2RL4/Service_Manual_03.html