First post... did I goof?

[luvmyi36]

Hello,
I have an '75 Islander 36 with the A-4 in it. Last Saturday the temp went up to about 200 when motoring back in, which is WAY above where it usually runs at 160. I jumped all over it and took off the inlet hose thinking there was an obstruction in the thru hull. Not the case. I then took out the t-stat, and it appeared to be in working order when placed in a pan of water on my stove for testing. I then spoke to a mechanic at my local marine center, who told me that occasionally the "t" just after the water pump gets clogged, and that is usually where he finds the problem. I inspected that, but found no obstruction. At this point I had not found this wonderful website yet, so I figured the next best thing was to do the old flush. I rigged up a flush kit to the hose on the backside of the water pump, and let her rip without the engine on, thinking it was an open system it would flow right through. As it wasn't an inline istallation, just a temporary thing, I leaked water all over the compartment, including the distributor. After coming home that night and finding this site, I am concerned that I may have pushed water back into the cylinders through the exhaust. I am unable to get to the boat for a few more days to check, and the suspense is killing me!!! Do you think that I have water in the oil now? Thanks to the Moyer's for putting this site together, just wish I had found it a little earlier!!! Thanks for any and all responses.

Jim

[luvmyi36]

Maybe I should rephrase.... I was looking on the forum and read a post about shutting the thru hull at spring commissioning, and water coming back in thru the exhaust if there is no pressure to push it out. This prompted me to wonder if what I had done without the motor running could possibly have dumped the water back thru the exhaust. The water pressure at my slip is fantastic, so I am hoping it just kept pushing it through. As you may have guessed, I am certainly no mechanic. I just hope that my trying to save a dime didn't cost me a buck. Once again, thank you for any and all replies.
Jim

[CalebD]

If the thermostat checked out ok then I would suggest checking the raw water intake impellor in the water pump (did you know that the water pump has a grease cap fitting that you are supposed to tighten fairly often?). If the impellor gets damaged it will slow down the amount of cooling water in the engine not to mention getting bits of rubber sent into the cooling system. While the engine is on you should always check to be sure that you have a generous amount of water flow coming out the exhaust.
As for water in the cylidars I would not jump off a cliff just yet. Now that you found this website and forum you should check here first if you are at all unsure about doing something on the A4. The advice here is pretty good and the price is right!

[luvmyi36]

Thank you for the insight. I forgot to mention that the very first thing I did was replace the impeller. The old one was not in bad shape, but I've only had the boat a year, and who knows when it was done last. I had thought I wouldn't go to the boat today, but, I just had to check. The first thing I did was pull the dipstick, and it was about a quarter inch above the full mark. I had just changed the oil about 3 weeks ago, and I know oil doesn't grow. I really couldn't tell if it was water though, as it seemed to be mixed in fairly well. I then pulled off the spark plugs and examined them, and it appeared that there were water drops in the gap. There it is. I pumped out the oil/water mix, and replaced with new oil and Marvel Mystery Oil mix. Put a little MMO in the spark plug holes as well, about a 1/2 teaspoon each. Then replaced the plugs and pulled off the coil wire, SHUT the thruough hull, and turned the motor over a bit. I didn't want to fire it just yet. I am going to let it sit over night, and do another oil change tomorrow, then give it the old college try. Any other ideas?

[CalebD]

Don't feel bad. I had to change the oil in my A4 3X after water got in our oil from a small flood in the cabin (read near sinking).
One hint Don or someone at MMI gave me is to use cheaper oil than the usual 30W oil that the engine likes when trying to get the water out of the cooling system. After the final oil flush replace the 10w-30 with something like Rotella T 30W oil. You really want to try to get your engine to turn over and circulate the oil a few minutes before you drain it so it can emulsify the water in your system so most of it can be drained out which is what you want to happen. I could suggest a shot or two of ether on the air intake before starting and wet cylindars might be a reason to try this but be very careful with ether onboard as it can cause instant fire when exposed to a spark.
If you do run the engine with the engine compartment open make sure to open any cockpit lazarettes (seats) and fore and aft hatches open for ventilation. CO2 can kill or at least make you kind of high and don't ask me how I know this but I have been there and done that and am happy to have my 12V oil change pump and my A4 still in reliable shape after 40 years of service to various owners (my boat is a 1967 Tartan 27'). It would seem that older engines like to have their oil changed pretty frequently so you have to check the oil fairly often on a paper towel and not be timid about changing the oil when the sample from the dipstick or your spark plugs when they get black.

[luvmyi36]

CalebD,
After I wrote my last post, I did some more reading and found a little more info on what we're talking about. I will run it today and get it heated up really well. It makes sense to get the emulsifying action going. The funny thing about all this, (not really funny), is that I have yet to determine if I have solved my overheating problem! I will get to the boat about 12:30 PST today, hopefully to find that I have indeed solved the overheating. When I did the flush, my buddy who was running the hose said he saw some pretty cruddy looking water coming out at first, let's hope he's right!! Thank you for your help on this, I really appreciate it.

Don,
First and foremost, thank you for this wonderful site!! There is a wealth of information here. To answer your questions:
1: I have a 1975 Islander 36.
2: It has a water lift muffler, and about 2 months ago I replaced the hose from the muffler back.
3: I have not checked the carb or flame arrestor for water. I will do that today.
Is there a schematic of the way water flows through the engine anywhere on the site? I think I have the idea in my head of how it goes, but I would like to be sure. As I mentioned in my earlier post, I am no mechanic. The last real mechanical work I did was in the 80's on my 65 Mustang, and the 289 and A-4 are hardly interchangeable.

Thank you both for your help!

Jim

[luvmyi36]

BTW, going back to CalebD's first reply, where is the grease cap fitting located? I have never tightened it. Does it need to be greased regularly?

[CalebD]

Jim,
Your water pump may not have a grease cap if it has been replaced with the new bearing supported model the MMI now sells. If it is an Oberdorfer 202 model (or such) you will see a grease cap fitting that should be tightened something like once per every 4 engine hours (just a guess on the frequency) and re-filled with grease annually or when tightened all the way in.

[luvmyi36]

OK, thank you CalebD. I think I found what you are speaking of today, but I don't see how to tighten it. Is it about 1" round?

As far as the water in the engine goes, problem solved. By the way, no water in the carb.

As far as the overheating goes, not solved yet, but I think I'm on the right track. I have good flow through the block, both from the "T", and the T-stat. When I Took off the top hose from the manifold, right before the burp valve, I got absolutely no flow. I pulled the manifold off and flushed it, also the burp valve. While I was at it I flushed the water lift muffler as well. There was a TON of crud built up in all 3. I just ordered a manifold gasket from MMI, so as soon as I get it and put everything back together I will know for sure. Keep your fingers crossed.

[Don Moyer]

Jim,

There is no schematic that I know of, but the system is described in detail in Chapter 2 of the MMI Service and Overhaul Manual if you can get access to a copy.

Don

[CalebD]

The service manual for the A4 that Don mentioned is a must have for doing work on our engines. I can't find my copy from a few years ago and am about to break down and buy a new one for myself.
I think you found the grease cap fitting (it is about 1" round). If it wont turn I suggest trying some WD40 on it (not PB Blaster which will eat up your gaskets!) to see if you can get it to turn. Remove the cap if you can and put grease in it and replace it. If the cap wont come off by itself (eg, is stuck to the inside housing which also unscrews) you could consider soaking the pieces in kerosene for some time to see if you can separate the parts. Alternatively, MMI sells a replacement grease cap kit.
I have often wondered about this fitting; what are it's importance and it's function? All I can come up with is that the old style (Oberdorfer 202M) water pumps have a shaft that is several inches long that turns the impellor on one end and gets driven by a belt at the other. The entire shaft turns inside a sleeve where the grease cap fitting attaches to the water pump. Logically, the grease from this fitting lubricates the shaft in this sleeve and gets dissolved by water over time, hence the need to tighten it forcing new grease into the sleeve every now and then.
Will the raw water pump eventually fail if you do not tighten the grease cap fitting? My guess is that the first symptom of this problem might be excessive impellor wear if the shaft has any play in it when it turns. Once the impellor is compromised enough the pump will fail to push enough cooling water through the engine. I just wonder how often this fitting has been responsible for peoples engines overheating.
If you don't even want to have to think about the grease cap MMI sells a new water pump that has ball bearings that replace the grease cap.

[Don Moyer]

All of the Oberdorfer 202M series pumps have a grease cup located between the water seal and the oil seal. I can't find any official Oberdorfer recommendations but we recommend a couple turns of the cup every 6 to 8 hours.

Don

[heinz]

Engine overheating

Jim, I am not sure if you had a chance to run your engine yet but I had a very similar experience yesterday when my temp gauge showed up at 200.
I check the exhaust, but it expelled water at a far amount.

My first though was that I may have a blockage in the engine since the impeller I replaced was missing a blade.
When I got back to the dock I removed the thermostat (which is working) and clamped the bypass hose. When I ran the engine I was getting a good flow of water.
I am wondering though if the sensor is defective. Does anyone know how I can check it. Or is there something else I am missing?

Any advise is greatly appreciated.

heinz

[luvmyi36]

Gentlemen,
Sounds like a plan. I will try to get the cap to budge tonight. Is it just marine grease that is used in it? And, should I have greased the impeller when I replaced it?

[tenders]

Waterproof grease, available just about everywhere.

You don't really have to grease the impeller. It might help to moisten it a little but they aren't too hard to get in.

Mr. Moyer also sells a remote lube kit which, via some clever brass fittings and a tube, allows you to move the grease injection point to anywhere within 6 feet of the water pump, and inject the grease through a zerk fitting with a standard grease gun. Very handy. (The grease gun itself need not be permanently installed.)

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