Problematical Mercruiser Ford 302 (888)

Read with interest the discourse betwixt Sans, CarbonKen & Gonzo relating to Mercury's Ford 302 (888) overheating problems. My neighbor has one such in all regards - the engine and overheating - plus additional complications. I understand that the engine is vintage of 1975 or thereabouts.He has owned the boat for some ten years and it has run fine until the summer of 2003. That season he was plagued with gasoline in the oil giving overfull readings on the dipstick and necessatating frequent oil changes before damage could be done to the engine. At the same time, it evidenced a decided problem with the heating similar to San's problem. We discovered that the choke butterfly was sticking and a proper adjustment thereto seemed to take care of that matter and the temperature gauge then seemed to behave itself, but we aren't certain of that due to the fact that the outdrive crashed before we could be confident of the results. It was a short season.

Over the winter he installed a factory new outdrive ($3200 worth) with the help of a professional Mercury mechanic, but not replacing the accordian boot that appeared good. Think that was a mistake. (hind sight !) Then launching for the new 2004 season it ran flawlessly for several runs out to the fishing grounds. Several runs plus one, halfway to the fish it burped, coughed, spluttered, blew out the boot and ground to an overheated stop.
Would probably be halfway there yet but for the outboard auxillary. Upon return to port the motor wouldn't turn over and it was dicovered that the oil pan was half full of water and the sparkplugs were wet with dewdrops. This was an even shorter season. Some gentle persuasion with a socket and breaker bar rolls the shaft over without any screeching or grinding sounds from the bowles of the engine and it sits now with the pan drained, awaiting
some expert diagnosis and advice.

I withhold my personal advice, insofar as when his wife gave him his choice between her or the boat a few years back, he chose the boat. Besides, he's my ticket out to the fishing grounds.

Any help out there, guys?

JohnF

 

Well it should be torn down and inspected. On a ford 302 it is easy to blow the head gaskets. I would also inspect the exhaust manifolds and risers very carefully. Once the heads are off you should be able to make a good assesment of the engines condition.

 

I aint an expert, but did this just happen? Where all sparkplugs wet? No earlier starting problems with engine? No choking of engine at start up? What I'm after is if the exhaust manifolds or risers are leaking water will fill up the engine. Sounds like something like that due to several sparkplugs were wet. I would check them up.

You,ve read my earlier thread. I think I have found the primary error. As said I aint an expert and when I checked the head gaskets for leaks I only looked at the mating surfaces. The metal rings on the head gaskets weren't stainless and due to that the metal had corroded and compression went THROUGH the head gaskets into the water channels and neighbouring combustion areas. My valves were somewhat corroded and I wonder if water may have found the way through the gasket. Can be worth checking up on your friends engine.

The fact that several sparkplugs were wet should indicate that it isn't just a blown head gasket or cracked head, then just one cylinder would be affected.

You should check the engine block for cracks as well.

Stefan

 

I'm rerassured by your preliminary assessment of a proper course of action in determining the fate of our Ford 302, as it coincides with my personal thinking. I'm hopeful that it isn't a cracked block or head because the motor has never been frozen (ice) and has run however sadly over the past two troubled seasons. My experience with motors is primarily in the automotive variety, and we were heeding CarbonKen's adomonition to Sans regarding not tearing one of these engines down without knowing for sure what the problem is. One concern that we have is whether the crankshaft journals have suffered from exposure to the water in the oil. The sump has been drained early on and the motor's been sitting since. We'd just as soon not have to lift the entire engine out to drop the pan, which would require discombobulating the outdrive assembly. Whatca think ?

JohnF

 

To sans -: Move over and make room for me, I'm no expert either ! See my earlier reply to Woodboat.
It's hard to say just when the problem(s) occured since the engine's been sick for a couple seasons. The blowout of the boot and seizing of the motor from overheat happened in late June of this year and we ain't been a-fishing
since that time. The other ailments mentioned persisted over the previous season and we aren't certain whether or not they contributed to the present impass. As said, I lean toward the theory (and hope) that a head gasket is the culprit and nothing more serious. Soon as we dig out from this past weekend's blizzard, we propose to commence exploring the various possible diagnosis. Meanwile, any further thoughts, comments or advice from any quarter will certainly be welcome.

We will keep the world informed of our fumblings as work goes on. Thanks !

JohnF

 

Water is not particularly hard on bearings but Antifreeze is. I am a little concerned though that it was left with the pan drained offering no protection from rust. When water is suspected to be in the motor the proper procedure is to "pickle" it, often with Diesel fuel, to prevent rust. I would due something ASAP.

 

To woodboat - -
Good advice. Will do that first thing.

JohnF

 

If you can't find anyone locally, I am in Milwaukee. From your description it will at least need a completer disassembly to check bearings and cylinders. Possibly rings, bearings and new gaskets may get you a reliable engine. However, there no way to tell before checking it out. A dry and wet compression test can give you an indication of the condition of the cylinders.

 

To gonzo -: Yep ! Thanks to y'alls good advice, we're formulating a master plan for determining where we go from here. As sans suggests, we's gonna start with a 50psi air load on each cylinder with the piston on TDC. We'll see what that tells us, if anything. Then as you suggest, if indicated, we'll use your wet/dry compression test. Some sort of a picture should develope to guide us in our further bumblings. Whatcha think ?

JohnF

 

I am a good hind sighter also. When ever a engine has it's oil dip showing a higher level than before, DO NOT start the engine! Have a good mechanic come to the boat with a cleaned out oil suction pump and a clean clear jar. have him remove a good sized pint of liquid then smell it. gasoline- should be a failure of the engine mounted fuel pump diaphram in the pump dripping into the oil. Cure is a new pump. No gas smell? Let the jar sit for 1/2 hour. Oil goes up - water forms a low layer so does a 50/50 mixture of coolant in closed cooling systems. Under no circumstances should you drain and refill. The bad oil will take the life out of the engine or size it if the gasoline leak persists. It has been known to vaporize out of the oilpan and go KABOOM.

 

Oh Yea,Richard - - KABOOM was definatetly a consideration back in 2003 before we replaced the fuel pump for that very reason. The problem of gas in the oil persisted so our attention was redirected to the choke and carb float level. After several runs out to the fishing grounds everything appeared to be o.k., but still not conclusive. When the oil level gained once more in early 2004 we first thought it was "back to the drawing board". We now presume that gain was due solely to water in the oil - - we hope.

We're fixin' to get going on testing for this and that as suggested by our other respondents prior to any tearing down that might be indicated. The Christmas preparations and doin's are getting in the way of that but we'll keep slogging alond and report via this forum as to progress. Thanks for jumping in and any further thoughts will be welcome.

JohnF

 

Here's a cutie. We had a 1958 ( car ) Mercury, with a 460 ? ci engine ( Lincoln engine ) and auto. Car could give vette's a eye opener for first 100'. Very bad milage when driven around town. Every thing else fine. 6000 to 10000 miles later we found out why. Carb front float chamber had a gap of only a few thousandths at the back edge next to the edge of the front 2 throats. Perfect enrichment that operated only at foward acceleration. We kids took it apart, studied it, never ran that great again. There is a moral in there somewhere. Rich

 

Yeah, Richard, - - I think the moral has something to do with thos big Lincoln engines. I had a 1950 Lincoln with a flat head V8 that could (and did) do 120 mph in a quarter mile. I bought it used in 1951 and was totally impressed with the fact that it was priced lower than a 1949 Ford Fairlane. I soon found out why, - - it couldn't pass up a gas station either.

JohnF

 

Did you put 2' of mainline railroad track at the back edge of the trunk to drive around in the winter ? Rich

 

Rich - -
No, but I swear that the rear wheels lifted two feet off the road every time I hit the brakes. Aaaah, the follies of youth !

JohnF