PDA

View Full Version : Engine Trouble 351, 285 HO


alp
07-31-2007, 04:52 PM
Our 92 PS 190 started leaking trans' fluid two weeks ago, about an once or two per hour. I took it to a local mechanic who said he could not find any leaks - nothing wrong. He said I may have spilled some when I changed the cooler recently. So I towed up to Vermont for our vacation, ran it and sure enough still loosing an once or two per hour.

I spoke to a ski boat service dept in the NY/VT area and they suggested I look very close behind the bell housing while under way. I did this but could not see anything leaking. To my dismay though I did notice a drop of water and traced it to what appears to be a hairline crack in the rear of the observer side cylinder head. Tiny beads of water seeping through crack.

So then with heart beat racing (vacation plans flying out the window $#! - I think back - it overheated at our home ramp two weekends ago. Within a few minutes of start up the temp was 190. Shut it down. Re-started and still hot. My buddy - former mechanic - suggested we run it down the lake for a minute to see if it clears up. It didn't. We returned to the dock, he tapped the thermostat housing and the temp went down to normal. I change the thermostat that afternoon and we ran it the next morning. Ran perfect, but at the end of the session there was pink fluid in the bildge.

So now I believe we overheated it, cracked the head, and damaged the front trans' seal.

Is this a likely explaination? More importantly what should I do? I certainly won't go back to the mechanic who said nothing was wrong. I'm Ok with basics like tune ups and have changed a carb, but not ready for changing heads or trans' seals. Should I consider a re-power or having the head repaired and seal fixed? Any recommendations on a repair shop in eastern CT?

Weird thing is it runs fine, smooth, pleanty of power, temp is steady at 150.

BrianM
07-31-2007, 04:59 PM
The trans issue sounds like what happened to my '88. It was a bad front seal that needed to be replaced. As for the cylinder dripping I don't really know.

93Prostar190
07-31-2007, 05:02 PM
ALP - sorry about the bad news ... I have a 93 with your motor .... before throwing my $0.02 into the discussion, can you please describe your motor oil? check the level and also see if you suspect any foreign fluids inside the oil .... that may help give a clue on how bad the "crack" maybe ... I am hopeful that your crack is a surface crack close to one of the factory water plugs, and not a more serious matter than that ...... I am also optimistic that the 351 motor in your boat should be able to tolerate a small amount of time in the 190 temp range (that is at the gauge sender) obviously the metal in parts of the engine may get hotter without cooling.

The pink fluid in the bilge could be water and tranny fluid mixed ..... are you sure there are no leaks around the transmission cooler and its lines as well?

alp
07-31-2007, 05:18 PM
Thanks guys. The seal seems to be a fairly normal issue. The motor oil is fine. The crack is on the valve cover side of the head, at the rear of the motor just to the right of the first spark plug from the rear. No leaks at the cooler and the lines look clean. It was replaced recently.

93Prostar190
07-31-2007, 05:22 PM
A surface crack may (emphasize "may") be fixable with a product like JBWeld ... after all one of the reasons that product was created was to fix larger marine engine blocks (for ships) ...

so maybe it is as simple as 1 seal replacement and some JBweld .... good luck.

rektek
08-01-2007, 02:12 AM
cast iron V-8's can handle a lot more heat than 190*, so it must have got much hotter than 190* or my guess would be a crack from freezing over last winter. if the crack did come from excessive over-heating then I'd start looking for other damage, Piston knock, ring damage, oil burning etc....

I wouldn't mess around with fixing that head, they are too cheap to fool with unless your trying to keep matching numbers from some kind of collector engine. I'd probably just buy a pair of heads and swap them out.

your trans leak could be anything, inspect all hoses and seals that you can. front input seals can be tough to inspect in a boat however.

if all the hoses look good pull the trans and have it resealed while you are doing the heads.

the heads could be done in a weekend, r+r the trans will probably stretch into 2 weekends, still not bad.

cheers;)

alp
08-01-2007, 01:43 PM
Thanks rektek.

No knocks, oil burn or water in crank case so far. Runs fine. Your right could be alot worse.

alp
08-09-2007, 02:02 PM
I've been checking the trans leak and it's pretty slow, maybe losing an once or so every 2 - 4 running hours. So I think I can nurse that through the end of the season and then have the seals replaced, maybe a rebuild time too.

I'm going to use JB Weld on the hairline crack, which is on the passenger side head, and goes from the rear freeze plug around to just before the first spark plug. I wonder if this is an area where a little water gathers and has caused the crack over time?

Looking forward I'm considering a rebuild or replacing the long block over the winter. Not sure how costly that may be. Perhaps trading up may be a better option.

I just love this hull though. A friend recommend that I look for a 97 - 02 MB Sports Boss 190, which MB started with the same hull (purchased mold from MC in 95) and tweaked it to eliminate the spray and flatten out the bump at 22. Then they through in a PCM GT 40 and 1 to 1 trans.

Any recommendations would be appreciated.

Thanks

rektek
08-13-2007, 11:13 PM
so it sounds like the mr. freeze did you in, I can't imagine JB weld having any effect on controlling your leak, Cylinderheads get smoking hot and expand and contract.

unless you give the boat away at a serious discount it's better to fix it and use it or fix it and sell it. motor parts are cheap, complete boats are not cheap.

good luck with your repairs.

J

Pete
08-16-2007, 02:24 PM
I have a 94 PS and all my ski buddies agree this boat has the best wake ever to ski behind it. Fix it, or let me know if you want to sell it.

I have a friend who was the lead mechanic at the M/C dealer in SE Mich for years. He is now on his own doing mobile marine service. He knows everything there is to know about M/C's. He is extremely thorough, knowledgeable and helpful. I would recommend him to anyone, he knows our PS inside and out. May be worth a call or road trip with the boat. His name is Bill Allen ph#734.417.3844.

Pete

alp
08-16-2007, 04:01 PM
Thanks Pete. I'll call Bill for some advice.

Looks like the freeze plug failed. The crack begins there. The trans' leak looks like the rear seal. I'm going to have that done soon. A ski buddy (former mechanic) recommends not changing the head as long as it continues to run fine - try to get another 200 - 300 hours, 3 - 4 seasons, then do a major rebuild when it's closes in on 1,500 hours? There is no change in performance. About one small drop of water per minute leaks out.

alp
08-16-2007, 04:02 PM
Thanks Pete. I'll call Bill for some advice.

Looks like the freeze plug failed. The crack begins there. The trans' leak looks like the rear seal. I'm going to have that done soon. A ski buddy (former mechanic) recommends not changing the head as long as it continues to run fine - try to get another 200 - 300 hours, 3 - 4 seasons, then do a major rebuild when it's closes in on 1,500 hours? There is no change in performance. About one small drop of water per minute leaks out.

JDK
08-16-2007, 11:39 PM
I'd be watching the spark plug closest to where the crack is. If it's clean (new looking) as compared to your other plugs you've got water leaking through the crack and into the combustion chamber and this needs to be fixed. If this plug looks like all the others, you're probably fine with the JB Weld fix.