Logo

Engine locked up

paul_rodgers

Regular Contributor
"I have a 7.4 litre MPI 454 ci

"I have a 7.4 litre MPI 454 cid, I was in the gulf of Mexico on a cruise, engine got hot,I was on wrong side of Island so I started the engine and went to otherside. I turned the engine off and it never restarted I am certain that it is locked up. If it is what can I do?"
 
"Dang! Since you ran it hot i

"Dang! Since you ran it hot it probably is shot. If it won't crank, buy a new full fresh water cooled drop-in engine; about $7500. You could get a lower priced longblock but w/the labor and the old saltwater used parts, you're going to spend close to the same; too many unknowns on the old parts to transfer to the longblock. Your decision."
 
"Yes, I expected as much but a

"Yes, I expected as much but as I am a maintenance
man I always try to see the good in things, so let me tell you where I am at so far, I started removing all parts from engine starting with exhaust then the heads. The heads look good, nothing out of ordinary that I could see on port side I could not get the exhaust off starboard side. My boat has been in freshwater for nine years as it is a 98 and three months in saltwater, I think I will buy a new block and transfer parts, As I will be doing all labor.. But problem is not solved what caused it in the first place? I need engine running to troubleshoot!! Thanks for your help Paul!"
 
I was on a trip to Horn Island

I was on a trip to Horn Island about nine miles
I had no problems getting there it ran fine. About an hour later we decided to head fishing as I was coming out of pass about 1/4 mile I heard the engine alarm. I then turned it off but I was right in the middle of passage way for all boats. So I really had to move and I did. My bad.
I pulled thermostat and it was working as I checked it in the galley. Then got towed back to marina and started this guest.
 
Remove outdrive and see if eng

Remove outdrive and see if engine spins over..........If you have not allready.

How hot is hot? if over 300' then a piston probably siezed in a cycl.
 
"The temp never went over 200.

"The temp never went over 200. I was watching the way back to other side of island. I have not considered the out drive being locked up, Everything turns fine from prop. I am in the middle of taking engine apart but 3 bolts on port side are rusted as I live in SC I did not have tools to remove bolts. I will keep you informed of what I find, But the out drive was replaced in 2006 with a new unit. Brovo III. Thanks for your help you guys are great. I don't have alot of experience with outdrives but motors
I can deal with. Again thanks."
 
Which 3 bolts? Rusted manifol

Which 3 bolts? Rusted manifold bolt heads can be cut off and then slip the manifold off.

Your seapump may have sucked in some trash.
 
"It is the last three on port

"It is the last three on port side toward transom,
I will be returning to Ms. on Saturday with enough tools to complete job. I will keep you posted on my findings. Thanks Paul"
 
"Hi,

The first thing I wou


"Hi,

The first thing I would do is pull your plugs and disconnect your coil wire. Then I would try to spin your engine. Depending on how much weight you had in the aft of the boat and or following seas you may of gotten hydro locked. That's when the sea water goes back down the exhaust into your engine. The only way to check for that is to take out all the plugs and crank the engine. Good Luck."
 
"I guess I got in to big a hur

"I guess I got in to big a hurry to take it apart, I have all off on one side and the other side I have three bolts that are rusted with little or no head left. I have gone this far I am going to look at other head while I am at it. I should have found this forum earlier might of saved me alot of time in the 95 degree temp here in Ms. I appreciate all your help and thanks for all good info. Paul D."
 
"I guess I just dodged a bulle

"I guess I just dodged a bullet, I have got the engine freed up and the pistons are going up and down ha ha, Yes I am relieved but still don't what caused it to over heat? When I pulled the engine apart the heads looked great almost new looking, When I get the heads back on I will do a compression test and give you guys an update.
I am kinda confused on the rockers an pushrods, I have #1 Cyl TDC and the seloc book tells me to adjust to 40 ft lbs and just adjust the rest and they should be ok. I was thinking each cyl had to be on TDC before adjusting? Can you help?? Thanks Paul."
 
Back
Top