165HP Mercruise wont start 224cid 4 cyc

[Bob Gutkowski]

I have a 165hp mercruiser and I have experienced high temps due to water impeller damaged. Engine wouldn't idle and would get hot. Stall when moved into gear. Replaced impeller but installed backwards removed installed correctly with all new parts.Then I changed the intake manifold gasket and noticed the gasket wasn't sealing correctly. I used solvent sprayed at the gasket increased rpms significantly. Rather than machine intake manifold surface I used ultra gray and now it wont start.​

Also I used the garden hose on the impeller pickup tube without engine running and filled up the exhaust manifold and oil pan with water. I drained the oil and water replaced filter and oil ran engine to get water out with plugs out. Replaced plugs. replaced exhaust manifold gasket after inspecting manifold.​

Question the manual doesn't recommend sealant on the intake gasket but my friend use it always. I wanted to know did I affect the amount of air to the intake manifold by sealing the gasket for no leaks. Is the gasket suppose to breathe air.​

I cleaned plugs many times and no help.​

Now I'm going to clean inspect plugs for fowling and try one more time.​

I never had problems starting this engine until I sealed the intake manifold gasket.​

 

[Scott Danforth]

Service your points

Repair your head gasket

 

[nola mike]

Wow, you have so many potential problems it's hard to know where to start. Overheat, water in the crankcase (that shouldn't happen, though I'm not sure where you placed the hose). Let's start with 1) are you getting spark? 2) is it turning over at normal speed?

 

[Bob Gutkowski]

Ok I just got it running but it was backfiring at first. Question now is the exhaust manifold has a port where engine exhaust blowing out. It exhausting at the top on to the transom wall.

 

[Bob Gutkowski]

https://streamable.com/qig4s

 

[Bob Gutkowski]

This is the video of the exhaust blowing out the port hole slot.

 

[nola mike]

There's a plug back there that rusts out, but I can't remember the specifics. stonyloam has posted about it in the past.

 

[Bob Gutkowski]

 

[Bob Gutkowski]

Freeze plugs

 

[Bob Gutkowski]

No1 170
No 2 178
No 3 150
No 4 150
compression test

 

[stomp10]

Hi Bob, I read this post earlier today but wound up answering on the wrong thread entirely! Suffering a bit of informational overload lately it seems. If any op out there would care to delete my post from that wrong thread, I would greatly appreciate it. Also my apologies for posting my reply to the wrong thread. I couldn't find a way to delete or edit my previous post either.....

I had the same problem on my trusty 470 about 20 years ago.The freeze plug just rots out apparently.
My fix was quite simple and has held up for the last 20 years with no issues. I had a hunk of 5/8" thick steel that was just the right size to span both the threaded hole and the freeze plug hole. I drilled it out enough to accomodate a bolt to pass through and screw into the threaded hole in the head. A nice hunk of gasket material the same size as the piece of steel, bolt it into place with a washer and lock washer on the bolt, and its enough to seal the hole permanently. I have had no freeze issues in the head as a result as I always trail it home after an outing, which is apparently enough to drain the head passages entirely from the motion of trailering. I'm pretty sure you could get away with using something not quite as thick like what you can pick up in your local hardware store. Anyway, I hope you find this info useful.

I know this engine has its own inherent engineering issues, but all of that aside, it has been a great engine over the years. I have no regrets in owning it at all. I am even still running on the original stator system, which I actually hate. I am looking to replace it with an ac\delco as I head into my own retirement.

 

[Scott Danforth]

No1 170
No 2 178
No 3 150
No 4 150
compression test

you have water in cylinders 1 and 2

or your gauge reads high and cylinders 3 and 4 have ring issues

 

[stomp10]

Question the manual doesn't recommend sealant on the intake gasket but my friend use it always. I wanted to know did I affect the amount of air to the intake manifold by sealing the gasket for no leaks. Is the gasket suppose to breathe air.​

Hi Bob, In answer to this question, intake manifold gaskets are not intended to leak air at any time or for any reason. The fuel air mixture must be metered by the carb or fuel injection system only.

 

[silverseal99]

Agree that right side of pictures appear to be of a rusted out freeze plug. It needs to be pulled and replaced.

Freeze plugs are in water jackets and not in the exhaust pathway. Exhaust blowing out of the freeze plug hole would indicate either a failed gasket between the exhaust manifold and the riser, or a perforation between the water jacket and the exhaust side in either the manifold or the riser. Since exhaust pressure is much greater than water pump pressure, exhaust leaking into the water jacket would displace cooling water and lead to a hot engine condition even if the raw water pump were functioning properly. I have a similar issue in a 5.7L V8 and would pull the riser to inspect/replace the gasket. If that is okay, I would suspect a manifold leak and want to pull, inspect and pressure test it.

View attachment CYLINDER HEAD AND ROCKER COVER.pdf
View attachment EXHAUST MANIFOLD AND EXHAUST ELBOW (ALUMINUM).pdf