The intake manifold wont come off?

[SharpeCon]

I have a mercrusier 4.3L V6 1989, I am trying to remove the intake manifold to get at the head gasket. I removed all bolts and have been prying and hammering & it just wont come off? How do I get it off? Please help! Thanks

 

[gadget73]

Re: The intake manifold wont come off?

Double check to make sure all bolts are out. You might also want to remove the distributor if you haven't already. If they are, drive a putty knife under the front edge of the intake, under where the thermostat sits. That should seperate the manifold from the block. Once that pops loose, you can pry each end up and remove it. Try to not gouge up the machined surfaces of the block and intake if possible. It should be just RTV in there, but its possible there is a cork gasket that you'll have to drive the knife through.

 

[SharpeCon]

Re: The intake manifold wont come off?

Thanks for the idea! I used a chisel & hammered it in there to get it off, now, I have water in my oil and I am a bit confused on where the head gasket is? is it the rubber gasket where the intake manifold attaches?

 

[fishingdan]

Re: The intake manifold wont come off?

The head gasket is between the cylinder head and the block on each bank of cylinders (ie you have two head gaskets on that engine). You have to remove the cylinder head to get to the head gasket.

It is not a small job.

 

[Don S]

Re: The intake manifold wont come off?

If you don't know where or what a head gasket is, you REALLY REALLY shouldn't be messing with it at all.
IF, you had an OEM service manual and knew anything about engines, you might stand a chance.

PS: There is a 99.99% chance that the head gasket is NOT the reason for water in your oil.

 

[jze1212]

Re: The intake manifold wont come off?

I'm with Don S on this, also be sure you did not damage the distributor while prying the manifold while it was still installed.. I'm all about DIY but you may want to start with the basics

 

[P 0 P E Y E]

Re: The intake manifold wont come off?

Danger....will Robinson the robot used to say.

If you have water in the oil and feel like taking manifolds off, you should start by checking to see if you have a bad exhaust manifold by checking for water in the combustion chambers....perform some tests before disassembly.

In other words, don't take the engine apart before performing some troubleshooting while the engine is assembled and in it's fail mode.

 

[fabrimacator21]

Re: The intake manifold wont come off?

Hammer and chisel to get an intake off? I'd be worried about scarring up the surfaces. I agree with the others... If you don't know what a head gasket is then LEAVE IT ALONE and get someone who has some more knowledge to do it.

That is if the head gasket is the problem.... could have sucked water up through the exhast or your intake manifold may be leaking water.

 

[ENSIGN]

Re: The intake manifold wont come off?

If you don't know where or what a head gasket is, you REALLY REALLY shouldn't be messing with it at all.
IF, you had an OEM service manual and knew anything about engines, you might stand a chance.

PS: There is a 99.99% chance that the head gasket is NOT the reason for water in your oil.

Thanks Don

 

[ryendube]

Re: The intake manifold wont come off?

you should of recorded your technique of the removal of intake for instructional purposes.








sorry but seriously.......

 

[SharpeCon]

Re: The intake manifold wont come off?

Ok, to my defense, I have already replaced the water impeller which I had to remove and disassemble the lower unit, I replaced the starter, the fuel pump, the water tempature sending unit, fuel filters, oil, and a few other minor things, so I'm not a complete amatuer. I can fix most things with a manual and not afraid to try. I read on mercruisers website that water in the oil is likey the intake manifold, cracked blaock or head gasket. or risers. So I started with the intake manifold, I have a clymers manual and following step by step. I have never changed a head gasket, car or boat, so it's just the fact of not knowing excatly what is where. I have had a host of marine mechanic tell me it's probably the head gasket or a cracked block, I intend to find out, one way or another, but I refuse to pay a 100 bucks an hour for someone to tell me, I find myself to be somewhat mechanically inclined so.. & 99.99% on it not being the head gasket? I think thats a bit of a exageration in IMHO. The previous owner overheated it many times. I like to work on engines, the inboard is a whole other can of worms, plus I want to learn my engine, inside and out, so I can fix something when needed. The intake manifold looks nasty, so does the gasket, looks like heat damage. I can research how to do this properly or I could get advice and help from some exp0erts on here, that is why I came on these forums. Thanks

 

[mkast]

Re: The intake manifold wont come off?

http://forums.iboats.com/showthread.php?t=288430

Look in here.

 

[ryendube]

Re: The intake manifold wont come off?

Ok, to my defense, I have already replaced the water impeller which I had to remove and disassemble the lower unit, I replaced the starter, the fuel pump, the water tempature sending unit, fuel filters, oil, and a few other minor things, so I'm not a complete amatuer. I can fix most things with a manual and not afraid to try. I read on mercruisers website that water in the oil is likey the intake manifold, cracked blaock or head gasket. or risers. So I started with the intake manifold, I have a clymers manual and following step by step. I have never changed a head gasket, car or boat, so it's just the fact of not knowing excatly what is where. I have had a host of marine mechanic tell me it's probably the head gasket or a cracked block, I intend to find out, one way or another, but I refuse to pay a 100 bucks an hour for someone to tell me, I find myself to be somewhat mechanically inclined so.. & 99.99% on it not being the head gasket? I think thats a bit of a exageration in IMHO. The previous owner overheated it many times. I like to work on engines, the inboard is a whole other can of worms, plus I want to learn my engine, inside and out, so I can fix something when needed. The intake manifold looks nasty, so does the gasket, looks like heat damage. I can research how to do this properly or I could get advice and help from some exp0erts on here, that is why I came on these forums. Thanks

i apologize for my comment but seriously, you say you have a manual but dont know what a head gasket is? obviosly you have jumped into the job without so much as openiong the manual. You realize the posters above are being helpfull by preventing you from completely screwing the pooch on this job.

chances of the head gasket being the culprit leaking water into your oil is slim. Regardless before you tear apart something A you need to familiarize yourself with how it works. B diagnose the problem

its good that youve done some minor tune up parts and bolted a couple accessories on but tearing apart a motor is a lil more involved. chisel and hammer? how do you expect to make a seal once reassembling?

 

[SharpeCon]

Re: The intake manifold wont come off?

I never said I didnt know WHAT a head gasket was. I wasnt excatly sure how to get at it. I have already disassembled elbows and risers, inspecting for cracks or damage. I removed the exhaust manifold and inspected it. I was advised to use a putty knife to remove the intake, granted it is skinnier than a chisel, My chisel was sharp and it did not do any damage that I can see with my eyes. That wont be a problem. It's clear there was alot of heat damage to this engine, paint is chipped off, the temp sending unit didnt work, the previous owner stated it over heated alot. Does that not cause a gasket to crack? I did just look in my manual on how to remove valve covers and heads & gaskets, So I will do that next. It's not like im just ripping things off & being careless here. I am careful when removing parts. Putting all parts that go together in seperate spots, and remembering where things go back on. Also, you say it slim its not the gasket, but you havnt stated why? Please elaborate?

 

[SharpeCon]

Re: The intake manifold wont come off?

Ok so if I already have removed things, when I SHOULD have done some tests first, what is the answer now? Put everything back and test? Or continue searching for the source of the oil in the water?

 

[ryendube]

Re: The intake manifold wont come off?

Thanks for the idea! I used a chisel & hammered it in there to get it off, now, I have water in my oil and I am a bit confused on where the head gasket is? is it the rubber gasket where the intake manifold attaches?

1 if you dont know how to get at it you dont know what it is.

it could very well be the head gasket but there are other failures that can cause it. through diagnosing before tear down you could of pinpointed it. Intake gasket more likely.

compression test would of diagnosed head gasket failuer

now that you have torn it aprt, might as well tear the heads off and check it out. (oh the head gasket is between the heads and the block) please dont use a chisel and hammer to remove.

head gasket failure can cause water leakage into oil, caswell as the sylinders.

reworded it not that a head gasket wouldnt cause it i mean that it is the head gasket other failures are more likely

 

[ryendube]

Re: The intake manifold wont come off?

I never said I didnt know WHAT a head gasket was. I wasnt excatly sure how to get at it. I have already disassembled elbows and risers, inspecting for cracks or damage. I removed the exhaust manifold and inspected it. I was advised to use a putty knife to remove the intake, granted it is skinnier than a chisel, My chisel was sharp and it did not do any damage that I can see with my eyes. That wont be a problem. It's clear there was alot of heat damage to this engine, paint is chipped off, the temp sending unit didnt work, the previous owner stated it over heated alot. Does that not cause a gasket to crack? I did just look in my manual on how to remove valve covers and heads & gaskets, So I will do that next. It's not like im just ripping things off & being careless here. I am careful when removing parts. Putting all parts that go together in seperate spots, and remembering where things go back on. Also, you say it slim its not the gasket, but you havnt stated why? Please elaborate?

sorry was posting as you wrote this I you say it over heated ALOT? gaskets fail blocks and heads crack warp,especially from over heating. You may have a whole lotta more than a gaskt problem

aswell how long has the water been getting in the oil?

 

[NoKlu]

Re: The intake manifold wont come off?

At this point I would remove the intake and heads and send them to a shop and have them completely checked and worked over. If you are using a generic manual they are not as detailed as the merc manual and it might be worth investing in the better manual. Because the engine has been overheated a few times the gaskets are probably burnt up and are holding things together a little more than usual. Check to make sure you have all of the bolts out of the intake manifold. Using a putty knife or better, a pry bar that looks like a large screwdriver with a wide blade on it work your way around the intake to loosen it up. You need something that will go between the intake and block on the ends where the rubber gasket is used and there is the most room between the 2 pieces. A chisel is the wrong tool. If you got all of the bolts out it will come apart. While the parts are in the machine shop clean all the surfaces and check carefully for any cracks in the block. Have the exhaust manifolds checked by an expert as well. With the proper manual it can be done correctly. The first time I removed a head I never had any help except the correct service manual for the car I was working on and it ran for years after with out any problems.

 

[SharpeCon]

Re: The intake manifold wont come off?

i did get the intake off, it is all milky in there. Hard to say if the intake gasket is junk, because it is all tore up from taking the intake off, it was bonded on there, proably from the heat, thanks for the advice! I suppose there is many ways water is getting in. I'm just hoping and have a feeling its not a cracked block, just a hunch

 

[fabrimacator21]

Re: The intake manifold wont come off?

First off you should never need a hammer and anything to get the intake off and if you feel you do then stick a piece of wood on the lip and smack the chit out of it... that should break the seal from the gaskets. Also I like to pull the water inlet out and yank up on it from the inlet hole. I know you already got the intake off but for future reference.


Second, the rubber gaskets at the front and rear of the manifold are complete junk and will leak. When you put it back on, use a thick bead of black rtv in place of the rubber gaskets. Since intake gaskets are 20 bucks I wouldn't touch the heads. You need to do a compression test as others have said and that'll tell you whether your head gaskets are blown or not.

You are probably right about the head gaskets if its chronically overheating.. But a compression test is a much easier way to go then yanking the heads.