Overheating...or not

[mstng]

Re: Overheating...or not

Will Do... Thanks Don

Would be lost without you guys. This could be my new hobby, I miss being able to work on autos as I did when I was younger.

On the 3 sides that had the plate covering the openings on the riser I was able to clear the holes that were plugged with a coat hanger and water is running through them fine now. I see that salt/rust as you said but I have loads of what appears to be a sand/oil mixture clogging things if that matters at all. We have a lot of sand here in Florida and easy to bottom out. Knowing the previous owner I'll bet that happened several times.

I ran a hose into the manifold and had to stick a coat hanger into the drain plug to move some black sand/oil to get it flowing and now it flows clear.

I'll keep at it, order some gaskets and post some picks before I reassemble. I am learning a lot here.

Thanks again

 

[mstng]

Re: Overheating...or not

I see that the manifold has a "core plug". Would I have more success using that to flush the manifold. Is it eeven possible?

 

[captmello]

Re: Overheating...or not

don't pull that plug, your on the right track now! Get the manifold cleaned out as best you can without removing it. Hose on the intake nipple like you're doing.

I miss being able to work on autos as I did when I was younger.

That's my problem too. I winterized three weeks ago and wish I could go work on it right now!!!!

Clean out the riser, Put it back together and your ready to flush with the saltwater flush kit. I hope it works out.

One other suggestion, you may want to pull the water drain plug on the bottom of the block. Poke in with a screwdriver. You probably have more of that sand and sludge sitting in the bottom of the block just waiting to make its way up into the riser.

Maybe Don could explain why there is a restictor plate. Seems like it restricts the sand from going straight through.

 

[mstng]

Re: Overheating...or not

Ok, I'll leave the plug alone. I forgot about the block.

Thanks

 

[Don S]

Re: Overheating...or not

Maybe Don could explain why there is a restictor plate. Seems like it restricts the sand from going straight through.

First of all, those passages are cooling passages, not places for sand to go. If you boat in sand, things get plugged up and you get overheats.
You can put water into the block with the block drain plug out and usually get most of it out. Same with the manifold and riser. Just pull the plugs and flush (Engine off) and keep probing the drain plug hole to get all the trash out.
The reason for the restrictor plate is to slow the water flow down so head from the manifold can actually transfer to the water. If all of them were open and no other restrictor in place the engine, manifolds and risers would get even hotter.
That's also the reason for the thermostat. When wide open it's still only a small opening compared to removing a thermostat. When you remove a thermostat, you only cool the engine around the stat hole where the water is actually moving. Without the restriction, the water doesn't flow as well in the back of the engine and it can overheat.
The water just has to stay in contact with the hot parts of the manifolds and risers just long enough to transfer the heat, then move on. To fast or too slow and you have an overheat.

 

[mstng]

Re: Overheating...or not

Thanks for the lessons guys...School never stops and I appreciate it very much. Thanks for including the science in all of this.

This is what I have ended up with. All water passages are finally cleared of the gunk. I got very little rust out of the center air passage although pic 7229 shows some pitting on the inner casing section that leads to the the exhaust hose. It doesn't yet penetrate. Hoping for the best, and if the riser becomes an inevitable replacement maybe I can save the manifold for a year or two. Waiting on the gaskets.

Thanks again

http://img185.imageshack.us/my.php?image=img7219rs5.jpg
http://img185.imageshack.us/my.php?image=img7220rv5.jpg
http://img241.imageshack.us/my.php?image=img7229hb6.jpg

 

[Don S]

Re: Overheating...or not

http://img185.imageshack.us/my.php?image=img7220rv5.jpg

That tells me the riser is JUNK. The sealing surfaces between the water passages and the exhaust passage are gone. If the manifold is even close to that, it's dead also.
Guess I was right the first time.

 

[captmello]

Re: Overheating...or not

That sucks.

Let us know how it goes.

 

[mstng]

Re: Overheating...or not

Not a good picture Don. It was taken at an angle. Resolution was lousy. I was showing the cleaning job...Didn't show it very well as it was taken at an angle.

All passages and metal look exactly symmetrical. Picture number 92 and 98 above is actually how the metal truly looks. My heart skipped a bit for a minute..

 

[captmello]

Re: Overheating...or not

All passages and metal look exactly symmetrical. Picture number 92 and 98 above is actually how the metal truly looks. My heart skipped a bit for a minute..

Not sure what your saying here...If any of the mating surfaces look like that, the part is junk.

Bondo pointed out the rust in the exhaust tube. That means water was getting into the exhaust and could be running into your cylinders, through the valves and into the combustion chamber and corroding the cylinder walls.

Document the job so we can all learn like you've so far. We'll help you along if needed. We might learn some more!!!

 

[mstng]

Re: Overheating...or not

Thanks for the response captmello.

What I meant was that if you look at those pictures from earlier, before I cleaned the riser you will see that the surfaces are the correct width and smooth. The latest pictures were deceiving. But not THAT deceiving as it caused me to take another look.

After Don's post and looking at it closer I noticed one side thinner than the other. Almost 30 percent thinner. That, coupled with the pitting and the missing of the small piece of metal on the tail end I decided to get a new riser. Thanks Don. It will be here Thursday.

The flushing of the manifold went well. I never really got much adverse materiel out of the stop ****, and was able to flush through the hose with the drain closed and get what was in the manifold out. Didn't seem like much at all. Maybe I (we) can save that. A new one may be in the future. I am holding to the comment I read about the manifold lasting longer than the riser. Could be fooling myself, and if I am I am sure Don will let me know

Any tips on installing this riser with regards to gasket, torque etc.? What do I need to be careful about?. I think the last time I used a gasket was for a carb rebuild 30 years ago...

Thanks very much for the help fellows. I would be lost without it.

 

[mstng]

Re: Overheating...or not

Wishful thinking and denial on my part. Went out and took a real good look at the manifold and it will need to be replaced as Don said.

It flushed fine yesterday, drain showed clear water, and water flowing through all 4 ports. After yesterdays shock at the condition of the riser had worn off, today I decided to take a good look at the manifold. I looked down in the water ports with a flashlight and found a large amount of gunk coalesced into a rock hard substance primarily in the unrestricted port with small amounts in the other 3 ports that were restricted by the plate.

Guess I have a busy weekend.

 

[a70eliminator]

Re: Overheating...or not

Chase the threads with the correct size tap, throw the old bolts away and use new ones, use never sieze on bolts. I don't have a manual so I can't comment on torque values.

 

[mstng]

Re: Overheating...or not

Could someone please take a look at this diagram and let me know what parts I need?

http://www.volvopentastore.com/Inta...6352441--**********.362787966--view_id.313910

Would it be just number 1 and 9?

Thanks

 

[Don S]

Re: Overheating...or not

That should do it for the manifold. The oem ones do come with new plugs, Don't remember if the elbow fitting came with it or not, but you still have the old one.
I would also have a look at your exhaust hose (#21) and make sure the inside hasn't been burned from lack of water.
Sure am glad you decided to double check, cause I know what I was seeing in those pictures was not what a good riser looks like.

 

[mstng]

Re: Overheating...or not

Glad I checked also. Thanks for hitting me over the head....


The riser seems like a piece of cake and I'll have both available shop manuals by Tuesday. Is this manifold replacement doable for a novice?

 

[Don S]

Re: Overheating...or not

My wife is a "Novice" . If she had access to all the tools I have, and all the manuals I have, she couldn't do it. So how can anyone but you answer that question. Read the manual, look at what you have to do, look at your tools, and think about your abilities. Can you do it?????????

 

[captmello]

Re: Overheating...or not

Wow, thats a cool manifold. Combo intake and exhaust. Doesn't look to tough. Mostly bolts and nuts etc. You can handle this one!!

I find with a job like this, its best to do it all at one time, keeps things fresh in the mind. read up and understand what the manual says about the job. All the specs should be in there. Don't get ahead of yourself. You may want to wait til your sure you've got all the parts so the job doesn't sit half done.

Take your time. Half day job I'll bet. Spend the other half flushing out the block with some of that Saltwater cleaner. If you get stuck you know where to go for help.

 

[mstng]

Re: Overheating...or not

Didn't want to leave you guys hanging without a question of the day. The riser is underway from iboats and should have it soon. Someone mentioned how screwed up Volvo is regarding part numbers and it seems to be true. I can get the OEM but this sierra one has all I need along with it. Could any of you verify if this OMC is the same?

http://www.iboats.com/Sierra_18_190...****.687770773--view_id.221953--viewcart.long

Here is the OEM...Lousy Pic

http://www.volvopentastore.com/Inta...6438924--**********.195753406--view_id.313910

And a pic of the OEM from ebay...They look exact

http://cgi.ebay.com/ebaymotors/_Boat-Parts-Accessories-Gear__Volvo-OMC-Exhaust-Manifold-3-0-4-Cyl-Holley-Carb_W0QQitemZ230306884001QQadiZ2823QQadnZBoatQ20PartsQ2cQ20AccessoriesQ20Q26Q20GearQQcmdZViewItemQQptZBoat_Parts_Accessories_Gear?hash=item230306884001&_trksid=p4506.c0.m245&_trkparms=72%3A543|65%3A12|39%3A1|240%3A1318

 

[Don S]

Re: Overheating...or not

If you run the OEM part number 3858870 in the Sierra part number interchange, you will find out that it does not have anything for that number.

If you are planning on keeping this boat for a few years, I would strongly suggest you stick with OEM parts.