79' Formula Thunderbird Overheating Questions (On Topic Thread)

[illtww]

THe Formula is running!! (Sorta..)

Stats:
Chevy 350 Motor
Quadra-Jet Crab (Needs Work)
888 Outdrive... (Local mechanic told me this..) Serial # 5354441

Here is a recap:

It only over heats when we have the outdrive is trimmed down and we go over 2000rpm. The temp comes right back down.

We we first put the boat in the water and ran it.. It dint overheat. But after about 5 minutes of cruising it instantly overheated. (10 seconds..)

Local mechanic familiar with the boat thinks it is a Exhaust restriction that is
causing it to overheat.... He was suggesting running transom exhaust to alleviate the possible exhaust restriction but I am not wanting to deal with all the exhaust noise.

The hose theory makes sense...
Does anyone have a parts break out chart for this hose?

So in Recap here are my 2 possible problems/solutions.....

1. Water hose in outdrive being kinked...
2. Exhaust not exiting fast enough at rpm's above 2000...

 

[HT32BSX115]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

Howdy,

I don't see anywhere that you replaced the raw water pump, and ensured that you located the remnant of any previous impeller failure.

Since that's a V-8, and you probably have power steering and an oil cooler, Have you inspected the raw water hose from the transom to the thermostat housing? The PS/oil coolers are usually in the cold water line and may have pieces of the impeller clogging them.

Also, it is possible that you have blockage (due to rust) in the cooling water EXIT points.... (I.E. manifolds/risers)

When the engine overheats at idle but is ok at above idle rpms, it's frequently a failed or damaged raw pump.

If they overheat at rpms above idle or at high power settings it's frequently low raw water flow due to blockage someplace downstream of the raw pump or blockage at the raw water intake....

If you don't have a service manual go up to the "Adults Only" sticky...

You can get a down-loadable manual there that will have a good troubleshooting section that includes things to check for overheating.


Cheers,


Rick

 

[illtww]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

HT32BSX115

I know the impeller failed on it a few years ago so there may be rubber pieces floating around in the system still... What is the best way to clean these pieces out?

Also,
Could the hose that brings the water up form the raw water pump getting pinched causing the flow to be restricted when the boat is trimmed down and running at higer rpms? MikeD suggested this as another problem.

Here is a pic of the outdrive:
http://i42.tinypic.com/2w3p6v8.jpg

 

[HT32BSX115]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

Whew!


Please resize your picture. It'll make a LOT easier for people to see the thread.

If you don't have a picture editor, Go to http://gimp.org/ for an outstanding (free) photo editor!
Scroll to the bottom of the page for the windows version (I assume you're using MS Winblows XP)


It's hard to say from the picture...

The pieces could range from too big to fit in the hose to small enough to go all the way to the t-stat and even into the block and heads. (if there's no oil cooler in the way)

Mine had impeller parts (all the vanes) crammed in the oil cooler inlet from a previous failure. The previous owner told me that he changed the impeller. I believe him. But he didn't say that he didn't locate all the pieces from the previous failure.


Luckily none of the pieces could get thru the little holes in the oil cooler.


You'll just have to fish thru the hose with a piece of wire.

Check the oil cooler (if installed) and the t-stat housing too.


Cheers,


Rick

 

[illtww]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

I do not believe it has a Oil Cooler.... (What does one of those look like?)

 

[HT32BSX115]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

There's several types.....here's a link with a few of them..

http://www.psepmarineparts.biz/store/mercruiser_oil_coolers.htm

 

[illtww]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

Does my water picku tube look like this?

THIS is from an alpha 1 gen 1

 

[MikDee]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

To check the raw water hose on the outside, turn your drive (or steering wheel) all the way to the right, go to the back of the boat look behind, and underneath the leg, at the transom plate for a 1 1/4" O.D. hose going into the boat. It comes up from the drive, then bends to go into the transom plate, inside the boat, another hose continues from there to the engine water circulation pump on the front of the engine,,, in between, you may find a power steering cooler. I think your boat is too old to have an oil cooler.

You may have to, raise the drive with the trim switch, to get a good look underneath.

This will just give you a look at the outside of the hose, and check the bend to see if it's kinked, if all looks ok here, you must check for an obstruction in the hose, then the thermostat, and the hoses coming off the thermostat housing, and finally the manifolds, & risers.

This is all assuming your water pump impeller in the leg is good, as you mentioned.

 

[ziggy]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

Stats:
Chevy 350 Motor
Quadra-Jet Crab (Needs Work)
888 Outdrive... (Local mechanic told me this..)

could be i suppose, but the way i get it is a 898 drive goes with a chevy 350, a 888 goes with a ford 302. no idea if they can be mismatched. both are 1 drives.

Local mechanic familiar with the boat thinks it is a Exhaust restriction that is
causing it to overheat.... He was suggesting running transom exhaust to alleviate the possible exhaust restriction

that seems kinda overkill to me. there are other reasons to have an overheat too. exhaust restriction is one, but if that ain't it, it'll still overheat with the thruhulls.

Does anyone have a parts break out chart for this hose?

the service manual does. has flow charts with all the pieces that the water flows through.

1. Water hose in outdrive being kinked...
2. Exhaust not exiting fast enough at rpm's above 2000...

yes, a water hose kink can cause over heat. you really do need to size that pic down. also, take a pic from the other side. the port side even. a kinked water hose may look like this..

that was restricting flow for me for sure. high rpm and it'd head towards overheat, but never in the red. lowering rpms would bring the temp down.

Does my water picku tube look like this?

yes, that's a water pocket cover + the water tube (a piece of copper pipe). if your considering replaceing that waterpocket cover. be REAL CAREFULL. the 4 ss bolts that hold the cover on will snap right off. then you'll be hosed for sure.
the way i got some of the broken impeller pieces out of my drive was to have the lower off the drive. then disconnect the water feed hose that goes up to the tstat. at the manifold or where ever it connects to on you rig. then flush water ft to back and back to ft. repeatedly till there's no impeller pieces coming out. impeller pieces can be trapped at the tstat like said before. reason i know the water pocket cover screws will break off is that while i was flushing my pieces out of the system. i noted water leaking at the gasket of the waterpocket cover. this leak can also cause over heat. but i assure you. DON'T BREAK THEM BOLTS OFF. you'll be sorry.

other possibilities of over heat can be flappers melted off and are trapped in you exhaust pipe. tstat. impeller pieces trapped in water passages in the block (i've no idea how you cure that) manifolds and/;or risers plugged with rust scale.

the place to start is the impeller in the lower. work fwd. from there...

 

[MikDee]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

Thorough & Well Done Ziggy!

 

[illtww]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

Someone talk me out of it....

I want to buy a new SEI-106 Outdrive for the boat.

That way i have piece of mind for at least 3 years and I dont have to spend tons of hours r&r my old type 1 drive...

 

[illtww]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

other possibilities of over heat can be flappers melted off and are trapped in you exhaust pipe. tstat. impeller pieces trapped in water passages in the block (i've no idea how you cure that) manifolds and/;or risers plugged with rust scale.

the place to start is the impeller in the lower. work fwd. from there...

Where are these "flappers" in the exhaust? Are they rubber or something?

Zigg: the thermostat is brand new. We had the heads and intake off the boat and was all gone through and cleaned. HAs to be in the outdrive..

 

[MikDee]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

Someone talk me out of it....

I want to buy a new SEI-106 Outdrive for the boat.

That way i have piece of mind for at least 3 years and I dont have to spend tons of hours r&r my old type 1 drive...

There's nothing wrong with a Type 1 Drive, if it's working the way it should, they are quite sturdy, don't waste your money! Overheating is usually not caused by the drive, it is commonly found somewhere in the water circulation system, old manifold, riser, or their wrong, or worn out gasket issues.

 

[illtww]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

i hear ya...

Can you or some one help me locate and buy the parts needed to revive my old drive?

I want to put a wholne new Impeller kit (even though it was replace a lil while back) A new gimball bearing vus it is making all kinds of racket and i guess a new water hose.

Want to work on it next week and get it going.

Im a lil confused on what all EXACT parts I need for my outdrive to revive it.

 

[ziggy]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

Im a lil confused on what all EXACT parts I need for my outdrive to revive it.

1st and most important tool in your tool box will be the service manual. it has the exact procedures for repair in it. read it. and read it carefully. i personally find that i can read it over and over and the next time i read it i'll find something i missed that was important info in 1 sentence i skipped over or didn't comprehend.
there are many places to get parts. your local mercruiser dealer comes to mind. you will need to id your drive by serail number. that way you'll know what your working on. not what someone thinks your working on. here's a couple a sites that will be helpfull.
http://www.dougrussell.com/
http://bammarine.com/
that's just a couple of them, there's gobs of them out there. personally, i like to use oem parts if i can afford them. they always work. aftermarket parts are available too, but may not fit exactly and may need modification to get them to work proper. many places that have them. iboats being one of course.

as for the exact parts you need. i've found it best to disassemble to find out what you need. every time i try to order what i think i need. i end up with parts i don't need or i need more parts than i thought. you need to inspect the parts in question, then decide what you need.

when i revived my 1 drive. best i can remember my parts list was..

drive shaft bellows, and bellows glue
shift cable & shift cable bellows
water hose
impeller and waterpump housing
very bottom seal in the upper
drive gear yoke
ft seal for the drive
drive gear brg. set
shift shaft
shift shaft seal, new style
shift shaft lever
gimble brg.
ujoints
there were misc. tools that i didn't have that needed to be acquired prior to doing the work (some i bought, some i rented, some i borrowed). things that come to mind are gimble brg. driver, large slam hammer to remove the gimble brg. large snap ring pliers, ujoint press, multiple torque wrenches, mercruiser shim tool for shimming the drive and driven gear on the upper. + regular mech. hand tools.

also you'll need various lubs. mercruiser 2-4-c, mercrusier spline grease, mercruiser gimble brg and ujoint grease, mercrusier hp gear lub. water proof grease are the ones that come to my mind right now.

for me, being a shade tree mech. this job took me a while to do. including doing the water hose 2 times since i didn't get it right the first time. which is not a fun job to do btw.

your parts list may look different than mine. these were just the items that were in question on my drive.

fwiw. in my case. i ended up around $800 (the yoke and brgs were a dollar killer for me) + lots of labor and lots of question here on iboat fourm. if i had to do it over again. i might consider doing the sei thing. only thing i'll say about doing the repair is that you'll get very intimate with your drive and you'll learn a lot... also, for me, i wanted a mercrusier drive to go with my all American made aristocraft. it just wouldn't be the same boat if i started putting on aftermarket parts imho..

oh, i don't know where your flappers are at (yes there rubber and generally melt off with a overheat). mine is right at the top of the exhaust pipe. i don't have a v8 though. suspicion is that they're in a similar place. bet if you go to the service manual it will tell you right where to look for your engine though...

 

[illtww]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

yea..

I can get a new one with cashback for 1000 shippped.... Prb just need to do that...

I do need to replace my gimbal bearing though....

What is the part # for the complete Gimbal bearing rebuild kit?

 

[illtww]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

Got the outdrive. (3 year warranty) A gimbal Baring kit new annodes for ~1100 out the door....

Wish me luck! Pics to follow. (Smaller ones this time!)

 

[MikDee]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

yea..

I can get a new one with cashback for 1000 shippped.... Prb just need to do that...

I do need to replace my gimbal bearing though....

What is the part # for the complete Gimbal bearing rebuild kit?

IMO, replacing the drive, unless it's shot, is a waste of money. Nothing usually goes wrong with an outdrive unless it leaks, and you run it without oil, Or, water gets in it from a bad seal (rarely) this will scald the gears.

The problems you may have is not with the drive usually, it is usually everything But! The items that are a permanent part of the boat, under the bell housing are sometimes the issue, like the Gimbal bearing, or the shift cable wearing out, or the 3 bellows drying out, and or cracking, or the raw water hose getting kinked.

You will have to check all these to see that they are not worn out, or don't leak anyway, if you take the drive off.

This is like replacing a Good rear end in a car just because it's old

 

[illtww]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

Mikedee I completely understand where you are coming form..

Although I do not believe a "REAR-END" is an equivalent car comparison

A transmission is a more fair comparison..

Maybe the prop = the rear end on car?

I know for a fact the boat has hit multiple logs and been run up on land about 2 or 3 times... (kids owned it before)

I now have a 3 year warranty on the outdrive.

I have a motor with less than 40 hours on it. A completely rebuilt topend with 1 hours on it and a brand new outdrive with 0 hours on it. (Have all the receipts to support it.)

I will be painting it and recovering the seats in it. Also have a ski rack to go in it.

Im siked!

Pics to follow!

 

[MikDee]

Re: 79' Formula Thunderbird Overheating Questions (On Topic Thread)

Wow! Knowing all the history now, Good For You Man!