Engine overheat and water in the oil this weekend.

I de-winterized my 2000 Chaparral 5.7 Volvo Penta GL friday and went to Canyon lake. After about half a day of cruising around we we on plane about 35mph when my wife started yelling that something was wrong. I immediately stopped and shut off the engine.

As soon as I stopped I could see smoke and smell burning oil, that's when I looked down and noticed the temp gauge was pegged. I turned on the blower and cleared the engine well of smoke and let it cool for awhile.

After about 10 minutes I opened the engine cowl, got some tools and started trying to figure out what happened.

The raw water pump was extremely hot to the touch, I left it alone to cool awhile. The recirc pump was extremely hot, recirc coolant hose was really hot and definitely under pressure, grey oil smelling smoke was pouring out of the valve cover breather, so I gave it an hour to cool before doing anything else. After it cooled a bit I restarted the engine, it took a few cranks, its usually easy to start, and started heading in. After about 1/4 mile, the temp needle started toward the red again so I shut it down.

After it had cooled again I took the front plate off the raw water pump, it was my first suspect. It looked fine, impeller still looked new. I jumped overboard and and checked the drive unit, no blockages or garbage bags or anything else blocking the intake ports. At that point I thought either the recirc pump was bad or the thermostat was bad so I got towed in and went home.

Next day at home I pulled the recirc pump and checked it, perfect condition nothing wrong there. Next I took the thermostat off and tested it in the kitchen with a pot of water and a thermometer. It started opening at 165 and was fully open at boiling temp. No prob there.

So I decide its gotta be a blown head gasket and pull the heads. I noticed when I removed the intake that the center bolts werent very tight, maybe 5-6 ft lbs at the most. I pull the intake and heads and the head gaskets are also in good shape, no signs of a blown head gasket. Once I got the intake off it was obvious that a lot of water had got into the crankcase, full of chocolate milk colored gel. So at this point I'm thinking cracked heads or block, but then it wouldn't have run half a day before ****ting the bed. The #8 cylinder shows seizure indications the other 7 are fine.

What else can I check?

Re: Engine overheat and water in the oil this weekend.

Cracked block. very common this time of year. Look in the lifter valley behind the push rods, that's where the cracks are normally found.

http://forums.iboats.com/mercruiser-i-o-inboard-engines-outdrives/water-your-oil-369864.html

Re: Engine overheat and water in the oil this weekend.

Loose intake bolts *could* allow some water to go places that it should not . . . I am surprised that you did not run a compression test and/or cylinder leak test prior to ripping the engine apart.

Anyway, like Don said, time to start looking for cracks.

Re: Engine overheat and water in the oil this weekend.

tpenfield said:

Loose intake bolts *could* allow some water to go places that it should not . . . I am surprised that you did not run a compression test and/or cylinder leak test prior to ripping the engine apart.

Anyway, like Don said, time to start looking for cracks.

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I have been planning a rebuild sometime this year anyway and didn't do a compression test since i going to bore and replace the pistons anyway. The short block came out of an 88 iroc camaro several years ago. It had 200,000 miles on it when I installed it.

I would gave considered a cracked block or heads earlier but it ran half the day perfectly. I,all inspect the block more thoroughly where son indicated when I get home from work.

How bad would it suck to rebuild and install a cracked block. Hopefully the machine shop would catch that when the bore and clean it.

Re: Engine overheat and water in the oil this weekend.

Loose intake could be because of the overheat, not so much the cause of the overheat.
Might also check the inside the engine side of the intake manifold under the thermostat. See if you have any holes or cracks.

Re: Engine overheat and water in the oil this weekend.

Don S said:

Cracked block. very common this time of year. Look in the lifter valley behind the push rods, that's where the cracks are normally found.

http://forums.iboats.com/mercruiser-i-o-inboard-engines-outdrives/water-your-oil-369864.html

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I'm not sure how but Don't was on the money. Tiny little hairline crack above the lifters, couldn't tell it was a crack at first. It looked like a dark stain until I wire brushed it , then could see a Razer thin hairline crack beside cylinder 8. Not sure how it cracked, I had all the drain cocks out an I live in Tucson. It might have just touched the freezing point once or twice this winter for a couple hours overnight.

Re: Engine overheat and water in the oil this weekend.

Taking the plugs out doesn't do much if the hole is blocked. When you remove a drain, always probe the hole with a nail, small screwdrive, screw or something to make sure the hole isn't plugged. If it is plugged up, it can crack the block, and it only takes one time at cold enough temps, and you obviously had that.

Re: Engine overheat and water in the oil this weekend.

Don S said:

Taking the plugs out doesn't do much if the hole is blocked. When you remove a drain, always probe the hole with a nail, small screwdrive, screw or something to make sure the hole isn't plugged. If it is plugged up, it can crack the block, and it only takes one time at cold enough temps, and you obviously had that.

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No doubt about that, its such a tiny crack too. Thanks for the help, I probably wouldn't have found that crack if you hadn't told me where to look

Re: Engine overheat and water in the oil this weekend.

I figured it would be a small crack, the bigger ones fill the crankcase full of water in 20 to 30 minutes. You got half a day.

Re: Engine overheat and water in the oil this weekend.

I've got the engine stripped apart now, deciding which parts to use in the rebuild and which to discard. I'm having a little trouble identifying the camshaft and was thinking someone here may be able to help. Its definitely an aftermarket cam, hydraulic roller for factory SBC roller block 87+, nose of the cam under the sprocket is marked as follows:

V8038
280-10
3108
HR13
E

these markings look to all have been made by hand with some kind of electric etching device. It also has two yellow dots on the front of the cam marked in paint.

On the tail end of the cam, "NY" Looks like it was stamped.

No other markings. I spoke with Comp Cams on the phone, they said that if they had made it there would be a CC stamp on the nose, but no such mark exists. The cam works well enough, the boat is a 2000 20ft chaparral and tops out at about 55mph. Had a fairly smooth idle and in 2 1/2 years of all year round use I never notice had any water reversion issues that i'm aware of.

Re: Engine overheat and water in the oil this weekend. Replaced engine. Pics!

Re: Engine overheat and water in the oil this weekend. Replaced engine. Pics!

I ended up scrapping the engine on this, the crank was scored pretty bad on two main journals, one of the sparke plugs had completely melted the electrode and the piston had some odd looking blisters. Only the cam, rods and bolt ons such as intake, exhaust, accessory pumps, sensors, etc were still good.

I decided to just start from scratch and got a 350 4 bolt block, Scat balanced 383 stroker rotating kit with forged probe pistons, pro-comp forged rods, Scat 3.75 crank, and a set of vortec heads and intake. I took all the accessories from my old engine over to the new long block. I'll be putting the new engine back in the boat this weekend.

My previous engine had an edelbrock air gap aluminum intake which held up surprisingly well considering its been in salt water about a dozen times and fresh water lots more. When I saw how well it held up, i ordered the same intake but comfigured for the vortec heads and also with a factory powdercoat to add a little corrosion resistance.

Hopefully it starts up easy this weekend and don't give me any guff, its my first 383 stroker build.

I did finally id the cam, kinda. The specs i uncovered are as follows: Its a custom grind from Comp, The V8038 is the serial number, the intake lobe is the 280-10 profile and the exhaust lobe is the 3108 profile. I measured the lift and duration myself as best as i could using some measuring tool from my old lathe.

The intake lobe has .511 lift with 1.5 rockers and 220 degrees duration, I started measuring duration in degrees of rotation when I got to .050 lift at the valve and stopped when it got back to .050.

The exhaust lobe was .498 lift, 215 degrees duration. The H113 means it was ground on a 113 lobe center blank according to comp cams. I've been running this cam for 2 1/2 years in my old engine and havn't ever notice any water reversion issues, so im going to keep running it in the 383 stroker and see how it goes.

I kept my K&N flame arrestor from the old engine as well, i just bead blasted it, painted it black and added a decal thats supposed to be good for at least 10hp to go with my new valve covers.

I'll still be running my 620cfm Carter AFB. This carb has been absolutely flawless in the past.









I really really wanted to start it in the garage, but my wife absolutely forbade it. She vividly remembers the day i started my Triumph Speed Triple engine on a stand with no headers and wants nothing to do with it.

The new Vortec heads are aftermarket Patriot brand with 185cc intake runners and 64cc combustion chambers. Combined with the 22cc dished probe forged pistons, the compression ratio shoud be 9.3:1.

Any guesses where I should be with horsepower and torque with this setup?

The last engine was an L98 longblock from an 88 Iroc, under the same edelbrock air gap/Carter AFB combo. I'm hoping this new setup will get the boat on plane a second or so quicker

Re: Engine overheat and water in the oil this weekend.

Wow. you've been busy. I like the Pics. Do you have the exhaust manifolds from the previous engine?

Re: Engine overheat and water in the oil this weekend. Replaced engine. Pics!

Re: Engine overheat and water in the oil this weekend. Replaced engine. Pics!

great job on this engine !

ken226 said:

Any guesses where I should be with horsepower and torque with this setup?

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hard to say, manufacturers mostly keep torque as a secret in marine applications , i nevertheless found a homepage of GM publishing the power and torque curves for their marine blocks.

a 5.7 marine vortec ( but with fuel injection ) is stated at 292 hp at 4800 and 360 lb-ft at 3200

PDF

in your case its hard to say, it mainly depends how your cams work in a marine setup . marine cams are optimized for good midrange torque for the cost of reving capability , your setup may end in a higher topend but a slightly weaker midrange.

my best quess for your carbed 6.2 is you will get similar numbers to the fuel injected 5.7 vortec - but nobody can say until you dyno it !

but whatever numbers you get - this engine is sure a lot of fun in boating !

Re: Engine overheat and water in the oil this weekend.

I was just thinking..so your '00 boat is now on its THIRD engine? hot damn! You beat the **** out of that thing eh? Rode hard put away wet!

Re: Engine overheat and water in the oil this weekend.

Yes, i'll be swapping over the manifolds from the previous engine. I sit them upright, closed the drains and elevated the hoses and filled them with water. I let them sit overnight and checked the water level in the morning to make sure they weren't leaking. Being on the same engine that froze and cracked the block, I wanted to be certain.

Yea, this is its third engine. The worst part is that none of the previous engines were worn out, all were cracked due to bad winterizing. The first engine was a previous owner though, I only screwed up one .

This is freaking Tucson Arizona for Christ sake, it gets down to 30ish degrees once or twice all year, and only for a couple hours. I use the boat all year, even through the winter, and I always leave the block and manifold drains open when its on the trailer, I never expected it to freeze hard enough to crack the block.

My plan this winter is put a lamp in the engine compartment to add a little heat, circulated antifreeze through the block, then open and leave open the drain cocks.

Re: Engine overheat and water in the oil this weekend.

ken226;4221054 My plan this winter is put a lamp in the engine compartment to add a little heat said:

when you open the drains and verified the water really flushed out ( look for a clogged drain ) you do not need a lamp for heat. air cannot freeze and expand.

be careful with your manifolds. if they were subject to freezing temperatures and full of water you may have small cracks which will only open when the manifold heats up during running and you do not see anything during your checking method.

if budget permits i would invest in new manifolds for this great engine or at least pressure check the old ones.

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Re: Engine overheat and water in the oil this weekend.

aerobat said:

if budget permits i would invest in new manifolds for this great engine or at least pressure check the old ones.

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Definitely. Are these manifolds/risers original to the boat? (since the last engine was out of an iroc, i would think the manifolds/risers were used from the 1st engine?) In any case, I would seriously check out those parts, hate to see that beautiful motor ruined because of old damaged/corroded manifolds. Make sure to check out the gasket surface on the manifold to riser connection as well.

Re: Engine overheat and water in the oil this weekend.

h2odick said:

Definitely. Are these manifolds/risers original to the boat? (since the last engine was out of an iroc, i would think the manifolds/risers were used from the 1st engine?) In any case, I would seriously check out those parts, hate to see that beautiful motor ruined because of old damaged/corroded manifolds. Make sure to check out the gasket surface on the manifold to riser connection as well.

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i'll do the pressure check, thanks for the advise.

My theory and reasoning for using a lamp is that even though the drains were open, perhaps there was a pocket of water above the cylinders which didn't drain. Im not certain how the cooling area inside the block is configured and I suppose theres the possibility water could pool up in some areas above the cylinders and not drain. Im not sure if this is possible or not, but if it is, its really cheap insurance.

Re: Engine overheat and water in the oil this weekend.

ken226 said:

i'll do the pressure check, thanks for the advise.

My theory and reasoning for using a lamp is that even though the drains were open, perhaps there was a pocket of water above the cylinders which didn't drain. Im not certain how the cooling area inside the block is configured and I suppose theres the possibility water could pool up in some areas above the cylinders and not drain. Im not sure if this is possible or not, but if it is, its really cheap insurance.

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With clear block drains, everything above them should drain out.

Your a big boy, and can make your own decisions when it comes to the manifolds.
IMHO though, If I just dropped a bunch of cake on a new engine, I would put some serious thought into a fresh exhaust system.

Have you separated the risers from the manifolds to check the condition of the cooling passages?

Re: Engine overheat and water in the oil this weekend.

RogersJetboat454 said:

With clear block drains, everything above them should drain out.

Your a big boy, and can make your own decisions when it comes to the manifolds.
IMHO though, If I just dropped a bunch of cake on a new engine, I would put some serious thought into a fresh exhaust system.

Have you separated the risers from the manifolds to check the condition of the cooling passages?

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Ok, I got the engine installed yesterday and went down to Patogonia lake for a test. I took the boat off the trailer and idled while I waited for her to park the truck and come back.

Before she made it back, the temp gauge started climbing, once it got over 210 and was obvious it was continuing up, shut the engine off. Sitting there rethinking my entire bad winterization/cracked block, overheated due to the cracked block theory.

Now I'm thinking theres a cooling system problem that cracked the previous block, and has now carried over to the new engine.

Wife gets back and we start diagnosing again, same steps as when I was broke down at canyon lake. I go overboard and have her start and let it idle, while I check for water being drawn in through the outdrive. Nope! None!

She kills it, I climb back in and take the outlet hose off the raw water pump, start it and water starts gushing out. So I'm thinking WTF, there must be a blockage between the engine and the raw water pump.

I reconnect the hoses and start it again, and immediately the temp drops to normal and it runs fantastic for the next 30 minutes.

I get it up on plane and the temp gauge starts heading north again, so I drop back to idle and watch it climb. Again, as soon as it heads north of 210 I shut it down. I feel the raw water pump, its hot to the touch. I go overboard and have her start it for a sec, and again, its not sucking in water through the drive. I climb back in, take the outlet hose off the raw water pump, start it again for a sec, this time no water coming out. I give it about 15 seconds idling this time, still no water comes out.

AT this point, I think I may have figured it out, "bad impeller" right?!

I pull the front plate off he raw water pump (Johnson F6b on the front of the harmonic balancer). The impeller looks perfect. I start up for a few seconds and watch the impeller spin in the housing, all still looks good. I reassemble the pump, start up "outlet hose still off", and this time water starts pouring out!! I hook everything back up and start up, temp gauge drops down to normal. We head in, put it back on the trailer and go home.

So having had all night to think about it, I decide that the only thing it could be is a leak between the drive unit and raw water pump. Must me letting air in, and not allowing the pump to prime. So I set my air compressor pressure regulator on 8 psi and pressurize the hose at the raw water pump end, seal the water pickup at the drive unit and listen for air leaks. None! No leaks! WTF, right!!

I strip the thermostat housing, check all the hoses, test the thermostat, everything I can think off. I pull the manifolds, elbows, check for obstructions, check the flappers, everything is fine!! At this point, I feel like someone is pulling a prank on me.

I decide to connect a hose to the raw water inlet, and drop the other side in a bucket. I start up and let idle with the hose in the bucket and its not drawing any in. After about 30 seconds I think damn, the impeller is bad after all. The moment I have this thought, the water level starts in the bucked starts dropping really fast, then empties. I shut the engine off and start wondering why it took 30 seconds to start pulling water.

I reassemble everything, all back together. Everything logically points to the impeller, except it looks fine. So, with the raw water pump front plate off, I start the engine and watch the impeller turn, then I reach down and let my fingers touch the impeller vanes while its running, and as soon as my finger touches it, the impeller stops turning.

Engine is still idling, center of the impeller is still turning, but the rubber portion, stops while my finger is in contact. When I remove my finger, it starts turning again, I touch again, it stops again.

Now I feel like a fu@&in dunce. I think I ruined he previous engine with a bad impeller because I didn't notice the overheat soon enough.
Despite having checked the impeller no less than a dozen times afterward, it was bad the whole time. It's only 2 years old, and not the slightest bit worn, but bad nonetheless.

So basically, it worked until it got some resistance on the engine side, from a closed thermostat, then the rubber part stopped turning while the shaft rotated inside it.


So what do ya think? The bad winterization, froze and cracked block theory is now sounding less likely. Think I cracked the previous block due to a failed impeller and overheat?


From now on, im replacing the impeller every year, regardless of how good that fuc$&r looks!!