Blown Head Gasket

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mark_fitzy

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1995 Regal 18ft Bowrider with 40 hour old Reco Chev 262 4.3lt V6 Mercruiser


Well I just got a call from my mechanic today as my boat has been in the workshop for about 3 week because of water in the oil(which I thought was because I left the plug out)

My mechanic tells me its a blown head gasket because the motor must have overheated.

I ask the question how did the motor overheat? The Impellor is 40 hours old as is the motor and water pump. The mechanic verified that the impellor is fine and the water is pumping out well. I thought maybe a plastic bag or something, but the mechanic said the impellor would show signs of stress if this was the case.

Can anyone tell me how the head gasket on a 40 hour old reconditioned motor would blow if the impellor is puming water? I dont mind paying to get the motor repaired but I need to know why it happened so it doesnt happen again.

The motor is still under warranty, could this be a warranty issue?

Need your thoughts!! :confused:
 

HT32BSX115

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Re: Blown Head Gasket

Howdy,


Couple of things, what do you mean by "reconditioned"? Is the mechanic that has the boat now, the one that "reconditioned" it (and providing the "warranty"?)

How does he know that the head gasket is "blown"? (I.E. did he do a compression check?)

Where do you store the boat? (are you located in "cold" country?)

Head gaskets don't usually "blow" ......... It does happen, but not very often. Usually, water in the oil of a marine engine is due to a crack in the cast iron (block, head, manifold(s) ) Not always.......but usually.


If you didn't overheat the engine, it's unlikely that the head gasket is blown due to that. In fact, head gaskets don't usually "blow" on an open cooled marine engine that gets a little "hot". (there's no coolant pressure at all.)
 

mark_fitzy

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Re: Blown Head Gasket

Recondtioned motor was purchased by mechanic off a motor supplier and it consisted of Reco Chev 262 4.3lt V6 Mercruiser style unleaded long motor, comes with new exhausts and risers, new water pump, reco balancer, new alternator, new thermostat housing, new starter, reco carburettor, new intake manifold, new electronic distributor and leads, new flywheel, marine head gaskets, new flame arrestor Cost $6300 #A130. 12 months guarantee. Runs on unleaded fuel. (this is a heavy duty motor suitable for salt or fresh water)

He has taken the heads off and found the blown head gasket.

I am from australia, boating all year round here. Always stored on trailer at home under a car port.

Lets say it did over heat without me noticing it, how did it happen with new waterpump and new impellor and impellor still pumping out water fine.

I have to meet up with the mechanic tomorrow and I dont want him telling me bull sh*t.
 

HT32BSX115

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Re: Blown Head Gasket

OK,


Sounds like "reconditioned" there may mean, "rebuilt" here.

It also appears that you probably do not have freeze damage.

If a head gasket failed, that's what it is. Head gaskets do fail from time to time. It's very possible it was defective from the start or the head wasn't torqued properly (or not at all)..

If the mechanic insists that an overheat caused the head gasket failure, you might ask him to show you the evidence.

If your raw water impeller hasn't failed, there's no reduction in water flow, the manifolds/risers are not plugged (with rust), you didn't run the engine out of the water, and you never saw the temp gage indicate an overheat............ (does the engine have an overheat alarm?)

I would say it's not all that likely the engine overheated.

As an aside, did you replace the manifolds AND risers with new units and did the riser gasket(s) show evidence of leaking? (I.E. water in the exhaust and combustion chambers)


You could still over heat an engine by having plugged manifolds/risers, the plumbing was connected wrong, or a plugged water line from the drive to the engine. You could also have impeller fragments from a previous impeller failure in the T-stat housing, or oil/power steering cooler (if installed) that would seriously reduce water flow. That would absolutely cause overheats.
 

mark_fitzy

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Re: Blown Head Gasket

The risers and manifolds are new with the motor, so they wouldnt be blocked and didnt hear any leaking.

Unfortunately it does not have an alarm, boat in 1995 built, not sure if it ever came with one.

No oil or power steering cooler installed as far as I know.

He says he has the blown head gasket for me to see.

As you can see my confusion, Im not sure whats going on!

What questions should I ask him?

By the way, thanks for your input, Im stressedto the max here :)
 

TilliamWe

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Re: Blown Head Gasket

If the impeller is intact, then the motor didn't overheat. If the headgasket is actually blown, it's because the head was improperly torqued by the "reconditioner".
This is a warranty issue.
 

mark_fitzy

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Re: Blown Head Gasket

Thats what im thinking TilliamWe. I smell a rat
 

TilliamWe

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Re: Blown Head Gasket

Thats what im thinking TilliamWe. I smell a rat

Unfortunately, I think you will find one.

Small Block Chevies handle overheats very well, as HT has been explaining. They don't normally blow head gaskets. They will crack heads in an overheat, but not usually blow gaskets. And they'll run with cracked heads, I know, I ran a SBC 5.7 for over 2 years after a 240F overheat. when I did take the heads off, for valve issues, one was cracked. Right in between two cylinders, but guess what? No headgasket damage!
If the blown headgasket is his only evidence of an overheat, that's not evidence at all. There could be something wrong with the head or the block.
Also, a blown headgasket shouldn't automatically equal water in the oil. There could still be something else wrong with that engine. Best of luck to you.
 

mark_fitzy

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Re: Blown Head Gasket

It all sounds fishy, and I am not sure really how to go about catching this guy out? Is 3.43 am and I cant sleep,cant stop thinling about it! :mad:
 

HT32BSX115

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Re: Blown Head Gasket

The risers and manifolds are new with the motor, so they wouldnt be blocked and didnt hear any leaking.
Hmm,

I donno how you might "hear" leaking. you might detect the results of the leaking though.

If you had a slight riser leak, some water would leak past a riser gasket back into the exhaust.

In any cylinder with an open exhaust valve you would have a little water run into the combustion chamber.

When you subsequently cranked the engine that little bit of water would cause a slight "hydrolock". That *could* cause a head gasket failure (due to the VERY high cyl pressures when the piston comes up against the water) but it doesn't always.......It usually just abruptly stops rotation while cranking.

It sounds like a weak or dead battery,but does it with a fresh or "jumped" (boosted) battery too.


If he "Mechanic" also installed the manifolds and risers, it's possible that he "screwed up" and either didn't install them correctly or they were defective. (or the manifold/riser casting surfaces weren't "square" and flat etc)
 

mark_fitzy

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Re: Blown Head Gasket

As far as the risers and manifolds go, the whole engine was complete when he (the mechanic) purchased it, he (the mechanic) just installed the engine.

Anyway I am talking to the mechanic today, I will update you with the outcome.
 

triman

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Re: Blown Head Gasket

Just a quick note.
It's a V6, not a SBC.

"Reco Chev 262 4.3lt V6 Mercruiser style unleaded long motor, comes with new exhausts and risers, new water pump, etc etc..."
 

TilliamWe

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Re: Blown Head Gasket

Just a quick note.
It's a V6, not a SBC.

"Reco Chev 262 4.3lt V6 Mercruiser style unleaded long motor, comes with new exhausts and risers, new water pump, etc etc..."

A 4.3 is the V6 version of the Small Block Chevy V8. As said above, same rules apply.
 

littlebookworm

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Re: Blown Head Gasket

One thing I suggest you have the mechanic check is the flatness of the heads and the block. Using a steel rule (and not the cheap one from the local home supply house) and a feeler guage, check the flatness of the heads and the block. Since this was a reconditioned engine, it is possible that the heads or block is not within specifications. This, to me, sounds like something which should be covered under warranty. Blowing a head gasket at 40 hours with no sign of water pump problems strongly suggests a problem with the rebuild. Hold your ground and demand the company which did the engine make good. Good luck. Hy
 

mark_fitzy

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Re: Blown Head Gasket

Thanks guys for all your input. I think we have the mechanic on the backfoot with all our question, thanks to you guys. He wont admit there is something wrong with the motor and insist that the motor overheated and claims that is was due to me leaving the bung out previously and the water got into the motor causing it to airrate and thus not lubracating enough so it overheated and cracked the head gasket.

He said he isgoing to push for insurance.

Hmmm still sounds fishy.I will let you know any further outcome
 

TilliamWe

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Re: Blown Head Gasket

Huh? He is saying that you left the plug out, water filled the bilge, entered the engine, foamed the oil, and that caused an overheat? Uuummm, that's just not true. The man is up to something.
 

sdoomaha

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Re: Blown Head Gasket

Someone please correct me....but I believe you may overheat without even knowing it if your thermosat is stuck closed. If you take a look at the thermostat housing and the manual for the 4.3 (at least in my '94) you will note the temp guage sending unit is on the cool side of the thermostat. Your impeller, water pump, temp sending unit, and guage can be working perfectly, but if the thermostat is stuck closed, it is never allowing the cool water to enter the block, nor the heated water to enter the thermostat housing. Since the temp sending unit is not in the block, but is in the thermostat housing and the heated water never reaches it....you never know you are overheating. The water in the block just continues to circulate, continuing to heat up more and more the longer ran and you will never know it by watching the guage. It will in fact look like it is running cooler than normal. Maybe unusual for a thermostat to fail after such a short time, but I suppose it is possible.

Someone please correct me if I am wrong...but this is what I experienced with my 4.3. Luckily I did not run my engine long as I was concerned it was never getting up to temp and replaced the stuck thermostat before it became a real problem.
 

HT32BSX115

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Re: Blown Head Gasket

claims that is was due to me leaving the bung out


Well,

Can we talk a little about this?

How much water entered the bilge? & how high on the engine did it get?


In reality, it would have to get high enough to run in the "breather" which is usually on TOP of the engine (oil fill cap/valve cover etc)


Yeah, you *could* get water into the engine that way, but I think you would have FAR MORE problems if that actually happened!
(like the boat partially sinking!!!:eek::eek:)


If you had enough water in the bilge such that it submerged the starter, it might damage the starter, but it wouldn't enter the engine.....


I'm with TW, I think the "Mechanic" is up to something......(or you're not telling all:cool:)
 

mark_fitzy

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Re: Blown Head Gasket

Yes about a month proir to my engine shutting down, I left the bilge plug out and the water filled half way around the engine after then it came on the floor, thats when I noticed I had left the plug out. The mechanic believes while the plug was out and I was driving the boat, the motor would have been deep in the water and bow was in the air, therefore letting water into the motor (somehow).
sdoomaha you might have something because I do remember the temp guage being unusually low but thought it must be fine as the thermostat was new also. It is on the cool side of the thermostat, so could be true. I do however always check the risers to see if they are ever to hot, and nothing really out of the normal did they get to hot. But its possible.
 
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