Engine Overheat

[jhenson]

Earlier this spring, I commissioned my CAL 27. After leaving the harbor for our first sail of the season, the engine began to overheat. This is a Volvo MB 10A raw water cooled gas inboard. Unfortunately, it does not have a temperature gauge. The first indication of overheat was steam coming from the exhaust.

I've had a Conlyn Marine, here at Herrington Harbor, working on it since. It has been a slow process, though they are highly respected here in this part of Maryland. They have changed the impeller, replaced the thermostat, pulled and cleaned the raw water/exhaust manifold, and cleaned the exposed passageways.

Yesterday, I got a call from to tell me that nothing they have tried thus far has improved the cooling problem. Under load, the engine consistently overheats in about 15 minutes of use. The mouth of the harbor here is 40 minutes under power.

They are indicating to me that the only remaining realistic option is a $16000 to $20000 re-power. That?s not an option for us with a boat that has a book value of $7500. I've owned boats with outboards before, and really don't want to go down that road either. We would sell the boat as is, for a loss, before I put several thousand in a new engine or outboard.

There are a few things I want to try immediately. I have already put $1000 for professional help on this, so I need to start doing the work myself. Though Conlyn Marine is not optimistic, I would, at least, like to try an acid flush of this engine.

I have several questions:

What would the best ratio of muratic/water be to clear a blockage? I know this has been discussed here before, but can someone detail the process for me?

How many times should I repeat the process before I worry about damaging the block?

Is there any realistic inexpensive way to determine the engine temp without a gauge, before it gets so hot that the exhaust steams? The mechanic has been using a hand held heat sensor to read off the temp. Are these things expensive to buy?

Should an acid flush not be effective, would a machine shop have any better luck at cleaning the block?

This engine runs well. About 5 years ago the previous owner had a local shop here rebuild it, so I believe the compression is good, though I haven't checked. Last fall, we really enjoyed the boat, and I spent most of the winter working on cabinets and other enhancements for this cruising season rather than working on my Triton. I hate to give up on it.

Thanks,

Joe

[Ceasar Choppy]

My first suggestion would be to get someone other than Conlyn.
He did a repower for me 10 years ago and while admittedly I was pretty green, he had no qualms about taking advantage of that fact. All he had to do was install a rebuilt A4 where one had sat previously. He ended up charging me 4 times what he originally quoted me. I believe he was probably trying to make the high rent Herrington Harbor North charges him per month. But I know I'm not the only one he has done this to.
I believe Vosbury Marine up at Whitehall does Volvo-- they might be an option

What is so ironic about your story is that this happened to a friend of mine with his Northern Lights generator. Bayshore Marine in Annapolis gave my friend this same run-around and basically told him to replace the generator. Turned out it was something to do with the exhaust-- but they still charged him enough money trying to figure out the problem that he could have bought a new generator.

Second: Go out and get a handheld infrared temp gun with a laser sight on it. Like this one:
This is the one I have and it is very handy. http://www.professionalequipment.com/ex ... ermometer/ If the engine doesn't have a guage on it, you need to know exactly HOW HOT it really is.

Third: You might find it useful to get Nigel Calder's Book on Diesel Engine maintenance:
http://www.amazon.com/Marine-Diesel-Eng ... 428&sr=1-3

Fourth: Search around on this forum and others about the muratic acid flush and other places the cooling passages could be blocked. One place commonly overlooked is at the raw water injection elbow into the exhaust.

Good Luck!

[jhenson]

Ceasar,

Thanks a bunch!! I was not even aware those thermometers existed and having one aboard would be a very nice addition indeed.

I'm looking for one locally so I can get to work on this problem in the next day or so.

Thanks!

Joe

[Noah]

I got my little portable IR thermometer at Radio Shack for $40. It works great, and you can return it within 30 days if you want to.

I just went through this with a Volvo MD11C in my Swede. I pulled the engine only because it was easy to do, and the rest of the work I did was much easier.

Have you checked simple stuff? When you run the engine is it putting out cooling water? Is the intake clear?

Use the IR thermometer to see where the engine is getting hot. For me it was just one place on the rear Cyl that got hot.

I used 30% Muratic acid in my engine. I removed the thermostat and didn't mix the cooling water with the exhaust (pulled to cooling water return line before the exhaust mixer and added a long piece of hose so I could recirculate the acid through the engine.)

The acid is nasty stuff, so wear protection.

I also removed the impeller and used a sump pump to reverse flush the engine with acid.

Plenty of tinkering later and it seems to be running well.

Also, you should have peticocks on the engine block used to drain the cooling water. Open those and see if you get water coming out, it may be able to help you track down the problem.

Good luck!

[Tim]

They are indicating to me that the only remaining realistic option is a $16000 to $20000 re-power.

For a Cal 27 that's already diesel powered!? Give me a break. That place sounds like rip-off central. (Pardon my bluntness.)

The "Padding the Pockets" surcharge must be steep at that yard. It's the only explanation for that sort of cost estimate for such a basic repower.

It's situations like these that drive many people either out of boating completely, or into the realm of the serious do-it-yourselfer who will forever stay clear of yards.

Clearly, Joe, you're well equipped to be the latter, so cut the strings and run away from that yard and focus on the problem yourself.

There are only so many reasons why an engine will overheat. Go through everything methodically yourself, including checking the blatantly obvious things like looking for collapsed or blocked hose, pieces of the old impeller stuck in a chamber somewhere (very common), growth or blockage on the exterior through hull, plugged raw water filter, and that sort of thing.

A yard looking to make 100% profit on a repower might conveniently "overlook" these most basic of potential issues.

Acid flush is worthwhile and you should certainly try it, though perhaps not until you eliminate all the "duh" things first (though there's no harm in it either way).

Perhaps the infrared thermometer will help you pinpoint an area that's hotter than the rest, or where the heat begins. That's a worthy tool to have on hand.

Good luck!

[Figment]

Well, I dunno about "rip-off central", but they charged me an hour's labor for pouring a gallon of antifreeze into the bilge.

[Tim]

Well, I dunno about "rip-off central", but they charged me an hour's labor for pouring a gallon of antifreeze into the bilge.

Well, gee. That sounds perfectly fair to me.

After all, it's tough to open those "child-proof" caps on those jugs, and those little foil safety seals are a bear to break.

[Rachel]

Guess it took them a while to figure out the safety cap on the gallon jug...

[Summersdawn]

This reminds me of the time I was travelling through Arizona with a friend when we were 19 in an old Datsun truck. The head gasket went, and damaged the heads. The truck wouldn't start. We got towed into the next town, pop. 500. The guys that owned the tow truck also owned a garage. The fiddled with things for a minute, and said the truck needed a new engine. They just happened to have an old engine lying around that was the exact same. $1600 for an engine swap (this was in '91). We asked if there was another shop in town, they said yes, but they had the only tow truck, and weren't going to tow us there!

The look on there face when we started pushing the truck the 1 mile across town to the other shop was priceless!! We had the heads re-built and installed for I believe less than $400. The mechanics at the good shop had to get some parts from the other shops engine, and said it was in horrible shape. He said the engine would have gotten us out of town, but no way it would have gotten us home.

I would be very leary of any shop that said they couldn't fix an overheating problem in an engine.

Do the repairs your self. Look at it this way - if you do the repair yourself, worst case scenario is you have to throw a few extra parts at it to get it going, which will end up being cheaper than paying for shop time.

[ArielHull97]

I think a 1 hour minimum labor is fair. I dont know your situation but I've done a lot of stupid things to boat that owners are to lazy to do, and if they are, and I do, then 1 hour minimum.

Now getting charged for stuff thats not done or gouged, different story, and why I dont goto Jiffy lube any more.

[dasein668]

An hour for pouring 3 gallons of antifreeze seems awfully steep on the one hand, but then again there's a certain aggravation factor for doing a 2-minute job that doesn't get covered if you charge 1/30th of an hour's labor.

In my business I charge a half hour minimum. It encourages my clients not to send me one-word change-orders one at a time!

[jhenson]

Regarding the use of these IR thermometers--- Will there be a significant difference between what the thermometer reads off the cylinder head and the water temperature itself? Am I looking for something around 180 degrees or so for the optimum temperature?

The plan is to take readings before and after the flush to compare. Also, I will certainly poke around to look for things they might have missed. I kind of assumed that 11 hours of labor would find that kind of stuff, but maybe not. There has been a frustrating lack of communication that I am not used to with the mechanics I work with.

There are only so many reasons why an engine will overheat.

Is it ever the case that a raw water marine engine can build up rust and scale around the cylinder walls to such an extent that it is beyond repair?

I should add that in from my discussion with them this morning, that the $16,000 does not include engine beds. That would be extra, they say. There a many very expensive boats here in this yard that will pay top dollar for boat maintenance.

Thanks guys and gals for the help!!

Joe

[Ceasar Choppy]

Regarding the use of these IR thermometers--- Will there be a significant difference between what the thermometer reads off the cylinder head and the water temperature itself? Am I looking for something around 180 degrees or so for the optimum temperature?

Point it at the block and the thermostat. Should read within 5 or 10 degrees of what it really is... at least mine does on my Perkins 4-108

The plan is to take readings before and after the flush to compare. Also, I will certainly poke around to look for things they might have missed. I kind of assumed that 11 hours of labor would find that kind of stuff, but maybe not. There has been a frustrating lack of communication that I am not used to with the mechanics I work with.

...I should add that in from my discussion with them this morning, that the $16,000 does not include engine beds. That would be extra, they say. There a many very expensive boats here in this yard that will pay top dollar for boat maintenance.

RUN AWAY. Do not walk, run! This is sounding like the same crap they pulled with me

Is it ever the case that a raw water marine engine can build up rust and scale around the cylinder walls to such an extent that it is beyond repair?

Maybe, but this does not sound like one of those times. If all you are getting is steam out of the exhaust, I doubt it. Check everything that has been mentiond here first.

Good luck!

[Tim]

I should add that in from my discussion with them this morning, that the $16,000 does not include engine beds. That would be extra, they say.
Joe

I'd sure love to see a cost breakdown of that estimate.

The engine only costs perhaps $7,000. If the estimate doesn't include engine beds, I wonder what in the world the other $9,000 is for. (Even if it did include engine beds, that'd still be incredibly high, by my way of thinking.)

It must be one of those places where they price things high to attract the "money is no object, so if it costs an obscene amount, it must be the best work" crowd.

Sail away. Quickly.

[dkall]

Pulling the thermostat and looking at it. Could be frozen or broken. Put it in a pot of boiling water and see if it opens up?

[Jason K]

The only experience I have with this sort of thing is with the Atomic 4, but I imagine the basic procedure is the same. When I did this last year, the engine also began to overheat after ten to fifteen minutes.

Although I'm not familiar with the Volvo, on most engines the coolant will flow through a number of easily accessible fixtures. I would suggest removing these fixtures in turn to see if you can determine where the primary blockage is.

Although I used about a 1:3 ratio for the muriatic acid/water solution, I ended up using much, much more muriatic acid when I found the primary blockage, which was in the manifold. That may or may not be the recommended method, but it worked for me when the regular strength solution failed to clean it out.

Even though they supposedly did the work already, I would closely examine the heat exchanger and the water pump. Also, have you had an impeller lose any vanes recently? The rubber bits can clog passages as well.

I assume coolant flow is the issue, given the steps the yard took to fix the problem? If it is, then I'm sure you can find the blockage.

[Figment]

Am I the only one to think it a little strange that $1000 worth of tinkering on an overheat problem would NOT include something so simple as an acid-flush?

I know I'm just a shadetree-mechanic, but to me steam in the exhaust says insufficient coolant flow into the exhaust system.
Step one: start breaking fittings open to see if the blockage can be located to something stupid and specific.
Steps two through five: acid flush.
Step six: start breaking down major components (head, manifold) to localize the problem.

Or is an acid-flush (as commonplace as it is) really more of a "home remedy", not something practiced by professionals?

Either way, "repower" is step thirty-eight in my book.

[Quetzalsailor]

It took several overheats for me to troubleshoot the waterflow problem on our previous boat with an A4. One by one, I worked my way down to the seacock; probably should have started there. It sure feels very strange to pull the hose off an open seacock and have no water pouring in! Turned out to be a plant living in the throughhull. Dad had a similar problem in that boat; turned out to be a very dead jelly fish.

Speaks to the advisability of having a straight barb so that one was able to rod out the bronze parts rather than come off the seacock with an ell. And speaks to the wisdom of using a strainer on the water-side of the throughhull: you can't rod it out.

We towed a fellow marina sailor home when his seacock handle broke off in the closed position in a dead calm. He would have been happy to have an adjacent seacock to temporarily relocate the engine's intake hose.

[dasein668]

I know I'm just a shadetree-mechanic,

Watch out Mike, Britton will throw a fit like he did in this thread here...

Of course, we haven't heard from Britton in a while, have we? Britton? Briiiiitooooooooon?

[Figment]

Yes, I should specify that the "just" applies to the "shadetree" component of the phrase, not the "mechanic".

Perhaps Britton has worked up one mother of a forum-busting post, pages and pages of pics and text and links, and his repeated attempts to upload the monster have been the true source of the recent error messages.
Yeah, that must be it.

[jhenson]

Ok, here is where I am so far:

-checked inlet seacock- good flow

-checked strainer and lines- clean/good flow

-checked exhaust mixer- clean

-replaced impeller and checked hose to manifold- good

-replaced thermostat

-did 2 acid flushes with 30% for 25 minutes- engine still overheating

-ran the boat at low rpm out to Herring bay and spent an half hour cleaning the prop with snorkel gear- performance under power was improved, however the engine is still overheating with the power up.

-pulled the exhaust/raw water manifold- clean (mechanic previously accomplished)

-pulled the head- relatively clean/ no major obstructions in water passageways

-removed engine drain petcock- passageway blocked initially but cleared with coat hanger wire. ?Pasty black gritty mess" flowed out with remaining water in block


There a six water passages into the block: 2 on the side through the manifold, and 4 on the top to the head. When I poke into the water jackets with a coat hanger, I get the same "pasty black gunk" on the coat hanger.

I am certainly willing to poke away for hours with a coat hanger to break some of this stuff off the bottom of the water jackets. However, there a 5 freeze plugs (2 on the front, 2 on the back, and one on the side that will give me additional access to the inside of the block. I will have to cut away the inside of a galley cabinet to put the new side freeze plug back in, but that?s not a big deal. How hard is it to get the new ones to seat? I guess you tap these things back in with a hammer to seat them? Any comments on something else to try to clean the gunk out this block? I feel like it I can mechanically loosen some of the deposits, flush them out the block side drain with a hose, put the engine back together, then run another acid flush or two, I might get this thing to cool down.

Thanks,

Joe

[Jason K]

Pasty black gunk describes what was clogging my engine as well. It blocked the loop from the head to the manifold and there was a lot of it in the manifold.

To get it out, I resorted to a very, very strong muriatic acid solution and I let it sit for about half an hour, I don't know if that will be harmful or not to the Volvo, but it's what work for me. The 25 or 30% solutions were inadequate to clear the clogs.

[jhenson]

Jason,

How strong do you think you went with the mix, around 50/50 maybe? I am getting lots of black liquid out on these flushes, so I know there has been some breakdown of the particles. Still, I think there is a long way to go.

Thanks for your imput, as always.

Joe

[Figment]

My limited experience with freeze-out plugs is that they're a royal pain to reinstall properly. The appopriate method, or so I'm told, is to set the plug in place, hold a drift against the middle of the plug, and tap it home. Of course the damn things NEVER go in evenly. Frustration ensues, and that's with the motor on a bench.

I'd continue flushing flushing flushing for quite a while before I'd resort to messing with the freeze-outs.

[Jason K]

It was pretty strong. Meaning very, very strong.

I tried with more dilute solutions and I was unable to clear the manifold. As I was willing to simply replace the manifold, or anything else that I screwed up, I used almost pure muriatic acid. The fumes were searing.

However, it did work. When I flushed it out with a hose, a fountain of black goop emerged and I ended up with great water flow out the exhaust.

I am not necessarily advocating this approach. Yes, it worked, but it was a tough Atomic 4 that I was about to give up on as a lame horse.

Click here for a link to the thread that discusses my attempts to solve the same problem

[jhenson]

I'm happy to report that this engine is running cool again.? My thanks to everyone who contributed to the thread, especially Ceasar for pointing me in the direction of Dick Vosbury at Vosbury Marine!??Dick Vosbury is a very nice guy?knows these old Volvo Penta engines?like Don Moyer knows the?Atomic 4.? He is an enthusiastic advocate for keeping these engines going, and enjoys dispensing his?knowledge from years of?working on them.? His shop is essentially a parts museum for obsolete Volvo Penta engines.? He was able to rummage around and find a temperature sending unit that fits?into the cylinder head and allows for a VDO gauge in the cockpit, which will be very nice indeed!
?
Dick patiently went over everything that that I had tried to date to solve the overheating problem.? He agreed that the only remaining thing left was to free up cooling passages inside the engine block.? His method involves using high pressure water to blast debris out the side of the block through the drain seacock.
?
I rigged some plumbing fittings to reduce the size of a garden hose down to 1/4" I. D. clear tubing (which had an outside diameter just small enough to push into the cooling passages into the engine block).? The reduced diameter also increased the outlet pressure.? I am fortunate to have a lot of water pressure at my marina.? There are 6 water passages into and out of the engine block.? I used 5 rubber stoppers to plug the passages that were not receiving the water so that the water would be forced to exit the block through the side.
?
I blasted each hole several times and poked at the block with stiff wire to loosen what I could between water blasts.? The water pressure was enough to blow the rubber stoppers out of the passages if they were not seated down very well.? Lots and lots?of junk came out of the block.? The process made a huge mess?in the?engine compartment, but I was able to see on the hull what was removed though the drain hole in the block.? I worked at this for a couple of hours before the debris essentially stopped?exiting the side?of the block.
?
I put the engine back together, wired and installed the new temperature guage, and ran the engine.? The engine now runs steadily at a little less than 140 degrees with full power and forward gear.? I'm excited to have this behind me, and I can say I now have much better familiarity with this engine.
?
Thanks again,
?
Joe

[Ceasar Choppy]

Joe,

Congrats! Glad it worked out for you!

I'm glad to hear that Vosbury was so helpful and I'm always glad to
steer any and everyone away from Conlyn Marine. :)

Hopefully, I'll see you on the water around naptown.

[Noah]

Nice! Two wins for this board getting Old Volvo's to run cool this spring! Mine turned out to be a collapsed raw water intake hose as well as plenty of gunk in the engine.

If you add it up between the two of us we probably saved $25,000 on new engines!

[Figment]

Happy day, fellas!