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AQ130C Please Help

bwingler

Member
"I am new to boating and bough

"I am new to boating and bought a 73 runabout with an aq130c and 270 stern drive. I have not been in the water yet. It keeps overheating, here is what i have done so far.

compression 1-170 2-150 3-180 4-180
Is my head gasket blown between 1 and 2?

Next i checked impeller looks new, nothing broke or missing, looks like new ones in picture.

Replaced all hose's.

Removed thermostat and heated water to 140 using a therometer and it opened fully.

Rodded out the oil cooler, was not clogged up.

Hooked up the garden hose to the water pump and the motor runs fine, dont have earmuffs that fit the 270, goes up to 160 then falls back then goes up higher and falls back alittle and finally goes to 200+ and i shut off the engine. I bring the rpms up to 2,000 and it does not make it get cooler. Also same test with out thermostat and same results. I am stumped. Water coming out the exhaust is hot.

Also i dont have any motor mounts and the motor leans forward some but have found nothing broke or missing. pictures at www.nature-powered.com/boat

Barry"
 
"Barry, regarding the overheat

"Barry, regarding the overheating, check the condition of the raw water hose connector in your outdrive. They become corroded/perforated with age and they are the most common source of overheating in Volvo Penta AQs due to air ingress.

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Luckily, they are cheap and easy to replace.

http://www.marineengine.com/parts/part_details.php?pnum=SIE18-2778&returntopage=80240788.htm

Also, lower compression in two cylinders does not necessarily mean a blown gasket: it could be leaky valves or piston rings. Also, many early AQ 4-cylinder packages did not have originally front mounts installed, but I think it would be a good idea to install them."
 
"If you are getting a good flo

"If you are getting a good flow of water out the exhaust outlet, and it is hot like you say, I would check to make sure the sender is not bad.(could be corroded)
My 120B was getting on the hot side, so I took the thermostat out. My temp will go to 210 at 4000 rpms and cruising, but that isn't real hot.
I would consider anything over 230 hot!
Also, you might not be putting enough water into the outdrive. There are three inlets. One on each side and also one on the bottom. Try putting it into a trash can or large bucket. Make sure you keep it in neutral,of course, to keep the prop from eating it up. Try it that way.
It is possible,too, with your compression readings that you have a slightly blown head gasket. But you would more than likely see white smoke out the exhaust port, or water mixing with the oil.
Nice looking boat for as old as it is. Looks well taken care of.
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"
 
"Thanks for the reply, i will

"Thanks for the reply, i will check the raw water housing. Right now i am not connected to it. I am connected directly to the raw water pump with a garden hose, and still over heat. Should i be worried about the compression?

Barry"
 
"What you are describing as ov

"What you are describing as overheating, really isn't overheating. I would take the thermostat out, reconnect the cooling system, check the sender, and do a water test. Make sure the coolant is fresh, and go from there. Like I said earlier, mine hits 210 at 4000 rpms, but NEVER goes over that. Runs just fine.
I can actually get my rpms to 5500, and then she wants to get hot, but that exceeds the recommended rpm for the engine, so I try not to make her move that fast."
 
"o.....as far as the compressi

"o.....as far as the compression readings go, if you aren't getting any white smoke or oil in the water, you probably have a little valve issue coming on. But you can still run it as long as it isn't missing.
Should be a concern in the future."
 
"Hi Eric,
Mine does not have


"Hi Eric,
Mine does not have coolant, raw water only cooling. Just took the end plate off of the exhaust manifold and flushed out a bunch of mud and rust flakes. Used a clothes hanger to get from the front to the back. My temp gauge only goes up to 200 nothing past that on the gauge.

Barry"
 
"Barry, your thermostat should

"Barry, your thermostat should be fully open at 153º, so if your engine is runing hotter than that thern there is obviously something wrong with the cooling system. A clean exhaust manifold is definitely a must to ensure correct water flow, but too many times the problem is air being sucked by the raw water pump, especially when the boat is on the plane and the raw water hose connector is above the waterline."
 
"I understand what your saying

"I understand what your saying, I am not in the water, I have bypassed that all together, process of trouble shooting. I am feeding water with a hose right into the inlet of the raw water pump. The motor is an aq130c. Once i get it to run at 160 then i will reconnect the raw water hose and go to the lake to see it it works. If it does not then i will replace the parts you said to, but i am not to that point yet. From what i was told the 270 does not have the impeller in the lower unit, it is in the raw water pump and that is where i have my hose connected. I am still in the driveway.

Barry"
 
"The sender and gauge are not

"The sender and gauge are not the problem because they are correctly reading a thermostat opening of 160 deg. That is the meaning of the gauge rising and falling, eg the stat is opening causing the temp to fall. Unfortunately, at that point everything goes south. The manifold looks like the culprit."
 
"Barry, Take a breath. You are

"Barry, Take a breath. You are not running that hot.
Everybody gets a little looney on this forum..........
I say take the thermostat out, and go on the water.
Carry a pocket size infrared thermometer. Sears has them for less than 50 bucks. Check the temp yourself. You are there. You can fine tune as you go, but a water test is the true way to see what you have. It runs, sounds like, it runs decent.
Take her to the water and see what happens before you get into the fine tune stuff.
Sorry......not trying to be a nut, just that we all get looney on here before we get the real results of a water test."
 
"Taking the thermostat out wou

"Taking the thermostat out would be an attempt to deal with symptoms instead of with the problem. The key question in any serious troubleshooting process should be: if before it was running well, what has changed that now it doesn't? And of course, the real challenge would be finding the right answer tothe problem rather than cutting corners.

Moreover, I understand that specifically the AQ130s runs hotter without the thermostat because of the way the cooling passages are designed.

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"
 
"Eric, I don't think that

"Eric, I don't think that anyone has said or even hinted that you need to shut-up. This is a forum where many of us (yourself included) are trying to help others to solve their boating problems by answering their questions to the best of our abilities. Having said that, I believe it would be inappropriate for any forum member not to correct statements being made by another member when he or she believes that wrong or inadequate advice is being given. If that makes you feel uncomfortable, that's too bad. I am not going to remain silent when I see that you or any other member gives advice that can lead to an engine being ruined (like removing a thermostat) or that can cause a fatal accident; like for example, advising others to use an automotive starter on a marine engine.

Not long ago, you made an outrageous claim about the speed your 21' boat was doing with your 110 HP 4 cylinder engine, and it was brought to your attention by someone more experienced than I am that your claim was physically impossible. I reviewed what you said and what Morten Ringvold said, and I stated that the only way your claim would be substantiated was by having a strong wind and a 10-knot current in favour

http://www.marineengine.com/discus/messages/12487/86841.shtml

yet, instead of trying to <font color=""0000ff"">learn</font> from more experienced people than you, you just dag your heels in the ground and started talking about negativity, yada yada.

Eric, in my opinion you don't need to shut-up, but I firmly believe that you need to understand that you are not always right (and neither am I nor anyone in this world), and there is nothing wrong with being corrected. Believe me or not, I have learned a lot from this forum, and I have admitted several times that I have been wrong in some issues when someone else corrected me. Does that mean I have to shut up? C'mon, man, we are only human."
 
"Hello,

I have read at anot


"Hello,

I have read at another forum that while an operating temp of 200 is OK for a fresh water cooled engine (still too high for my liking), it is not OK for a raw water cooled one. If you are running at 200 deg F in salt water with a raw water cooled engine, then the salt will stick to the inside of the cooling passages, which is why you want them to run at about 160 degrees. It won't happen at 160 deg.

Have a great day,

Rob."
 
"Do not run without a thermost

"Do not run without a thermostat in the AQ130. It is required due to the different way that water flows in this engine.

Its works this way. When the thermostat is fully closed, all water in the engine is trapped and all flow is diverted to the exaust. When the themostat is fully open, it blocks off the engine bypass to the exaust and all water flow is directed though the engine.

Without the thermostat in place the water entering the system fights its self for the easiest path out and that is usually the bypass directly to the exaust and the engine then dosnt get proper cooling.

Morten Ringvold is 100% correct in ghis statement about the head not getting proper cooling with the thermostat out.

Other engines that use fresh water cooling would have a different system (Likes Erics for instance) and run cooler without a thremostat."
 
Being that you stated that you

Being that you stated that you removed the front plate from the manifolf and mud and rust flakes came out it sounds like you have some restiction in the manifold. You could remove the elbow from the other end and completly run a rod through the water chamber to clean out all mud and flakes. Check the elbow out after you have it off. You could also take both parts to a rad shop and have it boiled.
 
"Thanks for everyone's rep

"Thanks for everyone's reply, I am going to pull the manifold, i had the elbow off already and cleaned it when i replaced the exhaust hose. It has to be in the manifold I also went and bought a mechanical water temp gauge, and none of the adapters would fit, but i held it in with a rag as that water was hot and it confirmed that is overheating and that the other sensor and gauge work. And yes you have to have the stat in this engine per volvo dealer. And man are parts expensive for this old engine. I will let everyone know what i find.

Also i have never had this boat out since i bought it a month ago. It has been problem after problem, but soon i hope. I want to go stripper fishing. I am freshwater only"
 
"Dont get discouraged, I bough

"Dont get discouraged, I bought my 74 Glastron with the AQ130c in it last july (06) and just finnaly got it in the water this August. I too am experiancing a overheating problem. I havnt had much time to work it out but im sure it will be overcome. Things that I overcame on mine were:

Water in Oil (impeller shaft seal leak)
Cracked Valve
Fuel problems (line sucking air)
Leaking water pipes on mainifiold
Replaced head Gasket


Hang out here and one by one all your problems will be diagnoised and hopefully fixed."
 
Ok i got the manifold off and

Ok i got the manifold off and it dont look all that bad. If i knock the freeze plugs out of the block should i be able to put the universal plugs back in it like the rubber ones? I dont know where else to look for blockage. Any other places i should look?
 
Ok i think it is a head gasket

Ok i think it is a head gasket leaking into the water jacket. Compression 1-170 2-150 3-180 4-180 i will check the torque tomorrow on the head bolts and if they are fine off with its head. Any one else agree with my line of thinking?
 
I to have been rebuilding an A

I to have been rebuilding an AQ130. I found my low compression cyl's (all but one) was caused by stuck 1st & 2nd compression rings - carbon sludge.
 
"AQ130C. Overheating- fluctuat

"AQ130C. Overheating- fluctuating temp then off the scale. checked as per these threads-very useful-finally found the cause. severe corrosion at stern end of exhaust manifold, in effect bridging water jacket and exhaust, and causing back pressure into cooling system. manifold severely choked with corrosion.
remedy- replacement manifold.
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Aq130 Manifold
 
"One more thing for all to not

"One more thing for all to not forget. When you are running your engine out of the water, the hose doesn't always provide enough cooling water to keep the engine from overheating at higher engine speeds. If you are running your engine out of the water and it is overheating at high speeds, relax! That is normal. Go to the lake and try it again in actual operational conditions."
 
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