volvo 3.0 overheating issue

I have a 2007 volvo 3.0 GLP-E with an SX/A drive. Serial #3869357 4012200520 (engine)

The hose going into the circ pump from the thermo housing popped off the other night, we noticed it quickly before the motor got too hot and put it back on and tightened the hose clamp. We noticed that the raw water outlet was a bit leaky as well, tightened that. In the morning we were cruising around at about 4kts for awhile fishing, noticed above average temp. Trolling home (8-9kts) the temp was a bit higher. Close to the harbor we ran the boat up on plane, and the temp started climbing so we shut her down and came in on the kicker. I checked the impeller, all good. Replaced a very rusted thermostat and ran the motor on the freshwater hookup all the way up to 2500rpms for 10 minutes or so, and the temp was great. Tried to fish again this morning, high temps under load at trolling speed (2600rpms). At washdown the temp was all good once again hooked up to the hose. Where should I start? Thanks for any help....

Re: volvo 3.0 overheating issue

http://forums.iboats.com/showthread.php?t=220416

Re: volvo 3.0 overheating issue

Sorry Don, im a moron. I have updated the original post.

Re: volvo 3.0 overheating issue

If that thermostat was all rusty, it may have caused the hose to blow off. Was the hose removed for draining during winterization and maybe not reinstalled correctly?
This is not an uncommon problem with the Volvo 3.0L, but I really can't remember anyone ever coming back with a cure. Hopefully I just missed it if they did and someone else remembers it.
My problem is how you can possibly build up enough pressure with basically holes at both ends, to blow the hose off.

Re: volvo 3.0 overheating issue

The hose came off because the hose clamp was loose, and we were running the boat at high rpms for a long time. My problem at the moment is that the motor will not stop overheating. I will take a closer look asap, but I hope there is just another leaky hose sucking air??? It only does it under a load on the water, not on the trailer hooked up to freshwater at the motor.

Re: volvo 3.0 overheating issue

Have you checked the impeller?

Re: volvo 3.0 overheating issue

Yes, as I stated in the original post I have checked the impeller and replaced the thermostat. Next thing im gonna do is remove the exhaust manifold and check for blockage.

Re: volvo 3.0 overheating issue

Does raw water run through exhaust manifolds? If sea water runs through exhaust, them maybe plugged up. Ran across it myself about three years ago with same issues.

Re: volvo 3.0 overheating issue

Might want to check the impeller again. All it would take is a plastic bag over the drive intakes to destroy a new impeller.
You can check your exhaust manifold and elbow as Monte suggested by removing the elbow and checking the passages to see if they are open.
If you had a previous impeller problem that lost some vanes, they can also plug up the exhaust and thermostat housing.

Might want to download read this Overheat diagnosis file before you take things apart. http://www.4shared.com/file/50572185/e88f1d89/Volvo_Penta_Overheat_Diagnosis.html

Re: volvo 3.0 overheating issue

I found the exhaust elbow to be significantly obstructed, partly by an old impeller vane as you suggested. For the rest of the build-up in the elbow, can I soak in an acid-bath? Thats what I have heard from others with similar problems lately, but I dont know anything about that. I cleared most of it with a screwdriver, and now I have to find some new gaskets to put it back on.

Last question, what is the purpose of the restrictor plate between the two gaskets?

Re: volvo 3.0 overheating issue

Heres what I did, I just used a hacksaw blade and ran it back and fourth while running water hose to rinse out the crap. It took awhile, but after about and hours worth of work on each of them and lots of garbage, Motor temp was good once again.!

Re: volvo 3.0 overheating issue

For the rest of the build-up in the elbow, can I soak in an acid-bath

Click to expand...

I wouldn't suggest it. They are plugged up with rust from inside the manifold and riser. When they get plugged up like that, they are dead. Consider it as a first warning that you need a new riser. The next step is water in the cylinders as they corrode through. Then, you can loose an engine along with your bad riser.

Re: volvo 3.0 overheating issue

Don S said:

I wouldn't suggest it. They are plugged up with rust from inside the manifold and riser. When they get plugged up like that, they are dead. Consider it as a first warning that you need a new riser. The next step is water in the cylinders as they corrode through. Then, you can loose an engine along with your bad riser.

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So you suggest a new riser? What about the manifold? I tried to remove the manifold, but the exhaust pipe was in the way and I could not remove it entirely. From what I could see it looked great. Cant say the same for the riser, tho.

Re: volvo 3.0 overheating issue

Monte1961 said:

Heres what I did, I just used a hacksaw blade and ran it back and fourth while running water hose to rinse out the crap. It took awhile, but after about and hours worth of work on each of them and lots of garbage, Motor temp was good once again.!

Click to expand...

I took your advice, and the temp is great now! I will start saving for a new riser and manifold...

Re: volvo 3.0 overheating issue

And you may be able to take the manifold out by removing the stud that is behind the exhaust pipe so the manifold can swing up and out.. Mine has exactly enough room. I used the nut from the front side to lock the nut on the back stud, then removed the stud from the head. You may or may not have room depending on how your motor mounts are adjusted.