AQ271C running hot

[brando913]

Ive searched through some of the threads and see alot of good advice. I'm hoping for some help on my repair.
Quick background...bought an '89 Sunrunner 235 w/ a VolvoPenta AQ271C, the Chevy 350 5.7 ltr. The boat was in dry storage in GA for 2 years when I got it and it had not been winterized. Heres what I've done so far. Drained all fluids and changed filters, replaced the fuel pump, starter, water circulating pump, impeller, thermostat and exhaust manifold gaskets. (the gaskets werent leaking but I pulled the risers off to get to the starter.) I've flushed the radiator twice and ran cleaners thru the block to remove any oil sludge from it sitting. I also did a compression test and all cylinders are within about 8 psi from the lowest and highest readings. New plugs, plug wires, distributor cap and rotor tab. There are no noticeable leaks from any hoses or gaskets.
The engine starts right up and runs good on muffs in the driveway but the temp starts climbing after about 10 minutes. The risers are pretty hot to the touch after this amount of time also.
I'm sort of stumped as to what I should check next. Any direction would be greatly appreciated.

 

[captmello]

Re: AQ271C running hot

Welcome.

You need to start at one end of the cooling system and check all the way around. You have a closed cooling system? Antifreeze in the block?

Start with the intake fitting on the outdrive. Pull the 's' hose off the fitting just below the ujoint bellows and check the fitting for corrosion. It's very common for those fittings to leak air into the system.

You don't say what outdrive you have but...

Here's a link, Part #25.

http://www.volvopentastore.com/Intermediate-Housing-290a/dm/*******.519661772--**********.521419933--store_id.366--view_id.329397

Let us know what you find.

 

[brando913]

Re: AQ271C running hot

Captmello,

Thanks for the reply. Yes, closed cooling system and the drive is a duoprop, I believe the 290. The manuals I have refer to 2 different ones for the boat but I think you're right with the 290.
I'll go thru the cooling system on Saturday and check for any blockage or corrosion. If theres no obvious signs of corrosion, is there a way to check for a link in the fittings?
I'll post what I find. Thanks again for the help.

 

[brando913]

Re: AQ271C running hot

sorry...meant any way to check for a leak in the fittings if I'm not seeing any fluids or corrosion?

 

[captmello]

Re: AQ271C running hot

sorry...meant any way to check for a leak in the fittings if I'm not seeing any fluids or corrosion?

The fitting I was referring to would require either a pressure or vacuum test. Both are tough to do without proper hoses and fittings.

Start by checking the intake fitting I mentioned simply by pulling off the hose. It will be obvious if the fitting is corroded. If the fitting is bad and leaking air into the cooling system, it will cause it to overheat.

You've done a ton of work to the boat, you didn't mention the raw water impeller. Is that new as well?

 

[brando913]

Re: AQ271C running hot

haven't had a chance to work on the boat since the last post. I pulled the intake fitting and apparently the boat had been in salt water at some point prior because the fitting was pretty corroded. There weren't any holes but it was brittle and definitely needs replacing. I ordered the new part and will get it replaced hopefully tomorrow. The main bellows need replacing as well so I'll tackle that next. Any tips on the best way to do this and can I do it without removing the drive? I've got some of the supports removed but would rather not pull the drive unless absolutely necessary.

To answer the last question, yes the raw water impeller was changed out when I replaced the water pump.

When running it on muffs last time, I noticed an exhaust leak coming from the drive. This isn't from the bottom where the flaps are but near the middle where the bellows are. Does this sound like a leak from the exhaust bellows?

Thanks for any feedback...the idea on checking the water fitting helped alot!

 

[captmello]

Re: AQ271C running hot

You need to pull the upper gear box to change the ujoint bellows.

Go to this link in the adults only sticky to see about pulling the upper.

http://forums.iboats.com/showthread.php?t=309095

You'll need the two orings that seal between the upper and intermediate sections of the outdrive.

Install the new intake fitting while the upper is removed. The fitting also requires a new seal. Make sure the seal installs correctly with the oring portion down in the groove correctly. You'll see when you do the work.

Let us know how it goes or if you have questions. Make sure you check your ujoints and your intermediate bearings while the upper is removed.

I wouldn't worry too much about the exhaust bellows. If you want, you can change it.

Good Luck!

 

[brando913]

Re: AQ271C running hot

Good, was hoping I wouldnt have to pull the drive. I'll post once I get this done and hopefully will be ready to get this thing in the water.

Thanks!

 

[brando913]

Re: AQ271C running hot

Ok, replaced the fitting and seal and installed new o rings when I pulled the upper drive. Got everything back together and ran it on muffs for about 20 min and temp stayed down around 140. Then it started to creep up to about 180+ before I shut it down. It didnt heat up near as fast as before but still seemed to be running too hot. I'm getting smoke from the tubes coming off the exhaust manifolds that run back to the flame arrestor. Also, the risers get very hot to the touch. Is 20 min too long to run it on muffs?
This has a closed cooling system and when I open the radiator cap (while idling) should I see any circulation with the coolant? Im not getting any noticeable movement with the coolant.
As far as the cooling system goes, I've replaced the water circulating pump and impeller, thermostat (made sure it was a marine part), sea water impeller, water fitting to drive and riser gaskets.
If the sea water pump has a new impeller and the pulley is working fine and not leaking, is there any thing else to check on it? Thats probably the only cooling part I havent replaced but all seems fine with it.
Any suggestions on where to go next would be great!

 

[captmello]

Re: AQ271C running hot

What temp thermostat did you install?

After 20 minutes the risers may get pretty hot. Running on muffs doesn't get the same water flow as having the boat in the water. Have you backflushed the heat exchanger?

Explain your closed cooling. Does it include the manifolds or just the block?

 

[brando913]

Re: AQ271C running hot

Im not sure of the temp rating for the thermostat but its the one listed for my set up thru the volvopenta store. I had originally put in a regular auto one for a chevy 350 and read that marine thermo's are different.
The cooling system includes the manifolds as well. When I flushed the cooling system, I didnt think to include the heat exchanger, Duh! This is all new to me so that one got past me.
I back flushed the entire system again today, including the heat exchanger this time, and this seems to have fixed the overheating issue. I ran it on muffs for about 20 min and the temp never got past 1/4. Even when I ran it up to about 3000rpm it would climb to about 1/2 and and then drop right back down to 1/4. Also, the risers never got hot. They were warm after 20 min which Im guessing is normal. Question, after back flushing the heat exchanger, I'm now getting a sound of a pump motor running whenever the battery power is on. I dont have any switches activated. Its coming from the front of the boat and the heat exchanger/water heater is at the back. Any ideas?

Sounds like you helped me cure the overheating problem. Cant thank you enough...but will bug you for one more fix!

The drive wont go down and not getting any sound at all from the hydraulics. I know you had said to check the connections because they sometimes will get corroded. Where exactly would I find the connectors and if I need to replace one or more of the relays, where are they located? This is for the DP 290A.
Thanks again for your help on the other issues...You've saved me a ton o' cash and a few headaches! This is a fantastic site...glad I found it!

 

[brando913]

Re: AQ271C running hot

...

 

[captmello]

Re: AQ271C running hot

Sorry, I know nothing about your trim system. I suggest starting a new thread specifically about the trim.

 

[brando913]

Re: AQ271C running hot

Ok...I really appreciate all of the help!

 

[brando913]

Re: AQ271C running hot

Captmello, wanted to see if you could point me in the right direction on an issue with my drive. The 290a DP...I pulled the upper gear housing to replace the bellows and water fitting. All went well and replaced the two O rings as you said. Everything is good and running right now but I went to test the drive today before putting it in the water. I cant get it to go in gear. I pulled the upper plate where the shifter is and noticed Ive got water in the oil. I read in one of the posts that theres a lower seal that goes in the upper drive that keeps water out???
I checked the shift linkage to make sure everything was put back together correctly and it appears to be. Also, I was able to get it in gear last week before I pulled the upper housing so I feel pretty certain I messed something up putting it back together.
All of the other repairs have gone fine and the boat sounds great...ready to go. Hope you can give me some ideas on where to trouble shoot this.
Thanks!

 

[captmello]

Re: AQ271C running hot

Make sure you have the correct amount of oil in the outdrive. DP's use 80w-90 gear lube.

Check to make sure the cable is moving the linkage. Have someone shift the boat, engine off, and watch. disconnect the linkage and verify it turns the same amount by hand.

You didn't disassemble the upper gear box, did you?

 

[brando913]

Re: AQ271C running hot

I'm not sure if this is what you mean by disassembling the gearbox but I removed the upper unit and removed the u joints. This way I had access to the bellows and the water intake fitting. When I removed the plate where the shifter is, I noticed the water in with the oil. The shifter moves when I disconnect the linkage so I'll check the cable tomorrow and make sure thats ok. I had just refilled the drive so I think the fluid level was ok. Any idea about the water getting the upper unit? Is there a seal to replace other than the two O rings I replaced?

 

[captmello]

Re: AQ271C running hot

So you removed #52 in this link? Before or after it wouldn't shift into gear?

http://www.volvopentastore.com/Upper-Gear-Unit-Aq-Drive-Unit-290-851340/dm/*******.431403964--**********.872896975--store_id.366--view_id.315489

Let me get this straight. You removed the upper to replace the ujoints and the bellows. You reinstalled the upper, using new orings, and now it won't go into gear?

And now you have water in the outdrive? When would water have gotten in the drive? Did you put the boat in the water to test? Or what?

 

[brando913]

Re: AQ271C running hot

The boat hasn't been in the water this season. I'm running it on muffs for all of the repairs. It was going into gear before I removed the shift plate.

Yes, I removed the upper so I could install the new bellows and water intake fitting. I put in the 2 new o rings, got the u joints lined back up, slid them back on the shaft, lined up the vertical drive shaft, pushed the unit back down and tightened up the upper housing.

I filled up the drive with 10w30 ( The Clymer Volvo shop manual I have says that models 100 and 200 use EP90 gearlube and models 250, 270, 280, 290, SP and DP use 10w30 or 10w40) Is it better to use 80w90?

After hooking up the linkage I started it up and it was running fine. I tried to put it in gear and cant get it to go forward or reverse.

I pulled the shift plate again to check for any obvious problem with the eccentric or shift shoe and thats when I noticed the water in the oil. I drained it all out and did some trouble shooting.

1. disconnected linkage and checked that the shift rod would move when the shifter was put in forward/reverse. This worked fine.

2. removed the shift plate again and was able to manually turn the eccentric. Also, the shift shoe was fine and wasn't binding.

3. removed the upper housing again and checked that the U joints were turning, the drive gear turns fine.

All of the parts are moving fine independently. I'm also guessing that all of the parts move when the boats idling as well. If so, then everything is working fine. Its just not going into gear.The problem seems to be once the eccentric and shift shoe goes back in, the roll pin at the back of the eccentric is sticking in the 12 o'clock position. I see where its notched at the back of the shift plate and is supposed to fit there but its not moving out of that groove when the shifter is engaged. Maybe something in the linkage thats not allowing it to move correctly??? I have no idea how these parts work, I'm only going off of what I've been able to sort of learn from taking things apart and looking at them.

Concerning the water in the upper gear case, The manual I have only refers to the two O rings that should be replaced when reinstalling the upper unit. I installed these correctly so I'm at a loss as to how water is getting in. This is the problem I'm most concerned about.

I'm guessing the shift problem is me just not connecting something correctly since it was working fine before. I'll continue back tracking to see what I might have missed.

Any ideas on this or the water getting in???? I really appreciate any suggestions. You've helped me alot getting everything else done and were almost ready to get this thing back in the water. Thanks!

 

[captmello]

Re: AQ271C running hot

If you have a Duoprop, Volvo recommends GL-5 90W gear oil. The older 270s, and 280s, etc with single props take engine oil.

I don't know how you would get water in the outdrive just running on muffs. The two orings seal the oil inside and water outside. The water from the muffs never passes through to the upper.

Don't know what to say about the shifting problem. I've never pulled the shift plate on my outdrive. I was thinking the same as Don about the coupler not being installed.

You could isolate the upper gear box by removing it and shifting it by hand to see if it engages the shaft. If it doesn't, then you know its in the shifting mechanism.