1987 AQ131D Can't hand turn crank

[mtodd101]

Hi Boaters. I was given a 1987 Bayliner Baretta, 17ft. with a volvo AQ131D engine and a Volvo Penta 275 outdrive that has been sitting at least 10 years. The guy i got it from had bought alot of new parts but never got around to putting it in the water, so now it's my turn. The outdrive had been put away up so i don't know if that's ok. I pulled the plugs and hand turned the crank with a couple of squirts of oil in each cylinder for the last few days. i re greased the tilt mechanism, but the tilt motor isn't working. So today I have the outdrive down, engine is turning freely by hand. Put new plugs and wires on (courtesy of the previous owner) and tried to start it. well it turn maybe a rotation and locked up. I can hand crank it about 3/4 of a turn freely then it hits something internally. Check to see if maybe the new plugs were to long. Took them out and still hitting something stopping the crank from turning. Then i saw the timing belt broke behind the heat exchanger so my long winded question is this, if the timing belt isn't turning the cam would that restrict the rotation of the crank somehow? Thanks for any help, Matt

 

[GA_Boater]

I think, not sure, the AQ131D is an interference motor, meaning the valves will hit the pistons if the cam timing is off. With a broken timing belt, the cam timing is off.

Don't turn the motor over until the belt is replaced and the cam is timed.

 

[mtodd101]

Ok, Thanks GA . I was hoping that I hadn't peeled a piston ring or something. I don't have a service manual yet but figured that with the timing off, maybe the crank was hitting something that should have moved out of the way but new to volvo so i wasn't sure how things work yet. Thanks for the reply. I'll order a new belt. Is there any seals I should be replacing also in regards to replacing the belt. I'm guessing the heat ex changer needs to come off to replace the timing belt?? the belt didn't look too worn and I can't get my fingers in to move the cam gear. hoping it will move freely. Thanks again

 

[GA_Boater]

I don't know about this motor in a boat. I just know about when it was used in a car.

When the manual arrives, it will have the steps to replace the belt. The V-P guys here can give any seal advice - Outta my league.

 

[mtodd101]

Thanks again GA.

 

[jerryjerry05]

Usually, if you remove a seal???
​It's best to replace.
They take a set and become twisted and have flat spots and when reinstalled they can leak.
Make sure the surface where the seals fit is absolutely clean and smooth.
Use a bit of grease when reinstalling.

You'll have to take off the pump and the shroud and the heat exchanger(I think, been a long time)
Lube the tensioner as they rust and can seize.

 

[mtodd101]

Hi Jerry. Thanks for jumping in. So I ordered a new timing belt and a set of cooling seals. As near as I can tell these seals are flat orings. I see the two that are near the impeller housing. I'm not sure if I'll need more than that and what's behind the heat exchanger. Looks like a seal at the thermostat housing also. I was trying to get parts lined up before I start to dismantle the engine. I have a new impeller and gaskets, key, drive shaft, so I'll do that at the same time. I was wondering why the belt broke in the first place. I assume because I could hand crank the motor freely, that the timing belt would be turning also, but when I hooked up the battery and tried to start it the belt broke. Any idea why that would happen? Thanks, Matt

 

[mtodd101]

Hi Boaters. So i have the front of the engine off to replace the timing belt and I have a question about the cam gear. When turning the cam, it feels kinda "spring" loaded and snaps a quarter turn. It does this 4 times for a full rotation. Is this normal? No matter where I leave it I can't get the crank gear into position lining up the mark. Thanks for your thoughts. Matt

 

[mtodd101]

Also, the boat is actually an 1989.

 

[mtodd101]

No Title

So I'm probably going to pull the head as there is an obstruction in the #4 cylinder that i can see but can't seem to remove through the spark plug hole. It seemed to be fixed to the wall of the cylinder and it closed the plug hole by maybe 20% or so. I tapped it loose and it's moving around in there. I tried to vac it out to no avail. I don't have a magnet that will fit through the hole, so i guess i pull the head. Here's some pics from my endoscope. Maybe someone can tell me what all the stuff on top of the piston says. I couldn't get a pic of the object though. Thanks Matt.

 

[mtodd101]

No Title

From what I've read, the VP AQ131D is not an interference motor. It is a non-interference motor. One OHC motors are non and two OHC are interference motors. Anyway here's a chunk of something in the cylinder. Doesn't look like a piston ring to me, maybe a portion of a valve? Thanks Matt

 

[dennis461]

If the color in your photos is correct, it looks like the engine had water in #4.
Then sitting for 10 years, the top of the piston corroded and no longer fits at top dead center.

 

[mtodd101]

Hey Dennis, thanks for replying. I don't doubt that there was water in the engine. It was outside in the NW rain for those 10 yrs. and probably more. Just had 5 or 6 tarps with holes in them. The floors will need replacing as well as most of the wood in the seats. The guy owed me a few hundred that he didn't have, so he offer the boat. So I'm ordering some gaskets for the valve cover, head, exhaust and intake and see how the underside of the head, valves and top of the pistons look like. I did get some pics of the cylinder wall and it didn't look like a lot of water would have puddle up in there. Also the old engine oil wasn't milky so maybe I won't have to go farther than the head. Any idea what the half moon object in the picture might be? Thanks, Matt.

 

[GA_Boater]

Turning cam by hand you will feel the valve spring tension causing it to feel jumpy.

That looks like maybe a valve seat. Not too many other things with a radius about that size.

I wasn't sure if your motor was interference or not. With that chunk floating around and the broken belt, it is now.

 

[mtodd101]

Hi GA Boater. I was just going to ask if anyone thought it was a valve seat or a seat ring. I was looking at an exploded view on the Volvo site and it has a couple rings that seem to be about that size. http://www.volvopentastore.com/Cyli...on_id.418034640--store_id.366--view_id.782301. So I was looking for a set of gaskets for the head, exhaust, intake and valve cover that are quality and won't double my investment in this boat. Matt

 

[dennis461]

No Title

inside view, aluminum head steel seats, right?

 

[mtodd101]

No Title

Haven't been able to break loose the head bolts so I'm not sure how my valve seats will look. From what i've seen so far from the exhaust manifold and head ports, mine are going to be bad.

 

[Bondo]

From what i've seen so far from the exhaust manifold and head ports, mine are going to be bad.

Ayuh,.... I agree with Ricardo on the other forum,....

Cut yer losses, yer not gonna get where ya wanta be cheaply,....

You need another copy of yer obsolete motor,....
I'm guessin' that one has been detonated to death,....

 

[PiratePast40]

Do yourself a favor and pull the engine to work on it. Much easier to work on it while on an engine stand. You're going to need to do it anyway to rebuild the deck, stringers, and transom. Had to do the same with my boat. Once you have the engine pulled and start to tear into the deck, you'll get a better feel for what you really have and you can make informed decisions from there. Do an honest assessment.

 

[mtodd101]

No Title

Hi Boaters. Thanks for your replies and suggestions. So I took the head off last night, well started. I stripped the last bolt at about dark and spent today drilling and grinding it out. So I found the obstruction. It was the valve seat and also the valve. It had broken probably long ago and let loose when I put a battery to it. Top of piston #4 was loaded with the white powdery stuff. I assume that is erosion from the Head?? Cleaned the piston top up and you can see the contact marks. Doesn't look too bad. Cylinder walls look good. Pistons are snug with very little play side to side. I can't tell if the rings are fused to the piston or not, but will look at that more closely. And who every said Volvos are expensive, wow. A brand new head, $4,000, New exhaust manifold, $1500. So I'll be watching Craigslist for some bargains I guess. Any way, here's some more picture to make you feel good about your boat. Matt