Volvo Penta AQ131D compression problem

[TrevorStott]

Not sure what you mean, what 2 cylinders are lazy? could the light colour be because I laid it upside down and poured a bit of gas into the cylinder heads to see which ones held? #1 had no compression and #3 is about 120PSI (on the low side). 2 and 4 were at 150PSI.

Had the head tested today and there's a problem with the #1 intake. I think I've found a good shop for fixing this. He's saying that if he can machine it, it's be $80 to $100. If it needs a new valve then we'll see but it shouldn't affect the overall price too much. Complete rebuild would be $350. Everything is in Canadian dollars...

 

[aimlow]

#4 valves are dark.

Piston crowns tell the story on oil control..if any area of the crown is "washed" at the edges, oil is getting past the oil control ring.

 

[TrevorStott]

So is that indicative of a piston ring issue? The motor is almost 30 years old. Is it a real issue or just not perfect? Cylinder 4 tested at 150psi.

 

[aimlow]

So is that indicative of a piston ring issue? The motor is almost 30 years old. Is it a real issue or just not perfect? Cylinder 4 tested at 150psi.

Could be an ignition issue, or a fuel distribution issue.

 

[TrevorStott]

okay, I'll take a look at the intake gasket. Plugs, wires,distributor were all recently changed not that that rules it out.

I'm impressed that you can look at the colour of the valves and pick that out, pretty amazing from my perspective.

Thanks everyone!

 

[TrevorStott]

It's been a while since posting on this thread but we're coming out of the deep freeze.

Got the head back from the shop and started reinstalling all the components. Amazing that the spec on the head bolts is 20Nm then 40Nm then just crank it 120 degrees. I would have thought there'd be a final spec. Head is on, timing belt is on, sea water pump has a new impeller and gasket. As I'm putting things back together there's a number of O-rings I need to replace on the sea water pipes. Are they special or do I just get plumbing O-rings?

Stern drive is coming as well, u-joints are out, bought new ones but the caps are taller. Everything else is the same in terms of locations but the distance between where the clip goes and the outer surface of the cap is about 1/16 more than the original. Any issues with that?

Also the stern drive smells like it has gear oil in it. The manual states that it should get the same oil as the motor which is 20W50. I bought extra so I could change the oil in the stern drive but should it have gear oil or motor oil? Seems odd to me to put motor oil in the stern drive.

 

[kenny nunez]

I was a Volvo dealer for many years. 30 weight motor oil non detergent was what was used then on all the AQ models. Anything heavier like gear oil would cause the drive to slip.
A new timing belt should have the yellow marks that line up with timing marks on the respective sprockets. The rubber sealing rings have a slot that fits over the flange on the ends of the copper tubing. And there are some that just slide over the tubing that fit in the oil cooler.
Did the machine shop check the valve lash? There are shims that fit under the “buckets” that set the lash.

 

[TrevorStott]

Okay so no gear oil in the outdrive, should I go with sae30 or stick with 20w50 motor oil as recommended?

Timing belt is reinstalled and all the marks align. Mechanic said that on the AQ131D there is no valve lash adjustments. When they rebuilt the head the head guy did work on the valves and i seem to remember him doing something there to make sure they aligned.

I'm not sure what you mean by the slot in the O-rings. I dont see that on the ones that are on there.

 

[kenny nunez]

Try to stick with 30 weight for the drive.
If the end of the copper cooling line is slightly flared then you need the ring with a receiver groove to fit over the end. Otherwise you may only need the ones that just slip over the end of the tubing. Quite often they can be used over if you cannot locate new ones.

 

[kenny nunez]

Valve lash on the 131 is between .015 - .016 cold. It is easy to adjust with the tool and shim washers that Volvo has. Hopefully your lash is in specification.

 

[TrevorStott]

okay, will pick up some SAE30 for the stern drive. Valve lash I'm going to have to look into more.

 

[alldodge]

okay, will pick up some SAE30 for the stern drive. Valve lash I'm going to have to look into more.

Have a look here

http://boatinfo.no/lib/volvo/manuals/131_171.html#/60

 

[dennis461]

okay, will pick up some SAE30 for the stern drive. Valve lash I'm going to have to look into more.

Just check to make sure no valves are 'tight'. The shimming process is simple enough, but you have to buy/rent the shim assortment pack, which is on backorder here...
https://www.ipdusa.com/products/6282...valve-shim-kit

If you find you want to dig into this, I have a spare cylinder head I could pull shims from, but it will be hit-miss for correct size.

 

[TrevorStott]

How does one remove the flywheel bell housing? I have the bolts out and about 1/8" gap between the housing and the motor but I can't get it to come any further. I've tried some prying and light taps but I know it's cast and not really meant to be reefed on. Thoughts?

 

[Scott Danforth]

if the PDS is not coming off, then the PDS shaft is rusted to the damper.

wood shims - equal pressure and slowly work it off.

then you have something else to fix

 

[TrevorStott]

Trying the wood shims. I've got them pretty tight in there and nothing so far. I'll leave tensiin on it for a bit and see if i can knock them in more. I tapped the shaft to see if i could break the rust too. Could I get WD40 down there?

 

[TrevorStott]

Pic

 

[Scott Danforth]

you can use kroil, PB blaster or a 50/50 mix of acetone and ATF. WD-40 is for dispersing water, and may work, however the others are penetrating oils and do work.

 

[TrevorStott]

Okay, thanks. II'll pick something up tomorrow when stores are open. Do I squirt it in front of the flywheel or behind, front being the motor side.

Thanks for your help! You mentioned something else to fix, I'm definitely doing the bearing, is there more now?

does it ever end?

 

[Scott Danforth]

you need to get the shaft spline to coupling spline area which will nearly be impossible to hit. not worth wasting time to spray anything between the flywheel and block as that wont get you anything.

most likely something may break. that would be the something else to fix.