Volvo 2.3 blown headgasket?

[Robj]

Hello,

I have a 2.3 l , Volvo, with closed cooling. Just getting it ready for the summer, pulled the plugs, and the picture below shows what the #4 plug looked like. There was some green stuff around the electrode, which I guess is antifreeze. I ran the engine to warm it up, pulled the plugs again and did a compression test. The numbers were: 1 - 175, 2 - 175, 3 - 165, 4 - 160. The cylinder with the suspect plug had the lowest compression. My guess is that the headgasket is leaking and needs to be replaced. Just want to make sure that I am on the right track before I start ripping things apart.

Thanx for your help and have a great day,

Rob.

 

[bruceb58]

Re: Volvo 2.3 blown headgasket?

I would first retorque the head bolts and recheck the compression numbers. Also maybe do a cylinder leakdown test.

Have you noticed your coolant level going down?

 

[Robj]

Re: Volvo 2.3 blown headgasket?

Thanx for your reply Bruce,

I did recheck the compression numbers several times since I was somewhat in denial that there was a problem. I also do not know how to retorque head bolts that are torque to yield. Can't just put a torque wrench on it. I am not really looking for an easy way out since I only want to deal with this once and do it right so I can be out on the water this summer not wrenching. I think that I caught this early enough before any major damage happened. I think I will pull the head, send it to the machine shop for inspection/repair and put it back together. I just wanted other opinions confirming that it is a head gasket failure.

Thanx and have a great day,

Rob.

 

[bruceb58]

Re: Volvo 2.3 blown headgasket?

Yes...I just looked up the torquing procedure. I see the extra 90 degrees after reaching final torque.

I would think you could loosen them all up and the retorque...following the final 90 degree requirement.

Volvo recommends replacing the head bolts if they are over stretched or removed more than 5 times.

 

[Robj]

Re: Volvo 2.3 blown headgasket?

Thanx again Bruce,

A friend suggested that the deposit could be due to it running too lean? Will wait for other opinions before I start taking things apart.

Have a great day,

Rob.

 

[Don S]

Re: Volvo 2.3 blown headgasket?

2.3 means nothing. What's the model of your engine?
It's not common to retorque angle torque head bolts.

 

[Robj]

Re: Volvo 2.3 blown headgasket?

Hello Don,

It is a AQ 131C. I believe it is the B230 block. Basically a marinized Volvo automotive engine.

Thanx and have a great day,

Rob.

 

[Don S]

Re: Volvo 2.3 blown headgasket?

To check for leaks between the cylinder and the water jacket, do a modified leak down test. Remove the heat exchanger cap and make sure it's full of anti freeze. Get the engine up on TDC in the firing position of that cylinder. Pressurize the cylinder with around 100 psi of air, and see if you get bubbles coming from the heat exchanger. If you do, you have a leak, could be head gasket, could be cracked head or block. But do not retorque the head.
It's also 120? angle torque, not 90?

 

[Robj]

Re: Volvo 2.3 blown headgasket?

Thanx Don,

My Seloc manual says 90 degrees also. Thanx for the correction. I think that I will do a wet compression test, and then do as you suggested. If anything shows up, I will remove the head and get it serviced by a machine shop. Rather do it now instead of during the boating season, which is late this year.

Have a great day,

Rob.

 

[Don S]

Re: Volvo 2.3 blown headgasket?

My Seloc manual says 90 degrees also.

See what I mean about those manuals

Here's a link to the OEM manual.
http://www.4shared.com/account/file...0_250_251_131151171.html?sId=t7ZEoVqEx0SnPAsI

 

[JustJason]

Re: Volvo 2.3 blown headgasket?

PM from Robj

Hello Jason,

When you have a sec, would you be able to take a look at my post Blown head gasket on a 2.3 litre Volvo. I would really appreciate your opinion. Trying to figure out the best way to deal with this.

Thanx and have a great day

Rob.

Rob at this point another compression test isn't going to help you. You do have a coolant leak into the cylinder. As Don said don't bother retorque the head, you'll more than likely snap a bolt. You really need to do a leak down test. The % gauge on the tester isn't going to help you either, Like Don said you just need to fill the cylinder with as much PSI as your compressor will put out and check for bubbles.
If you do not have a compressor/leak down tester. You can buy test kits to check for hydrocarbons in the cooling system. If coolant is getting into the cylinder, then fuel/air and exhaust gasses are getting into the cooling system. I got one from Napa years ago and it works okay. You just have to make sure you siphon out a little coolant first because you just want to suck air through the dye, not coolant. Google balkamps "block tester" or just go into a napa store a ask for one.
When you get into doing the actual job, make sure you use new bolts from volvo. Follow the torquing sequence to the letter. Instead of cranking them all down to max tq then angleing them. Go in small increments. For example, instead of tq'n 100lbs in on shot, go in 25lb increments and follow the order. The same thing for the angle, instead of 120, go 30, 30, 30, 30 all the way around the head. Pay attention the the small things like see what the manual says about dry bolts or oiled bolts.
Don't forget to check your head and block for flatness as well. You will ne a machinist straitedge and feeler gauges for that.
Good luck!!

 

[Don S]

Re: Volvo 2.3 blown headgasket?

The same thing for the angle, instead of 120, go 30, 30, 30, 30 all the way around the head.

That's not the way it's supposed to be done Jason. One smooth, continuous movement to 120?.

There are some engines that give 2 steps in angle torque. Volvo diesels are one I am familiar with. 90? then another 90, but they also say to do each step in one motion.

 

[JustJason]

Re: Volvo 2.3 blown headgasket?

That's not the way it's supposed to be done Jason. One smooth, continuous movement to 120?.

Interesting, I didn't know that. Honestly I've never done a head on a 2.3 VP but I have assembled quite a few auto blocks (soobies) that use TQ angle after setting the base TQ. I know we are comparing apples to oranges here but on those engine the block bolts are 18 inches long (you have to mate the block halves together first, and the head bolts go through both halves of the block to) And the way they want you to do it is to set the angle is small steps, spinning the crank after every increment to make sure you didn't pinch anything..... And that's why I'm not a master

 

[Don S]

Re: Volvo 2.3 blown headgasket?

And the way they want you to do it is to set the angle is small steps, spinning the crank after every increment to make sure you didn't pinch anything

Yes, but they tell you what increments to do angles and why. With even the method used by Chevy now, the torque is done in stages with a torque wrench, then final angle step.

 

[Robj]

Re: Volvo 2.3 blown headgasket?

Thanx for all your help. Jason I believe that I can reuse the head bolts, for upto 5 times. I believe this would be only the first time that the head has been removed. My logic for doing the wet compression test is to see if the difference in compression between cylinders is due to rings or valves. If the wet test shows uneven compression then I know the rings are in good shape. I know the difference in compression is within acceptable limits, but I would be happier if they were all even, or at least a little closer together.

Does anyone have any ideas as to what else could be on that plug other than anti-freeze? I have thought about the theory of that cylinder running lean and I think it has its merits. The plug insulator is white, and the boat was not running that great above 4000 rpm, it was surging.

Thanx again and have a great day,

Rob.