3.0 gl only running on 2 cylinders.

[gibby86]

I have a 2004 3.0 GLM-B volvo penta only running on 2 cylinders. I have replaced spark plugs, spark plug wires, and ignition module. The distributor cap and rotor look good. I also took the valve cover off and ran it to make sure a valve wasn't stuck and all look good. I tried to set the timing but it won't idle only running off 2 cylinders. I can run the engine and unplug the #4 and the #3 spark plug without any changes but if I unplug the #1 or the #2 the engine will die. I do have spark the the #3 and #4 spark plugs. Could The coil be bad and possibly not sending enough spark to the #3 or #4 spark plugs??? Any help would be greatly appreciated.

 

[gbeltran]

Re: 3.0 gl only running on 2 cylinders.

You need to do a compression test before doing anything else.

 

[gibby86]

Re: 3.0 gl only running on 2 cylinders.

Ok I did a compression test and the #1 cylinder is 150 psi, #2 is 45 psi, #3 is 43 psi, and #4 is 0. Now what can cause this?

 

[fishrdan]

Re: 3.0 gl only running on 2 cylinders.

#2 is 45 psi, #3 is 43 psi, and #4 is 0.

WOW that's bad. I would put compressed air into the cylinders and see where you hear it hissing out, carb, exhaust, oilpan/valve cover, another cylinder. 2&3 might be a blown head gasket between those cylinders, #4 might be a hung valve. You'll need to do some troubleshooting.

 

[Don S]

Re: 3.0 gl only running on 2 cylinders.

I wouldn't even waste time pressurizing the cylinders. With compression like that, you could have 2 things wrong and only the worst one would show up.
Time to pull the engine and pull the head and pistons and start inspecting things.
Once you find out what all is bad, it might lead you to WHY it all went that bad. Which is something you must find ................. The WHY.

 

[gibby86]

Re: 3.0 gl only running on 2 cylinders.

Well it's not the news I wanted to hear but I'll tear into it and see what I can find out. Thanks for the input guys.

 

[Don S]

Re: 3.0 gl only running on 2 cylinders.

Take pictures, and post some here. We can probably help you find out what happened.
Here's a link to the OEM service manual for your engine. It will help.
http://www.4shared.com/document/JryiDwmM/7743358_Engine_Manual_30_GL_GS.html?

 

[gibby86]

Re: 3.0 gl only running on 2 cylinders.

Thanks will do. I may be awhile bc I'm getting married in 2 weeks so my time is kinda pressed.

 

[Don S]

Re: 3.0 gl only running on 2 cylinders.

Thanks will do. I may be awhile bc I'm getting married in 2 weeks so my time is kinda pressed.

Are you kidding????????? Call off the wedding. Dude, we got a boat to fix here

Just kidding of course. Congratulation.

Post back when/if you can.

 

[redneck_cdn]

Re: 3.0 gl only running on 2 cylinders.

most likely the head gasket has blown out between #2 + #3 cylinders.
Is there any water in the oil?

I had a similar issue last spring with a "new to me" 96 Four Winns Horizon 175 3.0GS (HU) lost compression on #2/#3. $150 in parts to replace the valves, gaskets + the cost of getting the head machined flat again. Had the head/manifold off in 30 min in the garage. A bit of a pain on my boat as you have to remove/install the manifold and head as an assembly due to one of the long mounting studs on the rear of the manifold will not permit the manifold to slide off due to interference from the exhaust header tube.

Alex

 

[gibby86]

Re: 3.0 gl only running on 2 cylinders.

Alrighty so I pulled the head and exhaust/intake manifold off yesterday (took 45 min) and sure enough the head gasket was blown between 2 and 3 and the exhaust valve on #4 looked pretty rough. I just dropped the head off at a machine shop to get it resurfaced and to fix the valve. Now all I have to do is order the gaskets and I should be good to go I hope

 

[Don S]

Re: 3.0 gl only running on 2 cylinders.

Make sure the block is good between the cylinders. Use a straight edge to check. With the gasket blown, they tend to erode the metal away on the head and block.