Exhaust Manifold / Water Flow Question - AQ170

[keithc81]

77 Glastron - AQ170C - 280

Hello,
I have been having cooling issues. Should I be seeing more water come out through the exhaust or through the hole in the transom shield? New to boats and just trying to understand the exhaust manifold better. Yes I have the overheating troubleshooting guide.

Thank You

 

[Don S]

Re: Exhaust Manifold / Water Flow Question - AQ170

Should I be seeing more water come out through the exhaust or through the hole in the transom shield?

Depends on the angle of the boat and angle of your drive. Water takes the path of least resistance.

Have you replaced your impeller lately?

 

[keithc81]

Re: Exhaust Manifold / Water Flow Question - AQ170

Yeah Impeller was just replaced. I have also pressure checked the line from the outdrive to the raw water pump. I am now thinking either blockage in the manifold or bad head gasket. I am having a water in the oil problem but I suspect the oil cooler. I did a compression check and all cylinders came out within a few psi of each other right around 100.

As far as the water flow I would say it comes out 50/50 through exhaust and hole in transom plate. I am running it on muffs with the drive down on a level surface. Does that sound ok? My issues with heat are only at plane and to eliminate any outdrive air leak problems I installed a thru hull pickup but my temp is exactly the same. Usually runs about 150 - 160 at idle and then right up to 220 when running at plane speed. As soon as i back off the temp drops right back down.

The plan I have right now is to soak the manifold with muratic acid to clean it out. I am not able to remove the plates on the side so hopefully this will be adequate to clean it out. Also thinking now that its torn down to just go ahead with the head gasket. Any other suggestions or am I on the right track?

Thanks

 

[Maclin]

Re: Exhaust Manifold / Water Flow Question - AQ170

That sounds normal to me. The last time I ran mine in the driveway more tended to come out the relief ports than the main exit.

 

[boaterinsd]

Re: Exhaust Manifold / Water Flow Question - AQ170

77 Glastron - AQ170C - 280

Hello,
I have been having cooling issues. Should I be seeing more water come out through the exhaust or through the hole in the transom shield? New to boats and just trying to understand the exhaust manifold better. Yes I have the overheating troubleshooting guide.

Thank You

Hi, i see you are having the same issues as me. I took off my oil cooler and got it press cked , and its good. I then pulled the plugs and saw 1 and 6 wetter that the rest. I just last weekend pulled the head dropped it at the machine shop and got bad news back that its cracked in cyl #2. I also had milky oil and temp problems at times. I took the exhaust manifold off and looked into to to find the 2 passages from and too the engine were pretty plugged with rust and crud. I put the hose to it and got it flushed out. I found the water flows into the engine on the port side ( near the engine) and from on the outside of the manifold or starboard side. Also look for stuff in the water passages around the cylinders in the block, mine had crud also.

 

[boaterinsd]

Re: Exhaust Manifold / Water Flow Question - AQ170

That sounds normal to me. The last time I ran mine in the driveway more tended to come out the relief ports than the main exit.

sorry to say but yours is a v8, because the 6 cyl doesn't have relief ports in it its a different system, sorry......