x30 exhuast manifold temp variences

[DavidMCX30]

Just bought a 2002 x-30 this spring and loving it! We’ve done a lot of work on the boat but here is one problem we haven't cracked....we blew out an impeller at Lake Wawasee a few weeks ago while on vacation. The folks at the marina -- whom I like and trust -- replaced the impeller and did the standard blowing out of hoses and whatnot. However, the temperature in my port manifold was still high – 160 degrees vs. 100 degrees on the starboard manifold. They went back in and rechecked twice more for obstructions but found none. We went round and round on what the cause could be, with lots of varying opinions from various dealers. Ultimately, they called Indmar and tech support told them this variance in manifold temperatures was OK. So, we chose to leave it alone. The boat seems to be running fine. But I’m still left wondering if it is OK or if I could be doing harm? I’ve searched the discussion board but haven’t found this exact topic covered. Any thoughts? Thanks!

[ahhudgins]

I checked the manifolds on my 95 this summer because a poster had a similar question as yours. Using an infrared thermometer, the temperature varied at different points all over the manifolds and risers. My engine used the 143 degree thermostat (which I have since changed to the 160) and I got readings from 115 to 160 depending on exactly where I put the thermometer. Placing my hand on top of each riser, I can feel a little difference in the temperature. The only way to be 100% sure that you don’t have a blockage is to remove the riser and check. I’m not a big fan of the compressed air method. If there was a piece of old impeller in the manifold water jacket, blowing air into may have only moved it around.

[Cloaked]

I have had the same problem previously with the basic 351 engine.

One thing I learned from the fine folks at Discount Inboard Marine is their trick of the trade for testing the raw water pump for volume flow and, good impeller and housing integrity (wear plate and seals) is to get the engine running and rev it up to about 3k. Disconnect the thermostat end of the hose that comes directly out of the pump. It should fill a 5 gallon bucket in about 15 seconds. I tried this just this evening to see if it worked. Spot on for the 15 seconds, My pump is working fine. I have now eliminated that possibility of an issue I am dealing with. Saved me from rebuilding the pump unnecessarily. Good test. Next step now is to pull the riser from the mainfold and check the flow path there at the gasket. While the riser is off, I am replacing the exhaust hose going into the muffler. Those things are hard to replace without removing the riser. That 3" diameter hose is seriously stiff.

[DavidMCX30]

Originally Posted by ahhudgins

I checked the manifolds on my 95 this summer because a poster had a similar question as yours. Using an infrared thermometer, the temperature varied at different points all over the manifolds and risers. My engine used the 143 degree thermostat (which I have since changed to the 160) and I got readings from 115 to 160 depending on exactly where I put the thermometer. Placing my hand on top of each riser, I can feel a little difference in the temperature. The only way to be 100% sure that you don’t have a blockage is to remove the riser and check. I’m not a big fan of the compressed air method. If there was a piece of old impeller in the manifold water jacket, blowing air into may have only moved it around.

Originally Posted by Cloaked

I have had the same problem previously with the basic 351 engine.

One thing I learned from the fine folks at Discount Inboard Marine is their trick of the trade for testing the raw water pump for volume flow and, good impeller and housing integrity (wear plate and seals) is to get the engine running and rev it up to about 3k. Disconnect the thermostat end of the hose that comes directly out of the pump. It should fill a 5 gallon bucket in about 15 seconds. I tried this just this evening to see if it worked. Spot on for the 15 seconds, My pump is working fine. I have now eliminated that possibility of an issue I am dealing with. Saved me from rebuilding the pump unnecessarily. Good test. Next step now is to pull the riser from the mainfold and check the flow path there at the gasket. While the riser is off, I am replacing the exhaust hose going into the muffler. Those things are hard to replace without removing the riser. That 3" diameter hose is seriously stiff.

I think the marina did a similar test for me. They also put a clear hose on so they could see the water rate flowing through and to determine if there was too much air or other issues. I have to confess I'm fairly new to all of this, so I really have to rely on my mechanic and you guys at this point! Thanks for your insight.

[Cloaked]

Continued from the last post....

Dear Dave,

Further food for thought.....I removed the riser this evening to check for blockage. Nothing there other than clear space for water to run. So why in the dickens (remember the Bob and Tom audio skit - Dickens Cider? ) is the riser getting hot. Everything checks out from the raw water intake all the way through the block, back out the thermostat housing and into the risers. No problems so I am cleaning of the two mating surfaces to reinstall a new gasket for reassembly.... Hmmmmm what is going on? I poke and prod as I often do and felt of the exhaust hose coming off the riser. I felt a soft spot but moved on... Came back to the hose... Hmmmmm.... Removed the hose (since I had the riser off anyway, made it very easy).... There is was... an internally collapsed hose that was blocking the free flow of water out the exhaust. What appears to be going on is that water is exiting into the inner part of the hose (where the wall has collapsed) and is backing up, back into the riser (with a minimal flow going out the exhaust from a small opening where once was a large opening) with nothing but heated water coming back into the riser and being reheated by the exhaust in the manifold. The flow is restricted and is not getting the flow of cool raw water through the riser, as it should. I haven't tested it yet (got late tonight) but I am betting a dollar to a donut that is the issue. I had a spare exhaust hose so I'll reassemble tomorrow evening and move on.

That said, I chewed up an impeller last summer and heated it up pretty good before I realized the reactor was water-starved. I cleaned the pathway for the impeller pieces and found several but felt confident that I had that entire mess out, and as recent, confirmed the such. My point is that the heat from last year's core semi-meltdown did the hose in at that time and was only made worse by continued use of the collapsed hose (without realizing it then). Was late in the fall (then) so I put it away for a winter fix. Been wrestling with it since then and just today, I am satisfied that I have resolved the issue. I'll know in a day or so when I get it back together and lake test it.

[DavidMCX30]

Very interesting. Did it solve your problem? I am going to check my hoses. Great suggestion.
I guess my larger question is this: Is it OK to run with tempertatures of 160 on one side? based on what Indmar said and what I've read here, it seems like this variance might be normal. and it is OK. Your thoughts? Thansk again!

[DavidMCX30]

Originally Posted by ahhudgins

I checked the manifolds on my 95 this summer because a poster had a similar question as yours. Using an infrared thermometer, the temperature varied at different points all over the manifolds and risers. My engine used the 143 degree thermostat (which I have since changed to the 160) and I got readings from 115 to 160 depending on exactly where I put the thermometer. Placing my hand on top of each riser, I can feel a little difference in the temperature. The only way to be 100% sure that you don’t have a blockage is to remove the riser and check. I’m not a big fan of the compressed air method. If there was a piece of old impeller in the manifold water jacket, blowing air into may have only moved it around.

Thanks for the great reply. If I place my hand on the riser, I can feel the difference as well. I said they blew out the hoses, but that was my language; I don't think they used an air compressor--or hope not based on your comments! As the Wawasee Boat Co. mechanic went in three times to make sure there were no obstructions, I feel reasonably comfortable they've cleaned everything out. Your experience with varying tempuratures up to 160 gives me better confidence that I am OK and that this is not completely uncommon. They thought the temperature issue might be a problem because their experience with CorrectCraft is that the temparatures are more uniform. across the manifolds. Thanks for the help.

[DavidMCX30]

Fantastic! Glad to hear that you've solved your issue. I think this type of repair sounds above my skill level, so I'm going to ask my mechanic to take a look. I'll print this thread so he can look at it. Thanks for all your insight. Have fun on the water!

[Cloaked]

Originally Posted by DavidMCX30

Fantastic! Glad to hear that you've solved your issue. I think this type of repair sounds above my skill level, so I'm going to ask my mechanic to take a look. I'll print this thread so he can look at it. Thanks for all your insight. Have fun on the water!

If you can read the wrench size on the side of the wrench, you can do the change-out. Remove 4 bolts (per riser), unscrew three worm-gear clamps, remove the hose(s), install the new hose (easily cut-to-fit), reassemble with a new gasket and anti-seize on the new bolts. Done deal.

Not saying this is an issue with your machine, but the entire cooling system is nothing but simple wrenching.

Good luck and happy boating.

Here's a pic of the new riser gasket and a cleaned surface on the exhaust manifold where the riser / gasket attaches. Easy pickings. There's not much inside of there once it's opened up.


.

[ahhudgins]

Originally Posted by Cloaked

If you can read the wrench size on the side of the wrench, you can do the change-out. Remove 4 bolts (per riser), unscrew three worm-gear clamps, remove the hose(s), install the new hose (easily cut-to-fit), reassemble with a new gasket and anti-seize on the new bolts. Done deal.

Not saying this is an issue with your machine, but the entire cooling system is nothing but simple wrenching.

Good luck and happy boating.

Here's a pic of the new riser gasket and a cleaned surface on the exhaust manifold where the riser / gasket attaches. Easy pickings. There's not much inside of there once it's opened up.


.

Glad you posted that picture. I was just checking on riser gaskets for my Indmar and saw a note on the PCM gaskets. They said that one end of the gasket is blocked OFF (like yours) and the BLOCKED end MUST be installed towards the exhaust outlet. I was just wondering if the riser doesn't have a water port on the back side? If that were the case, you would have to flip the gasket around. I've got some old water stains on my Indmar so I thought I would replace my gaskets.