Overheating 96 GTS

[ethang]

I bought a 1997 GTS from a guy that seems to have neglected it. I have to do a few miscellaneous repairs to minor things. Finally took it out today and ran great, until about 5 minutes later I got a overheating alarm. Got to the dock and started checking lines. Both "pisser lines" had good flow but one was very hot. It was the one from the top of the cylinder cover and the water was steaming. I checked the cooling supply lines from the impeller and they all are clear and provide good water flow from the pump. I checked the discharge lines and found some sand in them but I cleared it out and the problem persisted. I also noticed that the engine drain line, which comes from the exhaust manifold, had almost no flow through it. So I flushed the engine. I removed the hoses one at a time to make sure water was flowing out of each one. I noticed that the small one running to the tuned pipe did not have any flow as I was flushing it, but all others did (except for the engine drain line). That being said, I know all external hoses have no obstructions at all. It must be internal to the machine. So my thought process says that I have a clog in the pipe or in the exhaust manifold or the engine. I have good flow coming from the cylinder head cover fitting so I don't think I should look there. That leaves the tuned pipe and the manifold. Can anybody tell me if it sounds like I'm heading in the right direction or not, and if so, is removal of the pipe and manifold a hard job? Any other advice would be appreciated as well.

 

[RodInEscondido]

I have found on several of my older skis (ok, all I got is old skis) that there has been moderate to severe sand build-up in the engine water jacket. The only real challenge to checking this is the warning to be very careful and patient in removing the bolts. If the ski has been running very hot there is the risk of bad head gaskets but they are relatively inexpensive.

Is this the 96 with 587 engine or the 97 with 720 engine?

Good luck and have fun.

 

[ethang]

My mistake, it's a 1996 GTS, not a 1997. How do I check the cooling water jackets? Just remove the head cover and vacuum out the holes? Could my problem be in the tuned pipe or the exhaust manifold as well?

 

[RodInEscondido]

I strongly recommend pulling the head. You may be able to stick a vacuum cleaner small adapter down the holes, but it is iffy. Looking at your location I assume this has been operated in salt water (I got the same situation, just a different ocean) which means more maintenance. By pulling the head cover you will get an indication if the previous owner did the reverse flush when getting out of the salt water. At that point I am saying to just pull the head so you can see the condition of the cooling jacket as well as the inlet to the jacket plus you can detect if there is any leakage through the head gasket into the cylinders and correct that before you kill the engine.

My train of thought goes something like: you say there is good flow out of the pissers, just very hot from the one coming out of the top of the head which indicates to me that the flow into the engine is ok, the cooling water is just not getting to the entire cylinder surface to give uniform heat exchange.

A couple pics of salty innards.

 

[andrewsilver]

Did you solve the overheating?

I also have a 96 GTS and it too is overheating - same situation, pissers are unclogged, right one is hot! Want to know if I should remove the head. If I do, do I need a new gasket? Thanks.

 

[RodInEscondido]

Always better to have the gasket in hand rather than days away when heading into the weekend (some person wiser than me said this), gasket is not very expensive and you really do not know the condition of the existing one until you pull the head.

 

[andrewsilver]

I finally figured out the issue on my 96 GTX. The fitting where the black outlet hose connects to the exhaust was plugged. I had to drill out the embedded sand. Thought I'd share for those with a 587 engine overheating.