No water flow, major overheating 5.7-4V....HELP!!!!!

[Fordiesel69]

1988 Four winns w/ V8 OMC cobra 5.7-4V

Boat ran fine all day. Pulled it out of the marina, pulled the boat 25 miles, dumped it into another marina. Started it up, it was already warm so I just drove off. We could not exit the marina and it was pegged. Went back to dock and riser, manifolds and engine is super hot. No rubber burning yet, and I beleive no damage.

One thing I will mention is twice a season I forget to put the drive down upon starting, and today was one, I turned the key and before I could relase, it started and idled. I, without a single pause put the drive down. Could this have ruined something for the 1-5 seconds while the drive was up?

Got home, pulled impeller housing, looks perfect and impeller is new. Hose going from drive to transome looks good and is firmly connected. I get no flow from the drive to the t-stat housing. Thus no flow to risers. Inlet holes look nice and clean. At a complete loss here.

If the hose came off the power steering cooler it would be puming into the bilge. Any ideas at all. I really need to get back on the water tomorrow as I will be letting a lot of people down that drove some pretty long distances.

 

[HT32BSX115]

Re: No water flow, major overheating 5.7-4V....HELP!!!!!

Hmm. Well, barring any blockage between the pump and the engine, here's something that *has* happened in the past......

See #38 below? They have known to break off.....

 

[Fordiesel69]

Re: No water flow, major overheating 5.7-4V....HELP!!!!!

I am not able to turn this piece with a pair of pliers. This piece could sure break if there was a siezure of the impeller, but I see no evidence of this and the impeller looks like new so I beleive the shop when they said it was replaced.

 

[Fordiesel69]

Re: No water flow, major overheating 5.7-4V....HELP!!!!!

1988 Four winns w/ V8 OMC cobra 5.7-4V

One thing I will mention is twice a season I forget to put the drive down upon starting, and today was one, I turned the key and before I could relase, it started and idled. I, without a single pause put the drive down. Could this have ruined something for the 1-5 seconds while the drive was up?

If this ever happens in the future, the correct procedure is to put boat on trailer, raise the drive up all the way. Pull the boat, lower drive all the way until water drains out. Put boat back in water, lower drive all the way, THEN start it.

Well guys, this right here was one of the problems, it caused an air pocket. I took everything apart and found absolutly no obstruction. Also spent a long time trying to get the drive to pull from a big tub. No avail. I talked to the mechanic that did the steering shaft seal and he said the cobra's get air locked and that they also do not pull from a tub, rather the drive needs to be submerged.

 

[malcome]

Re: No water flow, major overheating 5.7-4V....HELP!!!!!

I know this is an OLD thread, but I think I have something for others viewing this one to consider. I bought a used 1988 4Winns with OMC 4.3 a few years ago. First time out over heated bad, had to be towed in. I figured it was due to a bad outdrive W/P impeller. The impeller was bad, so I replaced it with a Seirra kit. That seemed to solve the problem, except I'd still occasionally overheat while motoring from the marina to the lake. Reving the engine would cool it down so I kept thinking it was the vent hose.
NOT...while recommisoning the boat last year I noticed the power steering intercooler was leaking. I remove it and using a propane torch to melt the solder I removed the end caps. I found it was clotted up with broken W/P impeller peices. Cleaned it out and resoldered it, no over heating issues since.

 

[Fordiesel69]

Re: No water flow, major overheating 5.7-4V....HELP!!!!!

This is good advice. I did inspect my PS cooler and all the tubes were clean. My impeller luckily did not fail.

 

[HT32BSX115]

Re: No water flow, major overheating 5.7-4V....HELP!!!!!

One other think to think about (which you briefly hit upon) if you want to use a "tub" when you run it out of the water, It won't work as good unless the tub water-line is at the same height as it is when the boat is actually sitting in the water.

When you do that, the waterline is just up to or slightly over the raw water pump in the drive. Those impellers have to be primed to work. They won't pump air.