Collapsed hose Over heating Help water flow from impeller?

[sebas54]

Hi I have a 1987 gm 4.3l merc. I/O aplha 1. I have been trying to figure out why my engine is overheating. Today I noticed that the hose coming from the thermo. housing going to the water cirrculator pump was completly collapsed at high rpms.

What cause a hose to collapsed? Old age?

Can this be the answer to my over heating problems? Just replace the hose?

I've checked the risers, the hoses for blockage, change the bellows kit, and changed the impeller.

 

[King Size]

Re: Collapsed hose Over heating Help

Re: Collapsed hose Over heating Help

that should have a wires spring in it , so replace it and open the t-stat, and take out the t-stat close it up and run it.

Fixed the problem? Put in a new t-stat, if you want.

 

[sebas54]

Re: Collapsed hose Over heating Help

Re: Collapsed hose Over heating Help

It does have wire springs.

 

[bruceb58]

Re: Collapsed hose Over heating Help

Re: Collapsed hose Over heating Help

you have a thermostat in there right?

 

[sebas54]

Re: Collapsed hose Over heating Help

Re: Collapsed hose Over heating Help

Yes I have a t-stat in there.


I pulled the t-stat out yesterday and tested it and it was functional.

Are you telling me to take the t-stat out and leave it out?

 

[bruceb58]

Re: Collapsed hose Over heating Help

Re: Collapsed hose Over heating Help

Yank Out The T-stat.

Bad Bad advice!

No..leave the thermostat in there. Never run without a thermostat. Is the thermostat in place where it is supposed to be?

Is the housing that the thermostat in free of corrosion so that no ports are blocked?

 

[sebas54]

Re: Collapsed hose Over heating Help

Re: Collapsed hose Over heating Help

Yes the t-stat is in there and free from blockage and yes it is in the right way. By replacing the hose do you think that will solve the problem?

 

[tim24]

Re: Collapsed hose Over heating Help

Re: Collapsed hose Over heating Help

Iwould replace the hoses, upper and lower & thermostat check the belt tension .if that dosen,t work then theres a water circulation problem check the water pump good luck Tim24

 

[bruceb58]

Re: Collapsed hose Over heating Help

Re: Collapsed hose Over heating Help

Iwould replace the hoses, upper and lower

Please explain upper and lower. There is only one hose that goes to the waterpump.

The waterpump suction is collapsing the hose so that shows the waterpump is good.

Have you checked the temps of your engine with an IR meter? While you are at it check the riser temps as well. If you have a hot engine yet cool risers, that will indicate that your impeller is doing its job and you have good water flow yet there is something wrong with the engine circulation. If both are hot, you need to revisit either the impeller or the riser manifold.

Taking the thermostat out tells you nada assuming you checked the function of the thermostat.

 

[tim24]

Re: Collapsed hose Over heating Help

Re: Collapsed hose Over heating Help

OK I was thinking as if it was a closed system . I would replace the hose & thermostat still sounds like a water circulation problem,does it do this as soon as it starts?

 

[tim24]

Re: Collapsed hose Over heating Help

Re: Collapsed hose Over heating Help

Well duh! I guess what im asking is does it do it when its not at operating temp? .The well duh was for me since you stated that it happen at high rpm
tim24

 

[sebas54]

Re: Collapsed hose Over heating Help

Re: Collapsed hose Over heating Help

So the hose that is collapsed is because of something down stream and not because the hose is old? So the cause of a hose collapsing is because of a restriction or obstruction and not due to old age? Thanks.

 

[sebas54]

Re: Collapsed hose Over heating Help

Re: Collapsed hose Over heating Help

please help. i removed the hose coming from the outdrive and it seemed like it had sufficient flow. it didn't shoot up 12" just a good flow at idle.

 

[gene8084]

Re: Collapsed hose Over heating Help water flow from impeller?

Given this is not a closed system, it sounds like the thermostat is not opening / not opening enough. Replace it.

I've had exactly this scenario in my 94 Suburban. After a substantial amount of troubleshooting I determined it was a failed pressure cap on the radiator. Oddest thing I ever saw...the hose would go flat, temperature all over the place at high RPM's...just as you describe. New cap and wella fixed. I didn't know they failed.​

 

[tim24]

Re: Collapsed hose Over heating Help water flow from impeller?

Is this boat in fresh or salt water most of the time ? . the water pasages in the block could be getting pluged up due to salt water .Iwould remove the pump and look at the cavity,also look at the impellers tim24

 

[sebas54]

Re: Collapsed hose Over heating Help water flow from impeller?

Thanks for the advise. I will change the water cirrculating pump tomorrow with a new thermostat and new cirrculation pump hose.

It is only used in saltwater.


Again, what is the cause of a hose collpasing? Old age or restriction?

 

[gene8084]

Re: Collapsed hose Over heating Help water flow from impeller?

Is this boat in fresh or salt water most of the time ? . the water pasages in the block could be getting pluged up due to salt water .Iwould remove the pump and look at the cavity,also look at the impellers tim24

ah, good point, the circulating pump could be starved for water due to clogging in the block.
​

 

[bruceb58]

Re: Collapsed hose Over heating Help water flow from impeller?

Before you go changing the water circulating pump, have you measured the temps of the risers? If those are too hot, you have a water flow problem, not a block circulating problem. Did you actually pull the risers and inspect the water passage?

Engine water pumps usually go bad because they leak. They don't stop pumping.

Have you recently driven your boat over sand or mud?

 

[sebas54]

Re: Collapsed hose Over heating Help water flow from impeller?

I did pull the risers and inspected them and they where in very good condition. I replaced them 2 seasons ago.

I didn't take the temp. of the risers but they are hot, to hot to keep my hand there for more than 5 seconds.


Should I take the exhaused manifold off and inspect them as well. I replaced those also when I replaced the risers.

I took the inlet hose off comong from the impeller and there was good flow. It didn't shoot out but it was flowing good.

Yes I have dirven it over sand a twice this season only for a second or two.

 

[bruceb58]

Re: Collapsed hose Over heating Help water flow from impeller?

If your risers are that hot then you are not getting enough water flow. Forget about the circulating pump and the thermostat for now. You need to get the water flow corrected.

Have you ever run the engine without water going to it...even for a few seconds? Who did the impeller change and how long ago?. Were there any pieces missing from the old water pump? Have you checked the power steering cooler for blockage? maybe some of that sand you went over got clogged in it.