xr4 over heating

[hl]

Having trouble overheating under 2500 rpm. the water pressure was showing 8-10 psi at wot. Replaced the water pump put new gaskets on the poppet valve but did not replace the spring in the poppet valve. Replaced the exhaust manifold gasket thinking a leak was causing the over heating problem. When flushing out the cooling system I noticed some water coming from the exaust. What could be the problem?

 

[j_martin]

Re: xr4 over heating

Most of the water goes out the exhaust. You should have a bit more pressure at WOT.

Did you replace the water pump housing and base wear plate, or just the impeller? Either you're not getting enough water, or you have bypass problems, either poppet or thermostats. You could have a bad outlet seal on the water pump.

Also, what is your WOT rpm with a light load?

 

[hl]

Re: xr4 over heating

I was hoping you would reply,JM. We replaced the complete water pump kit($52)
WOT shows around 5200-5300 RPMs. PSI does not pass 10. Also mention that when replacing the poppett valve last April, I found what appear to be a gas hose with a steel bolt stuch in. This was blocking the othe side of the poppett valve water flow. I put it back togher without the hose/bolt rig. after this is when I saw the drop in the psi. Before this the psi was 15-18. Good question for you, John. Where is and how do you check for outlet seal. I can finf this in manual

 

[j_martin]

Re: xr4 over heating

Don't know about the hose. If there is one on the poppet, it should be connected to the same fitting, top center aft the flywheel, that the pressure gauge is connected to.

Outlet seal should have come in the kit. Seals water tube to the water pump.

 

[hl]

Re: xr4 over heating

The hose/bolt was a rig someone said that served as a by-pass. ??? Could low rpm timing cause overheating at slow speed?

 

[CharlieB]

Re: xr4 over heating

Possibly gasket leak at the exhuast adaptor plate between the block and the mid, leaking water directly from the inflow into the exhaust and lowering pressure throughouut the whole RPM range.

 

[hl]

Re: xr4 over heating

Already replaced both gaskets on the exaust. Any other suggestions