2001 RX DI multiple small issues. Follow up

[mikekirk9020]

This post is a follow up from the original post from some time ago. I have been busy. search my earlier post as it was closed.

I replaced the MPEM, No joy. BTW have one for sale. PM me if interested.

Replaced the voltage regulator, again No joy.

Replaced the sensor a third time and No joy.

finally broke down and took it to the dealership.

The wiring harness where it connects to the MPEM was not making contact with the MPEM. They charged me 200$ for squeezing two connectors together. now out of limp mode.

RUNS LIKE A scalded cat.

However, it still overheats if I run at full throttle. I ahve blown out the cooling system with compressed air and water. Followed the manual to a T.

Follow me through on this,

Essentially, the cooling system does not have a pump and relies on the pressure of the impeller to force the water through the system. If they are not 100%, hence not providing enough cooloing water pressure, could that cause the motor to overheat at full RPM?

thanks.

 

[rolex101]

I changed my black cooling lines with clear ones so I can visualize the water flowing. Maybe you should do the same and it may help find the problem.

 

[Coastiejoe]

It is VERY common for sand to build up in the block and start to stack up. Simply flushing and blowing the lines out will not normally break this up. I bet if you remove the head, you will find parts of the water channels partially blocked.

 

[1of500]

It is VERY common for sand to build up in the block and start to stack up. Simply flushing and blowing the lines out will not normally break this up. I bet if you remove the head, you will find parts of the water channels partially blocked.

It will also collect in the pipe and case cooler on the bottom of the engine.

 

[Coastiejoe]

It will also collect in the pipe and case cooler on the bottom of the engine.

Yep,,, to the point that the block cannot even be drained...

 

[1of500]

I hate to say this but you may need to pull your engine. This happens from riding shallow area's.

 

[68ragtop]

Are you getting an engine over heat, or an exhaust over heat? the exhaust water injection cooling loops off that double tee on the right side just behind the fuel rail. Its completely independent of the main cooling system. Im guessing engine overheat, but its worth clarifying.

You really should be able to see where the water is flowing though some of those hoses that are clear, that might tell you something, also is your "pee" tell tail working on the left side? those will usually be somewhat dormant at idle, but off idle & to WOT should give you a a pretty strong stream. That would tell you if your pump is building pressure, but won't tell you how well water is flowing though your head and other areas If you have a boat launch ramp that isn't too busy, back it into the water & leave it strapped to the trailer. Great way to inspect things as it would be when riding. Hooking up on the garden hose is backwards flow, pipe first, then engine so that could be misleading if you've tried that already. In the water, cool water goes to the engine first, then to the exhaust pipe. But the cooling water in the exhaust pipe jacket, is not injected into the exhaust. That comes from the other loop I mentioned above. IF your engine was overheating from the pump, I would suspect the head pipe would be getting awfully hot to the touch as well.

If your impeller & wear ring are in good shape, it sure does sound like a blockage issue like the guys mentioned above.

 

[mikekirk9020]

Rgr, tracking. really didn't want to pull the engine. The telltale is putting out plenty. The head pipe (big black exhaust pipe) gets hot enought that I dont want to touch it.

I sucked a big rock last year that went through the grate and ended up stuck between the impellor blades and ended up pulling the housing. The clearances look a little large, but did not have a feeler gauge to check. I was just wondering if it was possible. The shop pulled the heads, but did not say anything about any sand in the coolant channels.

 

[1of500]

Why did the shop pull the heads?

 

[mikekirk9020]

I think as part of their inspection. they said there was slight scoring, but not very bad. Compression is still within good tolerances.

 

[1of500]

If compression is good I still don't understand why they would do that maybe someone else will chime in.

 

[mikidymac]

I have to agree, not sure why they would pull the head and "slight scoring" is not a good sign especially on the 950's.
Is it possible they installed the head gasket incorrectly and it is blocking the flow of water? I am not sure if these head gaskets are a one way or not like some of the automotive ones if they are not installed correctly they will actually block the water passages.

 

[1of500]

On the carb model sand tends to settle under the base gasket in the channel that goes to the cylinder drain.

 

[68ragtop]

Can't see the reason to pull the head either, unless they suspected a problem. Gasket only fits one way, so really shouldn't be installed wrong. Cooling water goes into the head first from the pump, then flows down into the cylinder water jackets & out into the exhaust pipe. (Not injected) from there, the majority heads out the hose that is used to back flush & some to cool the air compressor & some more out the 'pee" line.

There is also a drain hose that is connected on the block, just below the cylinders. this lets water out when running & of coarse is supposed to let gravity drain the block when its out of the water.

This hose is normally one of the transparent ones & if you can locate it, you can normally see water flowing through it & out the rear of the ski. there is usually two of them in the bottom of the hull heading out to the rear. One from the cylinder & one from the block & mag cover cooler. The block/mag line usually has a quick disconnect in line, this one would not affect engine overheating one bit. The other one "could" as it does let water flow Both should have water flowing out while running, weather its cooling from the pump, or from the hose.

If your pump is strong, it sure sounds like blockage somewhere.

 

[68ragtop]

On the carb model sand tends to settle under the base gasket in the channel that goes to the cylinder drain.

Sounds like the same setup as the DI