RICKY PEREZ

Need Help With Merc 600 Sci's . I'm Having Trouble Running My Engines Above 4700 Rpm. The Smart Craft Race View Is Putting The Engines In Guardian Mode Do To A Charge Temperature Overheat. I Have Checked My Strainers And They Are Clean. There Is Plenty Of Water Pressure According To The The Race View .there Is 35 And 37 Psi At 4700 Rpm. All Other Parameters Check Out Fine Except The Blown Air Temp. Any Ideas ??

Griff

As you say, its the intake charge temp that is too high. You might need to get some more fresh air into engine compartment to feed them.

Whats the outside air temp????

RICKY PEREZ

My Boat Has Two Large Scoops One To Each Side. Outside Temp Is In The Low 90's . Its Miami So It Is Always Hot. I Do Not Think It Is The Air Going To The Blower. It Is The Air Boosted After The Charger On The Way To The Manifold.

tomcat

I have only looked at these engines at the Miami boat show so I'm not an expert, but some thoughts anyway.

You need to confirm that water is flowing through the intercooler. Locate the intercooler outlet line where (I believe) it dumps into one of the tailpipes. Disconnect it and plumb extra line where you can see it dumping overboard. I think the intercooler is fed by the sea water pump so when you start the engine you should see water flow. If the intercooler is fed by a seperate pickup the boat will have to be on plane to see much water flow. This test will tell you if you have a blocked intercooler.

I don't know but maybe it's possible for stuff small enough to get through the strainer to be big enough to still block the small water passages in the intercooler. The water flow through the intercooler possibly helps relieve block pressure. Isn't 35 to 37 psi on the high side? Also suggests the intercooler is plugged?

Good luck

relaxalot

I have a 600 sci with problems. They always seem to point to low water pressure or hi intake charge temperature. I have spoken with four other 600 owners with the same problem. Does anyone have any words of advice? I replumbed the 600 with a bottom pickup for the motor/sea pump and I have the vertical holes in the XR all blocked with the front nosecone holes feeding just the intercooler. I changed the exit of the intercooler to dump overboard instead of back into the headers. I was getting hot exhaust gases back towards the intercooler with the "stock setup" . The boat will run great for a brief time but most of the time will not run past 4600 rpm. I am running a teague strainer (small). I know that this problem exists for many merc 600 sci owners. Any solutions? I have tried changing sensors but they are the same. Scan tool says low water pressure. There are no blockages in the system. I am going to try taking the strainer off line to see if that is the answer.

dcrighton

Had the same problem with my 42PR....I would back flush the intercooler and the oil cooler as there is probably debris stuck in the which is inhibiting water flow. This will inhibit the performance of the intercooler and you will get the "chrg air temp" code and ultimately "guardian mode" if you stay into the throttle. Trust me....been there, done that!! Drove me crazy for a few days as the guardian mode would come on immediately after the CHRG AIR code which led me to believe I was hitting the limiter prematurely. Ended up being a bunch of seaweed stuck in the intercooler and oilcooler which caused the problem.

Whipple Charged

Both go hand and hand. Not enough water, you get high IC discharge temps. I feel water psi needs to be at least 25psi whatever way possible. 28-30 is where th stock system goes into reduced power mode.

Whipple Charged

Listen to what DC said. I have no doubt you have debris or a block in the IC core or the oil cooler. I have a few things that will help this as well. Some water routing changes that will really help. Standard strainers do not filter the debris properly for the small water passages.

relaxalot

The mechanic is working on my boat again. I will have an update tomorrow.

relaxalot

The mechanic has run the intercooler to the outdrive nosecone only. The intake chrg temperature is good now. The problem is the water pressure. It is in the high twenties. I need to get it into the mid thirties. I have a through hull bottom pickup intstalled that is aggressive. He has bypassed the sea strainer to see if that helped. It did not. The oil cooler is clean and no passages are blocked. Everything has been backflushed numerous times. I guess it's back to the drawing board!