Omc Crossflow overheat alarm

[Lockjaw]

I have an intermittant overheat alarm on my engine. 89 GT175. I have the XP 2.6 heads, and I installed new temp sensors when I added the heads a few months ago.

Periodically, after running at WOT for a while, and idling in, when I go to restart I get the alarm, and of course the SAFE mode operation.

My H20 pump is in really good shape, I just checked it, and I have more then adequate water pressure when running.

Any idea's? The water temp at the lake saturday was 58 degree's, so I shouldn't have had any problems.

Thanks

[Riverratt]

Did you pull the thermostats and make sure they were not melted at one time?

[Lockjaw]

Yeah I looked at them when I swapped the heads. In fact, I used the one's off my engine.

It's really weird how it does too. First time it happened I was at Lake Guntersville, which is full of milfoil and hydrilla, and figured I just got some blocking the water intakes. Apparently not.

I guess its going to be time to replace the stats, and popets and all that mess. :mad:

[bw1969]

Does your motor still have the VRO? How about the vacuum switch? These can also set off the alarm.

[Lockjaw]

It doesn't have VRO, but it appears to still have the vacuum switch. The tone I get though is solid, and it limits engine speed to 2500 or so.

[racer]

Did you inspect the dividers when you had the heads off? Are you sure that both head gaskets sealed good?

[Lockjaw]

I am not sure what the dividers are, but the head gaskets seem to be sealed well.

Its just weird how it does. Not all the time, just every once in a while. :confused:

[Riverratt]

I am assuming the dividers he is talking about are the 3 black rubber divider plugs that go between the sleeves.

[Lockjaw]

I don't recall seeing anything like that. :confused:

Time to hunt on the BRP site.

[Lockjaw]

Is it called a deflector?

[Riverratt]

yes, that is the part I am talking about and pretty sure that is what racer is referring to but I may be wrong.

[Riverratt]

You may also want to pull the cover off the head and see if they is any build up in there that is blocking anything while you are checking out the thermostats.

[Lockjaw]

There shouldn't be anything like that, I just put the heads on a couple months ago, and I have only been in a very very clean lake. Besides, I had the heads tanked, and blasted, so they were spotless.

Whatever the problem is, it has carried over, even from prior to the head swap, and I replaced both temp sensors. I reused the original thermostats, and popets and all that. Took them out of my old heads, and installed in the new. They were all clean too.

I have good water pressure, always have. I do have the motor a little high right now, but it maintains good pressure, except when turning sharply. I was going to drop it 1/4 inch, but don't expect that to be a fix.

[Lockjaw]

How many of those deflector things do I need? 6 or 6 per side?

[Riverratt]

6 total 3 per side. Does the motor actually get hot or do you think it is a false reading? I Have seen water pump impellers that look good but still did not pump correctly. For a couple of dollars I would consider replacing the impeller. Hopefully racer will step in again with his input before you replace everything.

[Riverratt]

how much water pressure are you getting and what does it go to when you turn and it drops?

[racer]

Yes on the 6 rubber deflectors, if they are not round they tend to block off water flow and create problems, I have seen this missed way to many times. Replace the entire pump assembly if it will not pump a solid stream out the thermo cover when they are removed (at idle in a tank not a flusher). Of course assuming it is getting hot.

[Riverratt]

Yes on the 6 rubber deflectors, if they are not round they tend to block off water flow and create problems
racer could you explain this? I just installed new ones in mine and like you said they are round. When you say if they are not round they block water. Isn't this the purpose of these is to block water? I am just trying to better understand the cooling system. Thanks.

[Lockjaw]

I have 20 psi or so at wide open throttle, depending on the prop. I get more pressure with the raker.

It drops to almost 0 psi in a turn, and of course I don't keep going like that, but it is one of my tests to see if the engine is to high.

I guess I will have to order the deflectors, and head gaskets, and a couple other parts.

I have a steady stream out of the pee hole. I don't have any pressure at idle according to the gauge, when I am in the water and in or out of gear. I have a pump assembly new from the dealer, I haven't used yet.

Hey how do you get the impeller off? Mine wouldn't budge when I had the lower unit off.

Any tips to getting the deflectors in and out? Is it a hard thing to do?

Racer??

[Riverratt]

once you pull the pump housing off the impeller should pull straight up. There is a wedge shaped keyway on the shaft but that only keeps it from turning. I just use needle nose plyers to pull the deflectors out and I just spray a little wd40 on them to put them back in or spit on them.:D

[Lockjaw]

I could not get my impeller to budge, or I would have replaced it. I certainly don't want to by prying on stuff down there. That cannot be good.

Man I don't want to order all this mess again. :mad:

SUX!!!!!!!!

[racer]

The deflectors control flow direction and when they swell they block the flow on the intake side causing an over heat. Hold the impeller and turn the shaft opposite direction to get the impeller loose.

[Lockjaw]

Thank you Al!!! :)

[Riverratt]

The deflectors control flow direction and when they swell they block the flow on the intake side causing an over heat.
Thanks for explaining that racer I could see that being a problem if it swelled out into the main passage.

[yags]

you should have water press at idle. are you running the ss t stats they tend to blow horn with low pressure at idle. you can install long shaft pump housing with no bleed off hole in housing this will raise your water press.housing#435959. make sure your water tube is in pump housing all the way.have seen them crushed and shortened.you can also install v-6 offshore t stats 133 deg #437090 10 deg less than434841 crossflow t stats. while you have heads off check for warpage with straight edge and feeler gauge. .004 max. check corner to corner and straight down middle.:)

[Lockjaw]

I am running whatever thermostats came in the engine.

I got a brand new BRP water pump kit ready to go, not sure what the deal with it is either. My experience has been the BRP stuff is pretty well made.

I have a cheesy gauge, it came on the boat, so that could be part of the issue too. I don't think it picks up until 2 psi or something like that. Probably be a good idea to replace it with a better one.

I don't think I have any warpage issue's. Everything looks good there.

[yags]

you should see at least 5 psi at idle out of gear. don't assume your head is not warped check it. gauge may be correct since you are having an issue. didn't you say you used the t stats from your engine heads? the temp will be stamped in the vernotherm. this may be hard to read. if they have low hours and are omc or bombardia stats the cross v stats will have red paint on bottom of vernotherm and loop v offshore will be green. tony. hope this helps you out.