Settee Covers and Engine Overheating

[Nomad]

I come bringing gifts and also seeking advice.

The settee covers on my boat were rotten from sun and stained from what I can only imagine to be oily butts.  I called a few upholstery shops and was shocked at what the cost to recover them would be so I did some measuring.  After hours on the internet I found a cheap solution; full size futon covers!  I ordered a very tasteful set (girls comment) and they fit beautifully.  They are just the right length and have about 3 inchs left over on the width but that tucks behind it nicely.  They go for about $60.00 a piece... a heck of a lot cheaper than the upholsterer.  Tip: get the thin thickness listed as good for 5-6" mattresses. The covers have a zipper that goes around three sides and if those thoughtless people with oily butts make a mess you can take the covers off and throw them in the washing machine.

Now my engine problem: if I let the engine idle for about a half hour it overheats.  It runs cool for about 20 minutes between 160 - 180f and then spikes.  the oil temp light comes on and for some reason the fuel pump starts running making that annoying noise.  Background: I changed the oil and filter (thanks to your suggestion the smaller filter stopped the v-belt slap), I also changed the impellar because the old one was shot, I now have good flow out the exhaust at normal temps but flow is reduced as the engine heats up for some reason. 

Any suggestions?

Thanks Nomad 

[Craig Weis]

If the seat covers are a nagahide type material I use 'White Wall Tire Cleaner'.

Engine over heating...Hummmmmmm

Water passing through block and head too fast, not staying around the castings and valve seats to pick-up and carry away the heat. 

Maybe she is just rusted/scaled up inside the cooling passages and exhaust passages or manifold blocked.

Might want to drain the block and fill her up with the [?sorry brain fade] acid used to clean missionary jobs.
As long as nothing is aluminum you'll be OK. Local hardware store.

But you will find where everthing aluminum  WAS  after an all day soak. Thermostat to slow flow?

Air bubble, bleed the block. Air won't cool the casting. Are you running heat exchangers in a closed system? Are they plugged?

Water pump passages need to pass flow, not just change the impeller.

With a hose on the pressure side [say a 3/4 inch fitting]. Fire up motor and with hose several foot above block, the pump water should push water up this hose or more. Foothead, a indication of pumping capacity.

Oil cools about 40% of total btu's generated. Oil pressure/pump. Sump topped up?

Cooling water inlet clogged, Outlet Clogged. Strainer full of junque? [ours on the twin 383ci houseboat motors were full of Chicago River 'rubbers' as we traveled through Chicago to the Illinois/Mississippi. We had to stop and clean them out. Yuk! Hose pinched. Flow.

Timing too far advanced or retarded, or frozen and not working. Timing light and dwell meter. Set to specs. Wrong plugs...or

Is it a diesel? Fuel pressure setting is key here. A diesel will eat all the fuel you can pump it and then just blow up as a run-a-way rpm. Self destruct. See a real tractor pull competition.

Too lean. Gas 14.5 : 1 ratio. Carb not metering?

Prop pitch too much. Making the motor work too hard.

Shaft packing too tight? Should drip a bit.

Typical belt slipping?

All carboned up?

This really does not apply here, but...on my 1976 Jaguar XJ 12 Coupe that I use to own, ANY water temp was OK as long as it stayed in the enclosed syste. So let her reach 195 deg F.  skip.

Sorry can't come up with too much more. Good luck.

[Nomad]

Sorry if I did not include enough background

I have a 1987 CP 27 with a Universal M12 diesel engine in the standard configuration.  I was thinking last night that maybe the resevoir/water trap in the exhaust system is filling up and not allowing the seawater to flow out the exhaust creating too much back pressure.

Extra info:   the engine starts to slightly surge in rpms at about the time it spikes the temp.

I think that I will take it down the river tonight and see if the problem exists at higher RPMs.

[spaul]

Nomad, our friend Skip pretty much nailed everything. I have the 18HP yanmar diesel and found the intercooler had bits of rubber impeller blocking the intake side of the cooler. If you've had to change very many impellers, the PO's must have also. This is not too difficult to check but demands some dismantling on mine. Your's may be easier or harder.
While you're in there check the thermostat or just replace it for insurance sake. Do as Skip suggests and check the prop shaft, it should turn by hand but I suspect you're talking about idling in neutral. Let us know if you have success.

Steve

[Craig Weis]

Thank you friends for the kind words, skip is humbled.
As for Kevin and the fire ...wow that was close. Turned out well.

Impellers,,, A non-rubber inpeller that cost a wee bit more can be had. Use it!

Never have to replace that imp again. No rubber stuff floating around in the block.
Good sailing Good motoring. skip.

[perseverance272]

Just a thought. Maybe it's overheating due to the lack of raw water flow. I have a 1989 m2-12. I recently changed the raw water pump, but then ran into an issue of low water and overheating. The pump was working great, but the heat exchanger was clogged. I'm thinking the new pump and pressure  dislodged some gunk. I relaced the heat exchanger and the water flow was significantly stronger than it's been since I bought the boat. Temp's now don't go much over 140.

It's possible that gunk is clogging, then blowing through which might explain the variations.

- Jason

[Nomad]

Well it turns out to be mostly my fault.

A sizable chunk of rubber impellar was found in the elbow joint under the raw water input to the pump.  After it was removed the flow is amazing, I think I have gained a few knots on the speed due to the jetboat effect from the output (yeah right)  I will look into the non-rubber impellar as suggested to save this headache again.

During my easter egg hunt for a solution I did find a weakness in the fresh water system pressure cap.  It was original equipment and had lost its ability to seal.  $4.95 spent at the auto supply shop for a new cap and the system is pressurized now.

Thanks to all who submitted suggestions

Nomad   

[spaul]

Skip, I am terribly interested in the non rubber raw water impeller. Do you have a source for us?
Regards
Steve Paul

[Craig Weis]

I do have an outlet for these impellers so let me call the guy and and we'll hook you up. skip
Just be a day or two.   

So. No big deal the material talked-up is NEOPRENE not rubber.