now getting suicidal!!!

[gonfishing]

hi all
thanks to Peters in chi and advice from Barryh i have now rebuilt the top half of my engine and fitted new exhaust manifold, so i started the engine, it ran with a bit of a splutter then smoothed out, all ok so far. So still tied up on the pontoon, opened up the engine, revs picked up to 2800 and held her there ,watching temp gauge, all ok,so went to engine bay and checked thoroughly for leaks all nice and dry, but engine still seemed a bit warm checked temp gauge and thermometer again, and it was like a nightmare revisited !!!! bloody thing is still over heating!! guess it's going to be a lift out to check the pump intake, and leg strainer etc, unless anyone can think of anything i may have missed which would cause it to overheat over 2200 revs????

all new electrics, all new fuel system ,new impellor, and pump housing ok, head waterways appeared clear as did block water ways oil cooler remains cool, so i am totally at a loss now
so any ideas/PLEASE

bo***x to it i gonna get p****d

julian

<hr width=100% size=1>WHAT??? more petrol!!!

 

[NCT]

Hi there


I recently came accross similar symtoms on a car, and found that cause was that the thermostat would not open, replaced it and all was fine.

If the cooling water flow is controlled by a thermostat then it might be worth a try ?

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[JamesDavis]

Similar problem on a Bukh 20. I rebuilt the cooling system which did'nt solve anything. Eventually Gosport Boatyard traced the fault to a collapsed exhaust hose which looked fine from the outside . The narrowing of the exhaust produced a backpressure which restricted the flow of cooling water and caused the engine to overheat. A new exhaust was fitted and the engine has been fine since.

James (Rival 32.)

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[oldgit]

When you mention exhaust manifold are you refering to the exhaust riser.ie the bit where the ex gases come out and are mixed with raw sea cooling water to cool the whole thing down before going back into leg.

<hr width=100% size=1>Two boats please one here n one in the Med

 

[BarryH]

Not so much risers on the 130 volvo, but basically yes thats what hes talking about.

As has been mentioned by other posters. Check the 'stat. I've had a couple that were faulty out of the box. Also check that the by pass in the stat is free to flow water.

Other things that will make it run hot are lean mixture and miss set ignition timing. I know that you've rebuilt the head and the rest of the engine. Check the temp gauge and sender. I find on my volvo 145, that when I switch the bilge blowers on, the temp gauge will jump up towards the hot sector. Don't know if this is perculier to my lump/gauge. Its an electrical thing and not a heat thing.

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[ccscott49]

Put an external head temp gauge on it before doing anything else, one should be available from a friendly mechanic type. Then you will at least know whether it's really overheating, then I would check your thermostat, ignition timing, mixture etc. The hose from your engine to riser could also be disconnected for a very few minutes to check for flow.

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[gonfishing]

morning
having tried all of the suggestions at the weekend have still not discovered any thing conclusive so it's strip down time again suspect there is a blockage in the head so a caustic bath is on the agenda , or perhaps a visit to
<A target="_blank" HREF=http://coastalrides.com>http://coastalrides.com</A> may be the final solution. thanks again for all your advice

julian

<hr width=100% size=1>WHAT??? more petrol!!!