885 overheating sort of

[GeoffDEAL]

In your first post Top of radiator very hot Bottom of radiator cold -- radiator is not flowing -- tubes some or most are blocked , radiator shop will remove tanks and clean tubes with small rod, problem solved a lot cheaper than motor repairs.

[cobbadog]

While testing and waiting for the engine to warm up. hold your hand on the block in a few different places. If you get a cool patch and a warm one you know your block has a blockage.
Good luck with your testing and hope it all works out for you. If you spot that water leak at the back you will need to fix that too.

[garymiller]

Update- refitted thermostat, topped water up to half way up the header, let temperature build up and periodically taking the radiator cap off to see if any flow coming from the thermostat, no flow until about 75 degrees C and then it was quite obvious the water was flowing back into the top of the radiator. Left it running on about 1400rpm and temperature held steady between 75 and 80 degrees C ran in this way until I got bored then shut it off, as soon as the engine stopped rotatating the radiator cap lifted a threw about 300/400ml of water out and then sucked Air back in. Carried out several other test with the same results. On one occasion while watching the temperature gauge and reving the hand throttle the engine temperature dropped to about 65C in an instant, checking around the engine it had thrown about 300ml of water out of the radiator ( into a container I had set up) when I shut the engine down in it still threw an additional 300ml.

[garymiller]

Just took it for a test drive and it threw a load out of the radiator after about 5 mins running!

[db2d]

Cooling system becoming pressurised, probably caused by a cylinder head gasket failure.

[rid54]

A failed head gasket often sets pressure on the cooling system directly from start - the exhaust gasses seep out and the cylinder pressure is very high. If the engine throws water or shows signs of bubbling/vomiting even when cold, a head gasket failure is indeed probable. If the problems occur only after warming up, I'd be inclined to look at other parts first, before lifting the head. Is there an air bubble caught inside the system? Is there a blockage in the waterways that create hot spots in the block or head (causing local boiling)? Are all hoses in good condition (also internally)? Any leakage from the water pump?

[philedge]

As suggested above, sounds like youve got an airlocked section of the block/head that is getting very hot when running and when you stop the engine water is running into the hot area, boiling off, and the the steam is blowing water out. I'd guess theres a blockage high up in the water ways. They'll be lots of suggestions for clearing blockages but I'd be tempted to remove water pump and hoses and have a good prod round with a running hose and maybe even a blast with a pressure washer!!

[GeoffDEAL]

From your description the water is not circulating most likely due to a large number of blocked radiator tubes, went through all this with my 1494 until i had radiator out again and clamped a large volume shed hose to it and pressure build up showed tubes were mostly blocked so finally tock it to radiator repair and most tubes were blocked end of problems.

[garymiller]

Radiator off and being picked up this morning for stripping and cleaning by a specialist company. I also intend to get a hose pipe into the engine block water ways. No sign of bubbles or oil in the water, the head gasket is new.

[garymiller]

Quick daft question- the engine block drain cock is the brass section screwed full in to be open or fully out, mine appears to be blocked so cant tell, also if i want to remove it is it left hand thread?

[db2d]

The thread in the engine block is right hand.

[garymiller]

Just had a hosepipe into the block, removed the thermostat, blocked the by pass hole and filled with a hose, water came out of the pump suction crystal clear, but nothing out of the block drain. Did the same thing this time into the pump suction, blocking the bypass, water came out clear but nothing out of block drain. After messing around for a bit I removed the drain cock and the plug into the block to find the small water way into the block was blocked, unpicked and and cleaned it out the flushed using the two methods described earlier and water came out of the block drain, actually very clean. Finally connected the hose to the block drain and filled the block till it came out of the pump suction pipe, which ran clear straight away and then blocked the pump suction and continued filling until water came out of the thermostat housing, again crystal clear. Based on that I feel fairly confident there are no issues with the block water passages, just have to wait for radiator to return from its spring clean!

[cobbadog]

Sounds like a little bit of progress which is positive. When you think about it, if the drain cock on the engine was blocked and you have managed to open it up a bit to get water flowing there again. There must be a lot more in that area that is just sitting there waiting to cause more issues. Maybe a good caustic mix in the block left for a while to help loosen more rubbish will help. I bet the radiator is also blocked badly.

[tomryall]

I have used a pressure washer to clean out a cylinder block, put the end of the gun up tight against the hole where the tap was and any other opening you can get to where you took off the pump and thermostat,you can't hurt anything.

[garymiller]

Yes sounds like a good call with the pressure washer! What would anyone suggest for a caustic mix to soak in the block? Unfortunately I'll have to leave it for two week...I've got to go to work!
Really looking forward to getting running again, before fitting the new rings it took cold start, heat and about 20 seconds on the started, now she's away on just the key in less than 2 seconds...result!