13 replies to this topic

[designermatt]

And steam comes out of the cylinder head little valve which is near the bypass hose I believe.

 

Recently put a second hand engine in that was alright , bores a bit worn and 2 cylinders had slight bit of surface rust, but when

I compression checked it came out at 170psi  190psi 170psi 185 psi number 1 being timing chain side.

 

Are these figures reasonable , bearing in mind the 2 170 psi cylinders were the slightly rusted ones.

 

So anyway Ive been running this engine up for about 100 miles or so , and its had oil and filter, all new distributor parts, valve clearances checked , and new plugs (ngk bp7es) are they the correct plugs? Ignition timing set at about 1200 rpm vac disconnected to 10' btdc.

 

Fuel mixture I set by sound , and plug colour, Ive got it running okay , idling okay , and it pulls very slowly under load in 3rd gear, Im assuming its fuelling alright , but am not 100% I keep checking plug condition and they are slightly tan colour with weird little mould like deposits on them , is this indicating an okay mixture etc...

 

So shes started overheating after about 10 minutes of driving, the guage slowly goes up and at about 3/4 of the way i turn her off and refill her and get home after letting cool down for 10 minutes.

 

Aux belt is pretty tight , water pump was an old one I put on but im assuming it works, and thermostat I tested and it looked like it opened.

 

Any thoughts?

[panky]

I'd first get a new thermostat. It's pretty obvious when they open in a pan of hot water.

[gazza82]

There is no valve in the head near the bypass hose .... ?

[1984mini25]

Do the heater hoses and the top hose get hot? And with the engine running are you getting any bubbles in the radiator? Although obviously be careful removing the radiator cap, and not to do it when the engine is fully warmed/thermostat has opened.

[timmy850]

Does the heater blow hot air inside the car? Have you flushed the engine block, heater matrix and radiator prior to running?

[Spider]

Sounds like either it has a blown head gasket and / or the cooling jacket is choked up.

[gazza82]

water pump was an old one I put on but im assuming it works, and thermostat I tested and it looked like it opened.

 

 

Never assume anything!

[cal844]

If there is steam from that end of the engine it could be from the water pump

[designermatt]

Water jacket was full of bungy stuff when i got the engine, when I ran it up i flushed it out a few times and also fit a new heater matrix, but i dont think hot water is getting to the matrix either because of an airlock or a dodgey heater tap.

 

When driving to work i got out and noticed a trail of water , looking under bonnet it looks like theres water leaking out of the bypass hose which is new , or coming out of the water pump. ( do these mini water pumps leak when they go like modern ones)

 

So as a matter of course im going to get a new water pump, new thermostat, change heater tap for a straight through pipe so its always on, flush out the whole block again , and then run it up with rad cap off allowing any air to bleed out and then see where im at. If it still overheats then it must be the headgasket is blown, which was new when I built the engine up.

[gazza82]

 

 

When driving to work i got out and noticed a trail of water , looking under bonnet it looks like theres water leaking out of the bypass hose which is new , or coming out of the water pump. ( do these mini water pumps leak when they go like modern ones)

 

 

All water pumps will eventually leak .. the internal seals wear out or fail. If the car has been standing for any time it likely it has started to corrode the internals of the pump which will act like a scourer on the seal very quickly.

 

The other thing that could happen is the small pipe fitment in the head corrodes and clamping up the bypass hose too tightly breaks this .. and it leaks.

[designermatt]

stripped it all down , and the bypass hose was split on the top end, took one off a spare and fitted it all back up okay , I tested thermostat and it opens so i left it, also The water pump is in good condition so I have left it in there for now, however heater tap is blocked and I couldnt bypass it so willl have to find a correct fitting for that.

[Spider]

It does sound quite clear to me that the cooling jacked is pretty choked up.

 

Unless you clean it out, it will give on going problems.

 

You can use CLR or molasses for doing this, but if using Molasses, you'll need to remove and blank off any alloy parts, eg, the water pump for one.

[designermatt]

It does sound quite clear to me that the cooling jacked is pretty choked up.

 

Unless you clean it out, it will give on going problems.

 

You can use CLR or molasses for doing this, but if using Molasses, you'll need to remove and blank off any alloy parts, eg, the water pump for one.

yeah I would like to do this as when flushing there is always fine specs of rust and silt and oil residues inside , what is CLR , is it some kind of chemical that will break everything down so that it thoroughly comes out ?

 

molassess as in the sugar type thing?

[Spider]

CLR   https://www.amazon.c...over/B000KKKNUW

 

and molasses is the sugar one. about a 10:1 mix. It will take about 3 - 4 weeks to work.

 

CLR will clean the whole cooling system, however, the Molasses will only work on Cast Iron and Steel.

 

< EDIT: Dusky here on the forum has had success with Vinegar. I have heard of using Vinegar, but I've no experience with it to draw on.  >

Edited by Moke Spider, 27 May 2017 - 07:12 AM.