Z145 cooling problems

[Lava Rancher]

I purchased my z145 powered 135 with a 30 day return warranty. I promptly had surgery which prevented me from putting it through its paces other than some light grading and a few hours of mowing. The temp gauge didn't work from day one but like the idiot I am I monitored it by feel and thought that it was cooling fine. I'm now pretty sure that it is not. I went out today and switched attachments at an idle, maybe five minutes of running. Fan turns, radiator is clear of obstruction but it was pretty hot. I pulled the cap off an couldn't see coolant. Then I added... almost 3 liters. I've seen some loss and have been topping it up from time to time but three liters is quite a bit. I can see that it is pressurizing and blowing some at the cap. No white smoke. Oil seems new and clear of foam or other water contamination. The dealer replaced the temp gauge prior to sale and swore up and down that once replaced it worked. I could start with the gauge, $40 but my gut is that there is an underlying problem. Any ideas?

I'm thinking that before further use I need to tear in and make sure that it is cooling properly so that is priority one. I've also noticed that the fuel line to the carb is not metal. I'm guessing that this isn't the original configuration and I'd best rectify that as well. Looks like I'll have to rectify my lack of mechanical ability and get dirty. Still runs well but I don't want to ruin the engine or have it burn to the ground.

 

[Mike476]

Thermostat would be the first thing I'd check. If unable to replace it right away I'd remove the old one and run it without one until I could, better it run cool then too hot.

 

[MasseyWV]

Thermostat would be the first thing I'd check. If unable to replace it tight away I'd remove the old one and run it without one until I could, better it run cool then too hot.

I agree that the thermostat is the first thing you should check. Better yet, I would go ahead and replace it with a new thermostat just to be safe. Also, be certain to confirm that you are using the right thermostat that falls within the correct heat range. You may also consider replacing the radiator cap while you're at it.

Overheating a Continental Z-145 engine can be risky because the blocks are prone to cracking if they get too hot, and from the sound of things you were dangerously close to running it completely dry of coolant which would definitely not be good for your engine.

With regard to the fuel line, my Massey 135 does have a metal fuel line with flair nut fittings at either end. Making a new one out of steel or copper tubing should be fairly easy to do using parts commonly available at your local hardware store.

 

[Lava Rancher]

Thanks to both of you. Hopefully the block isn't cracked.

 

[MasseyWV]

Thanks to both of you. Hopefully the block isn't cracked.

If your block was cracked, there would probably be evidence of coolant in your oil. However, this doesn't automatically mean your block is cracked because a blown head gasket can cause the same thing.

 

[Mike476]

Once you've removed the thermostst run it with the cap off and look to make sure you've got good transfer of coolant, you shouldn't have any problem seeing it with the thermostat out.

 

[BobG_in_VA]

I'm pretty sure you have to take the gas tank off to get to the thermostat, etc....while you're doing that you might as well replace the water pump...hey...is the 135 a Delux, ie. does it have a tach/hour meter? If so does it work and how many hours are on it...you can tell if the thermostat is opening once it gets warm...take the radiator cap off, check to see if fluid is moving in the top of the radiator..if not, either the pump is not working or the thermostate is stuck closed....note that the fan pulley and the waterpump are actually separate parts, they are press fitted together...when the engine is off, try and move the fan with your hand,,,,does it move back and forth???BobG in VA

 

[Mike476]

I wouldn't run it for too long if it's getting that hot with the thermostat still in it. Once you've removed it and replaced the cast housing, check for circ through the rad cap. If you've got good flow replace the thermostat with an OEM thermostat, not a generic one, and check it again.

Don't think you have to remove the tank to change it, didn't on my Z134 and my manual makes no mention of it for the Z145, but I'll take that for what it's worth (IT manual).

I had to change the pump on mine, it is a press fit on the shaft, if you're going to check the water pump pulley and fan for play make sure you relieve the belt tension. Changing the pump isn't a difficult job, removing the pulley from the pump shaft takes patience but isn't difficult.

 

[Lava Rancher]

Tractor is a deluxe. No tach drive so hours show 4000+ who knows how much.... Eyeballing the waterpump looks newish. Can't see much in the radiator. The cap is not at the top but offset to the rear so you can't see into the top of the rad.

 

[Jerry/MT]

These old tractors don't have coolant over flow tanks so when you fill the cooling system, you should only fill to the about 1/4" above the top of radiator core. The rest of the volume is for fluid expansion, when it heats up.

The only way to tell if it's overheating short of having it sieze up is to measure the temperature of the coolant. get a high temperature thermometer or one of those infra red thermometes and measure the upper rad tank skin temperature. It will be within a few degrees of the coolant temperature since it's thin metal.

If it is over heating then things to look for are a stuck closed thermostat, clogged air side of the rad (dirt and chaff get in there from mowing , etc) Make sure the fan belt is tight and check the lower hose when you rev the engine. There should have a wire reinforcement in them to keep them from collapsing but sometimes people forget to put them in or use the wrong type hose.

Make sure the rad cap is holding pressure and has the correct pressure rating. Remove the rad cap start the engine and see if coolnt starts flowing from the water pump when it get warmed up. If it's not the thermoststat is stuck closed or the water pump impeller has corroded away.

Make sure the timing and the carb mixture are per the spec. Retarded timing and /or lean carb can cause overheating and also burn exhaust valves.