1989 Mits RHD overheating

I have a 1989 Mits with the 3g81 engine, it is a 3 cyl, rhd, 4x4. I recently started overheating so I checked the thremostat, and there is not one ( one is on order). Another problem is when I crank up black gunk shoots out of the tail pipe??? I have been told this is a head gasket, but wanted to see what you guys think. I am also not reaching top speed, max speed is 55 kmh. So I am not getting all the power it should be getting.

Thanks

 

No oil in the radiator, nor water in the in the oil

 

How does it overheat? At idle or only under load - like a long hill?

I'm only asking because mine has started to do it, too. It's fine under minor loads but if I have to climb a long 4th gear hill... the temp slowly climbs to dangerous levels.

It could be something like ignition (that's where I'm going next).

 

Shade tree mechanic

I'm not a mechanic, but I believe poor acceleration, overheating and black exhaust are all symptoms of a bad catalytic converter.

Of course, this assumes that Minicabs had catalytic converters in '89. I know my '94 does.

Robb

 

Mine overheats after driving it on normal terrain for about 15-20 minutes. That is fairly flat ground with various speeds. I have not even thought about the catalytic converter, but yes it does have one. Anyone else experienced this problem? If that is the case couldn't I
just cut the converter off?

 

black gunk in the exhaust is usually a stuck choke or rich mixture/clogged air filter(white smoke is oil or coolant burning)...check that your prewarmed air flap in the air filter is allowing cold air in the intake...warm position is for winter only...the Daihatsu has a manual switch over for summer /winter I assume others may be the same...if there are no coolant leaks, the fins in the rad are not blocked, and the electric fan is coming on ,your overheating is most likely due to the cooling system needing to be bled of air,or stuck/missing thermostat...running with no thermostat will cause both overcooling and overheating...overadvanced timing can sometimes cause overheating ,but you should notice pinging first.....lastly if you don't need the catalytic conv. for emmisions,you can replace it with straight pipe....if a cat is plugged though you will generally notice a severe power loss and it may glow red at night(not good) if you can light a ciarette off your cat it's days are over

 

Tonight I put a thermostat in the truck (there was not one before). I also cleaned the two lines running to the carb that have coolant running through them. I also replaced a vacuum port right beside the thermostat. I also drained all the coolant and replaced it with new coolant. I cranked the truck and it cranked and idled better than it has since I have owned it. I let it run at idle for about 10 minutes then it shut off and made a grinding noise??? I turned the key to try and start it back up and the engine is trying to turn over but there is a grinding noise coming from around the alternator/fan clutch. CAN ANYONE MAKE ME FEEL BETTER AND TELL ME THAT THE MOTOR IS NOT SHOT???? any advice is welcome and much appreciated.

 

hopefully it is the water pump ,which may have been the overheating problem..usually they start to make noise and dump coolant before you overheat..sometimes (rarely) all the fins corrode on the impeller and limit water flow..I would check the pump first...don't try to start it again till you check it as it..the bearing is prob. gone..they make a hell of a noise when they let go.

 

Water pump is a great place to start looking. Also, if your fan is engine-driven (by the belts), check your belt condition and your fan clutch. The fan clutch is a viscous coupling, and it is supposed to lock the fan to full-on when the temp reaches a certain point. Look for oil leaking from the center of the fan clutch area, maybe spreading out onto the fan blades. A failing fan clutch may have caused the overheating, which may have led to further damage, unfortunately. Lack of a thermostat is not a good thing. If the coolant is flowing through the radiator too fast to be cooled enough, this will lead to overheating at higher RPMs. I have seen people remove thermostats to cure overheating, and it may work under certain conditions, but they are usually removed to mask other problems. As far as the "grinding noise" and stall, I would suggest removing the accessory drive belts and trying to restart the engine, but only run it for a minute or less if it restarts. Spin the water pump, alternator, and any other belt-driven accesories by hand and see if they spin freely. I have seen bad water pumps, alternators, and other belt-driven items cause an engine to crank sluggishly and/or not start. Let us know what you find.

 

My spelling is most likely wrong on the "viscous" coupling, I think I meant "viscuous", but that doesn't look right either. Somebody help me here!

 

Is there a clutched fan on that truck??..my bad thought they were all electric fans...I think it's viscous..I'm too lazy to spell check

 

My 94(?) Mitsu has a belt-driven clutch fan, so I am thinking the earlier models did as well. Electric fan(s) wouls be nice--anyone done that upgrade?

 

Alright guys, I ran into another problem. My timing belt broke, I ordered a new one, replaced it, set the timing and the truck will not crank???? HELP

 

will it turn over by hand ? you must have had to turn it by hand when installing the timing belt? remove the spark plugs and turn it over by hand to see if it will do a complete rotation.and to see if maybe there is unburned fuel or maybe coolant in a cylinder causing hydraulic lock.check that the timing belt is 100% properly aligned(it's quite easy to install one 180 degrees off) Is this an interference engine ? If so it is quite possibly a bent valve as Greg stated

 

I would try removing the spark plugs and trying to crank it over gently using a ratchet and socket on the center crankshaft bolt. Give a second or third look to your timing mark alignment on the crank and cam gears, and anywhere else that has marks. There may be more than one mark per gear, and they may be hard to identify. If it is an interference engine, you may have bent the valves, as Greg said. Let's hope not.

 

My response was almost a carbon copy of fupabox's! Sorry for the repeat, I did not see his reply.

 

Expect a call from my lawyer

 

Crank or fire?

 

Was that the Dewey, Fukem and Howe law firm? I think I know those guys!! They are handling my home mortgage restructuring right about now.................
Anyone got a place to rent????

 

alright guys. My truck is back together and running. It now has a new timing belt, machined head, new valves, head gasket, intake manifold gasket, thermostat, electric fan, new plugs, wires, distributor and cap, and radiator cap. I am still over heating?? Just sitting at idle my temp gauge will go up to 1/2, and running in 3rd and 4th gear on flat road it runs in the red within 5 minutes. PLEASE HELP I am getting sick of not being able to use my truck. Only thing left could be radiator and water pump right?

 

Overheating 3G83

Wow!

You did all that and it's still overheating. Have you tried another form of checking the temp? Maybe the gauge is toast.

Please let us know how it goes. I'm about to rebuild my overheating engine, too. I think it's the pump in my case. It idles up to 1/4 temp and goes to the "danger" line after about 20 mins on freeway.

It looks like there's not much else left for you to check. Gauge, pump, and radiator.

I flushed my rad but it didn't help..

 

sounds like either an air lock in the cooling system(needs to be bled with the bleed screw up near the thermostat housing, the system if not properly filled with the heater on full hot and the bleed screw opened will easily overheat when under load),water pump not pumping properly (with the engine running at idle and holding a rad hose can you feel an increase in pressure when revved up?)...catalytic converter is possibly blocked..is it low on power? (unbolt the cat and shine a light through it..you should be able to see through the honeycomblike material inside)

 

BTW I had just rebuilt my engine and it was overheating the same way as before.. after a long load.

I had my radiator recored $300 and the problem is gone.... just sayin'.

 

Cooling System Troubleshooting Tips

Auburn,

This may provide some assistance in your troubleshooting approach.