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Hey all, so my poor L series has a bit of an overheating issue, the thing is it doesnt seem to use water? but if i go on the freeway and do over 80-90 the temp gauge will be right up near red hot and the water will start boiling, or if im just driving it around town for an hour or so it gets alot hotter then it used to.
I've tried bleeding it, as far as im aware theres no air in it.
The electric fan is kicking in when it gets hot.
Theres plenty of water.

I just don't know what it could be, ive checked for leaks, replaced the radiator cap and thermostat, still nothing, put a hose down the radiator and water flows through it fine?
Should i take it to a mechanic, anyone know what else could cause this?
cheers

Seen some stupid reasons like water pump impeller loose on shaft.

Rags jammed up inside heads from previous repair from 8 years ago.

Thermostats jamming at 1/3 of lift.

WATER???
Well thats ur problem right there!!! (american accent)
Nah but in all seriousness, is it just water in the cooling system?
Im pretty sure thats a bad thing as water boils alot lower than coolant.
If u have coolant in the system, leave the radiator cap open, and start the engine and keeep an eye on coolant level at the cap, it will rise a bit when pumping, so if it doesnt rise, the pumps not working.
Are you sure its boiling, have u opend the cap and and seen it boiling, or are you believing the gauge.

It's most likely to be a faulty sender unit or gauge.. I would keep some spare water, yes water is fine just not for long periods of time as it's got no anti corrosion inhibitor in it but it's got the best conductive property (heat transfer) in the car. I would monitor the fans.. see if they cycle on and off by themselves. If they do then you cooling system is more than likely ok. I would how ever, make sure before each summer that you have the radiator flushed and new coolant added.. this will guarantee you against over heating

I'd buy yourself an aftermarket temp gauge and fit that somewhere inside the car (easily seen from driving position) as these generally never fail.

yeah subaru gauges are pretty dodgy and being 30 years old i understand
im still battling over heating on my 2 but i think weve sorted it out, wired the auxillary fan in with the ignition so its always on

spike wrote:yeah subaru gauges are pretty dodgy and being 30 years old i understand
im still battling over heating on my 2 but i think weve sorted it out, wired the auxillary fan in with the ignition so its always on

Yeah Spike.. I've done the same to my Brumby (for now until the EJ25 goes in) but remember that the fan is now on constant and it never gets time to cool down.. thus in turn shortening it's life quiet considerably but good idea for a temporary fix

when my wagon was running ej22 and ej20turbo i ran two electric fans on the motor side of the radiator, one was ecu operated, the other was ran by a switch which i turned on and off when she heated up under hard driving.

i also do this with my patrol, as an extra lil safety thing. My patrol has one big clutch fan and an electric fan on the front of the aircon condensor for when the aircon is on. I disconnected the elctric from the aircon system and ran it to a switch in the dash. Just flick her on with constant boggy sand driving and shes sweet.

This way the fan doesnt have to be on constantly, if you see the temp rising, flick her on and 90% of the time itll cool off.

just remember if you do cook her and shes boiling, its not the best idea to turn it off strait away, just let it idle, turning it off will stop the water pump and youll leave the water boiling inside the motor. not good.

just some ideas for ya to think about.

alex

didnt think about that RSR but it should last a fair while i hope till i sort somthing more permament out.
the reason we hooked it to the ignition is so noone else who drives my car would either forget to turn the switch on and thus over heat the car, or forget to turn it off and thus flatten the battery.

atm my main problem is heat soak when i turn the car off will run fine on the road then when i come up the drive it starts to get hot and when i park and switch it off the radiator overheats and pours water into the over flow

once i take this car off the road and rebuild it im going to put in some little bits to help it out, radiator spray (like intercooler spray) double thermostat, oil cooler, custom radatior things like that just to keep the engine running better and more reliable once ive built my new one

just because water flows from one end of the rad to the other means it is OK. If you don't know service history of rad, take it to a rad shop to pull a tank off to show you limited flow, after you try it withou thermostat at all , just use a gasket and no thermostat - I know, you fitted a newie and same problem. Rad first then water pump is my way.

Just noted the OP mentioned that it does also boil, so definitely sounds like things are getting hot and the guage is probably reading correctly. Given the thermostat has been changed it would probably be and idea to have a closer look at the radiator as steptoe mentions, especially if it's still the original.

Thanks guys for the replies, its definatly not the gauge as when the gauge goes up and gets towards red hot, when i turn the car off you can hear the water boiling and bubbling. so i know its not a faulty sensor.
I'm going to monitor the water usage, i don't think its been using any, but ive been overseas for 2 months (was overheating before i went aswell) and just came back, didnt check any water level but noticed it needed about a litre in it.

Thing is, there is no noticeable water leaks, so is the water boiling and evaporating, or could i have a cracked head/blown head gasket.
I want to get the motor checked/overheating problem sorted before i put more $$$ into the car.

Should i take it to a mechanic, or a radiator place? i want to get it checked for worst possible outcome (cracked head/blown head gasket)?

A litre is a fair amount to add considering total coolant capacity. and was this straight into the radiator, or some the reservoir as well? have you checked the radiator cap? I too would support the idea of a radiator check and service. I suggest a radiator shop and theres one in Wyoming thats good if you are in that area of the C/coast. Also believe that DEMINERALISED tap water is ok for short term, however anitfreeze/boil + corrosion inhibitors are recommended.
Apart from altering freeze/boil points they provide lubricant for W/P seals and have benefit of being easier to detect system leaks as dyes used are easy to spot. Even when dry, coolant leaks are evident unlike plain water which just drys/evaporates completely without trace.
Sorry to ramble but after a frightfull experience with a broken hose and rapid loss of coolant recently, I thought my EA82 was done for. Fortunately I got onto it quickly. All iz good..

Yeah.. if you're not confident with trying to repair it yourself (as I suspect headgasket problem) then I'd take it to a mechanic and if he has to pull the engine out then get him to give the radiator to the rad shop and get it properly flushed/rodded out. Best to do it now before you do too much damage internally to your engine.

Welsch plug in head maybe. Had a similar problem and car was fine idling until going for a good drive then overheated. Never got any water in oil. Car was fine until got out on the road. Idling it held pressure and appeared to never use much water.

OK so starting from scratch, typical probelms with cooling systems are as follows
loss of coolant
loss of pressure (cooling systems need pressure to keep boiling point high)
loss of coolant flow
loss of regulation
ur not loosing much coolant at all, uve replaced the cap and thermostat, ur not seeing oil in coolant.
Just how hot is it getting?
check the seat that the radiator cap sits on, and ensure it has no scores or muck on it.
do a wet compression test in all cylinders, and attempt to do it with the engine both cold, and hot. (V important as it may answer all ur problems, all beit with bad news)
If any cylinder is out by an anomalous amount, (less compression) then uve found the problem.
this would indicate a black crack or gasket failure
If you need advice on a compression test PM me and ill walk you through it.

Just into the red on my L Series was 109 deg C - too hot for any relabilty