Subaru L series coolant overflow bubbling

[daaave]

Hi Guys,
Would appreciate any insight that can be offered on this.

My 1990 L series has coolant bubbling or boiling in the radiator overflow after driving for approximately 30 mins. The temperature gauge never goes past 1/3 and takes about 20 mins to get to this level.

Some other symptoms:
-Some coolant leaking from top of overflow tank- I guess if it is not sealed it will boil at a lower temperature?
- Heater does not work in car which i believe is somehow linked to the coolant?
-Uses approximately 100ml of coolant per 100km.
-Occasional ticking from engine indicating low oil pressure? Doesn't seem to leak or burn oil and the ticking noise comes and goes.

If anyone has any suggestions this would be great. Hoping it is possible i just need to replace radiator overflow cap to get better seal? Cheers,
Dave

 

[taza]

Hi Dave, first off I would be replacing the coolant with genuine Subaru Coolant and then see if the problem occures again. It might be old, inefficient and time for a change...
The radiator overflow cap doesn't need to be very tight as the overflow tank should never be full to the top! Only about half way up.

I can't help with the heater issue or ticking noise though, sorry. I don't own an L-Series. I will say that my Forester does burn oil and has done ever since new, its never been an issue though You might want to add your location and a signature containing some info about your vehicle too.

Regards
Taza

 

[dirtyRU]

Howdy & welcome to ORS daaave. Might be time to have the coolant system flushed out.
Does the ticking happen to come about when accelerating/ goin up hills?

 

[mr turbo]

G'day daaave & to ORS.
I agree with what others have said. Do a radiator flush & replace it with some new genuine Subaru Coolant & see if that helps.

Even though your temp gauge never goes past 1/3 is it possible that it's not functioning properly ? If so, it could mean that the thermostat is gone & needs to be replaced too.

Regards
Mr Turbo

 

[El_Freddo]

I'm with mr turbo - get the cooling system flushed and have the thermostat replaced while at it. Also replace your temp gauge sender unit - it's probably not giving you an accurate reading anymore which means you might have a higher temp than you first thought.

I use Techalloy (I think, its something like this anyway) coolant - when headed to the snow I use their anit freeze/anti boil coolant - goes well

Pull the radiator too - have it "rodded" at the local radiator joint, this is where the radiator guy cleans out all the cooling passages in the radiator - apparently an L series can still function ok on a radiator that's 50% blocked!

Other things to look at are leaks in the cooling system as these will not be helping. Pull up the passenger's floor covering and make sure there's no coolant there - if there is you've got an issue with your heater core. A simple U bend installed under the bonnet in the heater hoses (engine side) will keep you going, just without a heater until you pull the dash and replace the core. This is how I remove my dash.

The worst case scenario if the problem continues after you've check out the cooling system is that you've most likely done a head gasket. How far has your L gone so far? 300K Km is pretty common if the coolant hasn't been replaced regularly enough/had the level checked regularly.

Hope this helps out.

Cheers

Bennie

 

[daaave]

Thanks very much to everyone for the helpful replies. The car has done 265,000 km so hopefully it isn't a head issue. I guess one way to check would be to see if the bubbles occur before boiling point by using a themometer?

I was a bit suss about the temperature guage not operating accurately so I will get this sorted out and the radiator flushed and hopefully the car will have many happy years ahead of it.

Any idea what a head gasket replacement would roughly cost? I am located in Perth, WA.

 

[Prop1]

Bubbling is a sure sign of a bad head gasket. How does the oil look? Is there white smoke coming from the tailpipe? A bad head gasket can cause leakage of coolant into the oil and/or into the cylinder. Air bubbles are a sure sign of the latter.

 

[Kevin]

^yes, if your oil is milky it has been contaminated by coolant and signals larger issues. Also, your heater is not working because its not getting any coolant delivered to it and is a common sign of cooling system problems.

 

[El_Freddo]

Thanks very much to everyone for the helpful replies. The car has done 265,000 km so hopefully it isn't a head issue. I guess one way to check would be to see if the bubbles occur before boiling point by using a themometer?

The bubbles will occur at any time that the engine is running. This is why I'm suspect about the heads at the moment - you seem to build up to boiling and you haven't told us that there's coolant/air making the coolant overflow bottle bubble when the engine is running - this means a dead head gasket for sure!

Cost? Depends on who does the work. I've got no idea of anyone in Perth except a fella called RSR555 on ausubi who I think runs a workshop, but seems to be doing other things offshore at the moment...

Cheers

Bennie