Coolant Problems
 

Hi,

Having some grief as usual with my subaru :( I have a 1995 WRX Classic that is about to be set on fire. Before I bought the car, I had read about impreza's needing engine rebuilds, so I made sure I bought a car that had already had the engine rebuilt. Therefore my engine has 10k on it since it's rebuild, it was rebuilt with a closed deck block and nitrated crank, but apart from that it is standard running standard boost.

I was driving the car about for about 300 miles since I bought it then i noticed it started going up an extra couple of notches on the temp gauge and then going back down again. This went on for a week, so I checked the coolant and the header tank was empty! The heaters were blowing cold at this point, but they always had since I never tested them when I bought the car, lesson learnt there.

I decided to drain all the coolant out of the car, flushed the system out with a hose pipe, then refilled it with the correct coolant with a 50/50 mix. I also removed the thermostat and tested it was working properly which it was. When refilling the coolant, I don't know if it bled properly, but the process i followed was:

With the engine off, kept filling the header tank until I couldn't fill it anymore

Switched the engine on with the heaters on full, then continued to top up the header tank until i couldn't top it up anymore, i waiting until all the bubbles stopped coming out of it too. I waited a good half an hour before putting the cap back on.

The heaters never went hot, but I realised later that someone had unplugged the wires for the heater servo, so when I plugged them back in and the heaters worked :)

I've driven the car about for a week with no problems with a mixture of slow and fast driving, then tonight I noticed the heaters started blowing hot and cold intermittently every now and again. Then tonight the engine temp started creeping up past the half way on the scale and the heaters went cold, so I drove home, about 5 mins. The temp never reached the top of the scale though, but was higher than normal.

So I popped the bonnet and went to take the cap off the header tank expecting to see no coolant in it, instead the coolant burst out like a volcano and went all over the place.

Does anyone have any advice or suggestions on what to try next, or should I just burn it?

Any help would be amazing

Thanks

Ross

Sounds like there are some air locks since the coolant change that need bleeding out - but removing the pressure cap just after driving isn't the best way of doing it.
The older problem of coolant loss and the heater plug removed sounds a bit suspect though.
Get rid of the air locks and monitor the header tank level when its cooled down!
If still losing coolant then its time to pressure test the system/ exhaust gas sniffer test.

nick

Doesn't sound good mate to be honest - It's either an airlock, or your head gasket is on the way out/gone. Just paid £1800 on my 06 STI after the head gasket went so I know exactly how you feel !!

I would get the sniffer test done sooner rather than later, that will give you the indication you need although that isn't always 100% accurate.

What is the best way of doing it?

Yeah your right it does, I can't understand why unplugging the heater temp control would even hide a problem either?

[QUOTE=rossmc;9169201]What is the best way of doing it?QUOTE]

Start the engine, turn the heater to hot & remove the header tank cap, top the tank up to about 3/4 and raise the revs to around 2000/2500 ( you can use the throttle linkage under the bonnet for this) If the tank starts to empty then top it up to 3/4 again

Run the engine until the thermostat opens (steam will start to come out of the header at this point).

Run the engine for about another 60sec & then top the header tank up to the top & refit the cap, allow the revs to drop to idle. At this point go the the overflow bottle (by the battery) and ensure that the coolant level is between min & max.... Job Done!

Thanks, I'll do that, thanks for the guide, and not even one mention of squeezing hoses!

No point in over complicating things ;)

Update
 

Update - looks like my head gasket is away. going to try and fix this myself, engine coming out on Friday. Anyone any advice on removing the engine? I've got all the tools, a nice big garage and a crane

You send like my best friend :thumb: as I have an HG and the engine needs pulling.
Far from Northampton? :D

Nick

Doing a HG on a 1995... 80k... 90k... 100+k miles?

The restored, as-new compression/combustion pressures - after doing the HG/s - may be too much for your aged bottom end to handle.......???

It's no problem, the whole engine was rebuilt 15k ago with new block and bottom end, it is strange that the head gasket has gone again already?

Ah cool :thumb:

Yeah, what a bummer. :(