Hi Guys,

Just picked up a 1999 Impreza Turbo on Saturday and think I have to bleed the cooling system.
Symptoms are a hot top hose and radiator, but very cool bottom hose. I' filled the expansion tank right up when I first got it, and have topped up a couple of times since, but the problems still there.
Squeezing the bottom hose gives a gurgling noise in the radiator.
The most worrying bit is given a bit of a boot some steam comes of the radiator and out the intercooler vent in the bonnet and from the front offside corner of the bonnet.

Sound like just the cooling system needs checking? Or am I likely to have a broken water pump or radiator?

How can I check the pump? And the radiator? Or even (boo hiss) headgaskets?

Or should I just bleed the system, (can you give me directions), and hope that makes it better.

Sorry for the questions, new to Impreza's, (I'm used to mini's and can replace a headdgasket, and replace the whole cooling system in a little under three hours on one of those!).

Thanks, Dave

 

If by the offside front corner you mean the plastic expansion/overflow tank, this would suggest excessive pressure in the coolant system causing the cap to lift and release coolant to the overflow bottle. This can be a result of a leaky head gasket, failing cap etc. Rather than topping the coolant up, to ensure there are no air locks drain down and refill using the turbo water feed pipe IE the water pipe that runs from the header tank to the turbo. Don't fill by the header tank, this can be prone to creating air locks. Once done check and run again. also check for bubbles in the metal header tank when reving, this is another sigh of a leaky head gasket. The coolant should circulate as normal and engine will rise to temp normally with heaters blowing when filling this way. It's also worth flushing the rad out while this is been done in the unlikely event its blocked then work from there.

 

Hi, Thanks for the reply.

The steam is coming from the opposite side to the expansion tank, effectively the right hand side of the (UK) vehicle.

With the bonnet open I'd say it's the radiator matrix on that side, but the water pump is also on that side of the engine?

If I drain the coolant from the bottom of the radiator will that release all of the coolant? Then allowing me to know how much coolant needs to go in?

By header tank I presume you mean the small silver tank to the left off the engine, (looking in from the front of the vehicle).

I'll make sure I've heaters and everything on while refilling.

Dave

 

Sounds like the stat isnt opening> Id be inclined to drain and flush,Fit a new stat and refill using the above method.

 

You know, someone else said that to me, I think I'll add it to my to-do list.

Thermostat's on the bottom hose? How easy is it to get to? And can I buy one in (boo hiss) halfords? I ask as I'll pass one on the way home this evening.

D

 

Doubt you'll get one on Halfrauds> worth a try though> a decent motor factors will get one pretty easily>

Yep a couple of bolts (10mm heads from memory) bolt the housing down. best accessed from underneath> the bottom hose connects to the housing, just so you know your in the right place.

 

Okay cool, just phoned halfords theyc an get one in, at £29!

I can go for the motor factors, but not able to collect this evening, instead I'll take it out and test it in hot water. Guessing it'll open around 80deg.C

Will put the car on stands anyway, drain the coolant, check the thermostat and put in new coolant.

If filling right up where's best to fill from, *Un-Ink* above suggested the Turbo water feed pipe, take it off the housing and pour in? I presume with header tank, (the silver tank just above/infront of the Turbo?) cap removed to allow air out.

What's the capacity of the cooling system? Actually I guess that's in the manual.

I'd like to add this is just to quickly get the thing usable. When I've a day off, in two weeks, I'll be treating the car to a full service with filters, oil, plugs, leads, etc, etc.

Dave

 

Subaru Impreza Turbo UK Import Turbo Thermostat & Seal on eBay (end time 07-Nov-09 14:01:15 GMT)

If you can wait (but for Christ knows how long, what with the RM disruption) then you can get an OEM spec one form the link above for just over half that price, all in.

 

Thanks Joz,

I'll stick in an order for some bits, and see when they arrive. In the meantime I'll try some home handiwork and hopefully make things a bit better.

Might be able to free the thermostat off if nothing else.

Dave

 

Also, because the stat bolts to the water pump, you might wanna consider one of those too, while "you're in there":-

Subaru Impreza Water pump Impreza 2.0 & 2.0 Turbo EJ20 EJ20E EJ20G EJ205 EJ207 at Graham Goode Racing

It's remanufactured of OEM parts.

I have one - well over a year old - and it's working fine.

 

Although it may open in boiling water when you put it in its not always a 100% test> Cant remember at what temp they open but its some where around the 80 degree mark> 79 rings a bell for some reason> will probably be stamped on the stat.

 

OEM is 78C... Zero sports uprated jobs are 71C.

Yeah, unfortunately that boiling water test isn't conclusive. But it should open "reasonably briskly" if plonked into the boiling water. If it happens slowly, then best to replace anyway.

 

Okay, an update for you all.

I took *Un-Ink*'s suggestion and disconnected the turbo feed pipe, sticking a funnel in it, and hanging on a wire from the underside of the bonnet to make it a good half foot higher then the header tank.

Anyway, slowly pouring in coolant in, (and I mean slowly - took 4 litres), and squeezing the lower hose, I got air bubbling out, and managed to get coolant right round the system and back up into the header tank. I also added some radweld in case of any leaks, and took the car for a run.

All seemed much better, but I think I've still a small hole in the radiator matrix, somewhere near the top on the drivers side as there's spray on the inside of the body round the headlight aperture, (after a ten mile drive).

I'm going to top the coolant up again, and measure how much I put in, and see if it gets better. If not then I may have to consider the radiator and hoses on that side.

Dave

 

Dave, I had EXACTLY the same thing happen to my old orig rad (it was over 15yo at the time). Luckily I spotted the leak - but it was a miniscule pinhole in the top of the driver side plastic end tank (they get all brittle after about 10+ years).

If the headlight gets very wet quickly (as did mine) then when you have the engine running and up to temp, pop the bonnet, and you should easily see it pissing out of the end tank (could be the core or top hose instead/also), under pressure against the headlight area, etc...

 

Might be of some use, I replaced my radiator because of a cracked end tank (spraying water in the engine bay as mentioned) but when i filled the system back up I put about two litres in the header tank then started the engine and slowly poured the other 5 1/2 litres into the header tank. had no airlocks or problems. Checked it next couple times i use the car, everthing was fine.

 

Hi Joz,
Sounds like exactly the same symptoms, I have to say it's getting better now, (with a little rad weld), I'll have to take another look when I've got time, and see if I can find any holes. Then work out what to do with it!
Dave

 

Yeah, that rad weld is pretty effective stuff.

But keep your eyes peeled. Try not let the engine overheat if you can at all help it - the last thing you want is a HG failure, warped heads, or trashed block!...

Also, when you did the fill up through the turbo hose, did first you remove the little overflow bleed pipe form the header tank to the rad end tank (the thinner of the 2 pipes from the header tank)?

 

Sorry to butt in but how would you know if the waterpump had gone **** up?

 

Water pumps at not common failures on these car due to the metal impellers as apposed to plastic impellers on other cars, rads are much more common to fail on the classics and generally seem to go on the top and bottom of the end tanks where the inlet and outlet connects to the rad.

If the rad is leaking its best you just replace given the time of year its just going to get worse, they are on sale for £110 or there about. Every time the water level drops you risk doing damage to the engine

 

Agree wholeheartedly with the abiove ^^^ - been there; done it, lol

 

No - should I have done?

Yes - Probably next month, as I spent too much this month buying, taxing and insuring the car. I'll just keep a close eye on things for now anyway.

Dave

 

It helps with 'burping' the system, in that any air is expelled to atmosphere (rather than possibly into the rad again) when water starts to flow out of that pipe. So with the coolant still running out, then it's time to fix the pipe back onto the rad's nipple.

Prob not a problem though.

 

Okay - I'll know for next time, which it looks like there will be.
The radweld hasn't made a permanent seal, so I was going to disconnect and remove the radiator assembly, and fill it to look for leaks. Then decide if they're repairable.

I take it the small tap bottom drivers side is a coolant drain tap?

Dave

 

Didn't realise it had one!

 

It might not be, but there's definately something down there that looks like a drain. It's either that or pull off a hose.

Dave

 

It is a drain yes, but its easier to use the lower coolant hose.

 

Coolant's only been in there a week, I'd like to keep it!

 

You can reuse coolant.

Just catch it in a temporary container and reinstate it later...

 

I know, that was the plan! I'll pipe it back into the bottle it came from. I may put fresh in the Subaru, and stick this into the mini 30 as I've just replaced the water pump on that and not put any coolant in yet.

Dave

 

Makes sense.