chris.mcd

Hi

Hope you guys / girls can help me out. Long read please bare with me.

Last week I got my car remapped by Andy F. Since then my car has been over heating alot. Although I did manage to drive all the way to edinburgh and half way back with no problems at all.

It started by the temperature guage staying on red for like 2 secs then going back down to normal temp but then it started staying on red. Obviously I was not driving on red for any amount of time.

I discovered that the coolant from the header tank (top left of engine) was not staying in there, it just kept going into the tank beside the battery causing this to overflow.

I thought this was a sign of my head gasket going, so first of all i drained the coolant then replaced it with brand new stuff. Then I took it to a garage close to me to check the head gasket. They said nothing was wrong at the moment. I got the car back last night.

Last night I took it for a wee drive and everything was fine for about half an hour but again it started to over heat. Stopped at a garage and again nothing in header tank and the tank beside the battery had overflowed/ filled again.

Filled the resovoir tank back up with coolant and drove home 10 miles and it never over heated once.

I dont have a clue what this could be , Has anyone got any ideas at all???

Thanks

Chris

chris.mcd

Anyone got any ideas?

r1gixer1

i1ll be watching this with interest its happened to me too.

djquest

iTrader: (8)

i have the same problem, so i decided to drain the coolent system completely, and then flush it slowly once it was drained. i then refilled the system up with 5l of coolent and about a litre or 2 of water, i forgotten the word for it but it wasnt tap water. as i filled the water up, i would slowly sqeeze the radiator pipe which is on the top left of the radiator. this helped me get rid of any air locks. so far touch wood i havent had any problem.,

however keep in mind when you refill the system back, you may think you wont need any more coolent. however the best thing to do is to start the car and let it idle and keep an eye on the temps. then switch the engine off after 10mins and top up, until the system is full. then switch the car and wait for it to reach normal tempreture which is about halfway on the tempreture guage in the dashboard. if the temps stay at that level and fans come on and go off normally then all should be well.

take the car for a quick spin and once you have parked up. open the bonnet and check the the coolant bottle area. hopefully nothing should have come out of here. wiat for the car to cool down for about 15-30 mins and then check the header tank. if all is topped up their then its all good. but if after all this you still find that you are losing coolent, then check the rubber on the header tank, if this is badly worn this can coz you to lose coolent as well.


i hope this helps. just so you know, since i have done the above, i havent lost any coolent on my car. so im guessing it has worked.

then again their may be somone on here who has different ideas or experience.

all the best

djquest

chris.mcd

Thanks very much for the detailed response.

I will go try exactly what you did and see what happens.

Thanks

Anyone else with anything just say also

TonyBurns

iTrader: (3)

Check the bottom hoses to the rad, they can go, chances are its a pipe thats split and under pressure leaks

Tony

johnnyroper

thermostat sticking closed causing overheating and coolant to overflow and empty the one tank?

have you checked to make sure the radiator has even temperature across the whole core?

only say this as i cannot see a leak causing the problem as coolant is going from one tank to another and then overflowing.if it was a leak i would of thought you would just get level going down and not transfering

chris.mcd

Thanks for the replies guys.

As Johnnyroper said there are not visible leaks plus I am not losing coolant, its just transferring from one tank to the other.

A few people have mentioned a faulty thermosat on this and SIDC.

How do I check for even temperature across the radiator ?

Could it possibly be my radiator that is blocked or would this not cause the coolant to just transfer?

Thanks guys

johnnyroper

it could possibly be a blocked rad best thing to do is run it up to temp and switch off so fan cannot come in,put your hand on it and make sure the temp is even across the core and the end caps are both hot.check the hose from the thermostat is hot it is the one from bottom of block.
if the bottom hose is cold it would suggest a blocked rad or stuck thermostat.
one thing you could do is to remove top and bottom hose's and run the hose pipe in to the top and see if there is any flow through it.
you could also try running without the thermostat for a bit and see what happens then.

Turbotits

iTrader: (2)

If its moving from one tank to the other I'd be inclined to check the pressure cap on the main tank. These do have a blow off point to stop excesive pressure if theres a problem. Either get the blow of point checked using a decent pressure testing kit or buy a new rad/header tank cap.

Also check that the rubber seal is on the end of the cap. There should be two. One is at the top of the spring and the other is at the bottom on the metal disc

Area 52 Autosport

The most likely culprit is either a coolant leak somewhere else in the system, or a head gasket failure.

Is the exhaust smoking more when it's been topped up? Any witness marks where coolant is resting and drying. Any marks where the car is stood overnight, leave a piece of cardboard underneath it if possible to check?


Are you able to pull of the headers to inspect the exhaust port condition, and get a chemical test done on the header tank, your answer could lie within one of these two checks?



Mike.

rigga

iTrader: (4)

Mike....... as stated by the owner there is no actual coolant leak,just a transfer from one tank to the other...... smoking exhaust,coolant in headers,coolant underneath car etc would cause a loss not a transfer.

sturu

get the system and the cap presure tested sounds like there is either a leak or the cap is knackered . is the rad getting hot of staying cold as scoobys are a nigght mare to bleed sometimes

Area 52 Autosport

He said (I think) quite clearly that the fluid displacement (as it appears to be showing itself to him) had required him to fill it back up again? This to me indicates that fluid has most likely been lost.

The chances of there being a completely coincidental triggering of a cooling problem such as a water pump failure or sticking thermostat are incredibly low. The most likely (unfortunately) cause of this kind of issue is a head gasket failure.


Mike.

rigga

iTrader: (4)

From the above there seems to be no loss......... but could be wrong.

Area 52 Autosport

Pressure cap problem coinciding with immediate onset of the likely thrubbing it had while being mapped is again highly unlikely. It would also (if I've read the fluid displacement fault correctly), cause the reverse of the reported problem?

It is however completely true that they can be a pig to bleed, however that is only at point of a drain down and re-fill. This hasn't happened so I ruled that possibility out.


Mike.

Turbotits

iTrader: (2)

[QUOTE=Scooby Mania;7362446]. It would also (if I've read the fluid displacement fault correctly), cause the reverse of the reported problem?



Mike.[/QUOTE

Sorry i disagree!!!!! Only one of the caps is a pressurised type. If the cap on the main header is leaking or blowing off to early it will simply allow the coolant to escape and ultimatly fill the plastic header.

Area 52 Autosport

The answer to this is in your own reply.
What circumstance could cause the main (header tank) to displace water into the overflow, immediatley (as reported by the owner) immediately after a "mapping session", aong with an overheating problem.

You could alternatively run a poll with 2 options. 1 polling how many people have had a rad cap fail (under the same circumstances) and 1 polling people who have seen a HGF (under the same circumstances).

I think in over 8 years tuning Imprezas, we've seen on average less than 1 rad cap failure per year. I still suspect given all I've heard so far, that this is by a long way the most likely problem. (HGF, not rad cap failure).

The faulty/leaking rad cap "could" potentialy cause a similar problem, but the liklihood is far and away lower than the HGF diagnosis.

I'll also suggest that the way the owner has written it must also be wrong then, as he describes the reservoir (which I interpreted as the small overflow "neck" near the battery) as being where the water is being lost FROM, with the main (header tank) overflowing.

vindaloo

IMVLE (very limited)... Check the coolant system out. If the car is otherwise running fine, continue to top it up. Carry a water bottle in case it gets worse.

Mapping and post mapping enjoyment will likely have stressed things compared to the pre-remap time. Especially if you've been nursing an unmapped decat or similar for a while.

a) Check the bottom hoses for leaks. Ideally get someone to slightly rev. the engine whilst it's warm to get some movement in the cooling system.

b) Check the rad out for leaks and for blockages as previously stated.

c) Also might be your heater matrix. Not had one go on an Impreza but check around and ducts and the carpets around the bottom of the dash. Does the inside of the car smell of coolant or similar?

d) Pray it's not a head gasket. Though if all else fails, you can get a check done on your coolant to indicate whether there is likely a HG problem.

In my not so happy experience, some of these things seem to happen over an extended period. i.e. Once you get a cooling problem, other bits of the system can get stressed out and fail sequentially.

J.

Turbotits

iTrader: (2)

I agree the caps dont fail very often, But had assumed(maybe wrongly) that the garage that had given the all clear on the head gasget front had done a sniffer test for gases in the system at the very least. The cap idea was maybe a more cost effective way of covering all the possibilities before it got into more serious money being spent.

Area 52 Autosport

Haha, don't worry about it rigga. It's not impossible that the rad cap failing scenario is wrong, it's just exteremely unlikey, especially given the surrounding circumstances to the actual problem?

HGF's can cause some very odd (and lengthy) head scratching moments. some of the things they can cause, are highly implausible, but are still possible. The least likely is something like a HGF with water escaping the waterjacket into the cylinder. (Had this last week).


Mike

rigga

iTrader: (4)

I wont worry about it Mike......... its not my posting your quoting..... on the sherry tonight?

Area 52 Autosport

Haha, well spotted, wrong name used (apologies), send beer, there is a distinct shortage here right now.


Mike

Jolly Green Monster

iTrader: (4)

does the rad fans work?

tend to find if you have a leak and so the system is not pressurize it overheats and loses coolant..

if head gasket it loses coolant by blowing it into the overflow by the battery and then out the overflow of the overflow resevoir..

if the battery area is wet then I would say head gasket problem..

otherwise you have a small leak which is causing the system to depressurize..
check all the hoses for splits and leaks and check the clamps are tight, including all the oil cooler pipes etc..

Tend to find thermostates just fail rather than random..

Simon

Area 52 Autosport

And the indication from Chris, (unless he's described it badly) is that the opposite of this is happening. (and this scenario is possible btw)?

Which is why I suggested checking for "general leaks" in my very first post on this thread.

Hehe, <devils advocate> So what would you say is the difference between "just failing" and "failing randomly"?


Mike.

Jolly Green Monster

iTrader: (4)

seen that happen but cannot remember why..

sorry was trying to help poster sort it.. no deliberately repeating what had been posted already.

lol.. yeah okay I mean I have never seen a thermostat fail and then fix.. they seem to not open and never open again.. I got the impression the problem was varying with the driving.. ie.. it just overheated.. refill and drive with caution and no problem.. which doesn't sound like thermostat..

it's way too late to be splitting hairs

Jolly Green Monster

iTrader: (4)

just remembered.. rapid leak and the overflow remains full..

rereading the first post.. how can the header tank be overfilled.... did the poster mean over flowed which points to leak on a pipe connected to it or the cap.. or is he refering to the main tank as the one by the headlight?

Simon

Turbotits

iTrader: (2)

Whats all this ha ha bit like im giving in to your better knowledge which i certainly am not.

The fact is there are many reasons that could be causing this issue and they all should be investigated to solve the problem. Just telling the guy his head gasget(s) are gone before other investigation work is carried out is unreasonable and not really the advise he's looking for. Hes had it checked. Maybe a second opinion from another garage is a good idea. But not one thats just going to look at symtoms and say 'the head gasgets gone that'll be 000's of pounds' please.

Area 52 Autosport

I agree absolutely. That's why I suggested looking at other possible (cheaper) causes first. (in my very first post).

I totally don't think you're "giving into my better knowledge" at all, after all, hey, who am I, WTF do I know.

It matters not, what he's looking for in any way at all, the fault will be whatever it is like it or not. I've suggested checking (at the risk of repeating myself) the possible(cheaper) causes, but given what's been told so far, I'd still be leaning towards the likely fault being a HGF.

P.S. I also hope I am wrong.


Mike.

P.P.S JGM.

chris.mcd

Hey guys - Interesting read.

Hope I am not causing too much arguements, sorry.

Have to hold my hands up and say I have described it v. badly, sorry again. What i meant by reservoir (sp) tank is the one top left of the engine and main tank meaning one beside the battery. Original post also altered !

Therefore in short. The coolant is transfering from the header tank ( one top left of engine) and going into main tank (beside battery) this causing the main tank to overflow/ overfill and coolant to leak down beside the battery etc.

Few things :

Radaitor cap can be ruled out, I thought of that and replaced it with a new one but with no joy.

It seems to me the head gasket may have gone but would there we any other symptons? cause otherwise the car seems to run perfect, I managed to drive 60 miles without it overheating once but over last 2 days it starts to over heat everytime I hit boost.

Rad fans seem to work normally

I am going to give the car to another garage tomorrow to check the head gasket again - like someone mentioned get a second 'opinion'.


So with everyone knowing the true story ( sorry again guys!!) anymore advice / ideas?

Thanks

Chris