Hi all,

Went through routine checks today as the cooling fan seems to be on "a lot" lately and noticed the coolant was rather "black".

Looking into the tank, it seems quite flakey/sludgey.

Now common sense tells me this cant be right, but what has caused this?

If its going to cost me a load of money id rather not know

 

Head gasket

 

As above head gasket unless you've mixed different types of antifreeze.

 

Drain it out & rinse through with water. Fill new coolant & see if you notice similar symptoms.

 

inner lining of the header tank breaks down over time if its flakey id say its that, i know this happens on classics anyway. as it happened to me an i had the usual replies of 'head gasket' but it turned out to be the above..

 

Excellent.

It's a 2006 hawk sti. Theres no sign of power loss. oil has changed to black in a matter of a couple of weeks as it was changed a couple of months back and has done a mere 1000 miles. What would be the cause of head gasket going? Harsh driving? As i dont believe i have been that harsh recently.

Looks like i shall be leaving her sitting still until payday.

How much do you reckon im looking at if i go subaru? I want to keep to subaru as much as possible for service history etc.

 

As said your best bet is flush it and fill with clean water which should be ok just to see if its ok if it is add antifreeze.The oil colour doesnt sound bad to me has it used any water?

 

Ill give the drain a go. That is if its easy enough to do myself on the drive? If so whats the best method? just literally drain from the resevior? I havent looked in the bay too much. But if i can, ill give it a go tonight.

 

Just pull the bottom radiator hose of and run clean water through.When you fill up do it slowly squeezing the hoses regulary to get the air out.

 

As above, Before blaming head gasket ask yourself teh following:

When was the last time the cooling system was drained, properly flushed, and filled with fresh coolant?
Has it ever been filled with just plain water, or an overly weak mix?
Has OATs (or hybrid OATS ) antifreeze been mixed with normal Glycol antifreeze?

All the above can cause sludging, which is due to corrosion of intermixing metals because of degraded coolant (or lack of antifreeze). Antifreezes that are incompatible with each other can also give issues if the system isn't throughly flushed through with water beforehand (engine block, radiator, heater etc).

Flush witha hose pipe, by disconnecting the associated hoses.. Flush the rad through the top hose, and drain out the bottom house. Same with the heater, and flush the engine via the header tank.

 

Thanks for all the replies guys, ill give it a go the weekend and report back with results.

 

Just get some decent garage to do it for if you dont know how. Wont cost much.

 

What mileage, 30 to 55,00 typical 2.5 early head gasket symptums.

 

give it a good flush and keep an eye on it but you will need to bleed the system when you refill with coolant make sure you have hot air in your car blowing though in 5 mins if still cold you got a air lock make sure all coolant hoses are hot after 20 mins then you be ok as above just drop the bottom hose and flush with clea water till you see it come out clean ..

 

Hi all, sorry its been a while. Havent had much time to deal with it until recently. Anywho, a brief update on the situation. Ive had the coolant tested and head gasket failure is negative. PHEW!
However ive lost all oil in a mere 3-400 miles. After having a family mechanic looking at it hes suggested that my rad hoses are breaking down. And heres the findings...

The material in the overflow tank is much like a tar like substance. The header tank is clean but the top of the rad is full of it! After idling from a cold start on the driveway for about 30 minutes and a few "warming revs", switched off the engine and the top rad hose is burning hot almost too hot to touch. But the bottom hose is pretty much ambient temperature, along with the majority of the rad barring 2-3 inches from the top of it.

Left overnight, removed both hoses and attempted to flush the rad through with the hosepipe, it seems the rad is blocked with this tar ****e as there is a mere trickle exiting the bottom before the water pressure is forced out of the top. It doesnt look like ill be able unblock it as this tar stuff is real tough and sticky. So a new rad is looking like the way forward.
Along with samco hoses and a zerosports thermostat.

Aparently (as im no scoob expert yet) there are multiple sensors that read temperature and the one that reads for the dash hasnt been affected by this heat, but another sensor which has been reading extreme heat has been activating the fans constantly even though the rad has been stone cold. Would it make sense that as the engine hasnt been getting enough cooling it has burnt the oil off?

The family mechanic has offered to help me perform the required repair works, along with an oil change as long as i keep to a promise of taking him out for a spin afterward. I wouldnt mind this as itll help to boost my knowledge on the car etc...

 

Changing the rad is easy, but I'd be more worried about a) where else the tar-like substance has got to, and b), what the hell it is and where it came from in the first place

 

I still stand by the above, & your oil loss is is piston ring land issues.

 

Check out my "overheating" thread but not if you don't want bad news !

 

If the oil has turned black in a couple of weeks, it could be due to carbon contamination of the oil - this would point to ring land failure on one of the pistons (usually No2 or 4 piston on the left hand bank).

Mick

 

Does sound like it.
When did you buy the car & was it a private sale?

 

Bought it at beginning of may, yep private...

 

Ive accepted that my engine needs to come out now. So ill have raid the piggy bank. Ill most probably have parts upgraded whilst its out and open. Any recomendations for this sort of work to be carried out? Without being biased i hear alot of good words about API.