Hope someone can help. I've got a 03 sti and the heaters are blowing cold when turned to hot. Sometimes they blow hot while driving but not for long. Cheers

 

Have you checked the header tank for water???

 

Normally heaters blowing cold air is an indication on very little water in the system ! Check it ASAP mate.

 

How full should the header tank be ?

 

this happened to me last winter, realised there was no coolent in the car, topped it up and was fine.

 

How much coolant should I put in?

 

read the owners manual.

 

I would but left it at work. Need to buy some tomorrow 2l 5 litre or ?

 

approx 7ltrs in total..............

 

Buy concentrated coolant and dilute it to suit. Eurocarparts have pretty good deals on at the mo.

 

Might be wise to fill via the turbo to avoid air locks as well! If you aren't familiar with this procedure do a quick search. It's been covered loads.

 

As above.

Where has the coolant gone? Look in the overflow for evidence of a lardy looking deposit, or in the oil for greyness...if you find either, get a sniff test done. headgaskets are suspect.

 

I haven't lost any coolant all levels are ok. Have got a warning light on dash?

 

What light is on?

 

Has it had any repair, coolant change, etc?

 

Think it's fixed. Took off header cap and gave the pipe from the radiator a squeeze and there a big gurgle and the water when down so topped back up. Have had the car running for an hour now and engine temp ok and heaters are red hot. Hope this was the cause. Thanks for all your help 👍👍👍

 

I'd say that'll be it, air locks are very common on these. Might be worthwhile changing the coolant soon anyway, winter is coming and you can be sure there's no more air locks.