If your radiator cap looks like this...

[Torgie]

Then spend the $7.99 and get a fancy new one!

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I was having terrible overheating problems and the cap was spewing coolant all over. I got a quick replacement from O'Reily ... Seems to be doing the job so far!

Oh, and hi! This is my first post... I just got a '91 Talon awd tsi - and loving it! I'm sure I'll be posting more as time goes on.

 

[RadDsm]

Lol

That cap looks like it's been through hell.

 

[DSM1G90]

That's one half of the cure.

The other cure is to make sure that both surfaces in the water inlet area where the cap sits on, are clean and not corroded so both gaskets on the cap will seat completely.

If signs of corrosion is apparent, stuff a rag down the water inlet area and take a piece of fine grit (400 plus) sandpaper and smooth off the surface areas for the two gaskets in the new cap can seat completely and will definitely make a good water tight connection. This definitely helps keeping the pressure rating of the cap at the fullest so you won't have any blowouts due to bad gasket sealing.

Good luck-DSM

 

[Torgie]

Well then! It hadn't really crossed my mind to smooth out the contact points on the inside of the inlet -- sounds like some good advice... I'll check it out, thanks!

 

[JoshCorlin]

I wonder what the inside of you radiator and water pump look like.

 

[DSM1G90]

Then, it's a good time to take the radiator out completely, shove a garden hose through the bottom outlet of the thing and give it a horrendous flushing so all the junk and crud that loves to rest in the lower of the radiator can be all flushed out.

While you the radiator off, take the T-stat out and shove the hose in that inlet area and also flush out the block.

Let it all drain out and do a refill with 50/50 antifreeze-water mix with a new T-stat and gasket. Take your time to really get your levels correct, fill the overflow bottle to proper level, cap it off and you're set for a good long time.

Also, if you're getting ready to do belts or such, the flush job can wait since you're going to change out the WP anyway. But, with the pump out then a good block flush can be done since you got room and a good water outlet for the crud to flow out of.

When I got my car, I promptly did a belt/WP changeout in which I also did a block flush..and so glad that I did that flush for the block was so full of rust and did a long flush that I waited until the next day to do my replacement job since I had my driveway all wet and cruddy from the water and junk of my results.

Now, when I check my fluids, the fluid is still green of the antifreeze, not rusty color if I didn't do the block flush.

Good luck as always-DSM