Spitting Coolant From The Overflow

[artois7 21]

My mi16 seems to be spitting coolant from the overflow on the header tank once it's warmed up.

 

It's not a continuous stream, but just spits as you rev the engine up.

 

Running the engine with the cap off and there is white smoke from the header (I'm fairly sure it was smoke as opposed to steam but I could be wrong)

 

The car runs excellently otherwise; doesn't overheat, pulls hard in every gear, doesn't smoke.

 

Logic points towards a faulty headgasket so I'm going to try and get it sniff tested, or perhaps a sticking thermostat. Any other ideas or known issues on these?

[blandy 29]

Rad cap?

[Simes 248 2 Cars]

Mine looses water in a similar way. Rad cap is the answer.

A shame because the one Pug now supply is a crappy plastic one which makes it worse.

Compression test it, sniff test isn't reliable.

[welshpug 1,657]

never had any issues with the o.e plastic cap, theyve been supplied instead of metal caps for 15 years or so.

[Miles 331 1 Cars]

Plastic ones are **** *****, always had loads of issues with them, swap them with the original type the tanks where designed for and no problems at all

[artois7 21]

Flushed the old rusty, manky coolant.

 

Swapped the rad cap for an old one (it was replaced shortly before I got the car)

 

Ran it up to temp and thrashed it about a bit. No coolant spitting out but still either smoke or steam coming out of the overflow.

[artois7 21]

Drove it about 20 miles normally and it was fine, but driving it in anger causes it to start to spit out. Think I need to get a third rad cap to be sure.

[Henry Yorke 269 3 Cars]

I had this on my 1FM. I put a GTI6 cap on from my local factors as they are a higher pressure rating and all has seemed fine since. The factors sell the old metal look ones too. Also, how full are you filling the header tank? There is no real mark on them and you obviously need to leave some room for expansion otherwise it will overflow!

[artois7 21]

I had this on my 1FM. I put a GTI6 cap on from my local factors as they are a higher pressure rating and all has seemed fine since. The factors sell the old metal look ones too. Also, how full are you filling the header tank? There is no real mark on them and you obviously need to leave some room for expansion otherwise it will overflow!

 

I had filled it to slightly under half way up the top "half" of the tank i.e. where the logo starts.

 

I didn't have a hose on the overflow so of course it was spitting out over the header tank and looking way, way worse than it actually is. I ran a length of hose to the bottom of the car, and took it on track for a session at Castle Combe.

 

Between driving it on track then thrashing it home, it only spat out enough coolant that the level is sitting just under the "split" of the tank / bottom half. Probably not even 200ml.

 

Do you know the part number for the cap you bought? Thanks

[Anthony 1,003]

I've got a known good metal cap here if you're passing and want to try it Dan.

 

Sounds like you might have had the tank a little over-filled initially though which might explain things.

[artois7 21]

I had this on my 1FM. I put a GTI6 cap on from my local factors as they are a higher pressure rating and all has seemed fine since. The factors sell the old metal look ones too. Also, how full are you filling the header tank? There is no real mark on them and you obviously need to leave some room for expansion otherwise it will overflow!

 

Was this a 20 psi cap?

 

Potentially stupid question; not really sure. The original cap I have is marked at 15 PSI, but the aftermarket one is marked for 20 lbs. Are these (psi, lbs) interchangeable terms in terms of a rad cap?

[Anthony 1,003]

Psi = lb, same thing put differently.

 

The 15psi (1bar) cap is standard, the 20psi (1.4bar) cap is from TD models and will fit fine.

[artois7 21]

Psi = lb, same thing put differently.

 

The 15psi (1bar) cap is standard, the 20psi (1.4bar) cap is from TD models and will fit fine.

 

I figured as much!

 

Going to pick up a standard replacement from a local factors and rule out the rad cap as the problem. Haven't got round to it yet - been busy!

[welshpug 1,657]

beware of 306 caps, they dont fit the roubd tanks i know for certain, dont recall trying one on the square tank, but as mentioned above the TD cap is the same 1.4 bar rating.

[Henry Yorke 269 3 Cars]

www.continental-direct.com part CFC65 is 15lbs / psi. This looks like a normal 205 metal cap. I now have a 20 PSI one on my 1FM but havent got the part number to hand I am afraid.

 

306 one works fine on a phase 2 tank as I have one on my CTI