Welsh Plugs - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

docomo · 11-15-2003, 04:25

Sorry to ask this stupid question:
what are those welsh plugs for?

I've got a leaking welsh plug at the front and will it hurts?

The car now seems to be pretty difficult to start after some short runs (e.g. a 30 sec / 1 minute drive), especially under hot weather. The engine will misfire and stall, but will run if I press the throttle for a short period of time, does it have anything to do with that?

The car is a NA fairlane and the engine was rebuilt 80000km ago, a reconed alternator was put it but didn't solve the problem and even make it worse..........

ebxr8240 · 11-15-2003, 10:12

FIX them they are $2 each. Coolant is possibly leaking onto ignition causing a short...

yeah right · 11-15-2003, 14:23

They're WELCH not WELSH - they're not from Wales.

They're there only for manufacturing reasons - so the block can be cast in 1 piece. And they're plugged so your coolant doesn't spill all over the ground when you try to fill it up!!! If they leak - replace them - otherwise you could have one go & you'll cook the motor & get stranded. It's not a numbers game - just do them.

There's been plenty of info on the process of replacing welch plugs here - just do a search of click on one of the threads listed at the bottom of the page.

To remove use a screw driver on the inside of the plug near the side & a small hammer to knock the welch plug sideways then use poly-grips to pull the plug out of the block (be very careful not to damage the hole). Clean the hole & pop a new plug in with a LITTLE bit of marine silicon sealant (the clear silicone) around the inside face of the hole. Let the silicone set a bit - refill the coolant with the correct glycol proportion & get it pressure tested at the local radiator shop. Job done.

docomo · 11-16-2003, 02:02

Will have a look at that tommorrow, just hope that it didn't caused the head / gasket damaged.........

ebxr8240 · 11-16-2003, 05:48

They are there too so they pop out when or if the block ices up.. In some places they are called "Frost plugs"...For obvious reasons...

docomo · 11-19-2003, 03:17

ok, got the welch plug done on monday and went to a mechanics to see what's going on today.

Pressure tested the system and it would hold pressure at 20 and 25 psi. He forgot to recap the radiator cap at the overflow bottle and I notice that after driving for half an hour. Horrible dodgy mechanics >.<

Top the overflow up, seal back the cap and go back to the mechanics and asked him to get the engine compression checked (just in case) which is 170- 175 psi from cylinder 1 to 5 and cylinder 6 is 165 psi.

However, overflow will still agitates and blows out a bit coolant if rev hard.

Am I having a cracked head / blown gasket from the above symptom?

yeah right · 11-19-2003, 11:04

If the overflow bottle is filling and not drawing the water back into the system check the non-return valve in the radiator cap is working first - it's on the middle bottom of the cap - you should be able to suck air through it. If that's ok you've probably got a head gasket/cracked (or more likely) corroded head (alloy head+cast iron block = corroded head is there's not enough corrosion inhibitor in the coolant - aluminium corrodes more readily than iron......look up the galvanic series on the net)

Also the cooling system pressure doesn't become nil 10-15 mins after stopping the engine you likely have a problem somewhere there. Since the compression is down slighlty on #6 I'd say you have the typical back passage corrosion.

yeah right · 12-05-2003, 03:01

What's happening? Got it sorted?