Radweld in my diesel?

[Mark2000cc]

Right before everyone jumps on me shouting no no no! Could somebody explain to me what harm it would do to my car if any? I don't understand the principal behind it.
I have a slight coolant leak and my mother in law gave me some Radweld +??

I have not used it as I have heard some horror stories, so what would it do?
Thanks.

[GED75]

i could be wrong mark but i heard that it can block or reduce the diameter of the cooling pipes on the rad,the ones inbetween the fins,could be a old wives tale though ,but im sure someone with more knowledge will be along

[DaveyC]

Hi Mark,

Where is the leak?

Dave

[smallheathlad]

I'm sure someone with more current knowledge will post soon. I have used radwell but it some thing like 30 years ago in an Austin 1300. Then it worked as it created a seal on a small hole in a rad hose allowed me to drive home 30miles. The cooling system on the 1300 was very simple as was the engine! Not sure I would use on our cars given the relative complex nature if the cooling system.

[DMGRS]

The tiny waterways in your engine could become blocked - it wasn't so much of an issue with older, less intricate engines - but with the complexity of modern cars it's something I'd steer well clear of.

My diesel also has a minor water leak, it turns out it's the waterpump. Check that (and the attached thermostat) for coolant staining - it's down the back of the engine.

[Mark2000cc]

Originally Posted by DaveyC

Hi Mark,

Where is the leak?

Dave

It's where the top coolant hose (middle front of engine) meets the engine, just under the manifold.
Checked my coolant from this morning and it's still at the same level so it can't be that bad.
Thanks for the responses so far guys

[J1MBO]

Imho don't use it, find and fix the leak.

A long time ago I bought a Triumph Acclaim that somebody had "fixed" with radweld, cost me a new radiator and a head gasket kit .

[trebor]

The product is designed to bung things up and cant differentiate between what it is supposed to bung up and what it should leave well alone, so find the leak and fix that has to be the best advice

[okenora]

for a quick fix to get you home when you have no other choice then radweld or similar just about tolerable but it is still a temporary fix imo. The original problem will still need to be addressed and fixed, so if you can get away without the radweld and get it properly fixed then that's the way to go

Radweld reacts with the air and solidifies blocking any holes, one of which will hopefully be your leak but many of which could be internal waterways.
The correct way to use radweld and minimise the chance of waterways clogging is to add it, wait a few days then drain and refill with proper coolant.

after all that expense (radweld, new coolant, time to drain and refill) it probably would not be much dearer to simply fix the original leak.

[DaveyC]

Originally Posted by Mark2000cc

It's where the top coolant hose (middle front of engine) meets the engine, just under the manifold.
Checked my coolant from this morning and it's still at the same level so it can't be that bad.
Thanks for the responses so far guys

Is that the plastic fitting that folk fit the top hose thermostat mod to?

If the plastic is cracked then you'll need to replace it. If its just weeping where it meets the face of the block, then you may be able to tighten it up but I would avoid Radweld, it was probably OK back in the day but engines are a bit more fussy these days........

Dave