Club 80-90 Forums

Any brainwaves as to how to go about flushing the radiator? I don't mind taking it out if it means it'll get it working right again.

A hosepipe could be involved

Ah there has to be more to it than just banging a load of water through it right? Sure I don't have to take it out at all to do that.

A back flush might remove some or all of the sludge
It might not
So it might need a new core
Remove it then

When you flush, you should see any problem with flow
If the rad fills quickly then its fairly certain there's an issue

Just as a reference to anyone else who has this problem, I took the rad out which was a pain cause 2 of the anchor nuts sheared meaning I had to grind the bolt heads off but normal nuts can be used in place of the anchor nuts when it's going back in. Not too tricky. Flushed the radiator and in fact the whole coolant system and a good bit of gunk came out of the radiator and by the time I was finished the water was flowing through it a lot better and was coming out clear. Put the rad back in and the whole system back together and filled it with just water to give it another flush with the engine running. With the radiator unblocked now, it was so much handier to bleed! Took it for a good run over the whole weekend with just the water in it and not once did it overheat. Drove brilliantly and the temperature gauge stayed just below the light on the gauge. So that's that problem sorted! I'll drain it soon and put coolant into it. Thanks all for the help!

Do you have to remove the rad to flush it?

Good question, it must be poss to stick a hose in both ends (steady) and keep agitating the water till gunk dislodged?

If you can get access to a fire hose, they work great for this and the nozzle is a fair fit into the pipe (I used to work at a place that gave me access to a fire hose )

Yes you do have to remove the rad to do it. You're wasting your time trying to do it without removing the rad, unless you can bang a load of water through the rad like with a firehose as Ghost said. I was thinking of that myself when I was doing the job. Would be a lot handier. I took out the thermoswitch as well and pumped water through there too for a bit. Got some gunk out that way too. The good news now is even with the 27 degrees we had here and some motorway driving the engine is not overheating at all. I can safely say now that it's fixed, so it's worth doing!

I will be doing mine today
Radiator came out easily, took about an hour with a break.
It sure looks like its in a sorry state.

It's a 2 man job to get it back in Holding it up (quite heavy) against the locating pegs at the top whilst putting the nuts on the bottom

It won't be a cracked block but a cracked head on JX...