Breather Hose Pushing Out Water

Ian Lord · June 13, 2013

My 1990 LS400 had a failed thermostat 8 months ago, I replaced this (plus lexus rubber seal) and all was well.

Recently had overheat on a 25 mile trip, had to stop every 5 miles to top up water /let it cool down. when home tracked problem to leak at bottom of radiator, added 2 x bottles of radweld and leak fixed,

Now I get temp gauge showing normal, but after 5 miles of so VERY hot water comming out of breather hose from expansion tank. Is it possible the Thermostat got cooked and needs replaceing again? or could it be more serious? Oil all looks fine (no water mixing). Or could it be the radiator?

Would welcome feedback from any one who has had similar problem

regards

IAN

Bournemouth - UK

Malc · June 16, 2013

Possibly try the expansion tank cap ......... the rubber seal might have perished a little by now .... quite an inexpensive fix ( new cap )

Malc

ambermarine · June 30, 2013

Sounds like your water pump as failed the next thing to go will be the cambelt when it siezes and the cambelt shreds , won't bugger the engine as it as valve clearance ,happened to me 10 years ago on my mark 1, same symptoms went for two or three weeks after initial blowback through expansion tank. The cooling system keeps working as the movement of water through the block is caused by thermal flow as the water heats up and cools down as it goes through the rad. the problem is the water pump bearing siezes and the belt shreds.Get the cambelt changed and the tensioners at the same time as the water pump.

Ian Lord · July 19, 2013

As the guy who started this tread I wanted to say thanks to Malcolm in Kent and also to tell you how I solved the problem. New expansion tank cap was good advice (the rubber had split and was looking old) got a new cap and that increased the pressure in the water system result it blew holes in the radiator!!!

So searched for a new LS400 rad, found what I wanted online from ADVANCED RADIATORS LTD in Newcastle-upon-Tyne the cost of £61.86 inc VAT and delivery to me I thought was good value. (I ordered Monday received early Weds) you can pay more for 24 hr delivery.

I found various forum folks saying changing the rad is easy which it was (40mins to take out) 15 mins to transfer pipe to expansion tank from old rad and also to transfer the temp sensor, all simple stuff. Then 20mins to refit. All now seems well on the engine water side temp guage dead level never moves above this, and no leaks.

The long job was flushing out the water in the engine, 2 heat up sessions (with holts rad flush) , 2 draining sessions, and 3 refills, the time consumming part was letting things cool down so not to cause me any danger when draining off

The surprising item was where the rad was made!!!

Made by a company called DOLPHINheattransfer.com who are based in the United Arab Emirates, their website is massive,and they make rads for just every car I have ever heard of, makes you think what does it really cost to make a Rad?

Ian Lord

1990 LS 400

Bournemouth

Malc · July 20, 2013

Ian, so pleased it was such an inexpensive fix ....... when I had that same problem in my 1992 LS400, many years ago the radiator was, thankfully good.

UAE makes and sells to the UK other surprising stuff too .... just had a new bathroom installed and the toilet and washbasin were imported form ....... UAE !

Amazing ..... and sad I guess for UK manufacturing. ( They are just in throes , or were, of a building strike I'm told ( Dubai anyway ) .... for more wages, . the workers on the ground earn @ $200 per month ! Guess their manufacturing costs are just about as low as they can get.)

Malc

steve2006 · July 20, 2013

Excellent result.

Are you aware there are 2 drain valves on the engine to completely drain all the coolant from the engine block as there is quite a lot of remaining coolant in there if you just drain the radiator which could alter the coolant protection if the correct mix is affected.