fix crack in radiator tank?

[mikesands]

There's a crack in the left tank which apparently is made of plastic.  I topped up the fluid and a day or two later a lot of it has gone.  But how does it go - there's no pooling under the car and as far as I can tell no steam while I am driving?

And I think it's been like this for some considerable time before the dealer spotted it, and yet no warning light has come on and the temperature gauge stays in the normal range.  The dealer wants £600 to fit a new one.  Is there a way of fixing them in situ?

Mike (RX400H)

 

[stringbender]

8 hours ago, mikesands said:

 The dealer wants £600 to fit a new one.  Is there a way of fixing them in situ?

 

 

Milliput. Mends everything. I think there's even a mention of a car radiator in the pack insert. Sticks to plastic and now available in black !

Alan

[mikesands]

Been thinking about this a bit more because there isn't a low coolant level warning light on the RX400H.  So what if you lose most of your coolant through a leak and don't know about it?  Surely the temperature gauge is measuring the temperature of the coolant so if you haven't got much left, that's not going to be any use.  Are there ANY warning lights that will come on telling you that the engine block and cylinder head are getting too hot because you have lost most of your coolant?

Mike

[mikesands]

... and until I can get the car booked back in for a radiator change, I need to keep topping up the fluid.  Can I do this with tap water, or bottled water (our area has really hard water), or must I add antifreeze, and if so what can I use which I can buy on a sunday morning?

Thanks

Mike

[Herbie]

That's what the temperature gauge is for. As soon as it begins to rise from its normal position, that's your cue to panic.

Antifreeze also has rust inhibitors in so yes, you need to top up with some proportion of antifreeze and not just water. I'm not sure if you can just chuck any sort in or if you have to match what's already in there though.

[mikesands]

Thanks Herbie - that's what I was thinking, but if the temperature sensor for the engine is measuring the temperature of your coolant and you haven't got enough of it left, what kind of warning do you get - there's no warning light, and even if you kept an eye on the thermometer, if the sensor isn't in any fluid how's the gauge going to read (too hot or too cold?)

Mike

[The-Acre]

41 minutes ago, mikesands said:

Thanks Herbie - that's what I was thinking, but if the temperature sensor for the engine is measuring the temperature of your coolant and you haven't got enough of it left, what kind of warning do you get - there's no warning light, and even if you kept an eye on the thermometer, if the sensor isn't in any fluid how's the gauge going to read (too hot or too cold?)

Mike

Is it the expansion tank that's cracked? If it is then that doesn't mean the main block and radiator would loose coolant so it would still register the temperature and have enough to cool the engine.  Also the correct colour coolant should be used.

[mikesands]

it's the plastic tank that runs the full height of the radiator at the left side.  Fluid is leaking from this crack which is about 75mm long, but it's hardly weeping much at all. I'm going to see a radiator specialist tomorrow to see if he can heat weld it without removing anything.

Mike

(But I'd still like to know how you get a warning if you have lost nearly all of your coolant)

[The-Acre]

3 minutes ago, mikesands said:

it's the plastic tank that runs the full height of the radiator at the left side.  Fluid is leaking from this crack which is about 75mm long, but it's hardly weeping much at all. I'm going to see a radiator specialist tomorrow to see if he can heat weld it without removing anything.

Mike

(But I'd still like to know how you get a warning if you have lost nearly all of your coolant)

The thing is that the engine block will still be full of water but if that leaked out (which would mean a serious problem) them you would have alarm bell warnings. My Volvo doesn't have a temperature gauge but should the engine overheat there will be a visible and audio warning, I'm assuming it's the same with lexus.  Although you have a leak from a plastic tank you will still have several litres of coolant in the rest of the system.

[Barry14UK]

Hi,

It seems that even if you could electronically weld the plastic on the radiator you would need to do a lot of stripping out and remove it and then replace.  Then in this situation where the plastic has already split over an area would you be happy to trust it further.  Would it not make sense to replace the rad with a new one and avoid the possibility of  having to do the job again, with perhaps the rad failing at a very inconvenient time.  I believe a lot of the £600 would be attributable to the work involved in removing and refitting the rad.  A new but aftermarket one could be had for about £96 assuming that model correct for your car https://www.ebay.co.uk/itm/151379995581 So not a great saving over electronically welding existing one.

There are several videos on u tube showing what is involved which I suggest you watch first to see whether you fancy the job

. 

[Barry14UK]

Another video here 

 

[mikesands]

Thanks guys - took the plunge and getting teesside Lexus to replace it with genuine article.  Their price of £575 inclusive of labour and fluids seems reasonable compared to some I have seen on this forum and they collect my car and deliver it back same day.  I was quoted £45 for a plastic weld from a specialist but he said it was only a 50/50 chance it would fix it, and I would have had to strip the radiator off and refit it myself 🙂

Mike

[The-Acre]

1 hour ago, mikesands said:

Thanks guys - took the plunge and getting teesside Lexus to replace it with genuine article.  Their price of £575 inclusive of labour and fluids seems reasonable compared to some I have seen on this forum and they collect my car and deliver it back same day.  I was quoted £45 for a plastic weld from a specialist but he said it was only a 50/50 chance it would fix it, and I would have had to strip the radiator off and refit it myself 🙂

Mike

A wise decision I think, that way it won't always be in the back of your mind, plus the price sounds pretty good for Lexus!