Gs300 Mk1 Overheating

[mwmcgarva]

Hi- New member needs help- I have a 1995 Mk1 Lexus Gs300 that i bought six months ago.

I was on my way back to England on the eurotunnel when i had a overheat (i know i was risking it going abroad in an old car).

i was fortunate because i was just sat in traffic and killed it immediatly, so i dont think i have done any permanent damage -and they let me on the train so i could limp to the total garage in blighty.

The RAC guy that turned up did a compression test on the nearly empty radiator after he filled it and water gushed out near the back of the engine on the drivers side.

He said one of the coolent pipes that run around the back of the engine must be corroded. Doese anyone now if these pipes are accessible?

i am not keen to take it back to the garage since i have already spent more than i paid for it on service+timing belt, new alternator+battery and a rocker cover gasket repair with new sparks +leads.

Any suggestions greatly appreciated!

[norkep]

Hi and welcome to the club

It's not a risk taking an old car aboard, mines been to Germany and back a few times

The pipe in question sounds very much like it's the pipe that feeds the heating matrix inside the passenger cabin, mine went a few months back and is replaceable, not easy but can be done, the pipe will need to be brought from a lexus dealership due to the bend, shape and thickness of the pipe, not worth going cheap on this part, think it was only about £20, there are clips that hold the pipe into place, once removed, the pipe (or remainder of) will come easly but you may want to replace the clips for the screw on jublie clips, it made refitting a lot easier

One think you should be carefull of though is the heater valve (other end of the pipe), this can break easly so would be better remove completely so save damaging this, made this mistake and cost £60 to replace

Hope this helps

BR

Paul

[mwmcgarva]

Hi and welcome to the club

It's not a risk taking an old car aboard, mines been to Germany and back a few times

The pipe in question sounds very much like it's the pipe that feeds the heating matrix inside the passenger cabin, mine went a few months back and is replaceable, not easy but can be done, the pipe will need to be brought from a lexus dealership due to the bend, shape and thickness of the pipe, not worth going cheap on this part, think it was only about £20, there are clips that hold the pipe into place, once removed, the pipe (or remainder of) will come easly but you may want to replace the clips for the screw on jublie clips, it made refitting a lot easier

One think you should be carefull of though is the heater valve (other end of the pipe), this can break easly so would be better remove completely so save damaging this, made this mistake and cost £60 to replace

Hope this helps

BR

Paul

Thanks paul- i had a proper look in daylight at the pipes- the black one on the drivers side that gos into the cabin looks ok.

The leak is coming from the back of the engine block on the drivers side and dripping down on to the transmission housing. i think it might be the head gasket- i will have to take it in to the garage to get it checked out.

if its the head i think the car is a gonner. i will post the verdict after i take it in.

[General Banter]

I live in Hitchin and know one end of a spanner from the other, I will gladly take a look if you like :)

[TigerFish]

Can you get a mirror in there to take a look? I've no idea where the core plugs (round discs blanking off water way machining) are on the engine but is it possible one of those has gone? That should be a cheap fix if it is and could avoid the expense of head removal etc.

[mwmcgarva]

I live in Hitchin and know one end of a spanner from the other, I will gladly take a look if you like :)

If you dont mind, and have the time, that would be great because my mechanic is in hitchin and im not sure if it will make it there.

[General Banter]

Of course I don't mind ;)

I'll pm you my phone number and we can tee this up.

[mwmcgarva]

Can you get a mirror in there to take a look? I've no idea where the core plugs (round discs blanking off water way machining) are on the engine but is it possible one of those has gone? That should be a cheap fix if it is and could avoid the expense of head removal etc.

That sounds promising i will take a look- i think i saw a disc near the leak.

[mwmcgarva]

A big thank you to all for the replies to my coolant leak problem. The suggestions enabled me to fix the problem myself avoiding more mechanics bills!

Diagnosis - It was the coolant pipe that feeds the cabin heater matrix as ‘norkep’ suggested.

It was leaking at the point it connects to the back of the engine block at the top. i was able to see it leaking down the back using my girlfriends make up mirror and a torch.

It was bitching to remove because it was very difficult to get some pliers on the clip at the back of the engine, but it’s almost worth the pain for the satisfaction of finally removing it. In hindsight I wish I had just chopped through the clip instead of using pliers.

I got a new pipe from Lexus Hatfield for £20 and put jubilee clips in the place of the original tension clips. I used a jubilee clip with a wing nut for the engine block side.

Norkep was right- you have to be very careful with the heater valve side of the tube-Its very brittle- I broke a bit off the end, but luckily it seems ok.

I hope this thread helps someone because the location of the leak makes it look like its coming from the engine and a very expensive problem to fix( for an amateur mechanically minded owner) ,when all it takes is £20, a couple of days of backache and loss of some knuckle skin.

[norkep]

Glad you've got it sorted

We're a helpfull bunch on LOC