Bubbles From The Radiator...

[gav_logan]

... I'm just holdin on to some wishfull thinking here guys, can it be anyting else apart from the head?

The bubbles are really small, about double the size of soda bubbles I guess.

Any ideas?

(the car has overheated twice in the last week).

[amf1932]

Bad news. :( Sounds like a leaking head gasket.

[VGR]

Letting the engine temp gauge get in or even near the red zone is the #1 killer of cyliner heads and head gaskets. If owners would stop the car and call a tow truck or a mobile mechanic type outfil at the first sign of a rising temperature gauge they could save themselves thousands of dollars.

[gav_logan]

Just spoke to the mechanic (not lexus, referred from my parents), he's not free till wednesday...

He seems to be a pretty nice/straight guy. He said it can take (in some cases) up to a few weeks to completely bleed the cooling system of air.

As far as lexus go, is this false hope?

[gav_logan]

Yep, my car usually runs at 50%, never higher. It got to 3/4, at the times in question. Both times I was 1 min away from my destination, so I thankfully didnt have to go far.

[JPI]

When did the overheating problem occur? Did you get it fix? Are you losing coolant? It doesn't take weeks to get air pocket out of the system.

JPI

[gav_logan]

First problem was on monday night, top hose cracked.

Got home, chopped under an inch off the hose, and refitted. still not leaking there.

topped up and bled air tuesday. was fine till thursday.

Thurday after 30 mins driving, average warm day, overheated. Only (noticeable) fluid was coming from the overfolw tank.

Thanks for the info JPI. Any idea on a worst case scenario for the ammount of time to bleed air?

[SKperformance]

30 minutes is way more than engough with a hot engine not weeks.

If your hose blew you might have another one getting ready to also. More than likely it is the head but without a pressure test to trace the leak you will never really know. Check for coolant in the oil .

[Lexusfreak]

Just courious, is that the original rad? & how long since your last cooling system flush?

[VGR]

First problem was on monday night, top hose cracked.

Is the top coolant hose the factory original one? How about the hose clamp? If it's a screw type hose clamp then it's not factory original. If the hose clamp is not the factory original them someone likely installed a cheap aftermarket hose.

[jimbostar]

If the head gasket is severely blown, you'll see white smoke coming out of the exhaust too.

[gav_logan]

The hose clamp that connects to the radiator is a clamp, but the on on the engine is a screw.

I'm not sure when it had its last flush. but not in the 6 or so months that I've had it.

ok, so it's ok to just let it idle for 30 mins with the cap off, and keep on filling it?

[SKperformance]

you got it

[gav_logan]

Ok, done that. Still getting some reall small bubbles coming up. probably half the size of soda bubbles now.

I think I've spoted a little leak in the grill part of the radiator too...

I'm gonna have to sell this sucker just to get enuf money to pay to fix it :P

[gav_logan]

Ok, just back from the mechanics. Apparantly, he can't find anything wrong with the head at all. :D

I guess the next stop is to get to a cooling system specialist to make sure everything is ok...

Then maybe get the car serviced, as I'm abt 17,000 over :chairshot:

[Lex3486]

Not to spoil your good hopes or "burst your bubble" (ha..ha...ha, sorry had to say that) that's what my car did when the head gasket went; you could drive it for totally random amounts of time (sometimes 10 minutes, sometimes closer to 30 or 40) and it'd start overheating and bubbling out of the overflow tank. Also the radiator cracked (b/c of the excessive pressure in the system). I hope that's not what's wrong with yours! But then again, it isn't uncommon on the 92-93's...