My Overheating VPII

[kall]

Hi guys, First post on these forums and i'm hoping someone can help me. Sorry if it's a little off topic but i've tried on other forums including street commodores and noone seems to have the answer.

After 3 mechanics, 2 thermostats, coolant temp switches and senders, pressure testing, radiator flushes and much more my car is still overheating. The thing is though. When idle at lights or whatever it sits at it's normal half way operating temp that it should when idle, but when i'm driving the temp guage just sky rockets to full heat. I'm shitting myself that i'm gonna crack my heads. I don't know what else to look at?? Ever cruising along at 100km/h tonight in ~12degree temperatures it was sitting about half a notch from full heat. As soon as I stop at lights or something it cools right down?

I'm hoping you guys can help me as i've spent enough money on enough mechanics trying to solve this problem. It's a V6 and the waterpump is only 4 months old.

Any ideas?

Cheers
-Kall

[fatas]

can bet 100% that the head gaskets are goooone has happened to me twice just bite the bullit and get a head service and 2 head gaskets that will be the problem make sure you bleed it proply do you know how ? :)

[kall]

I've had all 3 mechanics check the heads and they all say they're fine. There's no bubbling. There are no signs of water in the oil or vice versa and no steam or anything like that coming out the exhaust?

Bleed what exactly? And what's the correct way of doing so?

[kall]

Forgot to mention.. It has been running a bit shithouse lately... Idleing very very rough at times. Other times fine and seems to have lost a fair chunk of power... Then again sometimes it's still seems pretty powerful.

270,000km's

Also, sometimes doesn't like starting when the engine is hot. Sometimes splutters.

[Peter B - CV8]

Is the thermo fan cutting in when it gets hot ? Had an uncle with a similar problem - turned out to be a corroded terminal on the fuse for the fan. Only discovered this after he had changed waterpump, flushed radiator etc etc.

[kall]

Nah the thermo fan is fine, that was the first thing i tested. Again today flushed the radiator and the block. New coolant new thermostat AGAIN.... still no effect. Just seems to be getting worse.

[paul05]

radiater needs to be replaced or recoed,i had the same prob with my vp vacationer.some radiater places paint the out core ,it;s a big mistake the core is aluminium and it keeps the heat in not allowing air to pass.
it's a flow problem if it cool on idle and hot on cruz.

[spiv]

Forgot to mention.. It has been running a bit shithouse lately... Idleing very very rough at times. Other times fine and seems to have lost a fair chunk of power... Then again sometimes it's still seems pretty powerful.

270,000km's

Also, sometimes doesn't like starting when the engine is hot. Sometimes splutters.

Sounds like the overheating has burnt the valves which would cause a loss in compression and power...Bleeding the cooling system simply means taking the air out as when you flush the radiator it is common to have air trapped in the system which can cause overheating.

[Peter B - CV8]

radiater needs to be replaced or recoed,i had the same prob with my vp vacationer.some radiater places paint the out core ,it;s a big mistake the core is aluminium and it keeps the heat in not allowing air to pass.
it's a flow problem if it cool on idle and hot on cruz.

I reckon you might be right !!! Seem to recall on old Gemini that I had (many years ago) - used to heat up at around 80k's, but dropped temp once you slowed down.
Turned out the radiator core was blocked up with a build up of crap. They removed the top & bottom & "rod cleaned" the core. It ran nice & cool afterwards.

[joe 09]

i had the the opposite problem with my vp ss over heating at the lights and cool down while driving, i changed everything water pump,radiator,coolant three times,thermostat twice.had the heads looked at three times and nobody found a problem.
after all that i fixed the problem myself i traded it in on a vx v6 supercharged and that only lasted 2 years untill i upgraded to my vx ss :lol: :lol:

[kall]

Could be the radiator. Had a pretty major front end collision over 12 months ago.. $6000 worth of damage, but the radiator was sent off and tested for any problems at the time and came back fine. Why would it only be playing up now? It's had nothing different or unusual done to it and it still passes water through it fine?


Might get the heads and cylinders tested for leaks one more time.... how likely is it to actually be the head gaskets? As I said there are no signs of them likely to be gone and as far as I knew I always have been told it's very rare for heads or gaskets to blow in the buicks.