FTO AUSTRALIA

Hi Everyone,

I have just brought a 97' GX FTO about a month ago and have been having some issues with it overheating lately that I could use some advice on. About two weeks ago I noticed the temperature jump up just past the three quarter mark before going back down just below three quarters. It then seemed to fluctuate between half way and three quarters with temperature rising and dropping quite quickly.

After noticing this I checked the thermostat first and it was operating correctly so I did a coolant flush as I expected it could be some air in the system. After doing this the engine didn't overheat at all for over a week and a half and I thought I'd fixed the problem.... Until today when the problem came back.

The car will usually take 15mins + to get past the half way and then all of a sudden shoots up before cooling back down a bit and then repeating. currently I'm out of ideas except for somehow air is getting into the system. I doubt it's a head gasket as oil is not milky and there is no smoke anywhere. There also doesn't appear to be any leaks in the system.

Any help would be great!

Thanks!

Replace your coolant temp sensors - one goes to ECU and one goes to gauge.

Why would changing the coolant periodically fix a faulty coolant temp sensor?

Sigh.

OK, don't listen to me then.

Sorry that came out wrong but was a serious question. Only new to working on cars and trying to learn as much as possible.

Daniel2019 wrote:Sigh.

OK, don't listen to me then.

"After noticing this I checked the thermostat first and it was operating correctly so I did a coolant flush as I expected it could be some air in the system. After doing this the engine didn't overheat at all for over a week and a half and I thought I'd fixed the problem.... Until today when the problem came back. "

I think he is asking why changing his coolant had temporarily fixed the issue.

Probably could of worded your response a bit better BobbyJ

What Daniel means is; change the coolant temp sensor, it could be faulty and thus giving a false reading. It's a cheap part and takes less than a minute to change. Could fix your whole issue

Yaahhhhh

After having changed the sensor, make sure your thermo fans are both engaging whenthey should. There is a fair chance the radiator is partially clogged and will need to be replaced. A flush wont get rid of all blockages unfortunately.

Yes that's exactly what I meant! Sorry again. Thinking about it more it could very likely be a faulty coolant temp sensor as lately I have noticed a slightly irregular idle and occasionally the revs will suddenly drop for less than a second before going back to normal. What i'm still unsure of, however, is how the problem disappeared for so long after the coolant change. Either way it can't hurt changing the sensor.. where is the best place to purchase one? Are any local shops likely to stock them or does it have to come of the internet?

As for thermo fans; I already checked this and they both operate correctly. I was leaning away from a blocked radiator as when i flushed the flow seemed quite strong and the coolant wasn't discoloured at all or carried any particles.

Thanks for the quick input everyone!

Sorry....

I have had a long day at work and the f**king RTA (c**nts)

Replace yo sensors, cheap and should be done anyway, takes 2 minutes each.

I did this the opposite way with my blue GPX - did the gauge sensor last and racked my brain replacing everything else. Fix/eliminate the easy/small stuff/basics first and then go from there.

If not sensors, may be blocked radiator as Dwayne said so see if you can borrow someone's or get a new one. If not, what kind of coolant are you using? How much are you putting in?

Are your thermo fans kicking in? If yes, at what speed? If no, are they getting power? Are they seized? etc.

Did u change the thermostat? Once u cook one they don't work properly again

Yeah I agree, deffinately a good place to start and thanks for the link kiz! Just as some extra information i quickly drove up the road to the shops and twice in first gear it feels as if the engine cut out making a very sudden jerk before going back to normal. Could this be related to the CTS or is going to be another new problem I have to figure out

Wait I read that as you changed the thermostat... my bad, like I said, long day I would start there, replace that first then go to your sensors, blocked rad. etc.

BobbyJ wrote:Yeah I agree, deffinately a good place to start and thanks for the link kiz! Just as some extra information i quickly drove up the road to the shops and twice in first gear it feels as if the engine cut out making a very sudden jerk before going back to normal. Could this be related to the CTS or is going to be another new problem I have to figure out

Check/change...Fuel filter, stepper motor on the throttle body, fuel pump. In that order

Okay so just got to work (about a 40 minute drive along the highway) and thought I'd keep a close eye on the temperature just to observe what it's actually doing. As usual the engine ran below half way for the first 15 minutes when i noticed an initial spike to around the 3/4 mark as I was slowing down to turn onto a different road. This spike quickly reduced back down to around 1/2 way before fluctuating between these points for about 5 minutes. After this the needle went back down below 1/2 way for the remainder of the trip.

I stopped in the car park and let the car idle with aircon on for a few minutes to see if the temperature would go up but it stayed under 1/2 way for that time so I turned the car off.

So it's official... this problem has got me stumped. I'm going to order a CTS tonight as the car is due for a new one and might try pick up a thermostat on the way home. Apart from that my only other thought would be air or a blockage in the system that somehow keeps unblocking itself.

Change the cluster

silverGPX wrote:Change the cluster

Do you mean the entire dash display or? Are these known to be faulty in an FTO?

Exactly what happened to me. Change your ECU temp sensor and your gauge temp sensor.