I'm not sure what that mark is since it's in kPa, but I guessed 150 which comes in around 20 PSI which is perfect while idling, even if it dropped to 80 kPa that'd still be 10 PSI which the rule of thumb is a minimum of 10 PSI for every 1k. Not sure how to say that for kPa, but I'm sure you get the point.

As far as Dex-cool, that's fine. If you can get your hands on a all makes, all models type, you'll still be golden. If you have about $15 (US) to spend, try and pick up some Lucas Super Coolant or RedLine Water Wetter, they'll help keep temps down on the car. You could also upgrade to a 160*F (72*C) thermostat.

 

i burped my system ofair completely and filled it up with lots of green prestone and purified water and it stays below the halfway mark most of the time unless im sitting still it goes a little above the middle mark. I'm on a 180 degree thermostat. I'll try to get some water wetter and see if i always stay under the middle check

 

I thought going to a lower temp thermostat was discouraged on these cars??

 

With my 94 V6 I discovered that, unlike other cars I have, you can't run the engine with the radiator cap off and expect to purge air from the cooling system. The electric fan doesn't turn on until unpressurized coolant exceeds the boiling point so you'll get coolant boilover. To bleed mine I removed the fan relay and temporarily installed a jumper wire to keep the fan running. That worked fine.

Oil pressure does look fine from here. IIRC the switch used to turn on the idiot light on other GM products tripped at something like 7 or 8 psi. So that's what they thought was okay at idle.

Guess you have a real export car since it has the metric gauges. Can't be many of then over there, huh?

 

I'm wondering if a 160 degree Would be good as well

 

It's not really discouraged, just not needed. The LT1 likes running a little hot, and the reverse cooling does an excellent job at keeping the cylinders cooler with reduced hot spots compared to your standard style cooling system. If the OP does a lot of city driving, I'd make the swap.

As far as the temps go, if it's now staying around the middle while sitting in traffic or idling, you're okay. The only time I'd get worried is if it got real close to the red and I didn't hear the fans kick on.

 

Cheers for all your help. Thats good about the oil pressure, from some of the videos I have watched online, the oil pressure guage seemed to stay in the middle, so I guess i was just being paranoid. It does sit in them middle when the engine is cold.

I've drained all the cooling and filled it with water and some radiator flush, bled the system and I am pretty sure the problem is gone. I'm just waiting for the thermostat to arrive (I had to order one in)

Is it normal for the temp guage to raise just above the half way mark when idling? I find when just sitting there with the engine going, it will heat up above the middle, but then go back down when driving.

I'll drain the water out when the termostat arrives, and put some good quality red coolant in, but it probably wont be dex-cool. The car isn't being driven at the moment.

Also, the low coolant warning is still coming on intermittently, usually when the engine has warmed up. If it is still coming on after the termistat and coolant change, I assume I have a faulty sensor. I understand its a simple sensor in the over flow tank? Will I have to drain the coolant again to change this?

 

It is normal for the temp gauge to raise about halfway while idling and then cooling down while moving. The reason for this is because when you're idling, there's no air flow going through the radiator, so the efficiency of cooling is lessened. But when you start moving, you have forced air coming through radiator to help the cooling process. However, if you it were to get too high while idling, the fans will kick on and pull air through.

That's sometimes normal when you mess with the cooling system. Once you have everything squared away and you've been driving for a bit, it should shut itself off.

 

So i've replaced thermistat and coolant, bled system etc but i'm still not 100% sure the problem is fixed.

While idling it seems to go up past the middle, to almost the 3 quater mark, then drop down to half way. If i leave it idling long enough it will then slowly raise again and drop again. When driving it seems to sit just below the half way mark.

I'm a bit concerned, however i'm wondering if there is still possibly an air lock, is there an easy way to tell if there is or not?

Also, is it ever normal for the coolant temp to raise above the half way mark? say to the 3 quater line, or even half way between half and 3 quaters? (if that makes sense)

cheers again!

 

Your car sounds normal to me, What you are seeing is the car running up to the point the fans kick on. The motor will not run that hot out on the highway. The car driving puts more air through the radiator then the fans do.