Some of you might like this feature but if i let the car warm up and then go for a drive,the motor cools down ...alotttt.I mean under 120*.Can this be from a major air pocket,i dont lose any coolant or nothing else unsual.But the motor doesnt seem to retain heat once i take her up on the highway or get to a decent speed.it cools right down as if it was just started first thing in the morning.

Any ideas?

 

Whats your gauge set up? It does have a t-stat in it right?

J.

 

While this is a cooling thread, I reused the LQ4 thermo with the 195 temp as I heard the LS engines like to run warmer. Any truth to that? My car runs good with zero issues when its 40* outside or ideling in 100* temp traffic.

Going back to the OP, it does seem that there is air pockets. You did connect the little steam vent to a pressured source right?

 

Sounds like you have your gauge temp sender mounted in the cooled side of the system. It should be from the cyl head is it?

 

the tstat is in there.its the stock tstat and it works fine.the car get upto temp and runs fine.im using the 3 wire cts and its in the driverside head.the steam vent its connected aswell.i drilled and tapped the waterpump and ran the line to the throttle body and then out to the steam tube.

ls motors do run hot from the factory to answer the above question.

 

Id look at air in the system. Easiest way to prevent air is to fill the engine from the top rad hose then once it runs out quickly stab it on the nipple and bolt her up. Works great for me Ive never had a problem doing it this way. Never had an engine that didnt run right at thermostat temps either these engines run very cool

 

When I first burped the system all i did was fill the rad with all the hoses connected.started the car and turned the heater on full blast.waited for the thermostat to open and kept filling the rad up.I repeated this 4 times untill it stopped taking more water and then put the rad cap back on.

not quite sure what you mean about stab it on the nipple and bolt her up?

 

"stab it on the nipple and bolt it up" means put the upper radiator hose back onto the radiator and tighten the clamp lol

 

oh ok lol,well how much of a difference would it make to just leave the radhoses connected.Im not losing any coolant in my system,when the motor is warmed up i do get good heat coming on.it just gets cold once i start driving.the factory fan settings and 190* tstat are functioning properly as i let the car get hot and watch the fan turn on at 220* and turn off at about 185-190*

 

I'm really not sure. I've always heard its hard to bleed an LS motor but I basically put all my hoses on , filled the rad to the top, put the cap on and filled my overflow jug. Nothing else.

 

I took the upper rad hose off the rad "nipple" and poured my coolant mix into the rad hose. After a couple of jugs it was full and started pouring out of the hose so rather than let it drizzle away I quickly stabbed it onto the rad nipple/fitting/whatever and tightened it down with the hose clamp and voila

 

so did i,and i bled to system 3 times without issue during the summer when i completed my swap.now that fall weather is here im noticing that my motor temps are too cold unless i let it sit and idle for 20 mins for it to get to 210*when im driving around city street it will drop to 150*,on the highway it goes 120 or lower.never seen that before.

 

Sorry I did not understand your initial post properly I thought you were overheating. If your too cold then change the thermostat and give it a go

 

lol nope..not overheating..thats the one thing i dont think this car will do right now lol.is it possible that the tstat is stuck open slightly.it just doesnt make sense..the car will warm up normally and fans cycle as they should and the temps are correct...but once i start driving around...temps go wayy down too cold and the car i can tell starts to run rich and the idle will pickup about 150rpm untill its warmer and then drop back to 850-900rpm.

 

Start with changing the thermostat its a twenty dollar fix and will likely solve your problem

 

Are you sure the gauge is reading correctly? Do you have someone with tuning software that can plug into the ECM and verify that the reading is accurate? My stock gauge in the cluster did some wierd things too. It would act like it was giving an accurate reading, for a few months actually. Now it only reads up to about 90*. I have the Aeroforce Interceptor scan gauge and I have one of the perameters always set to coolant temp so that kind of replaced the guage in the cluster.

 

the guage has been reading accruately for a long time.its never given me a problem.but the main reason why i dont think its the gauge is because the motor itself will idle high when the gauge is reading cold.if i had no other symptoms relating to the motor running rich or idling high or that i get no hot air with the heater on etc then i would just ignore the gauge.

so i will try burping the system some more now that its been a few months driving around in the summer i didnt have this issue since it was hot outside.

i do plan on building the motor in 3 or 4 months from now but id rather solve this now then later so that i know what to avoid so that i dont cook my rebuild lol

 

So just for an update. I "tried" burping the system and never encountered this before so bare with me.

I started the car cold and had the rad cap off,the heater turned on full blast.Waited for the car to get hot and the thermostat to open and the primary fan came on.At this point the rad began to suck in coolant but also was gushing more out than I could pour in.making quite the slippery mess too.

I filled it back as much as I could before then fan shut off and then put the rad cap back on.Then let the motor cool down,checked the rad and filled it back up and started her up again with the cap off.The fluid went down some more and I filled it up more and more while warming it up,I could see alot less bubbles coming up this time.Just before the fan came on..I put the rad cap back on and let the full tstat cycle happen and then shut the car off and cool down.

I repeated this 4 times and now I see no bubbling with the car running and the rad cap off,great.I figured this was as good as I can get and the car is warming up much faster.Time for a test drive.I made sure the car was fully hot before leaving my house and I hit the highway.Once on the highway my temps dropped to about 140-150*.This is better than before but still has me concerned I might have a good pocket still somewhere.My rad is a new rad for 3rdgens and I removed all my ac equipment so the rad is getting very good airflow right now.Im thinking to maybe put cardboard infront of the rad for the oldschool trick of retaining heat.I might take the car in to a local shop and have them flush the system with the proper machine to add in coolant without getting air inside.

 

as cam said I would change the thermostat. if your afraid to spend the money you can put it in a old pot on the stove and use a known good automotive or cooking thermometer that will read the water temperature see when it opens..


just an FYI if your lucky... Ive seen several cars (sorry not ls1 as of yet) stuck part way open due to debris in the cooling system. saw a 2.4 with a chunk of plastic holding it from closing

 

Its not about the money.I just want to sure im not tearing into my whole cooling system for something as simple as burping the rad.I would be more concerned had the motor started over heating lol.

 

You say it heats up very quickly now? An air pocket in the system will cause it to heat up a lot quicker than normal.

 

alot quicker meaning it doesnt take forever to warm up like it did before and retains heat better.

 

just a quick update
i did the old..cardboard infront of the rad and everything ironed right out oddly enough.i didnt think that remove my a/c stuff would drastically affect how well the rad was getting airflow.car now steadily hold 190-210* while driving and is even running better aswell.