Its a new setup, and its running a little hot. Its a LS2 402, F1C blower, ETP heads. The radiator is a Griffin, and its standed up straight, being cooled by two 11" Spal puller fans. The coolant temp was getting up to 220+, so we changed the water pump and the thermostat, now it has a Mezeire electric water pump with a 160 t-stat.
We didin't use any Dexcool this time, just distilled water and Watter Wetter. We fired it up, and it was idling for a while and coudln't get over 170 degrees at idle. Before we did these changes it would get hot real fast, even at idle. We figured it was all good now, and took it for a drive while to our dissapointment it slowly got hotter and hotter, almost just as hot as it was getting before. Just crusing in semi hot weather, the coolant temp gets up to 210-220 degrees(according to the BS3 temp sensor which is in the passenger side head). We then stopped and let the car cool down while it was idling, and it was still running hot. I think it keeps getting air pockets as we drive it. Why was it running at 170 degrees at idle when we first filled it up, and then a couple of hours later at idle it can't get below 210 degrees?

Can it be air pockets? The only thing I can't think off is that we are utilizing the rear steam vents on the heads, and have those meeting up with the front steam vents then going into the radiator. I think the line from the rear steam vents might be the highest point of the cooling system, but I am unsure. Would that make a huge difference? I have heard that the radiator cap has to be the highest point so no air gets trapped.

One thing that I am thinking of doing, is using a heat temp gun to see at what temp the water is as its going into the radiator, and what temp it is when its exiting it. Any ideas on if that will work? I know the ideal way to do this would be with sensors before and after, but that sounds lilke alot of work.

At what temp are your FI cars running at?
I appreciate any advice. Thanks!
Jimmy

 

Are you shutting the fans down at speed?

 

The fans are still being controlled by the stock computer, so yes they are programed to stop running once the vehicle reaches a certain speed. But I dont think thats the issue, as it is now getting hot even while its just idling.

 

This may be a dumb question, but have you changed the fan turn on temps in the ecm? Because the stock setpoints are really high (relatively speaking). I think the first fan comes on at 210 and the second at like 225.

Also, what stat?

 

Yea the fans are set to come on at 160-170, I forgot what the guy that previously tuned the stock PCM set them too. It currently has a 160 t-stat.

 

I had a similar problems after swapping my heads. I had an air pocket in the car that did not want to come out. I left the car with the rad cap off in the driveway with the nose pointed uphill for a long time. The pocket eventually worked itself out and no more problems. I do not know of any fast way to get them out.

 

I was thinking about trying that earlier, but never got to it. I may give it a try tommorow.

 

What could it hurt at this point right?

 

im having some issues as well. my rad cap is no longer the highest point, the bleed screw near the hose that T's off to the TB is now the highest point(its an lt1 car) and im haveing lots of fun with air pockets. filled the system up. no bleeding or any thing and drove around and it never got past half. stuck it back in the drive way, lifted the nose up and bled as much air out as i could. then it was all over the place, from below half to setting off the check gauges light.. beld it again well adding water threw the steam vent till the thermostat opened and now its more level and rids half but will still climb

its got a CSR EWP on it and the ginky rad set up that came with the turbo kit

 

Hey Jimmy how's it going.

Last week Thursday Alex (Sprayed 01) came by with his car and we kinda got on the cars alot.

Once I made a few rips here and there, the temp gauge sat at 210F. Once it went a hair over, and later it went a hair under. I was boosting 16 psi on pump gas and I didn't really do any cool downs at all. I have an aftermarket gauge so it's more accurate than stock.

I am running a puller, pusher, 1-2 bottles of water wetter, distilled water, and a stock LS water pump. I messed around for an hour, never really shut the car off. It ran fine at 210F, never started bubbling into the overflow or anything. Maybe Alex will chime in too.

 

John,
Its going good prety good other than its running hot. Were do you have your aftermarket temp sensor at? Whats the BS3 logging the temp at?
You should bring your car over by the shop one of these days so we can check it out.


My car will be going to Niles's shop so he can make me a better intercooler setup with aluminum piping. Now the car has one of those Ebay intercoolers and steel piping. While its there I will see if he can put some type of plate aluminum to seperate the intercooler and radiator. I was curious if you have anything seperating yours? I think since I dont have anything in between mine, the hot air from the intercooler is going onto the radiator and making things worse. It doesn't help that my boost bypass valve is after the intercooler. If it was before the intercooler than that air wouldn't be as hot.

 

Try using a IR temp gun to confirm the temp. Our cylhead temp sender is off a bit on the race car.

 

What should I point the IR temp gun to? Just the heads? I have the stock temp sensor in the drivers side, and the BS3 in the passenger side. They both give prety similar readings, but the passenger side is always a little hotter.

 

I started it today, the fans turn on at 160 degrees. Once the fans turn on, it dropped down to 150 degrees, fans turned off, then went back to 160 degrees and kept doing that. It couldn't get over 162 at idle. I took it for a drive, and it slowly kept raising. The highest it got was 214. I dont understand how it can run so cool at idle, and so hot when just crusing.

 

Well mine does that too as mentioned, and I know two other local LS1 turbo guys tend run 210-220F most of the time. When I used to mess with the cooling systems more 4-5 years ago, I ran the car cold with the cap off and topped it off... How are you and Pete doing it?

I don't have anything separating my radiator and intercooler.

 

It could be the tune, if the timing is out of whack it will cause problems. I'd say your cooling system is working pretty well if you can idle at 160.

 

I used Don Bailey for my tune, so I dont think the tune is mest up. Atleast I hope not lol.

John, we basically do the same thing to fill it up. I guess maybe its not running too hot if yours and other local FI cars are running the same way.

 

man I am have overheating problems to, 2004 408 iron block with D-1SC car gets all the way up 245 degrees after like 35mins of street driving. I have a Ron Davis Radiator and some custom fans, no help though. It runs great on the freeway. it sucks being in vegas heat.

 

sounds like a lack of airflow when moving. if its fine at idle, your having trouble getting air through the radiator to cool it.

 

Yea. I am starting to think that it is a air flow issue. Since we stood the radiator up, the lower air scoop isn't probably positioned to flow the air towards the radiator.
Has anyone else heard about blocking the air path between the intercooler and radiator, so that way the only place the radiator is getting air is from the bottom, and not the air that is being heated up by going through the intercooler? I know I read that somewhere and it seemed like good advice, I just can't find it.