Engine not reaching operating temperature

[Tonyrodz]

Update time! Its fixed!. Here is how I fixed it. Please keep in mind that this is NOT how it should be fixed but its how i fixed it and its working so far. If you wanted to fix this the correct way you would have to install an OEM radiator. Since i paid over 200 bucks for this one and they wont take it back i decided to make it work. The top hose going from the radiator to the surge tank needs to have some wort of restriction in it. I chose a 3/8 compression fitting. It fits perfectly inside the hose and you can close the ends kind of like a ball valve. Cut the top hose somewhere in a straight part and put your fitting inside. I closed the ends on my fitting about half way. Clamp the hose on both ends around the fitting. Make sure you use a good clamp. Don't cheap out on this. That's it! Start the truck and check for leaks. If you are still getting coolant rushing into the surge tank you need to close the fitting a bit more. You will always get fluid going through but it should not be rushing. Restricting it like this allows the engine to heat up normally and lets the cooling system vent off air like its supposed too. Please let me know if you have any questions. Again this is kinda rigged but has worked so far and ids a lot cheaper than a new radiator.

Can you post a pic of what you did.

 

[Fjs0001]

I pinched off the hose that goes from the top of the fill tank to the top of the radiator and the engine temperature rose to 210. I installed a 3/8” compression fitting and it did nothing. I’m going to install an adjustable valve next. What issues would I have if I plugged up both ends of that hose?

 

[corvette744]

Can you post a pic of what you did.

Can we get a pic of the fitting you put in the hose.

 

[Fjs0001]

Can we get a pic of the fitting you put in the hose.

This is what I used. I got it from summit. It's done great to stop the coolant from bypassing my thermostat.

Unfortunately I've having another issue now. As soon as winter ended my engine stopped reaching 210° again. It's not bypassing the thermostat like before though. I'm guessing the thermostat is getting stuck open. I don't really care right now since the weather is only going to get hotter. I'll deal with it in the fall.

 

[dcairns]

I know this is an older thread, but I had to register and thank you for the help. I have an 03 Silverado SS, but basically the same engine as the OP.

I replaced my leaking stock radiator with an all aluminum radiator in the summer (no plastic tanks). I did not notice any issues, but come winter, such as it is here in Southern California, I noticed the heater was not working that well, and figured I had a bad thermostat and replaced it. That did not help, so googled again and found this thread. Sure enough, that return line from the radiator to the overflow tank was sending a strong stream into the overflow tank. To test out the solution in this thread, I put a hose clamp on that hose and tightened pretty hard till the flow into the tank was noticeably reduced and sure enough, after driving around, it got back to normal operating temperature and the heater was toasty again.

I still had my old stock radiator laying around, so I went and looked at the fitting for the hose on it, and it does neck down a fair amount, and I am pretty sure they did not have that on the all aluminum replacement. I will look into a better way to do this than my hose crushing hose clamp, but that is just details now that I know the solution.

So thank you all for having this info! Saved me a ton of time/money troubleshooting.

 

[Fless]

I know this is an older thread, but I had to register and thank you for the help. I have an 03 Silverado SS, but basically the same engine as the OP.

I replaced my leaking stock radiator with an all aluminum radiator in the summer (no plastic tanks). I did not notice any issues, but come winter, such as it is here in Southern California, I noticed the heater was not working that well, and figured I had a bad thermostat and replaced it. That did not help, so googled again and found this thread. Sure enough, that return line from the radiator to the overflow tank was sending a strong stream into the overflow tank. To test out the solution in this thread, I put a hose clamp on that hose and tightened pretty hard till the flow into the tank was noticeably reduced and sure enough, after driving around, it got back to normal operating temperature and the heater was toasty again.

I still had my old stock radiator laying around, so I went and looked at the fitting for the hose on it, and it does neck down a fair amount, and I am pretty sure they did not have that on the all aluminum replacement. I will look into a better way to do this than my hose crushing hose clamp, but that is just details now that I know the solution.

So thank you all for having this info! Saved me a ton of time/money troubleshooting.

You can find a whole bunch of threads about this, but here's one that is referenced often:

Cold Case radiator

Somewhere in these threads a 45 cal Brass without primer installed was cited as a "perfect"fit restrictor. Is there a quick DIU for this? My aftermarket radiator ( Champion) also cools too well on cool mornings, and causes the same dash error. I have a zillion .45 brass laying around, and...

www.tahoeyukonforum.com

 

[dcairns]

I measured my original radiator and the opening in the fitting was 9.32mm or .367 inches, which is darn close to 3/8 inch (.375). So I got a brass 3/8 to 3/8 barbed splicer at the hardware store. I cut some old hose I had that fit the barbs and fit inside the existing hose (with some persuasion). Hose clamped that in place and I will see tomorrow how that works on a 50-something degree "cold" morning.

 

[adventurenali92]

I know this is an older thread, but I had to register and thank you for the help. I have an 03 Silverado SS, but basically the same engine as the OP.

I replaced my leaking stock radiator with an all aluminum radiator in the summer (no plastic tanks). I did not notice any issues, but come winter, such as it is here in Southern California, I noticed the heater was not working that well, and figured I had a bad thermostat and replaced it. That did not help, so googled again and found this thread. Sure enough, that return line from the radiator to the overflow tank was sending a strong stream into the overflow tank. To test out the solution in this thread, I put a hose clamp on that hose and tightened pretty hard till the flow into the tank was noticeably reduced and sure enough, after driving around, it got back to normal operating temperature and the heater was toasty again.

I still had my old stock radiator laying around, so I went and looked at the fitting for the hose on it, and it does neck down a fair amount, and I am pretty sure they did not have that on the all aluminum replacement. I will look into a better way to do this than my hose crushing hose clamp, but that is just details now that I know the solution.

So thank you all for having this info! Saved me a ton of time/money troubleshooting.

Glad to see this thread helping another GM rig out! Whereabouts in socal are you?

 

[dcairns]

Glad to see this thread helping another GM rig out! Whereabouts in socal are you?

I am in Orange County, but Big Bear is a fun place to visit

 

[adventurenali92]

I am in Orange County, but Big Bear is a fun place to visit

Cool cool got friends and lone time family friends there. Villa park and Yorba Linda so I’m quite familiar lol. Cheers to socal! Lol