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Cooling Problems on my 2007 2500 LBZ

I had to replace the radiator once and water pump 4 times in 250k miles on my 06 LBZ.

Radiator was replaced by a mishimoto and 2 of the water pumps had the impeller spin on the water pump shaft, one of those times caused a blown head gaskets at 350k miles
 
Are you happy with the Mishimoto radiator?? I have two delivered so far and between the weak way Mishimoto packs them and the UPS manhandles them they both have had to be returned. I know Therm doesn't like them but there are not a lot of options over stock. The third one is to be delivered today. If it is damaged I will have it returned and ask for my money back and reinstall the stock one.

I am installing a Merchants welded impeller water pump.
 
Stock radiators are more than adequite to cool these engines. I know somebody else who is running close to a 700 RWHP tune in his LLLY using a STOCK LB7 radiator, and even in ARIZONA heat he still manages to handle most grades without overheating. He does say it gets up to 230 or so in 115-125 degree temps pulling a 7% grade, but he can still hold highway speeds with it. The LBZ radiator is over 2 inches taller than the LB7 radiator, so I see no reason to add cooling. I know guys running these trucks for hot shot's, and they don't overheat with stock LBZ/LMM cooling systems grossing 30K+ provided the system is clean, working, and the fan clutch is good. As to the mishimoto, I wish you luck. Theres more than a few LBZ owners who have had the LBZ MISHIMOTO's fail in under 3 months. MISHIMOTO always blames the cab mounts, then radiator mounts, frame flex, and so on which I find HILARIOUS considering the radiator mounts to the intercooler, and the frame flexxing has NO impact on it.
 
If you are wanting extra cooling over the stock one and need to repalce yours frm age/ wear: have it re-cored but dont let them paint it after the chem dip. Tell them leave it bare. Then get the thermal coating paint- that stuff showed something like 20-25% better heat exchange than regular painted radiators and inner coolers.
Can you guess what is on my plans list for the hummer-haha.
 
THEFERMANATOR said:
Stock radiators are more than adequite to cool these engines. I know somebody else who is running close to a 700 RWHP tune in his LLLY using a STOCK LB7 radiator, and even in ARIZONA heat he still manages to handle most grades without overheating. He does say it gets up to 230 or so in 115-125 degree temps pulling a 7% grade, but he can still hold highway speeds with it. The LBZ radiator is over 2 inches taller than the LB7 radiator, so I see no reason to add cooling. I know guys running these trucks for hot shot's, and they don't overheat with stock LBZ/LMM cooling systems grossing 30K+ provided the system is clean, working, and the fan clutch is good. As to the mishimoto, I wish you luck. Theres more than a few LBZ owners who have had the LBZ MISHIMOTO's fail in under 3 months. MISHIMOTO always blames the cab mounts, then radiator mounts, frame flex, and so on which I find HILARIOUS considering the radiator mounts to the intercooler, and the frame flexxing has NO impact on it.
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So, I just received the 3rd Mishimoto today and it is also damaged. So, I am sending it back and getting a refund. Having completely done everything myself you are absolutely correct on your analysis Therm. I have my new Hayden 2886 radiator clutch and I will be cleaning everything to like new condition before reinstalling.
 
I had good luck with mine but I only had it 2 years, most people say it take 5 years to show issues.

I cracked 2 oem radiators so I only upgraded so I could get away from plastic tanks and it was worth it for me.

I still saw 237* before the t stats were fully opened and the fan clutch fully locked (didn't happen as often). I was also running a huge trans cooler that I had to cover in the winter. The trans cooler was a big help to my ECT's until my trans would finally heat up then I'm guessing that extra surface area of 250* trans temp blowing through the stack became an issue
 
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Factory stats don't go full open until 230-235 degrees. These engines can take alot more heat than most want to run. I ran for about 6 hours straight running 225-230 in mine when my fan clutch quit on my way home towing the travel trailer last summer.
 
THEFERMANATOR said:
Factory stats don't go full open until 230-235 degrees. These engines can take alot more heat than most want to run. I ran for about 6 hours straight running 225-230 in mine when my fan clutch quit on my way home towing the travel trailer last summer.
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I hear that the magic number not to exceed is 240*F.
 
240-245 is where things start getting hot. It's not like the olden days where people freak out at 205 as the stats are just really starting to open up then.
 
Until you posted that the t stats weren't fully open until 235* I was backing out while towing. After you said that temp was ok I I just kept my foot in to see what happened. Sure enough, I'd hit 237 according to my edge insight and drop to 200ish and repeat as the fan clutch locked and unlocked.
 
OK, latest update. The truck is running, no leaks and the temps seem great but I haven't towed the trailer yet.

I cleaned the stack after I separated the IC and the Rad using a pressure washer for the final cleaning. I couldn't get the fin areas clean enough with just house water pressure. I watch a video that Merchant's Automotive had on Youtube showing they used a pressure washer. Since the truck had 130K mi on it I replaced the water pump, both idler pulleys, the tensioner pulley assembly, the radiator fan clutch with a Hayden 2886, A Gates "green belt", both upper and lower radiator hoses, replaced all the glow plugs on the right bank, replaced the thermostats back to the AC Delco standard temp ones, and replaced both amber turn signal bulbs before reinstalling the front clip.

I hope to tow with it next week when the temps come back hot. Suppose to be a high of 54*F tomorrow at home. I am in Pace, FL doing electrical wiring for my son on a house that he is rebuilding.

Anyway, on the way down the temp ran mostly at 188*F on my insight instrumentation. It got up to 192*F once but the thermostats were very responsive and I am cautiously optimistic that the problem is solved. Hopefully I will be able to report that next week.

It took a while to get all of the air out of the cooling system but, I think I am there now.
 
any suggestions on dis-assembly of the stack? I dont want to bend anything and I dont want to evacuate the a/c system.

I need to work mine over.
 
I did not move the a/c condenser or the trans cooler. I did remove both inner fender wells (that was a big help removing the lower hoses on the passenger side. I also replaced the water pump and needed the drivers side removed also. Be careful moving the e/c cond out of the way and not bending the tubing. When I removed the stack I got two other persons to assist me. One to hold the condenser out of the way and the other to help me lift the stack out. I used the others also when it was time to put the stack back in. Of course a younger more risqué person could probably do it quicker with less assistance.
 
Cooling is really great now and wish I had figured the cooling stack cleaning a year ago. But, as they say , better late than never.
Thanks to all who provided input!!
 
Engine cooling temps are good but I am now towing a 14K lb 5th wheel camper and having some issues with EGT's. I have sanother thread on the LBZ forum here explaining what i am doing. Title is Mods to improve towing or something like that.
 
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