stoessjc

2008 Z51 LS3 coupe. Radiator starting leaking, needs to be replaced. Any recommendations on a replacement radiator, e.g. GM, aftermarket stock, etc.? I did a quick search and the non-GM replacements are about half the price.

Is there a thread on radiator replacement? If there is and you can provide the link, thanks.

I am thinking of replacing the water pump at the same time. Car has 140,000 miles, which makes me think the water pump is probably getting close to end of lifespan. Is the replacement any easier with the radiator removed?

vigman

Well... Yes the water pump is MUCH easier to replace with the RAD out, do ALL the rubber hoses at the same time.. I did a silicone kit which was OK but not GREAT... one of the heater core hoses is a bit short.. it fits fine but it is not long enough to use the factory support clip (Ty wraps to the rescue ) and the little hose going from the top of the raid to the overflow canister is a bit to fat to sit in the factory holding clips....

Is your car an auto or stick ?

I put a DURALAST GOLD radiator in my expedition ( Auto ) 1 week later the trans cooler leaked into the coolant causing an ATF milkshake, 2100.00 trans rebuild later and a replacement radiator it's been fine for 10K....So I'm leaning more OE in a situation where fluids COULD mix... causing BADNESS....

schpenxel

I just used AC Delco one off of Amazon.

Dewitts makes a nice one, but it ain't cheap

Won't hurt to change water pump and expansion tank while you're at it. I'd replace the tank for sure.

As far as installation goes, it's easier if you just break the tabs the tabs that hold the condenser to the old radiator. It's not like you need them anymore. Once those are gone the radiator comes out much easier.

stoessjc

It is 6sp manual. I think it still has either engine or tranny fluid running through the radiator. Went through a thread where there was a debate about whether a special tool was needed to remove the lines from the radiator.

schpenxel

You don't need a special tool for removal. Just pull the clips out with a pick and the lines will pull out.

Unreal

Dewitts is great if you want to spend the money. Otherwise OEM replacement works fine for most people.

No special tools needed. I wouldn't touch any other brands.

stoessjc

Appears there are three different radiators:

without oil cooler, manual trans. - GM part 15145946
with oil cooler, manual and automatic trans. - GM part 10353889
without oil cooler, auto trans.

My car is manual, Z51. I know the last one (auto trans.) is not the right one. Which of the other two is correct radiator?

schpenxel

Mine is a Z51 manual and had engine and transmission oil coolers built into the radiator. At some point I believe that changed though. Just go look.. it will either have hard lines connected to both sides or only one

This is the one I bought:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

vigman

If there are two small hard lines on the DRIVERS SIDE of the radiator, then you have oil cooling

CMY SIX

DeWitts rad with "black ice" coating internal oil cooler and they offer one with both oil/tranny. I've never been so cool!

schpenxel

That isn't the question. Some have 2 oil coolers, some have 1.

schizcat

Hard lines on the drivers side is the oil (EOC). Hard lines on the passenger side are for the transmission (TOC). If I remember correctly from the research I did when replacing my radiator was in 2007, the option changed and the oil cooler was external and the trans cooler was internal (if it was an option).

Unreal

Can always look through grill and see if you have an air/oil cooler or if it is built in.

Can always swap. If you have air/oil and want a water/oil then buy the one with built in and just plug the lines into the radiator instead of air/oil cooler.

2k Cobra

If it was my car and planned on keeping it, I'd get a Dewitts and replace water pump, hoses, pulleys while easy to get at.

YMMV...

stoessjc

My car definitely has an external oil cooler (air cooled) that sits in front of the condenser. I thought that oil cooler was part of the Z51 package. I also know it has hard lines on the passenger side of the radiator. For Z51, did they route the oil through both the radiator and an external oil cooler?

Unreal

Nope, one or the other. Passenger side is transmission cooler, drivers side oil.

Gearhead Jim

In our C5, we had two Bee Cool "drop-in" radiators that didn't drop in. The shop modified the shroud to work, then the first one started leaking after a couple of years and the replacement started leaking six months later. So I reinstalled the original OEM radiator and lived happily ever after.

Dewitts has a good reputation but I'm a bit leery of aftermarket radiators now.

05 Wreck

When rebuilding my car, I ordered aftermarket radiator off ebay, looked good performed as advertised until....On the way to the state inspection station the lower trans cooler line popped out. Replaced with GM part no problems after 1500 mi. Although the first one received the core was warped. This ain't rocket science, why can't we replace parts hassle free?

timd38

Changed in 08 I believe to separate engine oil cooler. 05 and 06 have both in the water radiator.

Gearhead Jim

GM is a real penny-pincher on many things, and their quality sometimes shows it. But they have the advantage of experienced engineers and producing tens of thousands of Corvettes and having to warranty them for the first few years, so problems tend to get identified and often (but not always!) fixed if they are causing warranty expense.

A smaller shop may or may not measure up.

If the radiator in a Corvette under warranty starts to leak, 99% of them will be taken to a Chevy dealer who will replace the part and GM (or the supplier) pays for that.
If the aftermarket radiator from "Joe's Live Bait, Body Piercing, and Radiators" fails after a few months, many people will just throw it out and not bother to spend the time/money to ship it back for their "free" replacement.

Dewitts has a better reputation.