REASON WHY 4TH GEN RADIATOR WON'T PROVIDE ADEQUATE COOLING IN A 5TH GEN?
 

Hey guys. Had a question for you all. The title pretty much says it. Recently purchased a 2k2, and had a brand new radiator from my '98 sitting in my closet. So I figured it couldn't hurt to see if I could still get some use for the part. The radiator fit perfectly; fan shroud and hoses lined up to a T. No leaks. I went for a quick run to the store and things were fine, then as I hit some stop and go traffic, the temp needle started to climb. Good thing I was close to home. I am going to swap back the original radiator, but was curious to the reason why the radiator didn't provide adequate cooling? Any info you may have would be great. Thanks.

I'm wondering if you installed it correctly. Did you verify all fans were working properly? All hoses, etc, in their correct place?

The A33B does have an oil cooler line from the t-stat that the A32 does not have, but other than that, the pieces should be very similar. I will have to check part numbers, capacities, etc and see what I find. :reading:

i checked everything out a second time to make sure all was snug and fitted properly, and it all looks OK. thanks for the info, and maybe you'll find something out that will shed some light!

Did you bleed the system correctly? A stuck air pocket can wreck havoc on the cooling system.

So out of curiousity...why did you even replace the radiator in the first place? If it ain't broke, don't fix it.

You didn't answer this question...but are your fans working?

S

i really could have left it alone - haha!

i just thought i could have made use of a brand new radiator. so much for that idea.

the fans are working fine, too

:sprint: Before you remove it.

differently tuned engines=different radiator??? the vq30dek (5.0 gen) has 30 more horsepower than the vq30de found in the fourth gen, and if you have a 2002 that means you have a vq35de (5.5 gen)....which has 60 more horsepower....more power/bigger engine=more heat

Not enough extra heat to provide the descrepancy he is having. Otherwise all of those people who put Vq35's in there 4th gens would be having the same issue. What about those people making 100+ HP over stock with boost, etc? No, it's some other issue he is having.

OK, so I just went out to check on it again, fired it up, and now the fans are not coming on at all. I let it idle for about 15 minutes, and nothing. All the fuses are good, all the electrical connectors for the fan are snug. They were running before when I first noticed the overheating, and now nothing. Isn't fan operation controlled by a coolant temperature sending unit - could it be bad?

Do you guys think swapping back the original radiator would make any difference? I suppose I could to rule it out. And so it goes...

i find it hard to activate the fans just by idling.. try driving around the block.. see what happens

:gotme: The original radiator in a Cutlass I swapped a 455 into worked fine with the 350, but couldn't handle the 455 in traffic. I had to pull the 4 row out of the Delta 88 donor car.

If the part number isn't the same on the 4th gen vs 5.5 gen radiator, there is a reason for it.

I do agree with the others that there may be air in the cooling system which is contributing to the problem. Could also be one of the cooling fan's wiring didn't get reconnected.

Thanks for all your help, guys. I re-flushed the radiator, paying extra attention to make sure I 'burped' the hoses. I haven't taken it for a spin yet, but I'll post up once I take it for a test drive. If I still have an issue I'll just swap in the original. Maybe I shoudn't have monkeyed in the fist place!

They look the same size and are the same material so why not. The dek and the 35 have better cooling passages in the engine than the 4th gen

Different engine, but on my 240 with the KA motor, I had to jack the front end up high in the air to get all the air to move out of the system. It was a PITA! Now, I didn't have any trouble bleeding my current car when I re-installed the motor, but it just goes to show that air can get stuck pretty badly.

Make sure you turn your heat all the way on and let it run for a few minutes once it's all the way warmed up, that way you flush the heater core of air as well. :thumbsup:

you might wanna use some wet wetter, it really helps tranfer heat better!

You mean water wwetter? I wouldn't say that. In his case, he needs to bleed the system out more. Water wetter wont help, and would sever as a band aid only.

Unless there is some sort of large airflow restriction on the 5th gen that the 4th gen does not have, then the 4th gen radiator SHOULD be adequate. Taking a look at my 4th and 5th gens last night, I didn't see any obvious flow restriction from one over the other. I still think your problem lies somewhere other than the radiator you are using.


Granted, did you get the 4th gen radiator from a reputable brand/source?

+1 on bleeding the system properly. An engine doesn't know or care what part number radiator it's using, so as long as the core size is pretty much the same, it should cool just as well as stock, as long as it's bled right and otherwise working right. I have a copper/brass radiator out of a Datsun 620 pickup in my S13. It has no problem whatsoever with keeping my 250HP SR20DET cool. As long as the radiator has enough cooling capacity, it doesn't matter what it's original application was.

+1 After reading the OP this is exactly what I was gonna say

+1 for all you guys who said to re-bleed. I have to say, I must have half-assed it the first time. I bled it again last night, and the thing was fine today to and from work, which is about 30 miles round trip. Thanks again for all your help!

Glad you got it worked out. I've spent hours trying to figure out a cooling problem that just ended up being air stuck in the system. At least you didn't pull the radiator again!!! :thumbsup:

where is the bleeder valve on the vq30de-k?

just before the water neck, driver side, top side of motor. Its a circular piece with a metric set screw in it.

i'm going to check on my lunch to see if i see it. i have to change out my radiator as the top of it is spewing 'green kool aid' lol

is it right on top of the thermostat housing?