Well since I’ve switched to a DEK manifold on my '96 Max I’ve experienced much higher coolant temps as logged thru the OBD-2 chip I have. My car has been running hot for months and even though I had replaced or cleaned most of the components of the cooling system I left my stock radiator alone. This weekend I finally decided to do something about it and swapped in a Griffin radiator for the '95~'99 Maximas.

Granted the Griffin is pure over kill for a N/A street driven Maxima, I like to take my car to road courses and would like the best radiator available to us for cooling. When I was racing down in Texas I logged temps as high as 220~230 degrees on the track and the temp gauge started to climb towards HOT on my car. My coolant was almost boiling and I had to race with my heater on 85 F in the 100 degree Texas heat. Not to mention I was still logging 200~210 degrees on the highways at cruising speeds with air temperatures of about 70~80 F.

Well check this comparison out I am quite happy with the results...



I’ve seen an average reduction of about 20~30 degrees with all driving conditions. I’ve yet to track race but this should help out none the less. I have not seen temps like this since I swapped the DEK manifold onto my car. I have a 175 degree thermostat and the coolant stays around that range, it may raise up to 185~190 when im stopped but it drops back down to 175 when cruising.

I would advise those who have swapped a DEK manifold onto a '95~'99 engine to monitor their coolant temps. My radiator may have been bad so I wouldn't advise anyone to go buy a $350 Griffin, but your stock radiator maybe on it's way out and in need of a replacement. I know my stock radiator had the capacity to keep 175~185 temps with the stock intake manifold but I regularly saw 195~210 with the DEK manifold swap. Now im back to where I used to be and my engine thanks me for it.

In my opinion if someone is going to go thru the trouble and cost of a DEK swap it's probally more logical to swap the whole motor. You will get a lower mileage engine that has the capacity to cool itself better with the DEK manifold. Oh and if this thread turns into a 2K VI vs MEVI arguement can a mod please lock this? Im not about to start anything Im just providing facts.

 

Excellent work Joe i can't wait to see how this added cooling efficency translates onto the dyno

 

Now that i think about it, it makes sense. The 00VI allows less engine heat to transfer to it since it's plastic, so more of it stays in the block and heads. I wonder if the 5th gens have a lower temp thermostat to compensate...hmmm...

 

Did you also disable your EGR system? The reason why I ask is because I seem to recall someone saying their EGT went up with the installation of the DEK VI. Your higher coolant temps would make sense then. My factory temp gauge hasn't changed since I installed the VI but then again, it probably isn't sensitive enough to record 20 degree changes. As an aside, does coolant boil at 232 degrees? I thought it had a lower freezing point and higher boiling point than water?

 

00~01s and all of the VQ35s Ive seen have a dual stage cooling system with TWO thermostats. One is for the block and the other is for the cylinder heads. According to a SAE paper released by Nissan the main goal of the dual system is to increase fuel economy by keeping the engine block hot and the cylinder heads cooler. But I think it also helps keep the engine cooler from that hunk of plastic over it.

 

Nope no EGR disable with the Krismax special. My EGR was left fully functional. Only proplem is that I get a EGR CEL but this didn't happen until after I came back from Texas, so EGR is not the cause of my troubles. From my experience when an EGR code is detected the ECU will compensate for it but my fuel economy get's worse.

The Factory temp gauge is garbage it will stay in the middle from 170 F to about 220 F. You need to use a OBD-2 data logger to record the temps of the coolant sensor. Even now my temp gauge stays in the same place with the Griffin but my data logger tells a different story.

When I pitted the coolant was steaming and expanded a great deal, I run 70% distilled water and 30% Toyota red coolant with a bottle of Redline water wetter. This would lower the boiling point but coolant temps above 220 are not good for an engine.

 

Great...which means my engine is boiling itself since my EGR is disabled and I'm on the stock radiator. Where'd you get the Griffin?

 

Data Log first please, your radiator maybe in better shape than mine was. When I opened the hood my engine bay was hotter than other Maximas, other people could tell as well. The entire upper support beam by the radiator was to hot to touch, I had to wait at least an hour to work on anything near it.

Also if your getting an EGR code the ECU knows to compensate, but if you have thrown resistors in there... Well then that's a different story.

 

no. same.

 

Yeah, Joe is the mang! Here is a couple of pics, video will be up soon.





One sweet lookin thang. I want that radiator too when I need replacement. Thanks for doing such a meticulous job on my car again Joe. We should get a huge max dot orgy meet with those girls at the 99!

See you at the Natick Meet!

Here's a short video of the radiator: http://gotnismo.net/Movies/Projects/...frad(12mb).avi

Hey, if you enjoyed the buffet of videos and pics I serve at my website, the least you can do is holla at my guestbook.



- ßaller

 

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Teh point is your engine is running hotter cus the 00VI doesn't absorb much heat from the motor...

 

im not talking about that thermostat boy

lol

 

The usim or mevi will transfer heat to the incoming air, so it acts just like a radiator (convector, actually), only the heated air passes through the engine and out the tail pipe.

 

By the way, I have an accurate coolant temp gauge and I have seen no temp rise from installing the 00vi.

 

Maybe cause it's always hot in Texas, so it wouldn't make a difference.

Seriously though that is good to know, im trying to find out if it's the norm or if my car is an isolated case.

Just for the record your engine setup is a 2000 VI maniflold, 4th gen lower, and 4th gen block/heads?

 

Huh?? While what you're saying might be true, i don't think it's germane to what i was saying. My point is that the 00VI will absorb less heat from the heads and consequently the heads will run slightly hotter. Whether or not it's appreciable is a different story.

 

First off, I didn't even know we had the option of upgrading our radiators. This is excellent. Especially since mine is starting to crack around where the radiator hose connects to it.
I agree that if people want the DE-K they should just do the swap

You were checking the water temp, right?.....It's time I plug in my Techtom and check my temps. If I'm lucky, my temp should stay under 200 while I'm cruising, right?

 

Yes we have that option, you can thank the boosted guys for getting Griffin to developing an over sized radiator for us. I believe I30Krab was the first to have this one designed and installed on his beast.

However you have a full DEK swap with the upgraded cylinder heads, your temps should be normal with the DEK manifold.

 

My temps did not get any hotter after the swap, maybe it was just your cooling system/rad?

 

Did you datalog coolant temp senser readings before and after the swap? The stock temp gauge doesnt indicate a change but the OBD-2 data logger did.

Im starting to come to the conclusion that mime was an isolated case and that I had a bad radiator. Now I have a bling bling overkill radiator in my car. At least it will be a nice insurance policy when I go road course racing.

 

Correct. You're right about it being hot in Texas, especially right now, but I've had the 00vi since November and I didn't notice anything then, either.

 

I was sort of agreeing with you but also pointing out that the main mechanism for heat transfer from the engine to the IM (once the IM is up to steady state temperature) is due to convection to the incoming cool air. The IM acts like a huge cooling fin. But the heat transferred from the IM to the incoming air then goes into the combustion chamber, resulting in higher combustion chamber temperatures and decreasing any net heat transfer.

The 00vi, on the other hand, significantly reduces the amount of heat transferred to the incoming air and CC temps are lower, but it is probably true that it increases the heat rejection requirements on the cooling system.

 

joe where did you buy the griffin radiator?

 

I drove around with my Techtom and my water temps were usually between 190-200. Seems good enough to me.
But I may still get the Griffin

Edit- Since this is sorta on topic, have any of you guys used some brand of "water wetter", and if so, what were your results?

 

http://www.bnecustoms.com/store/home.php

 

Seems alright to me as well, alittle high IMO but it's acceptable.

I tried two kinds of coolant additives and neither dropped the average coolant temps at all. First tried DEI radiator relief and that did nothing. Then I tried a bottle of water wetter and that didn't help me either. So either additive had no effect what so ever. I believe the Toyota red coolant comes with additives that have the same effect as water wetter. Like others have said, it's good enough for a Toyota Supra so it's good enough for our Maximas.

 

I have friends that work as mechanics for Toyota and they highly suggest not using the red Toyota coolant from their personal experiences. It seems to find areas to leak out from.

 

No leaks here.

Toyo red is highly suggested and it was cheaper than Nissan coolant, goto the fluids & lubricants section and ask them what they think.

 

i recall kris having a hard time keeping his temps under 200. was that on the 3.0vi or the 3.5?

that reminds me of zacks house .

 

well, since he's the only one with increased op temp so far with the 00vi, could it be that his water pump is at its last few days? just a thought after ruling out that others don't have this problem. how many miles on your ride? changed water pump yet?

my water pump recently f-ed up on 146k miles. and op temp is a little above half way in my temp guage. nowadays, it's making clinking and clanking noises. i just dropped the car off at the shop to do the water pump. as i searched the water pump problems on this forum, there are many others with water pump problems.

just a thought to help...

 

Water pump was changed with a new OEM one last winter, it's not the cause of my problems.