Thermostat

[theexbrit]

I keep hearing bad stories about Stant thermostats, anybody recommend a good brand?

[Rebelord]

From your posts that your in the desert most of the time. I would run no thermostat summer time.

I have had no issues with Napa ones for the past 20 something years. They have the premium 170* one for $16

[Precise1]

Considering that the ECU monitors the temperature and adjusts things depending on the reading , I think running no themostat is ill advised. The VGs seem to run better fairly warm and stable, and as long as the cooling system is in good shape it is more than adequate for almost any desert conditions. I'd say it would be qually important to divorce the transmission cooling from the radiator for extreme hot conditions.

 

Sorry Bud, I can't advise you on the quality aftermarket brands. Any reason you aren't just going with a Nissan unit?

 

B

[Rebelord]

True. Im still not fully familiar with Nissan engines.

Just past experience of running small blocks with no T-stats. Also, ran many GM LSx and Ford Modular engines with no T-stats in AZ. Never had issues. However, we were all modded and pushing quite a bit of power. So detonation was always a concern. *Cooler is better* in that sense.

 

The VG is a iron block, aluminum head correct? If so, then no t-stat shouldnt be a issue. However someone with some more experience with the sports car Nissans could probably chime a lot better info.

[vagabond]

Considering that the ECU monitors the temperature and adjusts things depending on the reading , I think running no themostat is ill advised. The VGs seem to run better fairly warm and stable, and as long as the cooling system is in good shape it is more than adequate for almost any desert conditions. I'd say it would be qually important to divorce the transmission cooling from the radiator for extreme hot conditions.

 

Sorry Bud, I can't advise you on the quality aftermarket brands. Any reason you aren't just going with a Nissan unit?

 

B

+1 have to agree here, I think mines a 170 in the 88 but I'm using the Maxima electric fans and have had no problems out in the desert

Edited May 28, 2013 by vagabond

[Alkorahil]

Old school notes from Nissan:

 

 

 

Pathfinder or V6 Truck

"For extremely cold climates interchangie to P/N 23100-2B000

No other interchange of thermostats is recommended"

Edited May 28, 2013 by Alkorahil

[theexbrit]

Considering that the ECU monitors the temperature and adjusts things depending on the reading , I think running no themostat is ill advised. The VGs seem to run better fairly warm and stable, and as long as the cooling system is in good shape it is more than adequate for almost any desert conditions. I'd say it would be qually important to divorce the transmission cooling from the radiator for extreme hot conditions.

 

Sorry Bud, I can't advise you on the quality aftermarket brands. Any reason you aren't just going with a Nissan unit?

 

B

 

I was thinking of going with no thermo but what you say makes sense. Never thought about getting an OEM stat to be honest.

[theexbrit]

+1 have to agree here, I think mines a 170 in the 88 but I'm using the Maxima electric fans and have had no problems out in the desert

 

What temp do you have your fans set to come on at?

[Precise1]

I was thinking of going with no thermo but what you say makes sense. Never thought about getting an OEM stat to be honest.

From my limited knowledge, no thermo works in older high performance, carburated motors in certain circumstances. The VG runs open loop until it warms up, then it monitors temps and adjusts timing and fuel map accordingly IIRC (correct me if I'm wrong). This all means you need to run above a certain temp at all times, but the more consistant the better.

I've found that the Nissan truck cooling systems work quite well as long as everything is functioning properly, which isn't hard to manage. If there are any issues, consider an all aluminum race radiator, that would surely take care of it!

The problem with changing the thermo is the time is the trouble to get to it. You have to pull the timing covers and if you spill any antifreeze on the belt, that has to be changed as well. For this reason, I suggest you get the stock Nissan T-stat (from Alkorahil, you will get a good price) and focus on the rest of the cooling system if there is an issue.

 

I'm no expert, but I live in Cali and have taken a 4 week run down to Cabo in July in a D720, so...

 

B

[adamzan]

You don't need to pull the timing covers to do the thermostat. Just the ac idler bracket.

[Rebelord]

From this thread I take it the DEI stuff isnt working out so well?

Remember I can give you the info for the full 1" aluminum radiator down here. Runs great for me. Stop n go heavy traffic with trailer I say below 199* F. Once moving back down to 175-180* F

[theexbrit]

It's really weird, it's fine nearly all the time & it does run cooler with the DEI, but anytime I get a long slow slog up a hill the temp goes up. It's just the long slow hills it doesn't like although it was a lot better this time, it was on the long climb up to Cerro Gordo that it started going up. As I said, it's better than before & it didn't get close to overheating (up to about 220f) like before but none of the others ran as hot as mine. I think the full rad is my next step, although I have my fans set to come on at about 190f & I'm wondering if that's too high?

 

PS. I should have my snorkel fitted this week, it's based on your design just a couple of minor differences.

[Kingman]

I've been having issues with cheap thermostats sticking open in my Pathfinder, the one that's in mine is doing it now actually and my fuel mileage is down quite a bit because of it. Bought a Nissan one to throw in but haven't done it yet. Both my old Zs had cheap thermostats and both failed closed. Moral of story: buy OEM Nissan thermostats. The extra few bucks is worth a good working part that'll last another 20+ years.

[Precise1]

You don't need to pull the timing covers to do the thermostat. Just the ac idler bracket.

Ok, thanks for the correction. I had both off at the time, and it seemed really close and hard to get to. I'd still be concerned about spilling the antifreeze though.

 

It's really weird, it's fine nearly all the time & it does run cooler with the DEI, but anytime I get a long slow slog up a hill the temp goes up. It's just the long slow hills it doesn't like although it was a lot better this time, it was on the long climb up to Cerro Gordo that it started going up. As I said, it's better than before & it didn't get close to overheating (up to about 220f) like before but none of the others ran as hot as mine. I think the full rad is my next step, although I have my fans set to come on at about 190f & I'm wondering if that's too high?

 

PS. I should have my snorkel fitted this week, it's based on your design just a couple of minor differences.

How do you have your tranny cooler routed?

 

B

[vagabond]

What temp do you have your fans set to come on at?

When I got the fan I also got the sensors out of the rad and the fitting that they screwed into also the fan relays, on the earlier pathys there is an air bleed in the top hose. It's a copper tube and I drilled a hole in the bottom of the tube to to take the fitting and soldered it into the tube.

assembly

fused hot wire to the sensor, wire out of sensor to relay,fused hot wire to relay, wire from relay to low speed fan.

High speed fan is wired to a switch on the dash.

If you want to go that way I have some extra tubes and might have 1 set up already just come over the hill

[vagabond]

When I got the fan I also got the sensors out of the rad and the fitting that they screwed into also the fan relays, on the earlier pathys there is an air bleed in the top hose. It's a copper tube and I drilled a hole in the bottom of the tube to to take the fitting and soldered it into the tube.

assembly

fused hot wire to the sensor, wire out of sensor to relay,fused hot wire to relay, wire from relay to low speed fan.

High speed fan is wired to a switch on the dash.

If you want to go that way I have some extra tubes and might have 1 set up already just come over the hill

I think the low speed fan comes on around 190

[Alkorahil]

The VG runs open loop until it warms up, then it monitors temps and adjusts timing and fuel map accordingly IIRC (correct me if I'm wrong). This all means you need to run above a certain temp at all times, but the more consistant the better.

 

Yep! That is correct. It runs in open loop when cold untill it warms up then goes to closed loop and the ECU starts taking readings and adjustig accordingly (about 5 mins or so usually as a good bench mark).

This is why so many people say their vehicle starts fine then starts running like crud after it gets 'warmed up', one it goes to closed loop and starts reading from one or more bad sensors such as the engine coolant temperature sensor or O2 sensor and getting bad input it runs lowsy. I would also adda proper working fan clutch-something people dont always think about.

 

I've found that the Nissan truck cooling systems work quite well as long as everything is functioning properly, which isn't hard to manage. If there are any issues, consider an all aluminum race radiator, that would surely take care of it!

 

I would agree!! All of mine have survived Texas summers for many years running the AC at full blast. The cooling system is relatively simple and straight forward. As stated if everything is working properly there shouldnt be any issues. A properly functioning radiator, good thermostat, a good radiator cap, proper coolant mixture that isnt years old, proper amount of coolant and good hoses are all that is needed.

 

 

The problem with changing the thermo is the time is the trouble to get to it. You have to pull the timing covers and if you spill any antifreeze on the belt, that has to be changed as well. For this reason, I suggest you get the stock Nissan T-stat (from Alkorahil, you will get a good price) and focus on the rest of the cooling system if there is an issue.

 

I'm no expert, but I live in Cali and have taken a 4 week run down to Cabo in July in a D720, so...

 

B

We stock that part.....

 

21200-V7206

THERMOSTAT R50 3.3L V6 10/95-05/01

$18.56 (list: $39.23)

Edited May 29, 2013 by Alkorahil

[theexbrit]

Ok, thanks for the correction. I had both off at the time, and it seemed really close and hard to get to. I'd still be concerned about spilling the antifreeze though.

 

How do you have your tranny cooler routed?

 

B

 

I left it running into the bottom of the rad when I switched the cooler. Maybe the tranny is contributing to the heating up on hills, I'll bypass the bottom of the rad when I get a chance, you really don't need it here in So Cal anyway.