GTM TT: Coolant Flush Advice?
 

A couple of months ago my tech performed work for the heater core TSB, and then he raised the front end of the car as part of the bleeding procedure. Since then it appears my oil and water temps are higher than usual on 100+ days. I've seen the water temps exceed 55-60% mark, and oil temps as high as 220-240F. This is simply daily driving in stop and go traffic (which makes it worse). After shutting down the car on a hot day I can still hear the gurgling sound in the heater core.

IIRC, when my turbos were installed the installer mentioned something about air in the water lines of the turbos and how difficult it was to get it out.

My car is going in tomorrow to get another flush, so I wanted to see if there's anything different that can be done.

Hey man, Sounds like he did not "Burp" the system, The gurgling sound you hear are air pockets, I'm not sure if thet do the "Burping" Differetly these days but I would run the car till operating temp with the RAD cap off, When the thermostat opens is pulls in coolant the level would drop , I would then top off the rad and close the cap, An make sure the cooalnt tank was at the proper level, Just take it back and have them recheck it.. Sounds like he missed a step.

Just follow the Nissan instructions in the shop manual and you will be fine.
It sounds like he may have filled the cooling system to fast Nissan talks about it in manual and tells you how fast to fill it.

Thanks guys. He lifted the front end of the car about 2-3 feet, had the coolant funnel on radiator, and had the car idling at least 30 minutes with the heater on max. We saw bubbles, revved it a few times, and just let it sat. It's such a long process.

Bringing this topic back... it was barely over 100F yesterday, and I noticed a couple of things:

• When ambient temps are below 100F with normal driving, peak oil temp is 205F. Hard driving, it's close to 220F. Water temps are good.
• When ambient temps are around 100F and above, water temps start to climb when oil temps are close to 220F. This is not from driving hard either. When I turn off the car and let it settle for a few minutes and start it up, water temp indicator climbs a couple points higher. At the extreme, it'll be close to the Hot zone if I let it sit for awhile.
• To make matters worse, oil temp pegged 240F with water temps nearing the Hot zone when I let it idle for several minutes while A/C was running. I pretty much got hung up talking to a friend while letting the car idle. I heard the idle drop for a little bit, and it smelled like burnt oil. Once I took off and got it on the freeway, it took several minutes for the oil temps to drop to 205F or so and water temps returning to normal range. It was easy to see it bounce back and forth an additional point on the gauge.

When the car was stock, I remember seeing the oil temps skyrocketing while stuck in traffic for long periods. Of course, with the turbos, everything heats up quite a bit.

SPAAAAAAL FANS :tup:

That's one very bad thing about our cars. I doubt our fan stays on to cool down the engine after we shut off the engine and when you jump back in the car a few mins after the temp spike gets crazy.

Wondering if there's a way to keep the fan running for a few mins or so after the engine is shut off or not. That would definitely help on keeping things cooler.

I've thought about that mroe than a few times, Wonder if its something UPREV could do, Like a turbo timer shut off fuction?

ok 86 that idea, Was just told the Fans are controled from the BCM not the ECU, :/.

Ah... so are you guys getting temp spikes while the car is idling with these ambient temps?

I had the A/C running so I was assuming the fans were already running, but it gets overwhelmed if the car is idling in one spot for awhile. Before FI, it would spike to 220F. With turbos, it's close to 240F. This thing starts cooking stuff under the hood.

I never have gone over 215 ever.

If I run my car and then shut it off and then jump back in 10-15 minutes later the intake & water temps both jump up. I figure this is from all the air is just stuck in the bay and not being vented, one reason I really want a new hood.
The moment I roll the car 5 feet either way it all drops back to normal almost as the system is getting fresh air and away from all the hot static air. I only have the GTM stage 1 so smaller intercooler but similar issue.

Good to know. These engines get stupid hot especially when idling in one spot for long periods when ambient temps are over 100F. I never got around to adding vents either, but I may start with the fender trim eventually. It was another hot one today, but it didn't get nearly as bad.

BTW, with hot days like this do you guys still hear the core bubbling? I still ear it after turning off the car despite the coolant flush. I'll try to remember to check it again tomorrow morning. I checked a few times after the recent flush and the levels were good, but that was a couple weeks ago.

Wouldn't work anyway. The fans draw air through the coolers (e.g. radiator and oil cooler), which in-turn cool the fluids that move through them and back into the engine. Without the engine turning and circulating fluids, even if the fans were running, you would just be cooling the stagnant fluid stuck in the coolers. You may get some movement of water due to the pressure increase from the high heat, but the oil won't move (other than draining down to the pan). The spike in temperature comes from the fluids sitting in the hot block getting superheated because they are not being circulated. Also why the situation quickly goes away. This is why turbo timers keep the engine going rather than just the fans going.