adamis

I did some searching for heat soak and I couldn't find much info regarding it and the VG. It seems like the VE boys have had the problem and are trying to figure it out. So does anyone else have the "heat soak" issue on a VG and did anyone find a solution for it?

RosenKen

Okay, before we get out of heand here. Generally the "hat soak" term has been wildly thrown around here on this board to represent a problem of VE Maximas only. The problem is: when they are cold (just starting up) they fly like banshees and are super quick. But when they warm up to operating temperature, there is a lot of lag and hesitation, especially at lower rpms. This is NOT caused by just the engine warming up since these cars certainly didn't do it when they were new. It has something to do with one or more sensors going bad or something's amiss in the wiring (corroded connections, etc)

I've never heard of it on a VG specifically. What's your symptoms?

AscendantMax

iTrader: (7)

isn't heat soak caused by the pop charger sucking in hot engine bay heat? hot air = less dense air = reduced engine output. correct me if i'm wrong but i think that lag is caused just by that reason and not the sensors going bad.

adamis

Well my symptons are pretty much like that of the VE. Runs nice and sweet when cold but when things warm up it can get slow. Maybe this is a transmission problem because it does feel like the torque convter isn't tightening up (I'm not an expert but I believe there is a torque converter in our tranny, correct me if I'm wrong). However this is in conjunction to the apartent loss of power from the engine. This usually occurs when the gas peddle is pressed about halfway, not enough to force the tranny to downshift. From the reading of previous posts I would agree that its got to be a sensor somewhere. The idea on the pop charger is a good idea to, really didn't think about that.

pezking4

No, since I have stock intake and hesitation, that kind of rules out that idea. It is sensor related, and I think the biggest culprit is the knock sensor.

RosenKen

NO, this is exactly what caused this "heat soak" theory to pop up in the first place. Wild speculations that sound correct to the uneducated masses (most newbies). It has nothing to do with mods. Bone stock VEs have it, and even very modified ones do too (James12345).

The problem is that when the engine is cold, the ECU doesn't take any inputs from the various engine sensors and runs in a closed-loop mode with a given fuel/air/spark map. When the engine warms up to a certain temp, the ECU runs in open-loop mode, meaning it starts taking inputs from sensors for peak efficiency. If everything was running correctly, the result should be a faster and more efficient engine. However, the VEs have a problem with sensors getting slow and lazy, but not completely failing. Thus, no codes pop up and it takes a LOT of effort to track down your bad sensors. I'm sure bad VTCs also have something to do with it. Even if the VTCs are grounded, they are still bad and will mess up your power band. When I installed new VTCs, I had some monstrous power up on the top end I've never felt before.

I've explained this in many posts before. Do a search for "heat soak" and my name and spend an hour reading up. I've been trying to diagnose this problem for a year now and have been mildy successful, but not 100%. However, I've never felt how a 100% healthy VE feels like so I dunno if I know quite what I'm looking for. I'm just using how it feels when it's cold as a reference, because I can light up the tires all the way through 1st gear when it's cold.

Aaron92SE

iTrader: (128)

Exactly! I don't think anybody knows what a perfect VE feels like. And if they've ever felt this perfect VE, then it was in 1994 or something.

And my auto has it really bad and I have exact track times to prove it. My 2nd to the last track visit, I ran a best of 15.44@89mph w/ 2.41 60'. And then I hot lapped twice before I left and ran a 16.24@86mph w/ 2.52 60' and then I ran 16.16@86mph w/ 2.51 60'.

My latest track visit with my latest mods, I ran a best of 15.32@89mph w/ 2.32 60'. Then, I only hot lapped it once, but I let it heat up and idle after the previous run. Then, I idled all the way to the staging lights. So, it was heated up all the way, but it was a cooler night than the times in the paragraph above. I ran a 15.74@88mph w/ 2.44 60'.

So, you see how the 60' times get worse and so do the trap speeds.

SmithAtlanta

Interesting you ask what a perfectly new VE runs like. I can tell you this since I have had mine since day 1. From day 1 it would pull strongly in every gear. When I mean pull strongly, I mean it would actually scare me and I would have to let off the gas. I remember the salesman taking me out on a winding road and scaring the crap out of me. I remember racing a friend in his new MX-6(6 cylinder) and pulling him pretty good.

Today, It still has much of that power but like you said some of it is lost when the car warms up.......especially if you floor it in a lower gear. This hesitation wasn't there day 1. Overall though it's been a good 9 years with the Max and I would do it all over again...

RosenKen, What all have you done to get your engine back to original stock feel?

James12345

Do all of you guys only have 'heat soak' in the lower RPM range?

Mine has it ALL across the board. But for instance...

Cool engine - I can floor the car in 1st gear from a roll and spin all the way through 1st and half of second

Warm engine - I can barely get anything and cant even chirp it between gears

It's slow and dopey and just feels like it's overall struggling through the whole RPM band. I can be on the highway and shift to 3rd at 75, it pulls, but not hard. Same if I'm on the regular streets, I can downshift to 2nd, it pulls, but not hard.

It's really really really ****ing me off. It's not just a little inconvenience, it's a night and day difference.

adamis

My car just seems to dog in the lower gears at lower RPM when its warmed up. For me if I floor it there is still power to be had but most of the low end ooommmph that our VG should have just isn't there.

chavez

When my VG is cold its runs like a banshee and sounds wicked.... but once it warms up... its as quiet as anything... A bit sluggish also.

AscendantMax

iTrader: (7)

thanks for enlightening me guys there were so many post about heat soak and all these people saying it was the engine sucking in hot air. i now know better