jwick76

iTrader: (1)

So, here's my situation. My radiator is about ready to get the heave, but I've been piecemealing some coolant options to take the load off of it to see what happens first. My first option was to get a 16-row aftermarket tranny cooler, which took about 20 degrees off of the radiator load, but it's still running hotter than I want. I'm hitting 250+ in the summer after I get off the highway and hit the city commute, which is bad enough, but I noticed that my idle is jumping to 3500 rpm, which is nuts. I've adjusted the BISS through evoscan, which seemed to get it to calm down a bit...but it's still jumping to 2500 with the BISS totally closed.

I'm thinking this is my idle control valve not dealing well with the extra heat, and I didn't notice any change with disconnecting the coolant lines...so I reconnected them. I wanted input on whether or not it would be worth it to do a separate cooler for the TB. I've done some research, and I can get a 13gpm 12v pump, two 120mm ip55 water resistant 12-24v fans pushing 130cfm each (using two), get a transmission/oil cooler from a motorcycle (4x10 in), and use a modified overflow reservoir for a motorcycle for my coolant load. I was wondering if this would cool my TB down to the point where I wouldn't have the idle issue under excessive heat, or if this setup won't work without a heat block plate between the TB and IM...and I already priced that out, so I might as well get the new radiator.

I won't be able to get the radiator I want until after my wedding next year, so I was hoping I could find a solution for less than $100 that would work for now.

Otherwise, I found a nice 3-row custom aluminum radiator I want to throw in.

But I'd like some input on the TB cooler, I figure the fan/radiator/water wetter combo should be enough to cool the TB down quite a bit, assuming at least a quart of coolant is used. The fans are a bit pricey at $24 each, so I don't think I'd go all out and do a combo push/pull setup using four fans, but just use two fans pulling. I would mount it on the lower right hand bumper, where the fog lights would go, using aluminum mesh for increased air flow. This same positioning works well for the tranny cooler on the other side. I figure if I could get it to decrease the relative temp of the TB by 30-40 degrees it should work.

thanks for the input.

Green_Bandit

iTrader: (25)

Well if you think the heat is what's causing the high idle why dont you do a coolant bypass mod? You say that you disconnected them but that should have gotten the tb temps down.

But, to do a cooler behind the bumper you could do like I did and use an evo oil cooler. It mounts perfectly. I also just got the cooler duct off of an evo. I'll be able to say how that goes soon.

Grind3r

Thats actually really interesting. I get random high idles when its hot out and I throw my car into park or neutral. But usually after a minutes it will finally drop itself back down to where it should be. Since my turbo is water and oil cooled, I thought about adding an additional oil cooler inline with the return side of my turbo. Which would help cool off the fluid better before its recirculated into the TB and back into the motor.

Green_Bandit

iTrader: (25)

You know, I asked the forum about adding a cooler after the return side of the of the turbo going to the tb & whether it would make a difference or even be worth it. Never got a response...

By the way what do you think about my tranny cooler set up Grinder?

Grind3r

I like it Think I'll be doing a setup like it too. Might as well get 3 and do them all at once. 1 for oil, 1 for tranny and 1 for coolant after the turbo. It can hurt thats for sure. I'm sure some might think I'm going overboard with the coolant cooler after the turbo, but who knows....tranny and oil are in for sure in my cars near future. Think I'll look into the added coolant one a little more

Green_Bandit

iTrader: (25)

Thanks! I'm considering doing an oil cooler also. It wouldn't be hard. just get a sandwich adapter with those 10 an ports and go to work. The hardest part of doing duals would be making the bracket to go on the other side of the bumper. But with using the Evo hardware, that may already be out there.

I couldn't believe how small the tranny cooler inside the radiator was. Not to mention the radiator can get up to 230 on a good day! With the evo cooler mounted after a normal drive I can touch the tranny cooler and not get burned. Only after spirited driving does it get too warm to touch. Now try that with the radiator!

I have a cooler duct on the way too. Should be here this weekend. When I get it ill add pics to my thread.

Grind3r

NiceIt'll probably be a month or 2 before I get what I need to set mine up (oil and tranny) I'll probably custom locate and make my own bracket mounts.

jwick76

iTrader: (1)

That bypass mod did squat. I noticed no change in anything, I wish I had a laser temp gauge to do a more thorough comparison, but in either case the TB was just as hot if not moreso than my radiator (by touch) with or without the coolant lines hooked up. I think that mod is more of a placebo effect than anything.

This is the cooler setup I'm planning for the TB:

Radiator
Fans
Reservoir
Pump (have to use regulator to keep voltage from going above 12v)


This is what I'm using for my tranny cooler:
Radiator
Fan


And this is the radiator I was looking at if I still need to get my temps even lower, let me know what you think about this purchase or if I should look elsewhere:
Haste Radiator (3-row)



I was thinking about doing an oil cooler as well, but it's a little tight with my sandwich adapter and my sending units I already have there...I really wish there were aftermarket oil pans with heatsink fins/extra capacity...but the pan is so low as it is I'd probably scrape it on every speed bump, heh.

jwick76

iTrader: (1)

I'm of the opinion that if you have the extra amps to spare in your system, why not? I have an optima battery and a relatively new alternator, so even with two aftermarket 14" fans on the radiator, an extra 8" fan for the oil cooler, and my two stereo amps and hi-power deck, I still sit around 14volts...

mcgarvey

It's a well known problem on these cars for the throttle cable to stick under high temps, causing the RPMs to hang high. The problem is not the throttle body or anything like that. I wrapped my throttle cable with several layers of heat shielding wire wrap and the problem has not returned.


When the issue occured, did you manually try to shut the throttle or disconnect the cable? I can pretty much guarantee the plate was hanging slightly open.

Green_Bandit

iTrader: (25)

That right! Why didnt I suggest that? Next time you getbthe throttle hang pull back on the gas pedal. I if it goes back to normal you should reroute the cable.

jwick76

iTrader: (1)

The cable sticks? at what point along the cable, where it passes along the valve cover and is encased in black? and wouldn't wrapping it impede it being able to move?

rhyzin

iTrader: (1)

I've been out of the loop lately, but does evoscan totally compensate for a 501 MAS with a CAI? The timing requirements are pretty different between a CAI and SRI with that MAS.

What happened to cheap easy checks like a new thermostat or a different throttlebody and ISC? is there gunk on your throttle plate? that throttle cable sticking thing sounds plausible.

It's been hitting low 100's for a week or two here and I run the 501 MAS w/ a modified airbox, 4G93 intake manifold, a SAFC2, and 230k miles on the motor and I'm not having any problems with cooling or idle. I'm also bypassing the tb coolant lines.

Curious to know...

jwick76

iTrader: (1)

I used the charts supplied by another member for the 501 MAF mod, as I'm running that, too. I did them in ecuflash... I can find the link if you need them, i think Senate posted them.

I'm on my third thermostat, as I found a lot of others don't open up at the temp they're rated to...the one I have now opens up at 190F (supposedly rated at 180, but that never happens...found the others I've tired didn't open until passed 200). I have an inline temp gauge that lets me know when the thermostat is working. I've had issues with a gunked throttle body causing me hesitations with acceleration, and make it a point to clean the TB every 12000 miles or sooner.

The issue I'm having now is only with the engine running 200+, I've never had issues before with a high idle that just keeps getting faster as the engine runs hotter. No misfires, no issues at all other than the excessive RPM.

I've checked the throttle cable and it doesn't seem to be sticking anywhere....pulling on the gas pedal or manually working the TB doesn't change anything. If anything, revving it up just makes it stick at a higher rpm, so I'm really leaning towards the iac valve malfunctioning at higher temps. Doesn't look like this is easy to take off without removing the TB and the price for a new one is a little silly, especially since it works normally within normal temps. I priced out a coolant setup for around $80, so I'm thinking I'll just go for it and see if it makes a difference. Worst case scenario it won't change anything and I'll just have to get a new radiator anyway.

I have an iacv sensor from an evo 8 that I could rewire and replace it with, but I'm not sure that will solve the issue as it might malfunction at out of spec temps, too.

jwick76

iTrader: (1)

So just an update, I finally got this installed and it has almost solved my problem. As long as I'm not stuck in traffice, I no longer have the increasing RPM and the TB is more responsive with the extra cooling. However, I think because I went with clear lines because I thought it would look cool with the neon green color all over, it's not insulating the lines enough and with higher engine temps and no air flow during heavy traffic, I find it creeping up to 1500rpm. BUT it does recover much faster once I'm in motion again.

So, I'll be upgrading the lines to actual coolant lines, and might even go the extra step of wrapping them with the aluminized tape.

Keep in mind, this is basically a stopgap measure to confirm that the higher temps are messing with the ISCV controller on the TB, which I've pretty much confirmed. It's not a sticking throttle cable, it's not a dirty TB, and it's not a fuel delivery issue.

Once I get the extra insulation in, I plan to post pics of the setup and do an IR temp comparison from the TB and the manifold/head.