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Jim G finds the "smoking gun" on the engine cooling issue

10K views 101 replies 28 participants last post by  Mike in AZ 
#1 ·
In doing more detailed research for my "The SSR Experience" book (1st chapter will go out to subscribers in a day or 2 - currently in proofing), I may have found the "smoking gun" on the engine cooling issues.

On page 76 of "SSR An American Original" by Gary Witzenburg, the author states

"Wedging the 5.3 liter V-8 into the SSR's low, short, tapered nose, then sufficiently cooling it, presented a huge challenge."

He then includes the following quote from SSR Program Manager Ed Ivey:

"We've got an engine designed for a truck with a certain amount of trailer towing capability, and it has an engine mounted fan. But in the SSR, that fan and radiator would stick out 10 inches beyond where we've got the hood. We had to eliminate that and go to the electric fan. We went through several iterations of packaging all the hardware to achieve the cooling requirements and maintain our 2,500 lb. tow rating."

The author then continues:

"Engine cooling - not powertrain muscle or structural strength - limits the SSR's towing capability to 2,500 pounds, and Ivey adds that the powertrain controller will reduce power ti protect the engine if it gets close to overheating."

Note especially closely the "we went through several iterations", and the "powertrain controller will reduce power" comments.

No wonder our electric fans are running 100% of the time in hot conditions and are failing. NO wonder the underhood temperature is over 200 degrees.

I7m not upset or angry about it. It just makes me even more confident that we need a 100% duty cycle fan that also has a much higher CFM rating than what we have as stcok equipment.

Jim G
 
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#2 ·
Has anyone tried to put a piggyback fan on the front side of the radiator that can be wired into the start circuit and run constantly while the engine is operating. This way the stock fan is left to control higher temps and overheat situations. Just a different idea? If I start having issues here in Southern California then I will look at this rather then messing with the stock fan and computer control. I have done this on many older muscle cars that had problems with slow driving and traffic, it always helps.
 
#3 ·
HMMMM!



2005SSR6Speed said:
Has anyone tried to put a piggyback fan on the front side of the radiator that can be wired into the start circuit and run constantly while the engine is operating. This way the stock fan is left to control higher temps and overheat situations. Just a different idea? If I start having issues here in Southern California then I will look at this rather then messing with the stock fan and computer control. I have done this on many older muscle cars that had problems with slow driving and traffic, it always helps.
 
#4 ·
The "pusher" fan is not a great idea for a couple of reasons.

1. If you go to any of the good fan manufacturer sites, they will tell you that a pusher fan is very inefficient compared to a "puller". (I think it's around 60% as efficient but don't remember the exact numbers)

2. The two fans' airflow patterns will "interfere" unless they are perfectly matched.

3. You will use a lot more electrical power than one good, high CFM, 100% duty cycle fan.

BY the way, I read earlier tonight that the radiator in the SSR is the same one as in the C6 Corvette, but with the expansion tank relocated. If this is true, it MIGHT be remarkably easy to replace the fan in the SSR with the dual fan setup in the C6 (where apaprently very few failures have been reported). The mounting points COULD potentially even be identical in the 2 vehicles.

Anyone out there have quick access to boht a C6 and and SSR to compare and maybe take some verifying measurements? That would be too easy and too "cool" (pardon the pun).

Jim G
 
#7 ·
Hey there 6 speed: Spend some time on this board checking out all the messages regarding overheating, etc. JimG has put a ton of work into researching and answering questions. I think the latest news, (rad. same as C6) is great. Like he said, someone needs to switch over and post results. Scheide
 
#8 ·
Towing and Cooling

Just got done towing 2000 miles. I had about 3000 to 3300 total weight being towed and in the SSR. I went through several mountain passes including the grapevine (tough one in CA). I tried a number of different gears and throttle positions and I'll be posting a summary one my thoughts are all in order.
 
#9 ·
I understand how much time has been spent on the overheating problems. I am trying to find a way to ensure I dont have a similar problem. I just dont know if the cooling setup in the 03/04 is different from the 05? Can anyone shed some light on this for me. I am all about trying something like the C6 cooling fans if the 05 is prone to overheating also. My 02 Z06 had a dual fan setup that worked great at maintaining temps and was also controled by the computer. At first everyone went for a 160 degree T-Stat, but without adjusting the computer setting for when the fan engages it did nothing. With the Z06 we learned that the fan circuit was 3 fold, it had an intial temp setting and then a/c setting (duals running) and last overheat setting. I am planning on giving MTI in Texas a call about some custom tuning, maybe they can shed some light on this. This sight is a wealth of information and I would like to play my part of helping others as well as my SSR.
 
#11 ·
gmpartsguy: I was told dual fans. Did they change from the Z06's dual fans to a single fan now?? If so, is the single fan in the C6 more durable than the one in the SSR (since C6 owners apaprently are not reporting fan failures like we get)?

Or, is there just one part number because both fans are the same part number?

Jim G
 
#13 ·
gmpartsguy: Ampmop also pointed out to me recently that while the backup light and licesne plate holder assembly on the back of the SSR is identical to the Corvette, the aftermarket billet replacement for the SSR costs more than the apparently identical part for the Corvette.

Something about what the market will bear?

Jim G
 
#14 · (Edited)
...

It would be “a good thing” (Martha) if we started a file of items that are interchangeable with other G.M. vehicles, like rear 3rd brake light lense. One for a price brake now, and two for 20 years from now, when SSR parts might get hard to find. :rolleyes: I read somewhere, that they used as much off the shelf parts as they could.
 
#16 ·
smoking gun

Hey guys this is what I've done....Black Magic fan..160 therm..........set the fan to come on at 180.....Wired it to operate without key on...This way it keeps the intercooleer from becomimg a heat sink......Temps run from 180 to 210 have not had a problem runing hot for a year now, even a Lake Mead at 125 temp................
 
#18 ·
Dual Fans???

Jim, do you think dual fans will work with the setup we have in the SSR? Since the current fan is a 2-speed fan, and seems to have a logic module in the fan itself which takes the current from each of the 2 relays that are controlled by the PCM, how would you hook the thing up? Unless the dual fans are also 2-speed... you wouldn't want to have each lead from the PCM relays to one of the dual fans, or you would be blowing air through only half of the radiator until the second fan kicks in.... you wouldn't want to hook both fans up to the relay 1 wire... might confuse the PCM... If the dual fan is 2-speed, seems like that is the only solution.
 
#19 ·
OOps.

Daven said:
Jim, do you think dual fans will work with the setup we have in the SSR? Since the current fan is a 2-speed fan, and seems to have a logic module in the fan itself which takes the current from each of the 2 relays that are controlled by the PCM, how would you hook the thing up? Unless the dual fans are also 2-speed... you wouldn't want to have each lead from the PCM relays to one of the dual fans, or you would be blowing air through only half of the radiator until the second fan kicks in.... you wouldn't want to hook both fans up to the relay 1 wire... might confuse the PCM... If the dual fan is 2-speed, seems like that is the only solution.
If there were two fans, they would need to be active at the same time. Switching only one on leaves a big hole to draw air from instead of it being drawn through the radiator.
 
#20 ·
I have a good mechanic friend with a really strong hot rodding and dealership car repair background looking at my SSR right now, with regard to both the transmission cooler and the engine cooling fan. He studied my Helms manual for an hour tonight, took some measurements, and said he will get back to me.

Jim G
 
#21 ·
will detail operation of ssr fan and relays so everyone will have better idea of how and when
thing happen

2 relays- one low speed/one high speed- these relays are grounded by the pcm which apply
curcuit to the fan- the fan has three wires coming to the fan( black wire=ground/ light blue wire=low speed/gray wire=high speed)
the low speed and high speed relays are located in left front of engine compartment
lwhen the low speed relay is grounded it applies voltage to fan (the speed is reduced
because a resistor is inline between the relay and fan
when the high speed relay is grounded battery voltage is applied to the fan from the relay
now for the operation parameters
without air condition on-- low speed is commanded(by pcm) on when coolant temp reaches
226 degree it turns off 219 degrees/ high speed turns on at 235 degree and off at 226
if the a/c is on low fan speed is commanded at 185 degrees and vehicle speeds under
35 mph-if coolant temp is low and a/c is on then high side a/c pressure is monitored and
low fan speed is applied at 200 psi and off at 150 and high speed fan will be commanded
when a/c high side pressure is 230 psi and off at 215 psi
the dash warning message is set to come on 257 degrees with radio chimes when states
hot idle engine-this message turns off at 252 degree
the next message is set at 261 degrees with a message of overheated stop engine

hope everyone can make sense of the operating system for the fans and the failsafe warning system

i'm currently working with my shop tech 2 and measuring the benefits of 160 thermostat
and operationing the fan on high when low speed is commanded by pcm- hope to come
up with simple way to rewire and not create any check engine lights or harm any parts
want to drive vehicle for a few days in heavy traffic before giving my opinion on fixes

john edge
 
#22 · (Edited)
John

Can you install the 160 degree T-Stat and use the tech II to adjust the low speed at 180 degrees and the high speed at 200 degrees. The A/C setting could be set at 160 degrees low speed and 180 degrees high speed. This is similar to what the Z06 guys were doing with the 160 T-Stat and computer. Thanks for looking it all up.


Has anyone talked with a company called Westers, they do computer reprograming for the SS Silverados and other GM vehicles. They are priced right too.
 
#24 ·
the tech 2(general motors diag tool) can bypass and commanded the fans on when you want
but you can't rprogram pcm only perform curcuit and relay test but i can determine how much
having the fans starting sooner and higher speeds will help operating temps.
firebirds had a similar problems a few years back and with a little creative engineering those
heating problems were made better. i think the current ssr cooling system has the ability
to perform if we can just find the right combination. will post my results when i come to some
conclusions

john
 
#26 ·
180 Thermostat

Johnedge et. al:
I understand the hot-rodding desire for a 180 or 160 thermostat. The Impala SS guys have been doing that and cold-air intakes with great sucess for years. BUT (and this is a big but) they have iron blocks and loose tolerances. The LS1 and siblings (that we care of) are all-aluminum and very tight-tolerance motors. The engines need to be at 210 to get all of the parts to the sizes they were designed to be. Running cool temps is very hard on a motor like ours. Just like running your VW beetle or older metric-bike hard before it warms up.

Keep focused on the goal, we need to get this equation balanced "heat-created = heat-removed" under the hood. Removing the thermostat has no effect on that equation. You just reduce the amount of heat held by the engine block for a short time. The overall goals here are two-fold:
  1. Increase fan reliability
    This will stop the overheating at low speeds, usually with no warning or error on the driver's part.
  2. Reduce underhood temperature at normal running tempurature (210)
    This will improve performance, long-term reliablity, fuel economy (MAS errors) and allow us to beat the crap out of these things without worry.

I am having my stock fan replaced and then it is time for some hot-rodding improvements in the cooling system. I think Ronin is on the right track, but I'm looking to get the overall underhood temps down, whatever it takes (new fiberglass hood?)
 
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