Yesterday I posted about the cooling problem I encountered while driving from Austin, Texas to Santa Fe, New Mexico on Sunday and Monday (see "Santa Fe Chevrolet rescues Jim G"). Today, I learned a lot more I really didn't want to learn.
To quickly summarize, my previously utterly drivetrain-reliabe SSR decided to develop a cooling problem whenever it was not on the highway doing at least 40 mph. At 40 and higher (I cruised at 78 mph), it was fine. The engine temperature guage never budged above 200 (just left of the 210 mark). But, whereas before Sunday it NEVER went above 210 with the fan on/off settings, it now started rising well above 210 whenever it was in stop and go traffic or idling. In fact, in Tucumcari, NM, at the absolute hottest time of a 91 degree Sunday, it reached 240 at one point. In Santa Fe on Monday, it hit 235 at a traffic light, and quickly subsided once I was moving at 40 mph again.
I guessed that the engine cooling fan was not activating when it was supposed to.
Today, Larry Martiniez, the technician who diagnosed it at Santa Fe Chevrolet, confirmed my guess. But, HOW that was confirmed is both interesting and disturbing.
Larry first took the SSR for a road test to verify the problem. That was utterly unsuccessful. The temperature guage never went above 210. He reported back to MaryAnn the service advisor that there appears to be no problem.
I am a persistent guy, and INSISTED that the vehicle be tested again, but at low speeds and idling.
Larry, bless his pragmatic heart, started it up and worked near it while he waited for some sign of temperature rise. For 90 minutes, nothing happened. The temperature needle got to 210 and stayed there. Then, at the 90 minute point (!!), Larry detected a change in idle sound. He checked the temperature reading. It was 235. He popped the hood and checked the fan. It was NOT running. He could hear the relay eing cycled regularly, but the fan did not respond. He tapped the fan motor housing with a screwdriver handle, and, believe it or not, it started running! He then reported a defective fan, and Santa Fe Chevrolet is overnighting a new one in that will get here Wednesday midday. Larry needs an hour to install it, and then I should have my SSR back later Wednesday afternoon.
Howeverm besides being persistent, I am detail oriented, and I distinctly remember seeing "fan on" and "fan off" settings in the PCM for TWO fans on the 03/04 SSR. I asked Larry about this. He swore there was only one fan. I insisted on a physical check with both of us there.
When I popped the hood, I saw 2 things:
1. There is only ONE fan behind the radiator
2. Larry had ripped my underhood insulator blanket by having the hood prop release accidentally when he failed to seat it properly in the catch hole.
I insisted on a new insulator blanket, and Santa Fe Chevrolet is working on that right now, and is supposed to call me to let me know if they can get one to Santa fe before I leave. I also told MaryAnn that I wanted the prop rod checked to ensure that it had not been bent (This prop rod falling out of its hole, ripping the insulator blanket, and sometimes bending the rod in the process, is a repetive problem caused by a louy prop rod design, and is the reason the 05 SSR has pneumatic lift cylinders instead).
The one fan versus two in the operating system software is an unexplained mystery.
The Corvettes all have dual fans. Owners of 05 SSRs: Does the 05 SSR have a single or dual fans?
Some possible explanations:
1. There is a 2nd fan somewhere not obvious - in front of the rad where it cannot be seen (I tried to look, but couldn't see one)
2. What the software may really mean is that the fan on the SSR is a TWO SPEED fan, with separately programmable on/off settings for it. This seems unlikely, but possible.
3. GM may have built the software generically to handle either one or two fans, and simply didn't bother to deactivate the optional settings for the 2nd fan (highly likely given that this is what they do with 4-wheel drive settings)
Anyone out there know the correct answer?
I am particularly disturbed about this whole incident for some very pragmatic reasons:
1. The fan failed at only 12,000 miles. This is completely unacceptable for ANY part on a vehicle 6 months old, but especially grave when it involves sometimes as critical as the engine cooling fan. That can cause EXPENSIVE damage and/or complete immobilization if your route happens to involve anything except PURE interstate driving to get home.
2. The SSR is particularly prone to overheating issues, because of the high underhood temperatures caused by both the body shape and restrictions on radiator size. It NEEDS that fan even more than other vehicles.
3. On most GM vehicles, and I assume the SSR is not unique, the transmission is cooled by a puny cooler mounted INSIDE the engine radiator. The theory behind this apparently silly location for a transmission cooler is that in cold climates, the engine coolant will HEAT the transmission fluid so that the transmission will actually operate (think Minneapolis on a -30 degree day). In hot weather, the theory is that the engine cooling fan will keep the engine coolant at a temperature below what would damage the transmission coolant. Since my fan took an early retirement, my transmission coolant was rising in temperature along with the engine coolant. It doesn't take a genius to figure out that if the engine coolant was oscillating between 210 and 240, the transmission fluid wasn't far below that. Transmission coolant life is cut by HALF by every 10 degree rise above an ideal 170 degrees or so. So, even though it was not for long periods, this heating of the engine coolant also degraded my transmission fluid.
4. Larry, with good intentions, nevertheless idled my SSR for 90 minutes, with the temperature climbing until the exhaust note and temp guage both indicated the temperature had been climbing during at least some portion of that time period. That can't have been good for either the engine or ANYTHING under the hood.
5. If the fan failed once, what is to stop it from failing AGAIN? My experience with electric and electronic devices has been that if they fail because of a manufacutring defect, they fail rather quickly. This one did not do that. It failed after 12,000 miles. Is this fan's duty cycle too low for use in the SSR? For those of you unfamiliar with the duty cycles of electric motors (
Most of you, I'm sure), the duty cycle of an electric motor is VERY inversely proprotional to the ambient temperature of its operating environment. Is this sucker going to fail every 12,000 miles or thereabouts?
6. Notice that the failure mode was intermittent. It worked fine for Larry for 13 miles of test driving at city speeds, and for most of a 90 minute test idle period, and then just stopped. A tap with a screwdriver handle awoke it temporarily (similar to a bump in the road?). This could make reliable diagnostics VERY difficult.
I'm starting to get pissed. What we seem to have here is a really neat vehicle with a drop dead gorgeous body but a chicken****, low volume, adapted SUV chassis that just maybe cannot handle the increased requirements of a vehicle with sporty aspirations (and that's how Chevrolet is advertising it, guys, not me. LOOK at their advertising). We may have an awesome engine (whether you have the 300hp LM4 or the 390 hp LS2) stuck in a chassis that just isn't on the same planet in terms of performance.
And here's something more to be concerned about. If the engine fan on the LM4 300 hp "truck engine" can't handle the thermal loads in this environment, how in blazes is the fan (or fans?) on the 05 going to cope with an engine that makes over 30% more heat?
Freezer or Marc: any feedback?
I am not happy.