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After a poorly executed repair at a (non-Porsche dealership) shop, our Coolant Reservoir exploded while driving 2004 Porsche Cayenne S. Though I was not in the car, my wife said it sounded like a shotgun blast followed by a tremendous poof of vapor!
Coolant reservoir now replaced by yours truly. Coolant system refilled ...by the book. Now, I handle all my own repairs. As such, I am seeking advice for reshaping the hood. Here are some pics:
Approximate size of the gap.
Looking down the hood toward the headlight.
Overall view of the hood.
Suggestions for reshaping this edge of the hood?
Thanks in advance for any words of encouragement!
PJ
Holy Crap! I would search for a new (used) hood in the same colour and install it yourself. That would be cheaper than getting a body shop to straighten that one.
As for re-shaping, I imagine you will have to bend it back, past where it sits in the car as there is inherit flex in the metal. Otherwise I would suggest a movers blanket and a lot of weight distrusted across the bend. But I suspect that wont work, as you will have to probably deflect past the fender.
I would try to measure the current amount of deflection from the center of the peak of the arch which is probably close to were the coolant reservoir is , (lets say 3 inches) then set it up on a couple saw horses, tables, etc as a bridge. Measure the deflection from ground to the same middle point you did earlier (again imagine you are pushing back where the tank exploded up in the first place), and then slowly apply pressure, measuring each time to get that 3 inches down.
Keep in mind never done this for a hood, just other things that need bending
Don't forget to mark where you removed the bolts and look up the torque spec!
What on earth caused the reservoir to blow up with that much force?
Unlikely that it can be repaired to proper fit unless you're a metal artist with a lot of time.
Also, no reason really to not go to your comprehensive insurance for this. If you don't like that shop, let your insurance company go after them for the damage to replace the hood, which is the most practical probably.
Depending on insurance, state, you might not have to pay a deductible, as it was not your fault. Pretty obv is you had the reservoir replaced, and it blew out the hood it was related to their work, not a lawyer
Thanks for all the input. Here is more of the backstory, since respondees seem so excited about the explosion (and I can't blame you).
About 2 weeks after buying our used 2004 Cayenne S, my wife noticed that the car started overheating. I met her at the mall parking lot to investigate. The car was definitely overheating. I filled the reservoir with bottled water that I happened to have in the back of my pickup. After about 2 minutes of adding water, it started to pour out "from the bottom". All the underbody panels and beauty coverings around the engine compartment made finding the exact source of the leak difficult, without more tools (note to self keep screwdriver in trucker, or a quarter, because those panels are really easy to remove!).
We had it towed to our trusty local place. They have always been very diligent with our non-Porsche vehicles.
The next day they called to report the source of the leak, the lower radiator hose was disconnected. They commented that the clamp was still around the hose, but the hose itself was no longer connected to the radiator. Simple enough!
They reported reattaching the hose and refilling the vehicle with coolant, though they couldn't figure out why they were occasionally getting some fluctuations in engine temperature.
We took the vehicle back and it seemed to be operational. We drove it for several days. One afternoon, while our daughter was driving with us in the car, the idiot warning signal came on for the engine overheating. We immediately pulled over to investigate (again, neither a screwdriver nor a quarter handy).
After calling a friend to come rescue us, I drove the Cayenne back down to the shop to have them sort it out. At high speeds, the temperature was more or less fine, but at idle it would fluctuate between 180F ish and redline.
They "refilled the coolant", double checked all the hoses, and test drove it for 4 days. I believe that they were doing the best they could. They admitted that it was outside of their normal area of expertise.
When we got the car back again, all seemed to be well. Again, drove it for days without noticing anything unusual. Then fwoooomp!
Following that, I decided to educate myself. I signed up for Porsche's online manual system. I read everything about the coolant system. I made long distance friends with the folks at the Porsche Dealership. I ordered parts and did the work myself.
My theory: I suspect that the local shop didn't vacuum-fill the coolant system. I suspect that they gravity filled it, like I might with an old pickup truck. I have not asked the shop about it, because I didn't care to discuss the matter with them after the explosion.
My theory continues that "air bubbles" (or gaps where air remained) in the expansive coolant system caused the odd behavior as the coolant vaporized upon hitting overheated components. Eventually the vaporization, i.e. air bubbles made their way to the expansion tank, but with extraordinarily rapid expansion, causing the expansion tank to rupture in half, violently.
Word to the wise, the UView Cooling System Leak Checker and Airlock Purge Tool Kit combined with an air compressor works beautifully.
Feel free to debunk or otherwise help me refine my theory. I am going on a sample size of 1, and ill-described symptoms.
Post my full repair work, the engine has operated normally for thousands of miles at a steady 180ish Farenheit. Woo hoo!
The resivior cap should have bled off the excess pressurebefore the explosion. Vacuum bleeding is a sure thing but a lot of guys have great luck bleeding normally. IMHO , engines that have been overheated that severely are never the same. Especially all alum. ones.
I'm with Mr Haney on the fact that I've drained and flushed my Cooling system (although it's a '06 CTTS) and just filled it, started the motor and filled it some more, then capped it off and drove it for a few miles, come home and let it cool, then topped it off. Might have taken a little more of a top off on the next drive but that was it. The pressure cap should have let off any over pressure. Something seems out of place.
The Coolant reservoirs are known to fail after 8~12 years but I've never heard of one going explosively? Cap issue? OEM or aftermarket Reservoir cap?
Thanks hahnmgh63 and Mr. Haney. A cap issue makes sense! I suppose if it is not regulating the pressure correctly, that would cause excessive pressure to blow the hose off the bottom of the radiator, if the clamp was not properly tightened. And it might cause the abnormal fluctuations in temperature if it was on and off working/not-working.
And, of course, when I replaced the coolant reservoir, I used a new cap. So, my scientific reasoning was not plagued by more variables that I accounted for.
The reservoir that exploded appeared to be original to the vehicle and the cap appeared to be original, as well.
Thanks for helping my reasoning!
I am interested in your comment, Mr. Haney:
IMHO , engines that have been overheated that severely are never the same. Especially all alum. ones.
What symptoms of trouble should I be watching for?
If you shut it down when the dash overheat light came on you should be safe as there is a buffer Porsche built into the warning but if the Coolant was actually boiling over it could be a sign of future trouble.
That the force of the coolant blow was enough to deform the hood makes me wonder if the Cayenne engine compartment isn't perhaps a little too well enclosed. Have you inspected the bulkhead seals and grommets?
Yea, I would definitely keep an eye on your cooling system. No way that should have happened regardless of how the system was bled. The cooling system has safe guards to release pressure in a cases like this. I wonder if the people who had your car before knew of the problem but decided to trade it in before fixing it? How does your oil and coolant look? Any signs of mixing? Just curious...
04-13-2015, 01:07 AM
Coolant Reservoir Explosion - Hood Warped
Backstory
