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Thermostat Housing replacement : 2 Pannies tackled at the same time
And so it all started. Doug and I are replacing the Thermostat Housing on both of our cars in sync. We've got our cars next to each other in my shop and doing both cars step by step. Cars involved are a 2010 4S and 2012 Turbo S. We'll get back to you guys with some learnings.
Judging from what we found in both my car (2010 60k miles) and Yves (2012 40k miles?) I would highly suggest that if anyone with a 2010-2012 Panamera have their thermostat housing checked.
If you go for a drive and then pop the hood and smell coolant - most likely the glued in pipe of thermostat housing is failing.
My coolant level never changed much, but I could smell coolant after a drive when I opened the hood. What I found when I took off my intake manifold was signs of leakage and the pipe came out of the housing with almost no effort.
Yves car was only slightly better, it also had leakage signs and the pipe came out with minimal effort!
I'm extremely happy that I decide to do this when I did.
Objective of our effort was to perform a preventative replacement of the thermostat housing. Said housing has coolant 2 pipes which are expoxied into the main body of the housing. There are reports of numerous failures where the coolant hose pops off under pressure, which can lead to catastrophic engine failure.
Our learnings :
1. The design of this thermostat housing is flawed and should be subject to recall. Both cars were leaking out of the left coolant pipe (when standing in front of the car). The 2010 4S had a loose coolant pipe and coolant accumulating in the V section of the engine. The coolant pipe could be pulled out of the housing without any effort. The 2012 turbo was weeping coolant at the bottom of the epoxy weld, but less so than the 2010 car. The coolant pipe could be removed with minimal effort (some twisting and turning with the use of only thumb and index finger). Conclusion : Porsche really messed up on this one. While 2 cars is not a statistically relevant sample, we both may have avoided catastrophic engine failure.
2. This is not an easy DIY, but it can be done by a shadetree mechanic. We tackled 2 cars during a weekend, 2 people, 16 hours each. Second time we could maybe do it in half of that time. However, you really need to take your time and be focused. Several of the hoses, connectors, etc…have been subject to a lot of heating and cooling cycles and as a result it is sometimes tough to disconnect them. Having 2 people around helped coming up with creative ideas as to how to remove the elusive bolt or nut only Germans could have put into the most impossible place to get to.
3. Instructions used : the relevant sections of the Porsche Shop Manual (the 10K page monster) and Ciaka’s DIY on the Starter Replacement. The latter covers about 75% of the procedure.
4. Parts needed : thermostat housing and the gasket for the water pump are essential. Any other gaskets we encountered were in OK shape and could be re-used. While you’re in there I would strongly advise to also renew the thermostat itself. They can fail and it would be a shame not to address this while you’re in there. Additionally, it was kind of tough to remove the original thermostat, so there is quite some risk of damaging it anyhow.
5. The Turbos are way more difficult to tackle than the normally aspirated cars. There is simply less space to work and way more pipes, hoses and connectors to deal with. Our approach was to first perform a process step on the 4S and then move on to the Turbo.
Do you happen to know the part number for the new thermostat housing? I went through some old service records and as it turns out, the original one on my car only lasted 22k miles! The original owner had it fixed under warranty. The part number the dealer installed during repair was: 948-106-080-00
anyone know if that’s the new one or the old / faulty one?
That is the new updated housing - sounds like your good to go
not sure if your response was before or after I corrected my typo. I typed “02” instead of “00” at the end. Does that mean I have the old faulty part still?
darn it, that typo gave me hope!
if it’s the old part, at least maybe the only good news is my “new” old part has 2 years / 22k less miles on it than initially thought
not sure if your response was before or after I corrected my typo. I typed “02” instead of “00” at the end. Does that mean I have the old faulty part still?
darn it, that typo gave me hope!
The part we put in our cars in ends in "02". You could easily verify by going in there with a small flexible camera/borescope.
That part was changed somewhere in 2015, when did your repair take place ?
In researching this problem, I found Porsche's response to an NHTSA safety inquiry regarding coolant pipe failures in certain 996 and 997 models, which can be viewed at:
It's an interesting read. Porsche's response to the NHTSA indicates that glued-in coolant pipes were also used on 2010 - 2014 Panameras and 2011 - 2014 Cayennes. Back when this response was written in 2013, Porsche believed the failure rate of the glued-in joints to be around 1.5% for the 996 and 997 models that were the subject of the inquiry. I'm sure that number goes up in a big way over time.
The bottom line for Panamera owners is that the new thermostat housing with the bolted-on coolant pipes didn't come online until the 2015 model year. As the owner of a 2013 Panamera Turbo, I'm keeping a close eye on mine. It's a covered part under my extended warranty, so don't want to necessarily make a preventative repair on my own nickel, but want to catch it when it starts to go but before I'm left stranded on the side of the road. No weeping or noticeable coolant loss so far, but I check it every few weeks.
