Well it finally happend to my '08 Vantage (16,400miles)--the Thermostat gasket came off which results in low-engine temp. My temp reads at 1/4 instead of in the middle of the gauge. Finally "check engine" indicator came on, then a message that says "Emission service required". So I called my dealer and will have the thermostat replaced later this week. Interesting that Aston-Martin seems to not have recognized this problem, as their design has not been changed--according to my dealer. Does anyone know of a replacement thermostat that I won't have to replace every 3-4 years?

 

Land Rover, Jag, Aston Martin..all the same engine platform with the same stat..and same problems..just I never heard of every 3 years. If your replacing every 3-4 years then you might need the housing replaced for there might be to much play

 

let us know what the cost of this would be from the dealership.

 

Irish07
I didn't mean to imply that I had that many failures, this is my first one, but I was hoping this is not such a poor design that it will fail often.

CJPatel,
My Vantage is still under the original factory warrantee, but I'll ask the dealer what the ususal charge would be.

 

Have not seen to many of these, have had them though. What I have seen is the gasket gets stuck in the thermostat causing it not to close correctly. Like Irish07 said, jag and rover same faults.

 

Couldn't say it better...it's a pretty simple design and pretty reliable, even when the stat does fault, it's a simple repair unlike some manufactures

 

I purchased the Jag thermostat from Autohaus and plan on replacing it before the cold weather hits (we still have some time here in Texas). Total for the part including shipping was $54 ...

It isn't too hard to install and there are instructions/tips posted in this forum, search under "thermostat". Saves your a few hundred $$$ and the trip to the dealer.

 

DickTahoe--does it run cold consistently or only under freeway conditions? I have had my 2007 (18K miles) run a 1/4 temp when I am driving in the early morning ( 50 degrees ) on the freeway at 70mph in 6th gear. All other times it runs at norm temp i.e. regular street driving or when I am on the track. Since I rarely drive on the freeway and have not had the CEL come on yet, I have let the issue slide for the last year. I asked the dealer about it and there was no diagnostic test available--they just said to replace the thermostat, so I decided to hold off. In many race cars they remove the thermostat since an engine running cold actually tends to deliver more power. Since fuel economy is not a priority I am just monitoring the situation.

 

Race cars do use thermostats, in a NASCAR and F1, Indy ..etc there engines are engineered with a stat at whatever operating range they engineered best fit..160F-210F, most cars on the street use 195F-210F. The reason race cars also use stats is to get the operating temps in the high temp range so bearing and rings seat correctly. If the engines did not use a stat this would shock the metal with lower temp coolant and warp the block,deck,heads, internals. So the stat helps keep the temps in spec range.

People tend to think putting a lower temp stat in the cars makes the car run cooler, say 195F is the OEM and they replace it with a 160F..just means the stat opens way to early when the engine was not engineered for this, thus you doin't get to the correct operating temp engineered for best performance, best mpg, best reliability. Even adding forced induction which causes higher heats without a intercooler does not need a 160F(unless engine was tuned and calibrated correctly for this)..these forced induction cars tend to over heat due to the high heats, but this is simply because they thought putting a 160F stat would solve the problem when really a larger core radiator is whats needed(not all cases, but a large percentage).

So to help run cooler on race cars they actually use a larger radiator to cool the coolant faster due to the high flow pump, but will still use a stat to regulate the temps for better performance and reliability.

As for your car running cool, if there was a problem, the PCM would pick this up on 2 back-to-back drive cycles. If the coolant had taken to long to reach it's spec temp at the needed time, engine light will come on and show Emissions Service Needed in dash display. My opinion would be to not replace the stat for I don't believe anything is wrong with it at this present time, if the stat was opening to soon or allowing coolant through closed, MIL light will come on and flag the DTC for stat open

 

Thanks for the detailed response-- your answer reassures me that I am OK ignoring my current situation-- as I said 95% of the time the temp is normal.
My comment regarding racecars comes from my experience racing spec miatas where most often the thermostat is removed from the car and you are limited to several specific radiators that can be installed. Obviously the opposite end of the spectrum from NASCAR, F1 and Indy cars. Thanks for the info.

 

klittlehale:
I first noticed the the temp problem when coasting down a hill with the temp in the 50s. Temp would be at normal, then in a long coast it would drop down to 1/4. More recently it has been low on the freeway when temps are below 50. For example, it was 42 the other morning and I drove on the freeway at 75 for about 15-20 miles at that speed and it never warmed to more than 1/4. It's in at Aston dealer in Marin now to get the thermostat replaced. I asked the mechanic about replacing with a Jag thermostat, instead of ordering one for the Aston from the UK. He said, "the ball on the Jag thermostat is different" and could melt. I don't understand this, but maybe someone on this site can comment "is the Jag Thermostat IDENTICAL to the Aston one?"

 

They are talkng about the bleed ball in the thermostat. I what to say they are the same, but it has been awhile.

 

I don't remember there being a bleed ball on these thermostats, The ball type is on thermostats that are mounted in the block/intake manifold..Aston/LR/Jag are not mounted in the block/intake manifold..they are mounted in a remote housing and monitored via thermostat sensor...

I've never held both in my hands at the same time to compare, all I can say is after changing numerous of them on all the brands..nothing has stood out as different. If the mechanic at your dealership says this "ball" is different, I can't argue for like I stated..never had them both in my hands to compare measurements

 

I think the Aston part came in a Jag box...lol....

 

I changed out the thermostat in my car this past weekend. It isn't too tough to do. I didn't have to grind down the bolts as mentioned in one of the other threads, it was tight though! If you can lift the car and take the underside tray off, it will make life easier when you drop the nuts/bolts.

You will lose some fluid, so be prepared to catch it for disposal ... I did not re-use my old fluid. I plan on topping it off with fresh stuff (Prestone Dexcool) as recommended by a "local" AM mechanic.

I bought the thermostat from the Jag dealership. I can say that after having both in my hand (OEM and Jag), they are identical.