TomiK

Parts ordered from dealer (no choice here, not as pricey as I expected). Low temp T-stat not available in this country AFAIK and shipping from US is too expensive with customs duty etc.

Will test the thermostat like you suggest, Macster.

A job for next weekend!

TomiK

No airlift or similar in South Africa but I can source a cheap one from China with free shipping and no tax.

Do you know if the Airlift will work with the little Porsche air compressor/pump? Or do I also have to find a real air compressor that the shops use? Can't seem to find a definitive answer online.

Macster

The air compressor that is intended to refill a low tire is almost certainly not sufficient to work the Airlift.

I hesitate to advise you to buy an air compressor because I do not know what would be the minimum acceptable. Perhaps you can rent one for the few hours you would need it?

Macster

For the Airlift 550000 system an air compressor capable of providing 90 psi is required. There is no callout regarding the amount of air the system needs to supply, how many cubic feet per minute.

Additionally the air compressor system should have an air dryer system.

Here's a link the the AirLift 550000 system instruction manual.

http://www.uview.com/site/ywd_uview/..._inst-book.pdf

clickman

I have a 4 gallon compressor which works fine, and I seem to recall others using less. I had rented a 10 gallon previously. I think smaller ones might take a couple of cycles but can still get it done.

clickman

Your comments usually seem well thought out. I'd be interested to know why you wouldn't use one.

TomiK

Back to the thermostat: The dealer here in Cape Town only sells the thermostat insert (for $50!) which apparently requires a special tool to remove/install (which they of course don't sell). Can it be done without the tool on a 987?

The dealer also said that they have not sold/replaced many thermostats at all and suggested I not bother replacing mine. I guess if it works, it works...

p.s. picking up waterpump today but need to wait 6 weeks for the vacuum purge/refill tool from China...

clickman

There is a way (or ways) of refilling by burping afterwards, but it seems hit and miss for getting all air pockets out.

Macster

The pro auto techs I hung out all recommended/advised replacing the T-stat along with the water pump. I am pretty sure this is SOP at the dealer. I doubt to pad the bill as the labor is the same and the T-stat cost is low compared to the total cost of the water pump R&R.

I do not know the details of the 987 water pump/T-stat replacement but would advise you to replace the T-stat along with the water pump.

For a (refundable) cash deposit and a box or two of donuts can you borrow the dealer's 987 T-stat tool over the weekend?

Since the T-stat is almost always replaced along with the water pump we have no real info on how long a T-stat lasts beyond the life of the water pump. It might last forever, it might fail real soon after. A water pump failure or a going bad water pump gives off signs of pending more serious trouble. A T-stat failure maybe not.

Thus by leaving the old T-stat in service you are treading on unfamiliar ground in that 1) there is the question of how long the old one will remain fully functional; 2) if it starts to go bad how will you know? And what kind of margin does one have? Is it a long drawn out failure? Or blink of an eye thing?

My advice would be to obtain the necessary tool unless the cost is prohibitive. What is "prohibitive" only you can decide. Obtain the tool and replace the T-stat along with the water pump.

Macster

A low temp T-stat is the wrong solution for a non-existing problem.

A properly functioning cooling system is quite capable of keeping the engine cool enough under even the most severe of operating conditions.

A good number of owners are blissfully unaware of the existence of low temp T-stats, even T-stats, and yet continue to day after day operate their Porsches in warm to hot temperature conditions in which the coolant temperature reaches the upper limit of what the cooling system allows and experience no issues other than the discomfort of having to get out of a nice A/C'd cabin and face the elevated temperature of the outside.

There will be a report once in a while from an owner of his car overheating during track running. I have to point out that these cars are not race cars. Just because one can drive one to the track get on the track and circle the track at a pretty good clip does not change this. While some owners are good with their track prepping their car others not so much. The ones that show up with old oil, diluted oil, a cooling system leak, or aged components, and experience trouble, often mis-identify the cause and blame the T-stat when it was in fact leaf/trash clogged radiators, low coolant or one with a pressure leak, heavily diluted oil, and so on.

As I have mentioned before, even in 116F heat with the coolant temperature at 226F my Boxster engine was just fine. While 226F may seem hot this was well within the operational margins of the engine and the oil and the rest of the car. (The human -- me -- was damned uncomfortable and at times bordering on break down but tough cookies.)

Might also mention -- and I do this to highlight how important this is -- the above occurred with "fresh" engine oil in the engine. Prior to driving in this heat in AZ I had the Boxster's oil changed at the Sacramento dealer. Thus the oil had around 1000 miles on it. However, I'm not suggesting one change the oil every 1000 miles to help the engine tolerate high ambient temperature operating conditions. I have encountered high ambient temperature conditions with nearly 5K miles on the oil. My oil change interval (every 5K miles) is based on my car usage and intended to provide plenty of margin so the engine has adequate lubrication at 1 mile after an oil change to 5000 miles after an oil change regardless of how I'm driving the car, regardless of any climatic conditions I might encounter.

(Prior to the oil change at Sacramento. I had driven all the way from the KC Mo area over to Idaho and then across eastern OR in very high ambient temperatures. I didn't spare the rod so to speak because the oil was "old", due to be changed. In fact it was quite due to be changed and my plan was to have it changed at Bend OR but the dealer there couldn't accommodate me so I drove on over to Eugene OR and did some business there and then drove on down to Sacramento where the Porsche dealer got my car right in for an oil change.)

Now then: Even though I have driven my Turbo through even hotter ambient temperatures than 116F, my Turbo has never had its coolant temperature that high. The Turbo runs much cooler even though the car is heavier, has a larger engine, a more powerful engine, with nearly double the HP of the Boxster engine (when the Turbo is under full boost), with of course more heat output.

Why? Several reasons. One of the most obvious is the car is equipped with a 3rd radiator.

Another less obvious reason is the car is aerodynamically better than the Boxster and air flow through the radiator ducts is much improved over lesser cars. (Another reason is the Turbo has a more sophisticated cooling fan stages map.)

(When I bought a new 2006 GTO one of the first things I did was buy a Predator tool and use it to customize the engine cooling fan stages, to boost the cooling a bit given how hot it can get where I live and drive. The GTO also got to run through the desert a number of times though I do not recall it being quite as hot as it was with my Porsches. But I wanted the car ready for it. Have to admit that a number of owners never bothered to do this and I did not see any posts by anyone with any overheating problems/issues or problems from the engine operating at a too high of a coolant temperature. I changed the fan stages not so much because they needed to be changed, but because I could.)

Almost every new model release Porsche has made since I bought my 2002 Boxster the sales literature has mentioned "improved cooling". As engine output rises, as top speeds go up, Porsche improves the efficiency of the car's cooling system and this includes helping the radiators flow more air under the same conditions as previous models.

Back to the 3rd radiator: When Porsche wants more cooling it installs more cooling capacity and primarily this takes the form of an 3rd radiator. Porsche does this even though a 3rd radiator adds weight, adds complexity, requires more coolant, requires parts be cataloged, stocked and instructions for their replacement be documented. Porsche does this, goes to all this effort, vs. slap a low temp T-stat in the engine. This alone should tell one how lacking in any real contribution to improved cooling there is with a low temp T-stat.

The trouble is installing a 3rd radiator for the shade tree mechanic is a bit of work. And can run into some money. Not much but some. Installing a low temp T-stat anyone that can change a water pump and T-stat can do. All it has going for it is it is easy to do.

But there is a negative to a low temp T-stat. The engine can take longer to get up to operating temperature. The desired targeted operating temperature. I have posted a chart of lab test results that show as engine operating temperature drops engine wear goes up. At at 210F operating temperature wear is nil. At 180F wear is up and it only gets worse as the operating temperature goes lower.

This lower operating temperature also means the oil doesn't get hot enough to boil away the unburned fuel and water that the oil collects.

I'm sorry to make a long post even longer, but I have to point out this can be a problem even with the stock T-stat in service. On a whim I had the oil in my new 2002 Boxster engine analyzed at around 4K miles. The oil analysis report came back with around 7% water content in the oil. With just over 9 quarts that represents nearly a 1/2 quart of water! Even though my usage didn't involve short trips, given the climatic conditions -- winter in the KC MO area -- the engine oil didn't get hot enough to boil away this water. This high water content was what prompted me to adopt a 5K mile oil/filter service rather than sticking to the factor's 15K mile oil and 30K (!) filter service interval.

Since the engine is operating at a lower temperature -- essentially it is operating at a temperature that was intended to be only a transient temperature on the way to getting up to operating temperature -- the oil is going to collect more of these contaminates. So the owner is driving along happy as a clam the engine is operating at a lower temperature. He decides to engage in some spirited driving, or he visits the track and pushes the engine real hard. Or he just gets caught in traffic going up 50 highway on the way to South Lake Tahoe and points east one July 3rd with the ambient air temp in the low 90's, as one such experience I had with my Turbo. Coolant temperature goes up along with oil temperature. But the oil being diluted with unburned fuel and water isn't up to the task and there goes the engine.

While some owners would want the engine to operate at a lower temperature my desire would be the engine get up to operating temperature and never deviate from that no matter if the engine was idling in traffic or racing up a mountain road WOT at near redline.

relinuca

Words of Wisdom:

No one has ever said, "Gee, I'm sorry I changed out that water pump too
early."

relinuca

TomiK

Update on this thread and a follow-up question:

Water pump started making noise - am replacing it this weekend. I managed to import a Chinese "Üview" and need to clarify where to attach the gauge. My Boxster S has two coolant/expansion tanks - one in the engine bay (on the right) and one in the trunk (next to the oil filler hole).

To which one should I attach the Uview to refill the system? Or does it not matter as it is a closed system?

Much appreciated guys - wouldn't do all this stuff without this forum!

JayG

There is only one coolant tank on a stock Boxster, in the trunk next to the oil filler
there is none in the engine bay,.

Post a pic of what you are referring to

You will need 3 gallons of undiluted Porsche coolant that you mix 50/50 with distilled water (go to walmart, .88/gal)

Lots of DIY info here, pelican and 986forum.com

Macster

The times I've seen the techs using the vacuum lift to refill a cooling system the thing has been connected to the tank accessible in the fluid access bay in the rear trunk.

The techs tell me they pull enough vacuum to collapse the hoses then shut off the vacuum and open the line to the reservoir filled with the fresh mix of anti-freeze and (distilled) water. This is of course vented to atmosphere so the pressure difference has the coolant transferred into the engine cooling system PDQ and with no air pockets.

Just to be sure the techs bring the engine up to operating temperature then shut it off and let it sit. This gives any leaks a chance to show up as well as well as give any air pockets a chance to exit the system.

The times my Boxster (and Turbo) have had their cooling systems done this way while I have given the cars a shakedown drive just to satisfy myself the cooling system is properly filled the shakedown drive turned up no issues.

The vacuum lift system is an impressive system for filling these rather large and complicated cooling systems.

TomiK

This is the coolant tank in the engine bay I was referring to.