Radiator Flush

[JFP in PA]

Which is why when using the newer cooler one will need the adapter plate, #35 and P/N 99610712900 MSRP $157.28 in the picture below.

Exactly, as stated earlier, the very early cars had an adaptor plate, which is what yours is; the later "S" cooler will still bolt in, and as Loren pointed out, is the only style replacement cooler available..........

As for the coolant, if the system is not drained prior to pulling the cooler, it will dump about 2 liters of coolant all over the engine, and some will most likely go down the oil passages. Removing the vent line will not cause the system to drain down; the cooler remains full of coolant when the engine is not running............

Edited September 1, 2011 by JFP in PA

[Sumflow]

Believe me all I want to do this morning is go terrorize some two lane blacktop and pass a bunch of cars for the honor of the marque. But how can the same part fit both blocks, when as you can see the blocks are clearly different. One has flat oil passages, the others are recessed. They tell me the same part shows for both years, but they cannot confirm that the adapter fits all 1997 blocks. I am not trying to buy a part number, I am trying to find a solution to an oil leak.

This is the newer block. The surface is flat, with the seals on top. This must be where the adapter lies. Don't get all confused with part numbers. I do not believe in part numbers. What do you see?

Does it look to you like there are the same blocks?

This is the original block, with recessed oil passages and seals.

This is the veteren oil cooler's oil passage connection. The cooler is bigger than the new one but in no way will it hold two liters, two cups is more like it oil and water both.

[logray]

You might want to have a look at Boxster technical service bulletin 1740 (8/97), this might help you, I'm not sure. It talks about extra o-rings required depending on what type of oil cooler you have.

Additionally, here is a picture of the adapter plate P/N 99610712900.

The adapter plate AND oil cooler requires the following o-rings (twice the number than if you don't have the adapter plate).

99970740940 qty 2

99970738940 qty 4

[AND depending on TSB 1740, qty 2 of 99970734440 in addition to the above]

99970719340 qty 4

(there may be a few extra orings you don't need there, but since they are cheap, better to have what you need than wait on more orders).

Newer engines do no need the adapter plate as you've pointed out in your picture, rather the oil coolers sit right on the block, the recesses for the o-rings are machined into the block surface.

The original oil cooler part for the 1997 engine is 99610702505. Porsche does not sell this anymore, instead they offer a replacement which is P/N 99610702507.

This new part, 99610702507 does not require an adapter plate for newer engines. For older engines, the new cooler might not fit without the adapter plate. The bottom of the new oil cooler looks like this:

Not having seen a 97 Boxster for myself, I can't tell you this for certain.

However, what I would guess (just a guess since I haven't seen it for myself) is that the o-ring resting in the bottom of the adapter plate recess fits over the area I circled in red below, and that oring seals that area of the block (and nothing needs to recess into the block as it does with the older cooler). After all, the bottom of the new oil cooler is flat, so the recesses for the o-rings would logically be in the adapter plate (as shown by the picture of the plate above).

That being said, the new supersceded oil cooler part 99610702507 shows as a direct fit for M96.20 (1997-1999 model year engines), and I don't see any other information about the requirement for an adapter plate, but I agree with you that I don't see how it would work without some sort of adapter.

Edited September 1, 2011 by logray

[Sumflow]

It looks to me,that if the original part is not replaced, that is if a part with a different part number is put on. Then a new oil pump with double-sided mount must be installed, and the oil pump must also have an intermediate plate installed.

[JFP in PA]

I really don’t see the relevance to this tread as the oil pump is on the other end of the engine from the oil cooler…………….

[JFP in PA]

You seem to like posting responses as comments to my profile, which are unfortunately being truncated so I cannot see everything you write. Either post here on the forum or send me a PM so I can read everything you have to say.

Thanks.

[Sumflow]

Two Porsche dealers, and the shown TSB 1001, seem to say that if you change the oil cooler to one of those new tiny ones, that you have to change all of this other stuff, and add adapters etc. It is a mess. The simplest thing is to just replace the original part and drive away. Porsche sees some connection between the oil pump in the front, the oil cooler on top , and the changes that would have to be made to the expansion tank in the boot. Changing the cooler will affect the velocities, the passage lengths, the volumes, and the breathing of the engine.

[JFP in PA]

Two Porsche dealers, and the shown TSB 1001, seem to say that if you change the oil cooler to one of those new tiny ones, that you have to change all of this other stuff, and add adapters etc. It is a mess. The simplest thing is to just replace the original part and drive away. Porsche sees some connection between the oil pump in the front, the oil cooler on top , and the changes that would have to be made to the expansion tank in the boot. Changing the cooler will affect the velocities, the passage lengths, the volumes, and the breathing of the engine.

From your other message as well:

"Two Porsche dealers, and the shown TSB 1001, seem to say if you change the oil cooler to one of those new tiny ones, that you have to change all of this other stuff, add adapters etc. It is a mess. The simplest thing is to just replace the original part and drive away. There definitely is some connection between the oil pump in the front, the oil cooler on top , and the changes that would have to be made to the expansion tank in the boot. Changing the cooler will affect the velocities, the passage lengths, and the volumes.

In any case, there must be some reason why Porsche says to change all of these parts if you want to use a different part than they originally designed for the application. I don't know what the reason is, and neither does anyone else that I talked to. But they all agreed that it must be done. I lost a lot of time, and a bit of money putting deposits down, and waiting for parts that I will not use, trying to follow well meaning advice, on how to Hot Rod the Boxster, instead of keeping it stock.

This is relevant to the oil cooler thread because Porsche says all of these thing must be replaced when the oil cooler is changed on the original Boxster."

OK, let's take this in steps: I have absolutely no idea why the oil pump has to be modified, if that is in fact correct. To my knowledge, the very old style oil cooler, the one without a top coolant bleed and that requires the adaptor plate to mate to the engine, is no longer available. As such, the newer design is the only available choice I can find in the Porsche parts system.

As for the coolant tank, that has previously been discussed in this tread; the early tanks did not have a connection for the small coolant vent line on the top of the cooler to connect to, this was a design error that Porsche corrected. The small line lets air trapped in the coolant section of the oil cooler vent to the surge tank; the first cars did not have this line and Porsche discovered that air collected in the oil cooler and caused problems, so they modified all cars going forward to have the line from the top of the oil cooler to the tank. Early cars that still have their original coolant tanks (and there cannot be very many) can still use the newer cooler with the nipple by simply plugging the outlet with a small section of blocked hose. As most of the early cars have long since changed out their surge tanks (they were prone to cracking), they probably already have a tank with the connection for the line (albeit plugged for the same reasons); if they do, it is a simple matter of running the rubber hose from the cooler to the tank. Either way, the new cooler works.

As for the oil pump section modification, I know the 97 cars had a different oil pump than the later cars from the part numbers in the PET, but I have no information on how it is different. Physically, the unit looks exactly the same as the latter part numbers, so what ever changed is not readily visible. The 01 and 02 cars also have different oil pump part numbers, but without explanation as to why. Porsche often changes part numbers as they update components due to information accumulated with owner miles, so that is nothing unusual. It is also not unusual for Porsche to want to sell you the updated components, particularly if the one you have are known problems, which appears to be the case in the TSB 1001 you quoted.

But what I have confirmed is that if you read the entire TSB, you will note that it clearly states that it is addressing oil/coolant intermix problems on the 97 cars. If further goes on to state that even if the oil cooler on the car is found not to be the cause of the intermix issue, you should change out all the other parts while you are in there as well. So the other parts are not actually required to change out the cooler, but are precautions against a future intermix issues from the other components.

What I can tell you is that, as mentioned earlier, we have quite a few cars running the newer and larger cooler, including a couple early models, none of which had the oil pump changed or modified, and all of which continue to do fine everyday to my knowledge. So I fail to see any validity in the comments about "velocity" or "passage lengths"; and as the oil cooler had nothing to do with the intake system, the "breathing" comment is equally questionable.

I am sorry you seem to have run into so many brick walls on this simple and very common upgrade, but as mentioned, with so many done and having run a lot of cumulative miles, I know it works.

Edited September 24, 2011 by JFP in PA

[Sumflow]

JFP :> The small line lets air trapped in the coolant section of the oil cooler vent to the surge tank. <

Why couldn't you just run this to the engine vent line, with a "T."

[JFP in PA]

That would work if the tank was one of the early ones without a connection, but if the connection available on the tank, it would be simpler to just connect it there.

[Sumflow]

The very old style oil cooler, the one without a top coolant bleed and that requires the adaptor plate to mate to the engine, is no longer available.

The original cooler does not need any kind of adapter. it fits into the block, with four seals and four screws.

The early tanks did not have a connection for the small coolant vent line on the top of the cooler to connect to..

These were the directions to replace the oil cooler. Although there was no reason to mess with the throttle intake. It does not show anything about draining the oil, or removing or replacing a vent line. There is no mention of any adapters, or air vent lines.

The line from the top of the oil cooler to the tank.

Can you please tell me the order of the three hoses top to bottom under the oil filler hose?

Oil cooler hose?

Radiator vent hose?

Coolant filler hose?

Coolant overflow hose?

Whoops that four, I only see three.

Does line 18/30 the top line go to the oil cooler?

Where does 16/01 the second line go?

Where does 20/29 the third line go?

We have quite a few cars running the newer and larger cooler, including a couple early models.

The newer cooler that the Porsche dealer got for me was smaller in height, width, depth and volume than the original oil cooler. It weighted noticeably less which is why it appears tiny to me.

There is very little space between the top of the cooler and the air-intake tube that runs from the air-filter to the throttle body, maybe 3/4 of an inch clearance maximum on the driver side. So if there is a bigger cooler it will be a tight squeeze.

the "breathing" comment

Isn't adding the action of venting, much like that of adding a breather?

Maybe the new cooler has tighter passages which require a different oil-pump to be efficient, or the new oil pump, runs at a different rate, which required a different oil cooler?

I was under the impression that there was an original vent from the top of the engine going to the surge tank. When they replaced the oil pump and all that, and added the new cooler. They ran the vent from the tank to the new cooler, which is higher than the engine, instead. Where is the unused inlet into the expansion tank?

Mahalo..