A/C Compressor Life

[hoss4659]

I am planning to upgrade the A/C system in my '88 Carrera. The odo reads just under 70k. Is the original Nippondenso compressor in the car near the end of its service life? Any reasons not to replace it with the Sanden 507?

[Discseven]

Hoss... Kuehl will answer this.

[billybek]

Oh good, an A/C thread!
I have been missing the chaos!

Has the A/C been charged and functioning?
Compressor may be fine with that mileage but may need a shaft seal if leaking.
If doing a complete system retrofit, I would go with one manufacturer/supplier.

Here is some good (and accurate information).
The Mr. Ice Project, Porsche 911 930 Air Conditioning Improvements and Upgrades

[wwest]

Originally Posted by billybek

Oh good, an A/C thread!
I have been missing the chaos!

Has the A/C been charged and functioning?
Compressor may be fine with that mileage but may need a shaft seal if leaking.
If doing a complete system retrofit, I would go with one manufacturer/supplier.

Here is some good (and accurate information).

Accurate

20 years ago maybe, seriously in need of an update/rewrite.

[Ronnie's.930]

Originally Posted by wwest

Accurate

20 years ago maybe, seriously in need of an update/rewrite.

So says the guy who ONLY reads (often failing to understand what he's read, however) about automotive a/c!

Who needs actual experience to be an expert on the subject, right?

[wwest]

Originally Posted by hoss4659

I am planning to upgrade the A/C system in my '88 Carrera. The odo reads just under 70k. Is the original Nippondenso compressor in the car near the end of its service life? Any reasons not to replace it with the Sanden 507?

My '88 Carrera now has over 100,000 miles and the compressor works as good as new. And that with numerous instances of R-12 leakage and having to recharge every ~2 years. Converting to R-134a a number of years ago now and no more leakdown.

Maybe a tad off topic but my 1995 LS400 at just shy of 300,000 miles has all the OEM A/C components including the factory R-134a.

No reason to fail providing its never low/run dry of refrigerant. Refrigerant "carries", circulates the lubricating oil continuously throughout the system.

[Discseven]

[Arne2]

Two comments, from someone who went through the A/C on my '84 last year. If you are going to go to the work of re-doing all the rest, I'd replace the compressor as well, especially if it has been some time since the A/C was last working. You don't want to go through the whole process only to find that the compressor is not up to par. I decided to re-use mine (at 160k miles), and while it works, it's rather noisy and I probably should have replaced it.

But if you do replace it, I'd recommend a new Nippondenso instead of the Sanden. Both the Densos and Sandens are fine compressors, but the Sandens have less displacement and so have to run more to maintain the same pressures.

[Ronnie's.930]

Originally Posted by Discseven

[crownarch]

And here I thought we would at least make it to spring of 2015!

[Ronnie's.930]

^^^ Cornstarch, do you have any popcorn left over from last summer? I recall that you ordered it by the dumpster load back then!

PS - it's mid 70s here today, with ungodly humidity, so home and auto a/c is a year round affair in these here parts!!!

[crownarch]

Originally Posted by Ronnie's.930

^^^ Cornstarch, do you have any popcorn left over from last summer? I recall that you ordered it by the dumpster load back then!

PS - it's mid 70s here today, with ungodly humidity, so home and auto a/c is a year round affair in these here parts!!!

Yes, I saved several bushels of Pcorn from this past summer as I knew it would come in handy. Since it is starting so early this year, perhaps I should order another truck load before supplier is all sold out.

[crownarch]

By the way Ronnie, Karl said he is still waiting for your 2000 page dissertation on "how to fix your AC".

[Ronnie's.930]

Gary, should the a/c dissertation include plenty of pictures of smokin-hot-chics sporting bikinis (seated in my car with body-language indicators of the chilly conditions inside, BUTTofcourse)?!?!

[kuehl]

Is the Original Nippondenso compressor in the car near the end of its service life?
It all depends on how the compressor was 'treated' during its life. There compressor you have is a good model for your car. The is little to gain in trying to improve upon its design. What wears out a compressor is lack of refrigerant/oil flow. The compressor needs a constant flow of refrigerant & oil to lubricate its moving parts and to keep it cool as well. Situations were it might see low flows are: empty system, low refrigerant level, plugged expansion valve. Other things that can wear it out are excessive pressures: leaving the engine deck lid up too long when the system is operating, failed front condenser motor, over charge, lack of oil, and a few others.

Since its rather old and has high miles, what you can do is disassemble the unit and inspect the bores/pistons, wobble plate, reed valves, section on shaft where nose seal makes contact. If all looks good then just drop in a seal kit. If you need an opinion just drop me an email.

Any reasons not to replace it with the Sanden 507?
Your Denso has more pumping capacity than a 507 so if I were in need of replacing a Denso I'd simply use a Denso otherwise you'll need to change adapter plates and possibly hose fittings. Typically we replace York's with Denso's.

[wwest]

Before I would begin the task of FIXING something I would to first confirm that it is broken.

Disassembly and reassembly of an A/C compressor is tough enough and being SURE of a clean work environment is paramount for this type of work.

I have no experience with A/C compressor repair but lots with hydraulic systems repair & test.

[88911coupe]

Is there a Sanden that is "preferred" over the 507? I thought I had a 508 but an AC guy here in Dallas thought it might be a 508. I can't seem to find much on the outside to actually identify which model it is.

[kuehl]

Hoss,
Here is a PP link article covering most of the R&R process on your Nippondenso.
Nippon RR
The article is 95% on procedure, misses a few points on inspection criteria, but overall Ron did a great job with it. Note in the 8th picture in the link Ron left the pistons and wobble plate with shaft inside one of the case halves; this is important so that assembly does not fall apart. Again, you can drop us a email if you get stuck.

On the 508 size question, lol.... size does not matter all the time. Below is a blurb from Sanden that summarizes it well in terms of size.
"Q: Will cooling performance improve if compressor speed or capacity is increased?
A: Cooling performance could improve by increasing compressor speed or capacity; however, HVAC system capacity is not based solely on compressor capacity. Control algorithms, evaporator and condenser sizing, as well as a host of other factors contribute to system capacity, so simply speeding up your compressor or upgrading to a higher-capacity compressor will not necessarily increase your actual system performance. Please consider consulting an aftermarket HVAC systems company if you need help in upgrading your system.

Griffiths, as well as other aftermarket AC companies, for example, have been replacing the old York with the smaller 507 design and performance is very good. However, in your situation, we suggest keeping the Nippondenso model you have.

[wwest]

Originally Posted by kuehl

Hoss,
Here is a PP link article covering most of the R&R process on your Nippondenso.
Nippon RR
The article is 95% on procedure, misses a few points on inspection criteria, but overall Ron did a great job with it. Note in the 8th picture in the link Ron left the pistons and wobble plate with shaft inside one of the case halves; this is important so that assembly does not fall apart. Again, you can drop us a email if you get stuck.

On the 508 size question, lol.... size does not matter all the time. Below is a blurb from Sanden that summarizes it well in terms of size.
"Q: Will cooling performance improve if compressor speed or capacity is increased?
A: Cooling performance could improve by increasing compressor speed or capacity; however, HVAC system capacity is not based solely on compressor capacity. Control algorithms,

"... Control algorithms...."?? The FLY in the ointment...

The factory control system in our 911's is simplistic in the extreme when compared to something more modern with a "control algorithm".

evaporator and condenser sizing,

"Condenser sizing" Hitting the nail squarely on the head!

as well as a host of other factors contribute to system capacity, so simply speeding up your compressor or upgrading to a higher-capacity compressor will not necessarily increase your actual system performance. Please consider consulting an aftermarket HVAC systems company if you need help in upgrading your system.

Griffiths, as well as other aftermarket AC companies, for example, have been replacing the old York with the smaller 507 design and performance is very good.

Begs the question... As a singular upgrade/replacement, or along with other upgrade/replacement items, say a fender well located condenser/fan?

However, in your situation, we suggest keeping the Nippondenso model you have.

The article speaks to "upgrading to a higher capacity or speeding up a compressor" I suspect it would read quite differently if the subject matter were "downgrading to a lower capacity or speed reduction of the compressor".

It has long been known, and widely acknowledged, that the single most major shortcoming of the factory A/C system is the lack of refrigerant condensing capacity with consistently low engine RPM operation. That's why the first and foremost improvement one should make, with little/least expense ,is to provide additional condensing capacity. And the easiest way to do that, also widely acknowledged, is to add more cooling airflow.

Since adequate pressurization of the refrigerant gas by the compressor volume is a BIG part of the state change equation, going to a lower volume compressor would represent a step in the wrong direction.

So, no, converting to a lower pumping capacity would be going in the opposite direction one desires. Adding cooling capacity (Op: "planning to upgrade") would raise the need/desire for adequate pumping capacity, not lower it.

[kuehl]

Originally Posted by wwest

i have no experience with a/c compressor repair

Ok. The original question and topic of this thread is about compressors and integrity.