Landseer

Thanks, I appreciate that. What is the cost of an analysis? How much oil do I send and how is it sampled?

IcemanG17

Blackstone will send the sample kits to ya for free...it costs $22.50 per analysis

http://www.blackstone-labs.com/

Maleficio

Used oil analyses are good. To make it easier to pull a sample, install a Fumoto drain valve. I've got one on my Volvo XC70, and it works like a champ, and is built to outlast any car you install it on.

http://www.qwikvalve.com/home.php

To learn all there is to know about UOA's (and anything else about lubes) check out http://www.bobistheoilguy.com

docmirror

Almost surely this is a result of surface corrosion in your rad. The corrosion inhibitors in coolant work at temp and with flow. No heat and no flow for a long time will let the oxidation build up the in the rad. You can try a special corrosion inhibitor, but usually, once it's on there, you can't get it off.

jcgoodlett2

Anyone know what the CR was when this 1985 928S came from the factory, and/or what the numbers are supposed to be for a 1983?? Any links to where I can read more on it would be helpful as well! Thanks much in advance!

Landseer

Just as a followup, the car ran hot at the time.

Why?

Long story short, injectors were partially clogged.

Once replaced it ran cool.

M. Requin

Chris, thanks for the followup! Overheating issues can be tricky, so this si good to have in the files.

linderpat

Wow; I would never had considered this correlation. Why would partially clogged injectors lead to a hotter running condition?

UpFixenDerPorsche

Hmmmm ... should I, or should I not ... ohh heck:

Plug colors:
- driver's bank - great.
- Passenger bank - ehhh gee Doc ... all looking a bit white for my liking (hot), still showing touches of tan, and no signs of blistering on the ceramic (fatal overheating).

Each bank has a similar spread of compression values.

So my first question is: what is different re combustion process in each bank, for the plugs in each bank to be so uniformly different in color?

I know nothing about fuelling in '85 cars, but at this point nobody has to, because by simple observation of plug colors, it's clear that each bank is experiencing different combustion conditions.

Over to the '85 fuelling experts.

Crumpler

+1

Chris if you have time, walk us through how you got there, ok edited out as well to be fair.

Landseer

Couple of telltales.
Downpipes were white inside, same if you looked up into the header pipes.

Intermittent oddball power loss and stutter under acceleration, putting foot to the floor would downshift the trans but the car would stutter and shake.

It wasn't getting enough fuel. Running lean, very bad. Very hot.

Everything else possible had been gone-thru at the time. New MAF, wires, caps, computers reviewed by Rich, intake job, fuel pump, strainers, regulator, water pump, timing, Radiator flush, thermostat and seal, all other sensors, really everything.

Changing injectors --- night and day. On first test drive it ran at the first line on the gauge, where the rest of mine run, instead of midgauge or higher where it had been.

Funny thing, car sat for 10 years, very early-on, during 1st posts about the car, Dr Bob advised at the time to service the injectors and I ignored that piece of advice.

Crumpler

Man, I find this interesting because I had some fuel delivery issues on the 86.5 when I did the last dyno. No symptoms under normal driving conditions, but she does always want to run lean. Then again my stock injectors tested in spec at witch hunter last year. My first move was the FP and filter, but I haven't jumped back on on it.
Did you use different stock injectors or change to a four hole variant?

Hey BTW, is this the 85 that you were parting out?

Landseer

Four hole. See Hilton's thread.
Yes, its the one that donated the hatch.
I still have the engine and the majority of the car.
Its a roller still.


Today we put the shell of the 86.5 parts car onto the trailer.
I spent 4 hours removing the perfect battery box and the 5 speed firewall overlay that allow mounting of the clutch cylinder. Couldn't bear to send it to the scrapper without removing those.

Crumpler

Hey I pulled all the hardware and trim off the 85 hatch, but it is still in one piece and the harness is intact I believe.
If the 85 is coming back from the dead, let me know and I can get the hatch back to you. Glad to donate it if you got the need buddy.