Techno Duck

I posted this in the general 944 forum, but figured id get a better answer here in the turbo specfic forum. Anyway i am looking at purchasing a 951 as a replacement to my 924S, i have a few questions regarding the car to better educate myself about it. First off this is just a curious question, what type of oil do the turbos require? I would think a much heavier weight compared to a n/a car.

Also what are some common areas for oil leaks? I noticed oil marks on the ground where the owner normally parks the car in his driveway. Is it correct that the oil pan gaskets frequently go? BTW this car is a 1987 and has 96k miles on it. The oil was changed recently, so that made my 'gritty oil test' a little useless. Are their any other trouble spots to look out for? I will very likley be having a PPI
on the car done before i decide whether or not to purchase it, but would like to get an idea of any problems that may come up.

Also would air in the clutch system cause the pedal to stick when released? Is it more likley a bad master or slave cylinder?

The car is completely stock with the exception of an aftermarket muffler (Which will be replaced with a SFR catback due to how ugly the thing looks) and what i think is a Lindsay Boost Enhancer.

jyoon

run the car and do a seat of the pants test to see if the turbo seems to be spooling properly. sometimes the boost will be erratic if somethings wrong. check to see if smoke comes out the tailpipe upon startup. the turbo could be leaking oil. i always do a pretty hard 1-2 shift to see if the clutch will slip. you should be able to chirp the tires pretty good depending upon wheel/tire size. check coolant, check oil, check headers or listen for exhaust leaks there. check cv joints, all your basic stuff. I guess you could pull the plugs and look at em if the owner doesn't mind.

oi-punx

I think a PPI is the best insurance you can get as a potential buyer and believe me you want it for these cars.

I used 20W-50 petrol based oil in my N/A and also use it in the 951. I know many swear by synthetics but I am afraid of developing new oil leaks and I never run the car hard or often enough to warrant it. Today's oils are very good.

As for potential leaks, when I had my car in for belts and the H20 pump I had oil some very small leaks. The front seals were leaking as well as the oil pressure sending unit. These were replaced and i'm now leak free...for the time being.

Sach951

PPI!

jyoon

PPI is always a wise move, but the logistics are sometimes a pita. Also, if i'm selling a car that I know is in great shape and someone wants to take it to any mechanic of their choice to "inspect" it, i'd be somewhat concerned with letting that unknown mechanic work/joy ride it. i could be way off here, i'm not exactly sure what they do in a PPI.

Techno Duck

I thought about that too with the PPI. I was thinking of asking the seller if he would be willing to take the car to a shop (which is only about 20 minutes from him) to have it inspected if i picked up the bill on it. I could understand why a seller would be hesitant to take a car to a shop, heck i was a little hesitant when i took my car into a tire shop to have them diagnose a vibration in the wheel. The guy took the car around the block for a spin...i was a little uneasy seeing the car leave my sight without me in it.

I think a PPI could be both good and bad for a seller, it could turn back the car is in top notch shape so it would be tough to negotiate a price, a not so good report would give the buyer a little bit of an edge when trying to negotiate i think.

Edit - And another just curious question, does the 951 need 93 octane or can you run on 87?

v944god

93 I think would your best way to keep it not from detonating.

jyoon

i thought 91 or 92 was good enough in stock form.

Sach951

91 is more than good enough in stock form. Chipped, however, is a different matter altogether

Kurt

Off the top of my head, I'm thinking that 89 octane is the minimum as stated in the owner's manual, but I'll have to double check that (or if anyone can confirm). I use 93 just because.

As for a PPI, the usual arrangement is for the potential buyer to pick up the bill. Take it to a dedicated Porsche mechanic with a decent reputation though. If that criteria is satisified, the PPI is worth its weight in gold - no matter the outcome, trust me.

As far as that outcome is concerned, if the buyer is uncomfortable taking it to a mechanic...then that does very little to reassure the confidence of the buyer. They shouldn't have any problems with an inspection - otherwise something may in fact be wrong.

Additionally, think about getting a compression test done as part of the PPI as well. Also worth the $.

jim944s2

If the seller refuses to let you pay for a PPI at your shop of choice, I would recommend walking away from the deal. You pay for the PPI, it's yours and not the sellers, he has no reason to see it. If he want's one as a selling tool, he can buy it himself. If it turns out good, you can simply tell him that you forgot the paper at the shop or your house and "the car seems to be in ok condition" which is about the best you can get from a ppi.
I would also request a leak-down test over a compression test. A tired motor can build compression, a leak-down will be more informative.