chris walrod

A few weeks ago I did a bunch of work on a good friends 93RSA, and while replacing the cyl head temp sensor, I found the connector to be really discolored. Has anyone else found this to be the case? This car has 108K miles on her.

Also found the real reason why his car was running like crap, a crumbling dizzy belt. He paid A LOT of money to a shop in Santa Monica (not TRE) for them to fix his poor running car. $800+ later, he got a valve adjustment, air filter, oil and oil filter, fuel filter and new spark plugs installed. Car still runs like crap, but this shop says all is well.. Receipt even says they adjusted the timing..WTF?PUHLLEEEEEZ!

Even better, this same shop a year earlier was paid to have this dizzy belt replaced 20K miles ago. Huh, funny...I removed the dizzy only to find the factory swaged pin that retains the gear, still there.. Crooks!!!

So, at the last minute, Hergesheimers had a belt in stock. I installed it, car runs like new!!

Father of 3

Oh man, would like to know which shop you are refering to.

kkim

All the more reason I try to do all the work on my own car.

Guess it's much easier and profitable for them to write down that they did the work than, heaven forbid, actually doing it, huh?

Good catch, Chris... ever think of moving to Hawaii? I could use a friend like you when major maintenance starts popping up

chris walrod

MMMMMMM, Hawaaaaiiiiiiiii.... I need

kkim

Anytime!!! You know, you and the wife are always welcome to visit. But... if you can't make it out to here, let me see what I can do about sending you a part of here, there. Gimme a couple of more days.

Mahalo, brah!!

Blaine S

Chris, I was wondering if you could get a temp readout from the cylinder head temp sensor? If it is a standard J-type or K-type thermocouple you could do some interesting tests with a small multi-channel data logger. For example, test to see what difference the rear engine tray has on cylinder head temperature with respect to ambient temperature.

chris walrod

Yes one could do just that. A simple data logger and a thermocouple placed on a cylinder head. Or, one on each bank.. Would be interesting data!

JasonAndreas

My CHT connector has turned slightly yellow (maybe from UV light?). Do you still have the old connector? If so can you look on it for the marks/letters that say what type of plastic it is?

When I rebuilt my distributor I used the factory pin (930-602-922-00) and I didn't dremel/remove the bottom sealing cap so you can't tell (visually) that it was ever apart. Of course the one difference is I actually replaced the belt.

The easiest way is with a Bosch hammer (this is how/why I posted that oil temperature could be off the chart but that doesn't necessarily mean the CHT would) but the response rate is only maybe 4/secs at best. If you want to sample the output;

0'C = 4.4 - 6.8 kOhms
15 - 30'C = 1.4 - 3.6 kOhms
40'C = 1-1.3 kOhms
80C = 250 - 390 Ohms
100C = 160 - 210 Ohms

Somewhere on a computer here I have the data curve that the ECU uses, if you want it let me know and I will look for it.

chris walrod

No markings on the white plastic connector, just a logo of some sort 'S' over 'W', or 'M' over 'S'. Not sure really. I wouldnt think UV light exposure is the culprit as the portion of the connector that is discolored, is what is coverered when connected. ???

The solid pin that secured the drive gear had three, very symetrical swagings on it, markings by a machine no doubt.. This belt had more than 20K miles on it.

JasonAndreas

On the inside of the female connector there is a "rubberish" seal that might be leaching (i was going to write bleeding but...) and that could be causing the redness?

Did you ever confront the shop? I still really wonder how/why so much of the Porsche aftermarket can still exist after all these years? A recent phenomena I've noticed are websites with photos of shops and equipment that are not "on the premises". And my favorite, the tuner that doesn't/couldn't work on a car to save their life but pretending that they do.

chris walrod

I didnt, but the owner of the car did. He went back with this failed dizzy belt and stated his case of paying good money for them to fix his car, and didnt receive a fixed car. Manager or owner, not sure who, had a, according to my friend, really embarassed look about him. This shop person offered absolutely nothing in return.

As far as the discolored connector, could be staining from the other end of the weatherpack-type seal. I'll have to pull my connector off to have a look on my 993. Now I am curious

Lorenfb

"I still really wonder how/why so much of the Porsche aftermarket can still exist after all these years." - JasonAndreas -

Obviously there's nowhere near the Porsche repair business now as there was
20 years ago here in SoCal (one of the largest if not the largest) Porsche markets
worldwide. Although, an increasing number of shops have closed over the last few
years, many still are strong because most older (out of warranty) Porsches are
serviced by independents. The reasons are:

1. preceived/real cost savings or value
2. more personalized service
3. experience with previous Porsche cars

There are always a few questionable shops, but these few are greatly out numbered
by the real quality ones. What was mentioned on this thread is more the exception
than the riule.

"Somewhere on a computer here I have the data curve that the ECU uses" - JasonAndreas -

Once the CHT drops below about 350 ohms, the CHT no longer affects fuel mixture.
So, one can always eliminate/isolate the CHT by shorting it out with a jumper.

Edward

Good post, Chris!

Two things come to mind:
1. One should do as much work on one's own car as one can, even if it "seems" harder than you're accustomed to. Taken with patience and good advice, most maintenance can be done by yourself.

2. Once you find a trustworthy and skilled mechanic/shop, build a relationship with them. Don't shop the "cheapest" price because the trust and skill you have found in that establishment is worth every dollar to both you and your car.

Edward

mmasse

I just installed a Supercharger kit on my 993 engine. After doing some research I got the impression that it will be critical to monitor the CHT, in particular because I am not running an intercooler (for the time being). So, I installed a CHT sensor (plug ring type).

I wonder what's the normal operating range for CHT. I would like to get an idea of what should be the temp under normal driving, and also under spirited driving (as in DE events). And, clearly, what would be the STOP IT NOW, level.

So far I have only driven the car a few miles on the road after the installation of the SC and the CHT rteading is between 250-300F.

Thanks for you inputs

Jeff96-993

That plug end reminded me of carbon tracks from electrical arcing... not a diagnosis, but first thing it reminded me of.