250 degrees is just too much...

UTKarmann_Ghia · 07-14-2003, 11:53 AM

Well, after battling with my engine temperatures, I'm punting and taking my car to the local Porsche shop to take a look at.
This morning is what made up my mind. Driving to work at about 75 degrees and about 30 minutes later my temp is at 250. I pull off for 20 minutes and let her cool down. Thanks for all the help you guys have given, but in the end I'm where I was about $500 ago

FYI:
had shop check temps w/infrared meter
checked int tstat (seems to be workin)
checked ext tstat (not sure about this, so replaced it)
checked for debris on top of the engine (perfectly clean)
thought the wrong sending unit was installed (it was correct)
checked timing 5dbtdc w/out vacuum lines
replaced fan belt (could be, right?)
new Mocal cooler (replaced trombone)
new ext thermostat
new cool collar

Alas, I'm at the end, having spent a bunch of bones to be right back at the beginning. I'll post if they find anything that might be helpful to somebody else here.

beepbeep · 07-14-2003, 12:27 PM

Well, it could be that your CIS is too lean for some reason which results in high temperatures...

UTKarmann_Ghia · 07-14-2003, 01:41 PM

Beepbeep, they are going to check the mixture when they get it. I'm here in Denver so usually a car gets very rich as the atmosphere is much thinner.

SPIKES · 07-14-2003, 02:56 PM

it seems like such a simple design. can't think what would cause your problem. was there anyway to check that the oil was circulating properly without restrictions? (then i suppose you would get high oil pressure?) hmmmmmm....just thinking aloud.

please keep us posted on results.

Doug Zielke · 07-14-2003, 03:17 PM

It's hard to believe the Kewl Collar did nothing to solve your problem.

UTKarmann_Ghia · 07-14-2003, 03:25 PM

he he he, I think the Kewel collar is a bit overrated

Spikes, both oil coolers get hot (how hot is the question) so I believe oil circulation is not the issue. It's possible that the AMOUNT of oil could be (as in an internal tstat partially opening). As far as my oil pressure it's usually about +1 bar over my rpms.

Dana_Drury · 07-14-2003, 10:54 PM

WAIT! WAIT! WAIT!

Please get another shop to check your oil temperature, using a dipstick style gauge. The reason I say that is that, if people remember, I battled with engine temperatures like that for almost 12 months.

I replaced everything including upgrading to a Carrera Oil Cooler and Fan.

After having it checked twice, it was found on the second time by a more reputable mechanic that the engine temperatures were displaying 36(C) on the gauge higher than what they were. So I was constantly seeing 120(C) (250F) + temps that weren't actually a problem.

My gauge/temp sender were mismatched and out of calibration.

There is no real reason you should be seeing 250F engine temperatures unless there is something really wrong. Even now, in 40 degree C summer I saw 105 C max temperatures in stop start city driving....

If you want to make sure, test your sending unit in boiling water (remember to ground it, or you won't see the gauge in the car move).

SPIKES · 07-15-2003, 05:27 AM

that was my first thought. is it actually getting that hot? you mentioned that the shop used a temp sensor to check it though.

i have a themometer with a probe on a wire. i run the car and then remove the oil tank cap and drop the sensor in the hot oil...that confirmed that the oil temp on the guage was accurate.

i would try this first as DANA suggested before spending more cash on it.

SPIKES · 07-15-2003, 05:28 AM

that was my first thought. is it actually getting that hot? you mentioned that the shop used a temp sensor to check it though.

i have a themometer with a probe on a wire. i run the car and then remove the oil tank cap and drop the sensor in the hot oil...that confirmed that the oil temp on the guage was accurate.

i would try this first as DANA suggested before spending more cash on it.

UTKarmann_Ghia · 07-15-2003, 06:51 AM

Spikes, I've been looking for a thermometer that I can poke down into my oil resivoir but I've had no luck finding one. I had thought the same thing that the engine isnt really that hot. I open the engine lid and I have to stick my hand pretty far back to feel much heat, but my hand is a poor calibration instrament

FYI, the ext tstat is brand new and if you've ever installed the older style, you're in for a treat. The newer model is MUCH easier to install. Funny thing is that the ext tstat doesnt open until the guage reads ~220 (dead center of guage). I KNOW the tstat is a 180 tstat too...

Anybody know where I can get some kindof thermometer long and narrow enuf to reach into my oil resivoir???

VincentVega · 07-15-2003, 07:23 AM

Check these guys out, http://www.mcmaster.com/ . I searched on thermometer and they have a ton of options, although I couldnt find a way to post a direct link because of the frames.

greglepore · 07-15-2003, 07:57 AM

Or you can try any cooking supply store-there are all kinds of digital thermo's with probes.

thabaer · thabaer's Garage

Matt,

Our CIS systems adjust mixture according to the mass of air moving the metering plate, so even up on Evans or Trail Ridge you should be getting the correct mixture. I didn't see any mention of an exhaust check so maybe that would reveal a lean problem.

If you try the boil test on your guage, remember that up here you'll be about 201F instead of 212 when the water boils.

I assume spending more money isn't high on your agenda, but you might find it worth while to pick up a matched guage with a sender that will thread into the drain plug of the oil tank. My '83 urQ has an ABT guage pod with the oil temp fed from a different sender than the ECU uses, nice to have two opinions built into the car

Dana_Drury · 07-15-2003, 04:06 PM

Quote:

Originally posted by UTKarmann_Ghia
Funny thing is that the ext tstat doesnt open until the guage reads ~220 (dead center of guage). I KNOW the tstat is a 180 tstat too...

Um, well, if that's the case, I would be more inclined to believe that your gauge is out of calibration, rather than your engine temperatures being too high.

After speaking with some mechanics, they said that this is [gauges and senders] are usually the case. One Porsche Australia mechanic said that he had only ever had to replace one external thermostat in his life because it was faulty, and that most high engine temperatures are for a specific reason - racing will produce really high temperatures if your don't have adequate cooling, crap in and on your engine will, running lean produces extra heat, but not a 30C difference or crushed oil tubes.

If your engine is in good running order, you have a working external thermostat, proper oil cooling happening then I would not worry. Like I said, we see 35+C ambient temperatures in Sydney in the summer, with my trombone cooler I would see 106-110C (232F) engine temps in that heat in stop start traffic.

Rather than do what I did, see 250C on your gauge, not get a second opinion then replace everything to do with cooling under the sun - get it checked out by a few people first.

I don't regret all the work I did because my car is now greatly cooled for the track, but back then it was giving me a heart attack to the point I didn't enjoy my car...

UTKarmann_Ghia · 07-15-2003, 04:58 PM

Thabaer - awsome tip about verifying the temp guage. I boiled some water (~200 degrees here at altitude) and dipped my sending unit into it. I also placed a thermometer in the cup and by the time I tested, it was @ 180. My guage read just below the first white mark which is where I expected 180 to be. Sooooo, the guage reads correctly at 180 and I would assume that it would read correctly at a bit higher temps too.

Dana, I replaced wayyy to much and I've had NO success in lowering my temps. I dont understand why the ext tstat would not open until about 220 degrees when the tstat is rated at 180 (and brand new). It's almost like the tstat is not warming up as it should, I dunno. I am exactly where you were. I absolutely dont enjoy driving my car anymore and I'm afraid to go for more than a 20 minute drive, because by 40 minutes I'm at 250 degrees (top white mark). I cant drive my car at this temp and I'm pulling what hair I have left out of my head. I have checked everything you mentioned and much more. Funny, I have not taken a car to a mechanic for at least 15 years. But I guess it's worth just about anything to have the piece of mind and get this fixed.

nostatic · nostatic's Garage

http://www.mainelycustombydesign.com/enginecomponents.htm

Scroll down to the dipstick...call and ask if it will work with a 911.

Joe Bob · Joe Bob's Garage

Yup, I'm there too with my 356....just took delivery of a new cooler, fan and 3qt. Accusump.....

250 F sucks....

UTKarmann_Ghia · 07-15-2003, 08:07 PM

Static, that thermometer is way too kewel

I says 912 and 356, I wonder if it's also accurate (oil-level wise) for a 911.

rfng · 07-15-2003, 10:23 PM

Why dont you check your sump plate. Sometimes if it is on wrong it will restrict the flow of oil being picked-up.

Dana_Drury · 07-15-2003, 10:52 PM

How do you know that the thermostat is opening at 220 F? Are you taking that from the oil pipes getting hot and the gauge on your dash reading 220F or have you measured it with a sensor?

Like I said, based on all the upgrades that you have done, unless you have thermal reactors and some really serious engine issues, there is no reason that you should be seeing 250F engine temperatures.

There is one possibility that might have been over looked that the Sender in water test will not pick up.

When I was having trouble with my car, I ran across a post where a guy described his "raising gauge" where the hotter the oil temperatures got, the more and more out of whack that the gauge displayed.

I personally kicked myself after spending lots of money and found out that all was fine. I think you might end up doing the same.....