Greetings,
I come to seek your collective wisdom again. I think my car runs too hot and I wanted to see what you guys think.


Car is '83 Euro S 5sp.

While driving home from work on Thursday afternoon, outside temp is 98 F. Traffic is creeping along (stop every two car lengths for 5-10 seconds and then again move a car length) I had the A/C on and it is working great.

I glance at temp gauge and it is slowly going up. It seems to settle at almost midway between last white mark and red, or at least if it was still going up, it was doing so very slowly and I could not tell. It made me very uncomfortable. All sorts of thoughts of warped heads, blown head gaskets and other uglies. <img src="graemlins/nono.gif" border="0" alt="[nono]" />

Fortunately at that point, the jam seemed to break and I was able to start moving again. The other curious thing was the oil pressure at idle was about 1.5 bar and everytime I would inch the car forward when letting out the clutch, the oil pressure light and the main warning light "!" would flicker on and off. That too was making me nervous.

After I got out of the snarl and was able to maintain 25-30 mph the temp came back down to below the top white line by maybe two needle widths, but would not go lower. That is typically where the car operates and it seems like it should be lower than that, but maybe I am being paranoid. The oil pressure returns to normal range as soon as RPM's get above 2k. So,
... Is there a problem? Am I overheating?

I would suspect fan clutch if the car didn't run so hot all the time. What do you guys think? Thermostadt? Radiator? Where should I look first? Thanks in advance.


JF <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
Portland, OR
'88 S4 A/T (never loses cool)
'83S Euro 5sp(my hot project)
928 Forum Subscriber

By the way, I experimented with turning off the A/C and even turned heater on briefly and those things did cause advance of temp guage to slow.

 

Joe,

I just went through this exact same set of symptoms and it was the fan clutch.

 

I agree with the fan clutch. When you get it checked out or replace do not put the fan clutch flat down, you have to keep it vertical. 928intl has details on this.

Also, I'd replace the thermostat (easy job) and flush the system out and put in 1 gallon of Dex-cool coolant, 1 water wetter (additive), and the rest water. Oh, you want more coolant in the winter time (if temperatures are near/below freezing)

For the oil pressure, put in 15w-50 or 20w-50 preferably Valvoline Synthetic or Mobil 1. Those are the recommended weights for 70+ weather.

Andrew
'84 928S
'87 928S4

 

98 degrees in Oregon?

Well. I'm used to hot weather- in fact I thrive on it. My a/c works fine, but even in 90 degree heat here in Central Florida I rarely use it. The windows down is fine.

My '85 S2 [Euro, similar to yours] has a tendency to run cool- the water temp. needle rarely moves above the center portion of the gauge, even with the a/c going and stopped up in Orlando's hideous traffic. Hurts gas mileage- I get about 13 in the city on a good day.

But what you've described to me sounds un-good. I have to agree with the others- it sounds like you've got an airflow problem, most likely the fan isn't up to snuff. But I'd attack that coolant first! I use Prestone Lo-Tox propylene glycol coolant in a 70% distilled water/ 30% coolant mixture with one bottle of water whetter added. I change this coolant out every two years, and last spring when I changed it, what I removed was nearly perfect looking. I had no scale or crud in the bottom of the reservoir either. Recently, also I changed the thermostat out and after both procedures, no change in temps was noted.


As to the oil pressure light coming on- this is not normal in any circumstances! I highly recommend you take your car to a good shop and have this checked. I had a Fiat Spyder that did this once, caused by a damaged main bearing that was wrecked because of a blown head gasket [water in the oil], and it eventually seized. Yuck. I bought the car for $900 and sold it to a priest down in Puerto Rico for $100. Ouch. If you smoke your 928's motor, you're going to be hurting a whole lot worse!

Good luck-

Normy!

'85 S2

 

I would also replace the fan switch and thermostat with the 75c degree ones available from the big three. They allow the engine to operate at a cooler temp so it takes longer to heat soak the cooling system. My 86.5 in Utah summers rarely gets off the bottom white line.

Dave

<img src="graemlins/drink.gif" border="0" alt="[cherrsagai]" />

 

Originally posted by Normy:
"As to the oil pressure light coming on- this is not normal in any circumstances! I highly recommend you take your car to a good shop and have this checked."


Normy,
Yup, sometimes it gets hot here in Orygun. I had the air on because with the windows open I was nearly being choked on exhaust fumes. Besides, it felt pretty good. <img src="graemlins/bigok.gif" border="0" alt="[thumbsup]" />

I did not mean that the oil light was coming on when engine was idling, only when I would let out clutch and pull revs way down while creeping along. At normal idle, oil pressure was about 1.5 bar or a bit better.


Barry, Andrew, Ketchmi
Thank you for your input. The fan clutch seems to be the consensus, but I think I will change out the coolant, thermostadt and fan switch to the cooler models as well.

Cheers <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

JF
another nice day
'83S Euro 5sp (hot project)

 

Here's a thought about the electric aux. fan. If my 86.5 was doing this, I would jump the freon temp switch so that the electric fan ran whenever the A/C was on. If your 83 is like this, you may want to do the same until you can look at the fan clutch. Would anyone disagree with his logic?

Greg

 

i'm with ketchmi on this. try replacing your fan switch and thermo with the low temp models from 928 intl. had same indications and thought it was fan clutch. replaced fan clutch and same temp indications. at upper white line or above. replaced temp switch and thermo and now runs between two upper white lines, toward lower line while at speed and upper line when in stop 'n go. never seen above upper line at this point.

 

Joe,
Befor you do all of that ... cover the engine with trash bags to protect electrics.
Grab the garden hose and flush out the radiator cooling fins.
After a while try to wash/flush from the back side.
I don't recommend use of a high pressure water system or carw wash wand.
Go cheap/simple first, then spend the bucks.
John S. <img src="graemlins/drink.gif" border="0" alt="[cherrsagai]" />

 

Has anyone here ever had their 928 radiator rodded out?

Just a thought

<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
Max

 

John,

Good suggestion. I will always opt for lo tech solution first. I will try that tomorrow.

Then I think the cooler thermostat and fan switch. While doing the thermostat I will do coolant flush. And, if it still is too warm, I will get into the fan clutch. Thanks for the suggestions guys, I appreciate it.

Cheers! <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

JF
'83S Euro 5sp (Hot project)