1984 911 running hot

[cooldaddysquid]

Lately, my 911 has had it's temperature gauge get to the third white indicator, running at about 3/4. I've checked the hoses behind the right wheel, and they're hot, indicating that it's not a thermostat problem. I've also pulled the heater levers with just the electrical on, and I hear the fan. Upon reading some other posts, I discovered the following two damage points on the oil line on the right side (one on the front fender, one on the back:





Just wanted to confirm that it is highly probable that this damage is what's causing the overheating. I feel it pertinent to mention that this occurs when I'm running an upgraded AC fan at full blast when the vehicle is in idle or moving. I haven't tested the condition without the AC fan, but I suspect the condition would repeat itself at a slower rate.

Thanks!

[911Freak]

I really doubt that those dents in the oil lines are causing your heat issues. Mine were nearly completely crimped flat in a couple of areas from the PO using a floor jack and my engine temps never reached the 9 position.

How's the tune of your engine? Timing? Fuel system? A lean fuel mixture can cause engine temps to elevate. Maybe your engine t-stat isn't opening all the way! Seems a lot of 911 engines have that issue this summer. Why type of of fender cooler do you have!

More info and detective work may be needed.

Btw you definitely want to repair those lines. P,entry of trick fixes listed here in the orum.

Cheers

[cooldaddysquid]

I had the whole thing checked out in a pre-purchase inspection last March, and everything checked out. The highest compression percentage was 10%, I believe. Since then, I've put less than 3000 miles on the vehicle. Now, I like to accelerate fast in this vehicle from time to time, and I like doing between 80 and 90mph on the highway with it, but otherwise, it's driven well below its limits. I run 93 octane gas in it, and it recently had it oil changed about 400 miles back with Valvoline 10W 50 racing oil. For now, that's all the information I have.

[KNS]

I'd agree with Freak. I've got some dents almost identical to yours and my 84 runs pretty cool (and I'm in Phoenix).

Check behind the alternator for any debris/rodent crap...

[gamin]

I would first be sure that the sender and gauge are giving you accurate numbers.

[Jdub]

The heater lever and fan won't be related to your hot engine. If you are just now driving the car in hot weather you may be seeing the way it has always behaved. Now you'll want to list the checks you want to perform to be sure the oil is being sent for cooling when it should be. Any recent changes performed on the car? Worth backtracking if this is sudden behavior, all else equal.

[cooldaddysquid]

No recent changes that I'm aware of. I've had some issues with the PO's upgraded AC blower melting fuses, but I've got that one figured out. Beyond that, I can't think of anything that was changed on the car recently. The fender cooler is stock.

[Joe Bob]

Hand held IR Pyrometers are cheap. You can shoot the lines, oil tank and other items to see if the gauge matches the actual temps.

You may not be aware that there ARE numbers on your gauge. Most likely in Centigrade. They are under the bezel near the door and you have see them from the right side of the steering wheel....then turn your head left.....

[cooldaddysquid]

I'll grab a handheld pyrometer, then. I drove the vehicle again today and the temperature stayed normal with the AC on 2. I then brought it into the garage and had it sit for 10 minutes with no change in temperature. As soon as I turned the AC all the way up to 3, the temp went up beyond normal. Moving the AC back down to 2 didn't bring the temp down. It kept going up, just more slowly.

I had reverted the wiring back to the way the PO had it (two components going into fuse position 2), and the fuse started to melt again. I'm putting it back into the working config (one wire in fuse position 2 and one in fuse position 3.) We'll see how it goes.

Thanks!

[cooldaddysquid]

Quick question (probably a no-brainer): The 28 row oil cooling unit should be hot (or at least warm) to the touch after driving it, right? The lines leading to it are really gunked up on the exterior right now.

[cooldaddysquid]

One more quick question. What are the lines running underneath the driver's side door? Is it normal for them to be cool? Obviously, the passenger side lines run to the oil cooler, but I'm curious about the driver's side.

Thanks!

[Reiver]

The lines under the drivers door are AC lines to the front condesor.
You didn't mention the ambient temp in your comments bt I suspect very hot in Dallas.
I have an 83 sc and had temp issues in our way hot 100's plus. Once the front trombone or tube cooler like you have heats up it/they do a lousy job of heat transfer....very inefficient.
I put a latter Carrera front wheelwell oil radiator/block off/ and fan in place of the trombone and have zero heat issues in 110 degrees...with the fan the temp drops at idle/stoplights.
In our heat with the AC going you are maxing out the cooling system.

[cooldaddysquid]

Thanks, Reiver. This is what I kind of suspected. Going to have the shop look at it soon just to make sure it isn't something that's related to the oil lines or the thermostat. The frustrating part about this is that I specifically asked the PO if the car overheats in the summer, and he said it didn't overheat at all. Arg.

[mueller944s2]

I'm a 944 guy, but my dad has two old 911s that always run hot (New Orleans heat). He takes out the running light on the right side and installs a fan to blow on the oil cooler. Once the temp gets up he flips a switch on the dash to turn on the fan and you can see the needle dropping instantly.

[Chuck.H]

Mine doesn't run hot between 80-90MPH (lots of data here). It runs hot when I'm between 0-10MPH. Timing has a bit affect on engine temp, do you feel any kind of engine 'miss'?

And I've had the same type of oil line dents since I've had mine (20 years now), never fixed them from the PO...

Chuck.H
'89 TurboLookTarga, 336k miles

[cooldaddysquid]

The engine doesn't really miss. I'm thinking an air scoop or an after market fan to blow on the cooler might be a wise investment.

[NoLift911]

Originally Posted by cooldaddysquid

The engine doesn't really miss. I'm thinking an air scoop or an after market fan to blow on the cooler might be a wise investment.

If you have a 28 row brass cooler, a fan will not do much if anything to help cool the car down. It is not a radiator style with many fins for the fan to do any type of cooling in addition to creating a seal around the cooler for forced air through it. It is more of a heat sink.

If you are planning on adding a fan you need to add the right radiator style cooler...

An air scoop will have minimal impact as well - better to remove the headlamp bucket and drill some holes - this will only have an effect at speed of course, a lot of folks do this for some measure of additional cooling at the track.

I have an 84 with a brass cooler and have never seen temps (even at the track on 100+ days past the mid level), or while idling in traffic. My A/C is long gone.

I would get the facts with a pyrometer and not trust the gauge until you have something to measure it against - if it is indeed running that hot look for the root cause. Sounds like the upgraded A/C might be some type of culprit in some form.

[schumicat]

your car is not really overheating just because the needle moves above the midway point. overheating would be when gauge gets into the red or very close to it (like the width of the needle away). the car will run hotter when it is very hot and you have the a/c on, especially if you are sitting in traffic (no airflow).

look at the new vintage USA website and you can see what the actual temps are in degrees.

those oil lines are not problematic. those dents are puny and almost everyone has them or signfiicantly worse with no issues.

if your thermostat in passenger rear wheel well is opening properly, the oil cooler in front passenger wheel well and the lines going to it will be very hot.

Originally Posted by cooldaddysquid

Thanks, Reiver. This is what I kind of
suspected. Going to have the shop look at it soon just to make sure it isn't something that's related to the oil lines or the thermostat. The frustrating part about this is that I specifically asked the PO if the car overheats in the summer, and he said it didn't overheat at all. Arg.

[CCM911]

You should be fine. Mine gets all the way up to the section before the red when I get stuck in traffic on hot days. This really only happens when the temp is above 90 or 95 degrees F.

Once I get moving it goes right back down, so if yours is only getting to the "nine o'clock" position, you are good.

Since I also have a 1984 Targa(Guards Read as well), we are definitely comparing apples to apples.

[SCadaddle]

I've been monitoring the temp on my 82 SC with a handheld pyrometer. The trick with the pyrometer is to aim the laser beam square to what you are taking a reading on. Otherwise the temp displayed can vary quite a bit. Good Luck!