Temp rises while under load PLEASE READ
 

I have read ALOT of threads trying to research this out. 76911s

no thermal reactors, no oil cooler up front. Most of the threads I

read say there operating temp rises sitting in traffic. My temp

stays normal until I get on the highway then creeps up. If I really

get on it, rises quickly. Does this point to anything? Found

threads suggesting to lean, tried adjusting that. A little under

the 250 mark or third line. PLEASE any suggestions will help!!!!!!!

Newbe please have patience!!!!!!!!!!!!!!!![

Anything you can throw out I will try.

Maybe it late no response Here is a pic of the girl that is overheating. If you dont have sympathy for me then do it for her!!http://forums.pelicanparts.com/uploa...1122009686.jpg

I had the same "problem" with my 2.7, but I didn't have any ill effects from it. In fact, the hotter the engine became (to a point), the better it performed. I didn't have an external cooler, either, which in retrospect would have been a good investment had I kept the engine.

Regardless, I'd easily rise up to 250 on a normal drive. I think you should become alarmed if it creeps up to 260 or so. At 270, just pull over and let the motor rest. Temps that high won't kill the motor, but they're not good for it, either, especially if it's a magnesium case. You might notice a loss in power at 260 or so.

I guess what I'm saying is, you should have an external cooler installed. Oh, and you mentioned "leaning" the mixture out. No, I think you want to richen it to give the engine added cooling.

Thanks for reply
 

It is my one year anniversary on Saturday and wanted to take the wife to Niagara Falls {3 hour drive} I have been dealing with several issues and solved others, but this was still haunting me. I have not driven her more than 45 minutes at a time. Other than external cooler any other suggestions to get the temp down?

Correct I meant that others have said if it is lean it would run hot.

11 blade blower fan or the 5 blade type?
With the 5 blade, no oil cooler and heavy load (hill, hard acceleration) it didn't take much for mine to heat up in hot weather. With 11 blade fan hot weather is less of an issue. With 11 blade fan and front cooler, no issue at all.

US '76s have thermal reactors. Engines with these run notoriously hot, that along with a 5-blade fan, retarded ignition timing and lean mixtures, all for emissions, take their toll on the cooling system and engine longevity.

Since yours no longer has the reactors, it's probably the hot weather, the other '76 engine specs and a lack of an external cooler keeping the engine hot.

The long-term prognosis includes a fender or front-mount oil cooler, 9-blade fan and correct ratio pulleys; to a minor extent, retime engine and reset fuel mixture.

Sherwood

Well...maybe you could try using heavier oil. Richen the mixture, as I said. If you have a/c, think about using it as little as possible. I still wouldn't worry too much until the temperature gauge closes in on 270. Once, when I was a newbie, my 2.7 got up to 300. It still ran, though, and ran well. But I don't at all suggest this.

If the engine "pings" under load, that might be something to consider. If this happens, go easy on it until it can cool down; don't rev it out.

glider,
my car is setup like yours..2.7, no thermals, no aux oil cooler. i typically see 220-230 on the freeway if i keep it around 70-75 on these 90 plus degree days. if i start to drive 80-85, i will see temps rise up to 240. the only time i ever see the dreaded 250-270 range is when i've been caught in traffic, hence little airflow in the rear across those hot cylinder heads.

what oil weight are you using? i would recommend a 20w50 weight..this multi-weight is good for heat..like a true 50 weight when it's very hot outside and you'll need this extra protection in your car. i assume you have the 11-bladed fan..you definitely need this. there are upgrades for the fan you can even do which involve replacing the crank pulley with a different size to make the fan turn even faster. but by far the best bang for your buck for you or me will be the addition of the aux oil cooler. if you aren't a diy guy it won't be cheap to add the extra thermostat, extra oil lines, cooler, fan, etc. but it will probably drop your average temps when hot by 30 degrees..a huge difference. i have a/c too so that complicates the issue as well, as my condenser is in the rear deck lid..the same rear deck lid that the fan is also fighting for the same air through.

other things to consider as i think your car seems to be running slightly hot even for its setup is whether your oil temp sender is functioning properly, whether or not you have gunk in your engine oil cooler or whether you have debris under the shroud on your engine interferring with cooling. anyway, this is a start for things to consider. good luck, pretty car!
ryan

Sherwood: he says he has until Saturday. :eek: Maybe he should take a different car up to Niagara.

Glider - you are using the highest octane fuel you can find, right?

She does have 11 blade fan and no thermal reactors. Another suggestions was thermstat, in the rear right fender well?
Thankyou for the suggestion and keep them coming. I really want to take it to Niagara on Saturday!!!!!!!!!1

oh 20- 50 oil also

93 with octane boost!!!!

Glider,
180F should be your target temp.
Doug
75 911S

What if I remove the Ac condensor blocking the air flow. I never use air any how. Effect on operating temp?

glider,
i really don't think your car will exceed that 240 mark if you remain in the 70-75 mph range up on your trip with ambient temps in the 90's. avoid prolonged time in traffic (actually that's always a good idea with these cars, especially if you have no auxillary oil cooling). your car and mine are realistically 'temperature-limited' on extremely hot summer days without extra oil cooling..just drive accordingly and anticipate it until you can upgrade some things..
ryan

Would removing ac make a difference [I dont use it anyhow}

sure, remove the condenser if you don't plan on using it..take off the compressor belt too while you're at it if you haven't already..
ryan

BIGCHILL

I think you maybe right 70-75 seems to keep temp down 80-90 and she starts to rise more.

I love Pelican. I had a problem with a high idle after warm-up and with direct input and old threads traced it to a hole in my airflow sensor boot. My wife is getting jealous, spending to much time here. Hopefully Falls will make up for it!!!!!!!!!

trust me on the highway speed thing. like i said, my car is setup like yours..i drive the freeway a lot and am always collecting 'data' and always know what to expect in terms of temps at any speed and outside temp..like clockwork my car stays in the 220-230 range at those speeds unless i get the urge to go faster and then it's up 10 degrees..get into the 90-100 mph range and my temp will hit 250.
ryan

If you aren't using the AC, you might as well remove the condenser from the grille.

Doug
75 911S

Yes, removing the A\C condenser will make a little difference, but probably not significant.

One thing nobody else has mentioned is that the top of your engine might just be really cruddy. If the cooling fins on the cylinders and heads and the engine oil cooler (forward right side) are crudded up, the engine will never cool properly, no matter what you do.

It's a PITA, but with the removal of the alternator, you'll have good access to get in there and do some cleaning. Never know what you might find: rat's nests, old newspapers, etc.

Really helps to have a front cooler though: see what you can find used from an SC or Carrera... Good luck,

ianc

"Other than external cooler any other suggestions to get the temp down?"

Well, if you can't install one by Saturday morning, how about starting the drive in the late afternoon or early morning when it's cooler? Got A/C? Need A/C?
- Recapture the refrigerant, then remove the condenser from the rear grill for slightly better air flow.

- An auxillary fan under the grill will help shove more air into the engine compartment if traffic precludes driving at speed.

- Disconnect and plug the vacuum retard hose. Reset the timing to 5ºBTDC. Verify you don't have more than 35º of advance @ 6000 rpm. You'll probably need to reset the idle speed after this.

- Make sure the fan belt is adjusted correctly. A loose belt won't allow the fan to push the correct volume of air. If you want to get fancy within 24 hours, connect the fan to a thermal relay circuit that automatically reverses the air flow when the car is heat soaking with the engine OFF (fan draws hot air out).

- Is 45 minutes the magic time limit before overheating? Then stop at 44, take a stroll and see the sights, have bite to eat. In other words, kill time. Repeat every 44 minutes.

- If you're really desperate to drive it even though it still overheats with the above mods, find yourself a garden sprayer, one with a 5 gallon tank if possible. Extend the hose another 8 feet and fix the nozzle end so it points toward the fan. Tape the trigger open. Fill it with water. Politely and lovingly ask your wife of 1 year (still doable) to pump when you give her the signal. Don't worry what passing motorists think when they see her pump. Trust me. The water spray into the fan shroud will work as well as this exercise in domestic compatibility. If she's a good sport, keep her. If she doesn't, then do the best you can, just like many of us.

RE: Oil. Don't rely on premium oil to keep the engine cool. It won't. It will, however, provide add'l high temp. protection against viscosity breakdown (no film strength = metal-to-metal rubbing). However, overheated engine parts expand too much and decrease oil/running clearance, especially the space between the piston and the cylinder (about "0.001 and 0.003"). The best oil won't prevent parts from seizing if they have their little minds set on it.

Have a good weekend and let us know how it went.

Sherwood

for me it's a tradeoff..sure, at times i'd like to go over 90 mph on long stretches, but even though i'm a diy guy, i'm in no hurry to shell out $500 to install the cooler myself. if i can hang another 6 weeks or so anyway, it will start getting cooler..once winter gets here, you have the reverse problem - it isn't easy to get the oil warm enough. in winter, the ideal solution ironically is to have the 5-bladed fan..in fact there are those who swap them out for the change of seasons. i'm saving my pennies to overhaul my a/c this fall with new barrier-style hoses and new receiver/drier. arguably, i probably should make the oil cooler a priority, but until i do, i will drive smart..i'm making my sweating ass a priority instead! ;)
ryan

Thanks!!!!!!!!!!!!! You guys are great!!!!! I will post pictures from the falls!!!!

Personally, I think you'll make it to Niagara with flying colors. Just drive conservatively, and your car will be fine. With all the stop-and-go-related high temps I put my old 2.7 through, it never shut itself down and stranded me.

missing that 'ol 2.7, eh..david? ;)
ryan

glider-guy:
don't forget to store your car in a secure garage while at the falls. Niagara is a pretty rough place these days.
you don't want your car to become "hot" in the other sense!!

joe with 77 2.7 with external cooler and mobil 1

gliderguy,
I would first 'shoot' the sender with an infrared temperature measure device to verify that it is sending the proper signal. In my daily driver the sender went south and my temperatures at idle in a standstill was very normal and quickly rose to the red zone and soon as I was at highway speeds. After replacing the sender everything was normal.

you must get a front cooler for any relief. A used front cooler should be tested before install.

yes becareful around the falls. A friend of mine just had (6 months ago) a Ford F250 taken from the falls area. With Canada just a bridge away. Never recovered.

If you don't go to the falls this weekend , come out and play with us at the PCA. it would be fun.

brian

Here is the gauge after 40 minute run.http://forums.pelicanparts.com/uploa...1122042364.jpg

Glider Guy,

I see that as about 235F. Yes, that is hot but it is not killer hot.

I trust that photo was taken at idle as that oil pressure looks pretty low. You should have 10 PSI for every 1000 rpm even when hot. Fresh 20W50 will help this and that is something you can do before tomorrow.

Secodly, there was a lot of discussion about this with Bigchill, myself, patkeefe, and Grady Clay just about the 4th of July. Grady is a huge proponent of higher revs for more air flow over the cylinders. Do a search on "Grady" and I am sure you will find the thread.

Defnitely keep the revs up around 2000-2200 when stopped. Even when coasting. This not only keeps air circulation over the cylinders and oil cooler, it keeps the oil pressure up, and much better circulation of the oil.

Definitely keep the car at 65-75 MPH and the slower that you can tolerate, the better. The load on the car due to wind resisitance increases with the square of velocity. So 10 mph requires a lot more energy to push the car through the wind.

Lastly, Have fun.

Don

I have witnessed higher oil temps, lower head temps at higher RPM, and lower oil temps and higher head temps at lower RPM. The comparisons are between 4th and 5th gear at 65-70. Temp differences are within 5F either way, and a nominal oil temp of 180F.

Doug
75 911S

Donstevens


This was at idle, and the pressure will go up, as I go thru the gears. Once at highway speed pretty much stays around 20psi.

Again thanks for the replies. I could take another vehicle, but what would be the fun in that!!!!!

PS to Donstevens, I am in Florida nov/dec at Treasure Island, just noticed you in Clearwater. No more hurricanes!!!!!!!

20 psi is too low in my opinion at highway speed. You should be seeing 45-60 psi -15 psi per 1000Rpm. Surely at highway speeds you are not below2000 RPM. Either your sender is bad or your oil pump may be going. If the latter, may explain the higher oil temps. Or maybe you are low on oil. I'd get it checked.